Study of excited charm-strange baryons with evidence for new baryons {xi}{sub c}(3055){sup +} and {xi}{sub c}(3123){sup +}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aubert, B.; Bona, M.; Boutigny, D.

We present a study of excited charm-strange baryon states produced in e{sup +}e{sup -} annihilations at or near a center-of-mass energy of 10.58 GeV, in a data sample with an integrated luminosity of 384 fb{sup -1} recorded with the BABAR detector at the PEP-II e{sup +}e{sup -} storage rings at the Stanford Linear Accelerator Center. We study strong decays of charm-strange baryons to {lambda}{sub c}{sup +}K{sub S}{sup 0}, {lambda}{sub c}{sup +}K{sup -}, {lambda}{sub c}{sup +}K{sup -}{pi}{sup +}, {lambda}{sub c}{sup +}K{sub S}{sup 0}{pi}{sup -}, {lambda}{sub c}{sup +}K{sub S}{sup 0}{pi}{sup -}{pi}{sup +}, and {lambda}{sub c}{sup +}K{sup -}{pi}{sup +}{pi}{sup -}. This study confirmsmore » the existence of the states {xi}{sub c}(2980){sup +}, {xi}{sub c}(3077){sup +}, and {xi}{sub c}(3077){sup 0}, with a more accurate determination of the {xi}{sub c}(2980){sup +} mass and width. We also present evidence for two new states, {xi}{sub c}(3055){sup +} and {xi}{sub c}(3123){sup +}, decaying through the intermediate-resonant modes {sigma}{sub c}(2455){sup ++}K{sup -} and {sigma}{sub c}(2520){sup ++}K{sup -}, respectively. For each of these baryons, we measure the yield in each final state, determine the statistical significance, and calculate the product of the production cross section and branching fractions. We also measure the masses and widths of these excited charm-strange baryons.« less

Observation of B{sup +}{yields}{xi}{sub c}{sup 0}{lambda}{sub c}{sup +} and evidence for B{sup 0}{yields}{xi}{sub c}{sup -}{lambda}{sub c}{sup +}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chistov, R.; Aushev, T.; Balagura, V.

We report the first observation of the decay B{sup +}{yields}{xi}{sub c}{sup 0}{lambda}{sub c}{sup +} with a significance of 8.7{sigma} and evidence for the decay B{sup 0}{yields}{xi}{sub c}{sup -}{lambda}{sub c}{sup +} with a significance of 3.8{sigma}. The product B(B{sup +}{yields}{xi}{sub c}{sup 0}{lambda}{sub c}{sup +})xB({xi}{sub c}{sup 0}{yields}{xi}{sup +}{pi}{sup -}) is measured to be (4.8{sub -0.9}{sup +1.0}{+-}1.1{+-}1.2)x10{sup -5}, and B(B{sup 0}{yields}{xi}{sub c}{sup -}{lambda}{sub c}{sup +})xB({xi}{sub c}{sup -}{yields}{xi}{sup +}{pi}{sup -}{pi}{sup -}) is measured to be (9.3{sub -2.8}{sup +3.7}{+-}1.9{+-}2.4)x10{sup -5}. The errors are statistical, systematic and the error of the {lambda}{sub c}{sup +}{yields}pK{sup -}{pi}{sup +} branching fraction, respectively. The decay B{sup +}{yields}{xi}{sub c}{sup 0}{lambda}{sub c}{supmore » +} is the first example of a two-body exclusive B{sup +} decay into two charmed baryons. The data used for this analysis was accumulated at the {upsilon}(4S) resonance, using the Belle detector at the e{sup +}e{sup -} asymmetric-energy collider KEKB. The integrated luminosity of the data sample is equal to 357 fb{sup -1}, corresponding to 386x10{sup 6} BB pairs.« less

Observation of B{sup 0}{yields}{lambda}{lambda}K{sup 0} and B{sup 0}{yields}{lambda}{lambda}K*{sup 0} at Belle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, Y.-W.; Wang, M.-Z.; Chao, Y.

2009-03-01

We study the charmless decays B{yields}{lambda}{lambda}h, where h stands for {pi}{sup +}, K{sup +}, K{sup 0},K*{sup +}, or K*{sup 0}, using a 605 fb{sup -1} data sample collected at the {upsilon}(4S) resonance with the Belle detector at the KEKB asymmetric energy e{sup +}e{sup -} collider. We observe B{sup 0}{yields}{lambda}{lambda}K{sup 0} and B{sup 0}{yields}{lambda}{lambda}K*{sup 0} with branching fractions of (4.76{sub -0.68}{sup +0.84}(stat){+-}0.61(syst))x10{sup -6} and (2.46{sub -0.72}{sup +0.87}{+-}0.34)x10{sup -6}, respectively. The significances of these signals in the threshold-mass enhanced mass region, M{sub {lambda}}{sub {lambda}}<2.85 GeV/c{sup 2}, are 12.4{sigma} and 9.3{sigma}, respectively. We also update the branching fraction B(B{sup +}{yields}{lambda}{lambda}K{sup +})=(3.38{sub -0.36}{sup +0.41}{+-}0.41)x10{supmore » -6} with better accuracy, and report the following measurement or 90% confidence level upper limit in the threshold-mass-enhanced region: B(B{sup +}{yields}{lambda}{lambda}K*{sup +})=(2.19{sub -0.88}{sup +1.13}{+-}0.33)x10{sup -6} with 3.7{sigma} significance; B(B{sup +}{yields}{lambda}{lambda}{pi}{sup +})<0.94x10{sup -6}. A related search for B{sup 0}{yields}{lambda}{lambda}D{sup 0} yields a branching fraction B(B{sup 0}{yields}{lambda}{lambda}D{sup 0})=(1.05{sub -0.44}{sup +0.57}{+-}0.14)x10{sup -5}. This may be compared with the large, {approx}10{sup -4}, branching fraction observed for B{sup 0}{yields}ppD{sup 0}. The M{sub {lambda}}{sub {lambda}} enhancements near threshold and related angular distributions for the observed modes are also reported.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yokosawa, A.

We summarize activities concerning the Fermilab polarized beams. They include a brief description of the polarized-beam facility, measurements of beam polarization by polarimeters, asymmetry measurements in the {pi}{degree} production at high p{sub {perpendicular}} and in the {Lambda} ({Sigma}{degree}), {pi}{sup {plus minus}}, {pi}{degree} production at large x{sub F}, and {Delta}{sigma}{sub L}(pp, {anti p}p) measurements (Fermilab E-704). In the future we plan to investigate the proton-spin crisis by determining the gluon spin distribution in inclusive production of direct gamma, {chi}2, and J/{psi}. 20 refs., 5 figs.

Measurement of {pi}{sup -}p{yields}{eta}n from threshold to p{sub {pi}}{sub {sup -}}=747 MeV/c

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prakhov, S.; Nefkens, B.M.K.; Clajus, M.

2005-07-01

The differential cross section for {eta} production in reaction {pi}{sup -}p{yields}{eta}n has been measured over the full angular range at seven incident {pi}{sup -} beam momenta from threshold to p{sub {pi}}{sub {sup -}}=747 MeV/c using the Crystal Ball multiphoton spectrometer. The angular distributions are S wave dominated. At 10 MeV/c above threshold, a small D-wave contribution appears that interferes with the main S wave. The total {eta} production cross section {sigma}{sup tot} is obtained by integration of d{sigma}/d{omega}. Starting at threshold, {sigma}{sup tot} rises rapidly, as expected for S-wave-dominated production. The features of the {pi}{sup -}p{yields}{eta}n cross section are strikinglymore » similar to those of the SU(3) flavor-related process K{sup -}p{yields}{eta}{lambda}. Comparison of the {pi}{sup -}p{yields}{eta}n reaction is made with {eta} photoproduction.« less

Differential cross sections and recoil polarizations for the reaction γ p → K + Σ 0

DOE PAGES

Dey, B.; Meyer, C. A.; Bellis, M.; ...

2010-08-06

Here, high-statistics measurements of differential cross sections and recoil polarizations for the reactionmore » $$\\gamma p \\rightarrow K^+ \\Sigma^0$$ have been obtained using the CLAS detector at Jefferson Lab. We cover center-of-mass energies ($$\\sqrt{s}$$) from 1.69 to 2.84 GeV, with an extensive coverage in the $K^+$ production angle. Independent measurements were made using the $$K^{+}p\\pi^{-}$$($$\\gamma$$) and $$K^{+}p$$($$\\pi^-,\\gamma$$) final-state topologies, and were found to exhibit good agreement. Our differential cross sections show good agreement with earlier CLAS, SAPHIR and LEPS results, while offering better statistical precision and a 300-MeV increase in $$\\sqrt{s}$$ coverage. Above $$\\sqrt{s} \\approx 2.5$$ GeV, $t$- and $u$-channel Regge scaling behavior can be seen at forward- and backward-angles, respectively. Our recoil polarization ($$P_\\Sigma$$) measurements represent a substantial increase in kinematic coverage and enhanced precision over previous world data. At forward angles we find that $$P_\\Sigma$$ is of the same magnitude but opposite sign as $$P_\\Lambda$$, in agreement with the static SU(6) quark model prediction of $$P_\\Sigma \\approx -P_\\Lambda$$. This expectation is violated in some mid- and backward-angle kinematic regimes, where $$P_\\Sigma$$ and $$P_\\Lambda$$ are of similar magnitudes but also have the same signs. In conjunction with several other meson photoproduction results recently published by CLAS, the present data will help constrain the partial wave analyses being performed to search for missing baryon resonances.« less

Data for polarization in charmless B{yields}{phi}K*: A signal for new physics?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Das, Prasanta Kumar; Yang, K.-C.

2005-05-01

The recent observations of sizable transverse fractions of B{yields}{phi}K* may hint for the existence of new physics. We analyze all possible new-physics four-quark operators and find that two classes of new-physics operators could offer resolutions to the B{yields}{phi}K* polarization anomaly. The operators in the first class have structures (1-{gamma}{sub 5})x(1-{gamma}{sub 5}), {sigma}(1-{gamma}{sub 5})x{sigma}(1-{gamma}{sub 5}), and in the second class (1+{gamma}{sub 5})x(1+{gamma}{sub 5}), {sigma}(1+{gamma}{sub 5})x{sigma}(1+{gamma}{sub 5}). For each class, the new-physics effects can be lumped into a single parameter. Two possible experimental results of polarization phases, arg(A{sub perpendicular})-arg(A{sub parallel}){approx_equal}{pi} or 0, originating from the phase ambiguity in data, could be separatelymore » accounted for by our two new-physics scenarios: the first (second) scenario with the first (second) class new-physics operators. The consistency between the data and our new-physics analysis suggests a small new-physics weak phase, together with a large(r) strong phase. We obtain sizable transverse fractions {lambda}{sub parallel{sub parallel}}+{lambda}{sub perpendicular{sub perpendicular}}{approx_equal}{lambda}{sub 00}, in accordance with the observations. We find {lambda}{sub parallel{sub parallel}}{approx_equal}0.8{lambda}{sub perpendicular{sub perpendicular}} in the first scenario but {lambda}{sub parallel{sub parallel}} > or approx. {lambda}{sub perpendicular{sub perpendicular}} in the second scenario. We discuss the impact of the new-physics weak phase on observations.« less

Optogalvanic spectroscopy of the C"5Pi ui-A' 5Sigma+g electronic system of N2.

PubMed

Pirali, O; Tokaryk, D W

2006-11-28

We have recorded spectra involving the 3-1, 4-2, 2-0, and 2-2 bands of the C" 5Pi(ui)-A' (5)Sigma+(g) electronic system of N(2) using optogalvanic detection in a discharge through a supersonic jet expansion of argon mixed with a trace of nitrogen gas. The spectra have an effective rotational temperature of about 45 K. They involve all five spin-orbit components of the C" 5Pi(ui) state, which has allowed for precise determination of the spin-orbit coupling in this state. Analysis of the C" 5Pi(ui) state Lambda-doubling shows that it is caused primarily by a first-order spin-spin effect rather than by interaction with Sigma(u) (+/-) states. Our results allow us to assign lines in the 4-2 and 2-0 bands observed in a fluorescence depletion experiment conducted over ten years ago [Ch. Ottinger and A. F. Vilesov, J. Chem. Phys. 103, 9929 (1995)], and to comment on the suggestion that perturbations to the C (3)Pi(u) v=1 level of N(2) arise from interactions with the C" 5Pi(ui) state.

Hypernuclear Weak Decays

NASA Astrophysics Data System (ADS)

Itonaga, K.; Motoba, T.

The recent theoretical studies of Lambda-hypernuclear weak decaysof the nonmesonic and pi-mesonic ones are developed with the aim to disclose the link between the experimental decay observables and the underlying basic weak decay interactions and the weak decay mechanisms. The expressions of the nonmesonic decay rates Gamma_{nm} and the decay asymmetry parameter alpha_1 of protons from the polarized hypernuclei are presented in the shell model framework. We then introduce the meson theoretical Lambda N -> NN interactions which include the one-meson exchanges, the correlated-2pi exchanges, and the chiral-pair-meson exchanges. The features of meson exchange potentials and their roles on the nonmesonic decays are discussed. With the adoption of the pi + 2pi/rho + 2pi/sigma + omega + K + rhopi/a_1 + sigmapi/a_1 exchange potentials, we have carried out the systematic calculations of the nonmesonic decay observables for light-to-heavy hypernuclei. The present model can account for the available experimental data of the decay rates, Gamma_n/Gamma_p ratios, and the intrinsic asymmetry parameters alpha_Lambda (alpha_Lambda is related to alpha_1) of emitted protons well and consistently within the error bars. The hypernuclear lifetimes are evaluated by converting the total weak decay rates Gamma_{tot} = Gamma_pi + Gamma_{nm} to tau, which exhibit saturation property for the hypernuclear mass A ≥ 30 and agree grossly well with experimental data for the mass range from light to heavy hypernuclei except for the very light ones. Future extensions of the model and the remaining problems are also mentioned. The pi-mesonic weak processes are briefly surveyed, and the calculations and predictions are compared and confirmed by the recent high precision FINUDA pi-mesonic decay data. This shows that the theoretical basis seems to be firmly grounded.

Observation of the {omega}{sub b}{sup -} baryon and measurement of the properties of the {xi}{sub b}{sup -} and {omega}{sub b}{sup -} baryons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aaltonen, T.; Maki, T.; Mehtala, P.

We report the observation of the bottom, doubly-strange baryon {omega}{sub b}{sup -} through the decay chain {omega}{sub b}{sup -}{yields}J/{psi}{omega}{sup -}, where J/{psi}{yields}{mu}{sup +}{mu}{sup -}, {omega}{sup -}{yields}{lambda}K{sup -}, and {lambda}{yields}p{pi}{sup -}, using 4.2 fb{sup -1} of data from pp collisions at {radical}(s)=1.96 TeV, and recorded with the Collider Detector at Fermilab. A signal is observed whose probability of arising from a background fluctuation is 4.0x10{sup -8}, or 5.5 Gaussian standard deviations. The {omega}{sub b}{sup -} mass is measured to be 6054.4{+-}6.8(stat){+-}0.9(syst) MeV/c{sup 2}. The lifetime of the {omega}{sub b}{sup -} baryon is measured to be 1.13{sub -0.40}{sup +0.53}(stat){+-}0.02(syst) ps. In addition,more » for the {xi}{sub b}{sup -} baryon we measure a mass of 5790.9{+-}2.6(stat){+-}0.8(syst) MeV/c{sup 2} and a lifetime of 1.56{sub -0.25}{sup +0.27}(stat){+-}0.02(syst) ps. Under the assumption that the {xi}{sub b}{sup -} and {omega}{sub b}{sup -} are produced with similar kinematic distributions to the {lambda}{sub b}{sup 0} baryon, we find ({sigma}({xi}{sub b}{sup -})B({xi}{sub b}{sup -}{yields}J/{psi}{xi}{sup -})/{sigma}({lambda}{sub b}{sup 0})B({lambda}{sub b}{sup 0}{yields}J/{psi}{lambda}))=0.167{sub -0.025}{sup +0.037}(stat){+-}0.012(syst) and ({sigma}({omega}{sub b}{sup -})B({omega}{sub b}{sup -}{yields}J/{psi}{omega}{sup -})/{sigma}({lambda}{sub b}{sup 0})B({lambda}{sub b}{sup 0}{yields}J/{psi}{lambda}))=0.045{sub -0.012}{sup +0.017}(stat){+-} 0.004(syst) for baryons produced with transverse momentum in the range of 6-20 GeV/c.« less

A Search for Sigma^0_5, N^0_5 and Theta^++ Pentaquark States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yi Qiang; John Annand; John Arrington

2007-05-01

A high-resolution ({sigma}{sub instr.} = 1.5 MeV) search for narrow states ({Lambda} < 10 MeV) with masses of M{sub x} {approx} 1500-1850 MeV in ep {yields} e' K{sup +} X, e' K{sup -} X and e' {pi}{sup +} X electroproduction at small angles and low Q{sup 2} was performed. These states would be candidate partner states of the reported {Theta}{sup +}(1540) pentaquark. No statistically significant signal was observed in any of the channels at 90% C.L. Upper limits on forward production were determined to be between 0.7% and 4.2% of the {Lambda}(1520) production cross section, depending on the channel andmore » the assumed mass and width of the state.« less

Doublet-spacing enhancement caused by {Lambda}N-{Sigma}N coupling in {sub {Lambda}L}i hypernuclear isotopes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Umeya, Atsushi; Harada, Toru; Research Center for Physics and Mathematics, Osaka Electro-Communication University, Neyagawa, Osaka 572-8530

2011-03-15

We theoretically investigate energy spacings of doublets in {sub {Lambda}L}i hypernuclear isotopes with A=7-10 in shell-model calculations with a {Lambda}N-{Sigma}N coupling effect. The calculated results show that the energy shifts are {Delta}{epsilon}=0.09-0.28 MeV and the {Sigma}-mixing probabilities are P{sub {Sigma}}=0.10%-0.34% in {Lambda} ground states for the isotopes because of the {Lambda}N-{Sigma}N coupling in the first-order perturbation. It is found that the energy spacing of the doublet is enhanced as a neutron number N increases; the contribution of the {Lambda}N-{Sigma}N coupling interaction is comparable to that of the {Lambda}N interaction in the neutron-rich {Lambda} hypernuclei. The coherent mechanism of this doublet-spacingmore » enhancement is also discussed in terms of Fermi-type and Gamow-Teller-type {Lambda}N-{Sigma}N couplings.« less

Alternatives to Greek-Letter Organizations Warrant a Second Look

ERIC Educational Resources Information Center

David, Marc C.

2004-01-01

Because of the discriminatory practices and lack of appeal of many predominantly White Greek-letter organizations, students of color sought the development of their own. Alpha Phi Alpha, Rho Psi, MALIK Sigma Psi, Lambda Theta Phi, and Alpha Pi Omega set the stage for later African American, Asian, African, Latino and American Indian Greek-letter…

Coulomb Scattering in the Massless Nelson Model III: Ground State Wave Functions and Non-commutative Recurrence Relations

NASA Astrophysics Data System (ADS)

Dybalski, Wojciech; Pizzo, Alessandro

2018-02-01

Let $H_{P,\\sigma}$ be the single-electron fiber Hamiltonians of the massless Nelson model at total momentum $P$ and infrared cut-off $\\sigma>0$. We establish detailed regularity properties of the corresponding $n$-particle ground state wave functions $f^n_{P,\\sigma}$ as functions of $P$ and $\\sigma$. In particular, we show that \\[ |\\partial_{P^j}f^{n}_{P,\\sigma}(k_1,\\ldots, k_n)|, \\ \\ |\\partial_{P^j} \\partial_{P^{j'}} f^{n}_{P,\\sigma}(k_1,\\ldots, k_n)| \\leq \\frac{1}{\\sqrt{n!}} \\frac{(c\\lambda_0)^n}{\\sigma^{\\delta_{\\lambda_0}}} \\prod_{i=1}^n\\frac{ \\chi_{[\\sigma,\\kappa)}(k_i)}{|k_i|^{3/2}}, \\] where $c$ is a numerical constant, $\\lambda_0\\mapsto \\delta_{\\lambda_0}$ is a positive function of the maximal admissible coupling constant which satisfies $\\lim_{\\lambda_0\\to 0}\\delta_{\\lambda_0}=0$ and $\\chi_{[\\sigma,\\kappa)}$ is the (approximate) characteristic function of the energy region between the infrared cut-off $\\sigma$ and the ultraviolet cut-off $\\kappa$. While the analysis of the first derivative is relatively straightforward, the second derivative requires a new strategy. By solving a non-commutative recurrence relation we derive a novel formula for $f^n_{P,\\sigma}$ with improved infrared properties. In this representation $\\partial_{P^{j'}}\\partial_{P^{j}}f^n_{P,\\sigma}$ is amenable to sharp estimates obtained by iterative analytic perturbation theory in part II of this series of papers. The bounds stated above are instrumental for scattering theory of two electrons in the Nelson model, as explained in part I of this series.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Akaishi, Yoshinori; College of Science and Technology, Nihon University, Funabashi 274-8501; Myint, Khin Swe

The overbinding problem of {sub {lambda}}{sup 5}He is solved by introducing a concept of coherent {lambda}-{sigma} coupling which is equivalent to a {lambda}NN three-body force. This three-body force is coherently enhanced in the 0{sup +} states of {sub {lambda}}{sup 4}H and {sub {lambda}}{sup 4}He. The 0{sup +}-1{sup +} splitting in these hypernuclei is mainly due to coherent {lambda}-{sigma} coupling and partly due to the {lambda}N spin-spin interaction. A {lambda}NN three-body potential is derived from the coupled-channel treatment. The origin of the repulsive and attractive nature of the three-body force is discussed. Coherent {lambda}-{sigma} coupling becomes more important in neutron-rich hypernucleimore » and especially in neutron-star matter at high densities. The possible existence of ''hyperheavy hydrogen'', {sub {lambda}}{sup 6}H, is suggested.« less

First Observation of Charmed Resonances in the $$\\Lambda^0_b \\to \\Lambda^+_c \\pi^- \\pi^+ \\pi^-$$ Inclusive Decay and Measurement of Their Relative Branching Ratios at CDF

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barria, Patrizia

2012-01-01

We present the observation of themore » $$\\Lambda^0_b$$ decay into a $$\\Lambda^+_c \\pi^- \\pi^+ \\pi^-$$ final state, in $$p\\bar{p}$$ collisions at $$\\sqrt{s}$$ = 1:96 TeV. The data analyzed were collected by the CDF II detector at the Fermilab Tevatron collider, and correspond to 2:4 $$fb^{-1}$$ of integrated luminosity. We fit the invariant mass distribution of the reconstructed candidates to extract a signal yield of 848 $$\\pm$$ 93 $$\\Lambda^0_b$$ into $$\\Lambda^+_c \\pi^- \\pi^+ \\pi^-$$....« less

Measurements of the branching fractions for B{sub (s)}{yields}D{sub (s)}{pi}{pi}{pi} and {Lambda}{sub b}{sup 0}{yields}{Lambda}{sub c}{sup +}{pi}{pi}{pi}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aaij, R.; Bauer, Th.; Beuzekom, M. van

Branching fractions of the decays H{sub b}{yields}H{sub c}{pi}{sup -}{pi}{sup +}{pi}{sup -} relative to H{sub b}{yields}H{sub c}{pi}{sup -} are presented, where H{sub b} (H{sub c}) represents B{sup 0} (D{sup +}), B{sup -} (D{sup 0}), B{sub s}{sup 0} (D{sub s}{sup +}), and {Lambda}{sub b}{sup 0} ({Lambda}{sub c}{sup +}). The measurements are performed with the LHCb detector using 35 pb{sup -1} of data collected at {radical}(s)=7 TeV. The ratios of branching fractions are measured to be [B(B{sup 0}{yields}D{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -})]/[B(B{sup 0}{yields}D{sup +}{pi}{sup -})]=2.38{+-}0.11{+-}0.21, [B(B{sup -}{yields}D{sup 0}{pi}{sup -}{pi}{sup +}{pi}{sup -})]/[B(B{sup -}{yields}D{sup 0}{pi}{sup -})]= 1.27{+-}0.06{+-}0.11, [B(B{sub s}{sup 0}{yields}D{sub s}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -})]/[B(B{submore » s}{sup 0}{yields}D{sub s}{sup +}{pi}{sup -})]=2.01{+-}0.37{+-}0.20, [B({Lambda}{sub b}{sup 0}{yields}{Lambda}{sub c}{sup +}{pi}{sup -} {pi}{sup +}{pi}{sup -})]/[B({Lambda}{sub b}{sup 0}{yields}{Lambda}{sub c}{sup +}{pi}{sup -})]=1.43{+-}0.16{+-}0.13 We also report measurements of partial decay rates of these decays to excited charm hadrons. These results are of comparable or higher precision than existing measurements.« less

SEVEN-YEAR WILKINSON MICROWAVE ANISOTROPY PROBE (WMAP ) OBSERVATIONS: POWER SPECTRA AND WMAP-DERIVED PARAMETERS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Larson, D.; Bennett, C. L.; Gold, B.

2011-02-01

The WMAP mission has produced sky maps from seven years of observations at L2. We present the angular power spectra derived from the seven-year maps and discuss the cosmological conclusions that can be inferred from WMAP data alone. With the seven-year data, the temperature (TT) spectrum measurement has a signal-to-noise ratio per multipole that exceeds unity for l < 919; and in band powers of width {Delta}l = 10, the signal-to-noise ratio exceeds unity up to l = 1060. The third acoustic peak in the TT spectrum is now well measured by WMAP. In the context of a flat {Lambda}CDMmore » model, this improvement allows us to place tighter constraints on the matter density from WMAP data alone, {Omega}{sub m} h {sup 2} = 0.1334{sup +0.0056}{sub -0.0055}, and on the epoch of matter-radiation equality, z{sub eq} = 3196{sup +134}{sub -133}. The temperature-polarization (TE) spectrum is detected in the seven-year data with a significance of 20{sigma}, compared to 13{sigma} with the five-year data. We now detect the second dip in the TE spectrum near l {approx} 450 with high confidence. The TB and EB spectra remain consistent with zero, thus demonstrating low systematic errors and foreground residuals in the data. The low-l EE spectrum, a measure of the optical depth due to reionization, is detected at 5.5{sigma} significance when averaged over l = 2-7: l(l + 1)C {sup EE}{sub l}/(2{pi}) = 0.074{sup +0.034}{sub -0.025} {mu}K{sup 2} (68% CL). We now detect the high-l, 24 {<=} l {<=} 800, EE spectrum at over 8{sigma}. The BB spectrum, an important probe of gravitational waves from inflation, remains consistent with zero; when averaged over l = 2-7, l(l + 1)C {sup BB}{sub l}/(2{pi}) < 0.055 {mu}K{sup 2} (95% CL). The upper limit on tensor modes from polarization data alone is a factor of two lower with the seven-year data than it was using the five-year data. The data remain consistent with the simple {Lambda}CDM model: the best-fit TT spectrum has an effective {chi}{sup 2} of 1227 for 1170 degrees of freedom, with a probability to exceed of 9.6%. The allowable volume in the six-dimensional space of {Lambda}CDM parameters has been reduced by a factor of 1.5 relative to the five-year volume, while the {Lambda}CDM model that allows for tensor modes and a running scalar spectral index has a factor of three lower volume when fit to the seven-year data. We test the parameter recovery process for bias and find that the scalar spectral index, n{sub s} , is biased high, but only by 0.09{sigma}, while the remaining parameters are biased by <0.15{sigma}. The improvement in the third peak measurement leads to tighter lower limits from WMAP on the number of relativistic degrees of freedom (e.g., neutrinos) in the early universe: N{sub eff}>2.7(95%CL). Also, using WMAP data alone, the primordial helium mass fraction is found to be Y{sub He} = 0.28{sup +0.14}{sub -0.15}, and with data from higher-resolution cosmic microwave background experiments included, we now establish the existence of pre-stellar helium at >3{sigma}. These new WMAP measurements provide important tests of big bang cosmology.« less

High-resolution oscillator strength measurements for the A(v') - X(0) bands of carbon monoxide with 11 less than or equal to v' less than or equal to 14

NASA Technical Reports Server (NTRS)

Smith, Peter L.; Stark, G.; Yoshino, K.; Ito, K.

1994-01-01

Band oscillator strengths (f-values) for four bands of the Fourth Positive system (A (1)Pi - Chi(sup 1) Sigma(+)) of CO have been determined from high-resolution (lambda/Delta lambda approximately equal to 150,000) absorption spectra. The bands, (14, 0) through (11, 0), are at wavelengths between 121 and 127 nm. Our f-values for the (11, 0) and (12, 0) bands support those of Chan, Cooper, & Brion (1993), which have been shown to be consistent with observations of CO in the clouds in the line of sight to zeta Oph. Our f-values for the (13, 0) and (14, 0) bands are the first directly measured values for these bands.

Direct measurement of sub-Debye-length attraction between oppositely charged surfaces.

PubMed

Kampf, Nir; Ben-Yaakov, Dan; Andelman, David; Safran, S A; Klein, Jacob

2009-09-11

Using a surface force balance with fast video analysis, we have measured directly the attractive forces between oppositely charged solid surfaces (charge densities sigma(+), sigma(-)) across water over the entire range of interaction, in particular, at surface separations D below the Debye screening length lambda(S). At very low salt concentration we find a long-ranged attraction between the surfaces (onset ca. 100 nm), whose variation at D

ASYMMETRIC ABSORPTION PROFILES OF Ly{alpha} AND Ly{beta} IN DAMPED Ly{alpha} SYSTEMS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Hee-Won, E-mail: hwlee@sejong.ac.kr

2013-08-01

Damped Ly{alpha} systems observed in the quasar spectra are characterized by a high neutral hydrogen column density, N{sub HI} > 2 x 10{sup 20} cm{sup -2}. The absorption wing profiles are often fitted using the Voigt function due to the fact that the scattering cross section near the resonant line center is approximately described by the Lorentzian function. Since a hydrogen atom has infinitely many p states that participate in the electric dipole interaction, the cross section starts to deviate from the Lorentzian in an asymmetric way in the line wing regions. We investigate this asymmetry in the absorption linemore » profiles around Ly{alpha} and Ly{beta} as a function of the neutral hydrogen column density N{sub HI}. In terms of {Delta}{lambda} {identical_to} {lambda} - {lambda}{sub {alpha}}, we expand the Kramers-Heisenberg formula around Ly{alpha} to find {sigma}({lambda}) {approx_equal} (0.5f{sub 12}){sup 2}{sigma}{sub T}({Delta}{lambda}/{lambda}{sub {alpha}}){sup -2}[1 + 3.792({Delta}{lambda}/{lambda}{sub {alpha}})], where f{sub 12} and {sigma}{sub T} are the oscillator strength of Ly{alpha} and the Thomson scattering cross section, respectively. In terms of {Delta}{lambda}{sub 2} {identical_to} {lambda} - {lambda}{sub {beta}} in the vicinity of Ly{beta}, the total scattering cross section, given as the sum of cross sections for Rayleigh and Raman scattering, is shown to be {sigma}({lambda}) {approx_equal} {sigma}{sub T}(0.5f{sub 13}){sup 2}(1 + R{sub 0})({Delta}{lambda}{sub 2}/{lambda}{sub {beta}}){sup -2}[1 - 24.68({Delta}{lambda}{sub 2}/{lambda}{sub {beta}})] with f{sub 13} and the factor R{sub 0} = 0.1342 being the oscillator strength for Ly{beta} and the ratio of the Raman cross section to Rayleigh cross section, respectively. A redward asymmetry develops around Ly{alpha}, whereas a blue asymmetry is obtained for Ly{beta}. The absorption center shifts are found to be almost proportional to the neutral hydrogen column density.« less

The low-lying {pi}{sigma}* state and its role in the intramolecular charge transfer of aminobenzonitriles and aminobenzethyne

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Jae-Kwang; Fujiwara, Takashige; Kofron, William G.

2008-04-28

Electronic absorption spectra of the low-lying {pi}{pi}* and {pi}{sigma}* states of several aminobenzonitriles and 4-dimethylaminobenzethyne have been studied by time-resolved transient absorption and time-dependent density functional theory calculation. In acetonitrile, the lifetime of the {pi}{sigma}*-state absorption is very short (picoseconds or subpicosecond) for molecules that exhibit intramolecular charge transfer (ICT), and very long (nanoseconds) for those that do not. Where direct comparison of the temporal characteristics of the {pi}{sigma}*-state and the ICT-state transients could be made, the formation rate of the ICT state is identical to the decay rate of the {pi}{sigma}* state within the experimental uncertainty. These results aremore » consistent with the {pi}{sigma}*-mediated ICT mechanism, L{sub a} ({pi}{pi}*){yields}{pi}{sigma}*{yields}ICT, in which the decay rate of the {pi}{sigma}* state is determined by the rate of the solvent-controlled {pi}{sigma}*{yields}ICT charge-shift reaction. The {pi}{pi}*{yields}{pi}{sigma}* state crossing does not occur in 3-dimethylaminobenzonitrile or 2-dimethylaminobenzonitrile, as predicted by the calculation, and 4-aminobenzonitrile and 4-dimethylaminobenzethyne does not exhibit the ICT reaction, consistent with the higher energy of the ICT state relative to the {pi}{sigma}* state.« less

Study of B{yields}{lambda}{sub c}{lambda}{sub c} and B{yields}{lambda}{sub c}{lambda}{sub c}K

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, H.-Y.; Hsiao, Y.-K.; Chua, C.-K.

2009-06-01

We study the doubly charmful two-body and three-body baryonic B decays B{yields}{lambda}{sub c}{sup +}{lambda}{sub c}{sup -} and B{yields}{lambda}{sub c}{sup +}{lambda}{sub c}{sup -}K. As pointed out before, a naive estimate of the branching ratio O(10{sup -8}) for the latter decay is too small by 3 to 4 orders of magnitude compared to experiment. Previously, it has been shown that a large enhancement for the {lambda}{sub c}{sup +}{lambda}{sub c}{sup -}K production can occur due to a charmoniumlike resonance (e.g. X(4630) discovered by Belle) with a mass near the {lambda}{sub c}{lambda}{sub c} threshold. Motivated by the BABAR's observation of a resonance in themore » {lambda}{sub c}K system with a mass of order 2930 MeV, we study in this work the contribution to B{yields}{lambda}{sub c}{sup +}{lambda}{sub c}{sup -}K from the intermediate state {xi}{sub c}(2980) which is postulated to be a first positive-parity excited D-wave charmed baryon state. Assuming that a soft qq quark pair is produced through the {sigma} and {pi} meson exchanges in the configuration for B{yields}{xi}{sub c}(2980){lambda}{sub c} and {lambda}{sub c}{lambda}{sub c}, it is found that branching ratios of B{yields}{lambda}{sub c}{sup +}{lambda}{sub c}{sup -}K and B{yields}{lambda}{sub c}{sup +}{lambda}{sub c}{sup -} are of order 3.5x10{sup -4} and 5x10{sup -5}, respectively, in agreement with experiment except that the prediction for the {lambda}{sub c}{lambda}{sub c}K{sup -} is slightly smaller. In conjunction with our previous analysis, we conclude that the enormously large rate of B{yields}{lambda}{sub c}{sup +}{lambda}{sub c}{sup -}K arises from the resonances {xi}{sub c}(2980) and X(4630)« less

Mended chiral symmetry and the linear sigma model in one-loop order

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scadron, M.D.

1992-02-28

In this paper it is shown that the linear {sigma}-model in one loop order in the chiral limit recovers meson masses m{sub {pi}} = 0, m{sub {sigma}} = 2m{sub qk} (NJL), m {sub {rho}} = {radical}2 g{sub {rho}}f{pi} (KSRF), along with couplings g{sigma}{pi}{pi} = m{sup 2}{sub {sigma}}/2f{pi}, g{rho}{pi}{pi} = g{sub {rho}} (VMD universality) and Weinberg's mended chiral symmetry decay width relation {Gamma}{sub {sigma}} = (9/2){Gamma}{sub {rho}}. The linear {sigma}-model combined quark and meson loops also properly predict the radiative decays {pi}{sup 0} {yields} 2{gamma} {yields} e{nu}{gamma} and {delta}{sup 0} (983) {yields} 2{gamma}.

VizieR Online Data Catalog: H2 d3{Pi}u excitation by elec

NASA Astrophysics Data System (ADS)

Liu, X.; Shemansky, D. E.; Yoshii, J.; Johnson, P. V.; Malone, C. P.; Ajello, J. M.

2016-05-01

Electron-impact excitation of H2 triplet states plays an imp role in the heating of outer planet upper thermospheres. The d3{Pi}u state is the third ungerade triplet state, and the d3{Pi}u-a3{Sigma}g+ emission is the largest cascade channel for the a3{Sigma}g+ state. Accurate energies of the d3{Pi}u-(v, J) levels are calculated from an ab initio potential energy curve. Radiative lifetimes of the d3{Pi}u(v,J) levels are obtained by an accurate evaluation of the d3{Pi}u-a3{Sigma}g+ transition probabilities. The emission yields are determined from experimental lifetimes and calculated radiative lifetimes and are further verified by comparing experimental and synthetic d3{Pi}u-a3{Sigma}g+ spectra at 20eV impact energy. Spectral analysis revealed that multipolar components beyond the dipolar term are required to model the X1{Sigma}g+-d3{Pi}u excitation, and significant cascade excitation occurs at the d3{Pi}u (v=0,1) levels. Kinetic energy (Ek) distributions of H atoms produced via predissociation of the 3{Pi}u state and the d3{Pi}u-a3{Sigma}g+-b3{Sigma}u+ cascade dissociative emission are obtained. Predissociation of the d3{Pi}u state produces H atoms with an average Ek of 2.3+/-0.4 eV/atom, while the Ekdistribution of the d3{Pi}u-a3{Sigma}g+-b3{Sigma}u+ channel is similar to that of the X1{Sigma}g+-a3{Sigma}g+-b3{Sigma}u+ channel and produces H(1s) atoms with an average Ek of 1.15+/-0.05eV/atom. On average, each H2 excited to the d3{Pi}u state in an H2-dominated atmosphere deposits 3.3+/-0.4eV into the atmosphere, while each H2directly excited to the a3{Sigma}g+ state gives 2.2-2.3eV to the atmosphere. The spectral distribution of the calculated a3{Sigma}g+-b3{Sigma}u+ continuum emission due to the X1{Sigma}g+-d3{Pi}u excitation is significantly different from that of direct a3{Sigma}g+ excitation. (2 data files).

A Measurement of PSI(2S) Resonance Parameters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dunwoodie, William

2002-11-08

Cross sections for e{sup +}e{sup -} {yields} hadrons, {pi}{sup +} {pi}{sup -} J/{psi}, and {mu}{sup +}{mu}{sup -} have been measured in the vicinity of the {psi}(2S) resonance using the BESII detector operated at the BEPC. The {psi}(2S) total width; partial widths to hadrons, {pi}{sup +} {pi}{sup -} J/{psi}, muons; and corresponding branching fractions have been determined to be {Lambda}{sub t} = 264 {+-} 27 keV; {Lambda}{sub h} = 258 {+-} 26 keV, {Lambda}{sub {mu}} = 2.44 {+-} 0.21 keV, and {Lambda}{sub {pi}+{pi} = J/{psi}} = 85.4 {+-} 8.7 keV; and B{sub h} = (97.79 {+-} 0.15)%, B{sub {pi}{sup +}{pi}{sup -}}more » = (32.3 {+-} 1.4)%, B{sub {mu}} = (0.93 {+-} 0.08)%, respectively.« less

Beauty Baryons at CDF and DO

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kryemadhi, Abaz

The results from Tevatron in the baryonic sector are presented. The lifetime of {lambda}b {yields} J/{psi}{lambda}, the observation of hadronic decay of {lambda}b {yields} {lambda}c{pi}, the semileptonic decays of {lambda}b {yields} {lambda}c{mu}{nu}, the hadronization of the b-baryons, and the {lambda}b decays to {lambda}b {yields} p{pi} and {lambda}b {yields} pK are discussed. These measurements paint a nice picture of our understanding of the beauty baryons.

Relative intensity calculations for nitrous oxide.

NASA Technical Reports Server (NTRS)

Young, L. D. G.

1972-01-01

A tabulation of calculated rotational line intensities, relative to the integrated intensity of a vibration-rotation band, is given for Sigma-Sigma, Pi-Sigma, Sigma-Pi, Pi-Pi, and Delta-Pi transitions of nitrous oxide. These calculations were made for temperatures of 250 K and 300 K. A summary of band-intensity measurements is also presented.

How Well do State-of-the-Art Techniques Measuring the Vertical Profile of Tropospheric Aerosol Extinction Compare?

NASA Technical Reports Server (NTRS)

Schmid, B.; Ferrare, R.; Flynn, C.; Elleman, R.; Covert, D.; Strawa, A.; Welton, E.; Turner, D.; Jonsson, H.; Redemann, J.;

Dipole moments and transition probabilities of the i 3Pi sub g-b 3Sigma(+) sub u, c 3Pi sub u-a 3Sigma(+) sub g, and i 3Pi sub g-c 3Pi sub u systems of molecular hydrogen

NASA Technical Reports Server (NTRS)

Guberman, Steven L.; Dalgarno, A.

1992-01-01

Bonn-Oppenheimer-based ab initio calculations of dipole moments from the i 3Pi sub g-b 3Sigma(+) sub u, c 3Pi sub u-a 3Sigma(+) sub g, and i 3Pi sub g-c 3Pi sub u transitions of H2 have been conducted, to yield a tabulation of the dipole transition probabilities and Franck-Condon factors. These factors are given for transitions originating in the lowest vibrational level of the ground X 1Sigma(+) sub g state.

Measurement of the E Polarization Observable for yd --> pi^-p(p_s), yd-->K^0Lambda(p_s), and yd-->pi^+pi^-d(0) using CLAS g14 data at Jefferson Lab

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ho, Dao

Photoproduction of mesons from the nucleon has a long and ongoing tradition for exploring nucleon excitations and the baryon-baryon interaction. Polarization observables which play a role in the photoproduction mechanism are, therefore, essential in addition to the differential cross section. The CLAS collaboration at Jefferson Lab, has been active in measuring these observables, but until now only on a proton targets. However, a comprehensive picture of the pseudoscalar meson photoproduction requires neutron data as well. That is, paired measurements of observables in p and n reactions are necessary to disentangle the photoproduction mechanism on the basis of isospin I =more » 0, and I = 1 photo-coupling transition amplitudes. The g14 experiment with 'HDIce,' a longitudinally polarized solid target of molecular hydrogen-deuteride with low background contamination from other nuclear species, provided an unique opportunity to measure several polarization observables|for the first time|on the neutron for different channels. In particular, we present our measurements of the E beam-target polarization observable, which requires circularly polarized beam and a longitudinally polarized target, for p pi^-, K^0Lambda, and K^0Sigma^0 channels in the energy range of 1.5 lte W lte 2.3 GeV. In addition, we also utilized the g14 dataset to investigate the intrinsic spin of a possible dibaryonic ND bound state by measuring the E (beam-target) observable on the d-pi^+/-d channel of the reaction yd --> pi^+pi^-d(0). Finally, this thesis also discusses a highly efficient multivariate analysis method called Boosted Decision Trees, which we employed extensively for this work and which has not been used before in CLAS data analysis.« less

Charmonium Decays of Y(4260), psi(4160), and psi(4040).

PubMed

Coan, T E; Gao, Y S; Liu, F; Artuso, M; Blusk, S; Butt, J; Li, J; Menaa, N; Mountain, R; Nisar, S; Randrianarivony, K; Redjimi, R; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Zhang, K; Csorna, S E; Bonvicini, G; Cinabro, D; Dubrovin, M; Lincoln, A; Asner, D M; Edwards, K W; Briere, R A; Brock, I; Chen, J; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Adam, N E; Alexander, J P; Berkelman, K; Cassel, D G; Duboscq, J E; Ecklund, K M; Ehrlich, R; Fields, L; Galik, R S; Gibbons, L; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Meyer, T O; Onyisi, P U E; Patterson, J R; Peterson, D; Phillips, E A; Pivarski, J; Riley, D; Ryd, A; Sadoff, A J; Schwarthoff, H; Shi, X; Stroiney, S; Sun, W M; Wilksen, T; Weinberger, M; Athar, S B; Avery, P; Breva-Newell, L; Patel, R; Potlia, V; Stoeck, H; Yelton, J; Rubin, P; Cawlfield, C; Eisenstein, B I; Karliner, I; Kim, D; Lowrey, N; Naik, P; Sedlack, C; Selen, M; White, E J; Wiss, J; Shepherd, M R; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Gong, D T; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Poling, R; Scott, A W; Smith, A; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Zweber, P; Ernst, J; Severini, H; Dytman, S A; Love, W; Savinov, V; Aquines, O; Li, Z; Lopez, A; Mehrabyan, S; Mendez, H; Ramirez, J; Huang, G S; Miller, D H; Pavlunin, V; Sanghi, B; Shipsey, I P J; Xin, B; Adams, G S; Anderson, M; Cummings, J P; Danko, I; Napolitano, J; He, Q; Insler, J; Muramatsu, H; Park, C S; Thorndike, E H

2006-04-28

Using data collected with the CLEO detector operating at the CESR e+e- collider at sqrt[s]=3.97-4.26 GeV, we investigate 15 charmonium decay modes of the psi(4040), psi(4160), and Y(4260) resonances. We confirm, at 11 sigma significance, the BABAR Y(4260)-->pi+pi- J/psi discovery, make the first observation of Y(4260)--> pi(0)pi(0) J/psi (5.1 sigma), and find the first evidence for Y(4260)-->K+K- J/psi(3.7 sigma). We measure e+e- cross sections at sqrt[s]=4.26 GeV as sigma(pi+pi- J/psi)=58(+12)(-10)+/-4 pb, sigma(pi(0)pi(0) J/psi)=23(+12)(-8)+/-1 pb, and sigma(K+K- J/psi)=9(+9)(-5)+/-1 pb, in which the uncertainties are statistical and systematic, respectively. Upper limits are placed on other decay rates from all three resonances.

RAMAN SCATTERED He II {lambda}4332 IN THE SYMBIOTIC STAR V1016 CYGNI

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Hee-Won

Raman scattering of He II line photons with atomic hydrogen is important in studying the mass loss processes in many symbiotic stars and a number of young planetary nebulae. We calculate the scattering cross sections and branching ratios associated with the Raman scattered He II {lambda}4332 feature formed through inelastic scattering of He II {lambda}949 with a hydrogen atom. At the line center of He II {lambda}949, the total scattering cross section is computed to be {sigma}{sub tot} = 2.5 Multiplication-Sign 10{sup -22} cm{sup 2}, and the branching ratio into the level 2s is 0.12. We also present a high-resolutionmore » spectrum of the symbiotic star V1016 Cygni obtained with the 1.8 m telescope at Mt. Bohyun to investigate the Raman scattering origin of the broad feature blueward of He II {lambda}4338. Based on the atomic calculation, we perform Monte Carlo calculations for the line formation. The scattering region is assumed to be a part of a uniform spherical shell that subtends a solid angle {Delta}{Omega} = {pi} steradian with a neutral column density N{sub HI} = 1.0 x 10{sup 21} cm{sup -2}. By adding a far-UV continuum around He II {lambda}949 normalized by the equivalent width of He II {lambda}949 to be 2.3 Angstrom-Sign , we obtain a good fit for both the Raman scattered He II {lambda}4332 and the broad wings around H{gamma}. Our analysis of the Raman feature blueward of H{gamma} in V1016 Cyg is consistent with the previous study of the Raman features blueward of H{alpha} and H{beta} by Jung and Lee.« less

How well can we Measure the Vertical Profile of Tropospheric Aerosol Extinction?

NASA Technical Reports Server (NTRS)

Schmid, Beat; Ferrare, R.; Flynn, C.; Elleman, R.; Covert, D.; Strawa, A.; Welton, E.; Turner, D.; Jonsson, H.; Redemann, J.

2005-01-01

The recent Department of Energy Atmospheric Radiation Measurement (ARM) Aerosol Intensive Operations Period (MOP, May 2003) yielded one of the best measurement sets obtained to-date to assess our ability to measure the vertical profile of ambient aerosol extinction sigma(sub ep)(lambda) in the lower troposphere. During one month, a heavily instrumented aircraft with well characterized aerosol sampling ability carrying well proven and new aerosol instrumentation, devoted most of the 60 available flight hours to flying vertical profiles over the heavily instrumented ARM Southern Great Plains (SGP) Climate Research Facility (CRF). This allowed us to compare vertical extinction profiles obtained from 6 different instuments: airborne Sun photometer (AATS-14), airborne nephelometer/absorption photometer, airborne cavity ring-down system, ground-based Raman lidar and 2 ground-based elastic backscatter lidars. We find the in-situ measured sigma(sub ep)(lambda) to be lower than the AATS-14 derived values. Bias differences are 0.002 - 0.004 K/m equivalent to 12-17% in the visible, or 45% in the near-infrared. On the other hand, we find that with respect to AATS-14, the lidar sigma(sub ep)(lambda) are higher. An unnoticed loss of sensitivity of the Raman lidar had occurred leading up to AIOP and we expect better agreement from the recently restored system looking at the collective results from 6 field campaigns conducted since 1996, airborne in situ measurements of sigma(sub ep)(lambda) tend to be biased slightly low (17% at visible wavelengths) when compared to airborne Sun photometer sigma(sub ep)(lambda). On the other hand, sigma(sub ep)(lambda) values derived from lidars tend to have no or positive biases. From the bias differences we conclude that the typical systematic error associated with measuring the tropospheric vertical profile of the ambient aerosol extinction with current state of-the art instrumentation is 15-20% at visible wavelengths and potentially larger in the UV and near-infrared.

Observation of Exclusive B Decays to Final States Containing a Charmed Baryon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jessop, Colin P.

2003-05-23

Using data collected in the region of the {Upsilon}(4S) resonance with the CLEO-II detector, they report on the first observation of exclusive decays of the B meson to final states with a charmed baryon. They have measured the branching fractions {Beta}(B{sup -} {yields} {Lambda}{sub c}{sup +}{bar p}{pi}{sup -}) = (0.62{sub -0.20}{sup +0.23} {+-} 0.11 {+-} 0.10) x 10{sup -3} and {Beta}({bar B}{sup 0} {yields} {Lambda}{sub c}{sup +}{bar p}{pi}{sup +}{pi}{sup -}) = (1.33{sub -0.42}{sup +0.46} {+-} 0.31 {+-} 0.21) x 10{sup -3}. In addition, they report upper limits for final states of the form {bar B} {yields} {Lambda}{sub c}{sup +}{bar p}(n{pi})more » and {Lambda}{sub c}{sup +}{bar p}(n{pi}){pi}{sup 0} where (n{pi}) denotes up to four charged pions.« less

Switches from pi- to sigma-bonding complexes controlled by gate voltages.

PubMed

Matsui, Eriko; Harnack, Oliver; Matsuzawa, Nobuyuki N; Yasuda, Akio

2005-10-01

A conjugated polymer/metal ion/liquid-crystal molecular system was set between source and drain electrodes with a 100 nm gap. When gate voltage (Vg) increases, the current between source and drain electrodes increases. Infrared spectra show this system to be composed of pi and sigma complexes. At Vg = 0, the pi complex dominates the sigma complex, whereas the sigma complex becomes dominant when Vg is switched on. Calculations found that the pi complex has lower conductivity than the sigma complex.

Autofluorescence spectroscopy of oral mucosa

NASA Astrophysics Data System (ADS)

Majumdar, S. K.; Uppal, A.; Gupta, P. K.

1998-06-01

We report the results of an in-vitro study on autofluorescence from pathologically characterized normal and malignant squamous tissues from the oral cavity. The study involved biopsy samples from 47 patients with oral cancer of which 11 patients had cancer of tongue, 17 of buccal mucosa and 19 of alveolus. The results of excitation and emission spectroscopy at several wavelengths (280 nm less than or equal to (lambda) exless than or equal to 460 nm; 340 nm less than or equal to (lambda) em less than or equal to 520 nm) showed that at (lambda) ex equals 337 nm and 400 nm the mean value for the spectrally integrated fluorescence intensity [(Sigma) (lambda ) IF((lambda) )] from the normal tissue sites was about a factor of 2 larger than that from the malignant tissue sites. At other excitation wavelengths the difference in (Sigma) (lambda ) IF((lambda) ) was not statistically significant. Similarly, for (lambda) em equals 390 nm and 460 nm, the intensity of the 340 nm band of the excitation spectra from normal tissues was observed to be a factor of 2 larger than that from malignant tissues. Analysis of these results suggests that NADH concentration is higher in normal oral tissues compared to the malignant. This contrasts with our earlier observation of an reduced NADH concentration in normal sites of breast tissues vis a vis malignant sites. For the 337 nm excited emission spectra a 10-variable MVLR score (using (Sigma) (lambda ) IF((lambda) ) and normalized intensities at nine wavelengths as input parameters) provided a sensitivity and specificity of 95.7% and 93.1% over the sample size investigated.

Dynamically generated N* and {Lambda}* resonances in the hidden charm sector around 4.3 GeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu Jiajun; Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, E-46071 Valencia; Molina, R.

2011-07-15

The interactions of D-bar{Sigma}{sub c}-D-bar{Lambda}{sub c}, D-bar*{Sigma}{sub c}-D-bar*{Lambda}{sub c}, and related strangeness channels, are studied within the framework of the coupled-channel unitary approach with the local hidden gauge formalism. A series of meson-baryon dynamically generated relatively narrow N* and {Lambda}* resonances are predicted around 4.3 GeV in the hidden charm sector. We make estimates of production cross sections of these predicted resonances in p-barp collisions for the experiment of antiproton annihilation at Darmstadt (PANDA) at the forthcoming GSI Facility for Antiproton and Ion Research (FAIR) facility.

Prediction of narrow N* and {Lambda}* with hidden charm

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu Jiajun; Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia; Molina, R.

2011-10-24

The interaction between various charmed mesons and charmed baryons, such as D-bar{Sigma}{sub c}-D-bar{Lambda}{sub c}, D-bar*{Sigma}{sub c}-D-bar*{Lambda}{sub c}, and related strangeness channels, are studied within the framework of the coupled channel unitary approach with the local hidden gauge formalism. Six narrow N* and {Lambda}* resonances are dynamically generated with mass above 4 GeV and width smaller than 100 MeV. These predicted new resonances definitely cannot be accommodated by quark models with three constituent quarks. We make estimates of production cross sections of these predicted resonances in p-barp collisions for PANDA at the forthcoming FAIR facility.

Observation of the {Xi}{sub b}{sup 0} Baryon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aaltonen, T.; Brucken, E.; Devoto, F.

The observation of the bottom, strange baryon {Xi}{sub b}{sup 0} through the decay chain {Xi}{sub b}{sup 0}{yields}{Xi}{sub c}{sup +}{pi}{sup -}, where {Xi}{sub c}{sup +}{yields}{Xi}{sup -}{pi}{sup +}{pi}{sup +}, {Xi}{sup -}{yields}{Lambda}{pi}{sup -}, and {Lambda}{yields}p{pi}{sup -}, is reported by using data corresponding to an integrated luminosity of 4.2 fb{sup -1} from pp collisions at {radical}(s)=1.96 TeV recorded with the Collider Detector at Fermilab. A signal of 25.3{sub -5.4}{sup +5.6} candidates is observed whose probability of arising from a background fluctuation is 3.6x10{sup -12}, corresponding to 6.8 Gaussian standard deviations. The {Xi}{sub b}{sup 0} mass is measured to be 5787.8{+-}5.0(stat){+-}1.3(syst) MeV/c{sup 2}. In addition,more » the {Xi}{sub b}{sup -} baryon is observed through the process {Xi}{sub b}{sup -}{yields}{Xi}{sub c}{sup 0}{pi}{sup -}, where {Xi}{sub c}{sup 0}{yields}{Xi}{sup -}{pi}{sup +}, {Xi}{sup -}{yields}{Lambda}{pi}{sup -}, and {Lambda}{yields}p{pi}{sup -}.« less

Measurements of the Temperature and E-mode Polarization of the CMB from 500 Square Degrees of SPTpol Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henning, J. W.; Sayre, J. T.; Reichardt, C. L.

We present measurements of the E-mode polarization angular auto-power spectrum (EE) and temperature-E-mode cross-power spectrum (TE) of the cosmic microwave background (CMB) using 150 GHz data from three seasons of SPTpol observations. We report the power spectra over the spherical harmonic multipole range 50 < l <= 8000 and detect nine acoustic peaks in the EE spectrum with high signal-to-noise ratio. These measurements are the most sensitive to date of the EE and TE power spectra at l > 1050 and l > 1475, respectively. The observations cover 500 deg(2), a fivefold increase in area compared to previous SPTpol analyses,more » which increases our sensitivity to the photon diffusion damping tail of the CMB power spectra enabling tighter constraints on Lambda CDM model extensions. After masking all sources with unpolarized flux > 50 mJy, we place a 95% confidence upper limit on residual polarized point-source power of D-l= l(l + 1)C-l/2 pi < 0.107 mu K-2 at l = 3000, suggesting that the EE damping tail dominates foregrounds to at least l = 4050 with modest source masking. We find that the SPTpol data set is in mild tension with the Lambda CDM model (2.1 sigma), and different data splits prefer parameter values that differ at the similar to 1 sigma level. When fitting SPTpol data at l < 1000, we find cosmological parameter constraints consistent with those for Planck temperature. Including SPTpol data at l > 1000 results in a preference for a higher value of the expansion rate (H-0 = 71.3 +/- 2.1 km s(-1) Mpc(-1)) and a lower value for present-day density fluctuations (sigma(8) = 0.77 +/- 0.02).« less

Microwave response of high transition temperature superconducting thin films

NASA Technical Reports Server (NTRS)

Miranda, Felix Antonio

1991-01-01

We have studied the microwave response of YBa2Cu3O(7 - delta), Bi-Sr-Ca-Cu-O, and Tl-Ba-Ca-Cu-O high transition temperature superconducting (HTS) thin films by performing power transmission measurements. These measurements were carried out in the temperature range of 300 K to 20 K and at frequencies within the range of 30 to 40 GHz. Through these measurements we have determined the magnetic penetration depth (lambda), the complex conductivity (sigma(sup *) = sigma(sub 1) - j sigma(sub 2)) and the surface resistance (R(sub s)). An estimate of the intrinsic penetration depth (lambda approx. 121 nm) for the YBa2Cu3O(7 - delta) HTS has been obtained from the film thickness dependence of lambda. This value compares favorably with the best values reported so far (approx. 140 nm) in single crystals and high quality c-axis oriented thin films. Furthermore, it was observed that our technique is sensitive to the intrinsic anisotropy of lambda in this superconductor. Values of lambda are also reported for Bi-based and Tl-based thin films. We observed that for the three types of superconductors, both sigma(sub 1) and sigma(sub 2) increased when cooling the films below their transition temperature. The measured R(sub s) are in good agreement with other R(sub S) values obtained using resonant activity techniques if we assume a quadratic frequency dependence. Our analysis shows that, of the three types of HTS films studied, the YBa2Cu3O(7 - delta) thin film, deposited by laser ablation and off-axis magnetron sputtering are the most promising for microwave applications.

Integral cross sections for the direct excitation of the A 3 (sigma) u +, B 3 (pi) g, W 3 (delta) u, B' 3 (sigma) u -, a' 1 (sigma) u -, a 1 (pi) g, w 1 (delta) u, and C 3 (pi) u electronic states in

NASA Technical Reports Server (NTRS)

Johnson, P. V.; Malone, C. P.; Kanik, I.

2005-01-01

Integral cross sections for electron impact excitation out of the ground state (X 1(sigma)g +) to the A 3(sigma)u +, B 3(pi)g, W 3(delta)u, B' 3(sigma)u -, a' 1(sigma)u -, a 1(pi)g, w 1(delta)u, and states in N2 are reported at incident energies ranging between 10 and 100 eV. These data have been derived by integrating differential cross sections previously reported by this group. New differential cross section measurements for the a 1(pi)g state at 200 eV are also presented to extend the range of the reported integral cross sections for this state, which is responsible for the emissions of the Lyman-Birge-Hopfield band system (a 1(pi)g (rightwards arrow) X 1(sigma)g +). The present results are compared and critically evaluated against existing cross sec In general, the present cross sections are smaller than previous results at low impact energies from threshold through the excitation function peak regions. These lower cross sections have potentially significant implications on our understanding of UV emissions in the atmospheres of Earth and Titan.

VizieR Online Data Catalog: H2, D2, and HD c3Πu;

NASA Astrophysics Data System (ADS)

Liu, X.; Shemansky, D. E.; Yoshii, J.; Liu, M. J.; Johnson, P. V.; Malone, C. P.; Khakoo, M. A.

2017-11-01

The c3{Pi}u state of the hydrogen molecule has the triplet-state excitation cross-section, and plays an important role in the heating of the upper thermospheres of outer planets by electron excitation. Precise energies of the H2, D2, and HD c3{Pi}u-(v,N) levels are calculated from highly accurate ab initio potential energy curves that include relativistic, radiative, and empirical non-adiabatic corrections. The emission yields are determined from predissociation rates and refined radiative transition probabilities. The excitation function and excitation cross-section of the c3{Pi}u state are extracted from previous theoretical calculations and experimental measurements. The emission cross-section is determined from the calculated emission yield and the extracted excitation cross-section. The kinetic energy (Ek) distributions of H atoms produced via the predissociation of the c3{Pi}u state, the c3{Pi}u--b3{Sigma}u+ dissociative emission by the magnetic dipole and electric quadrupole, and the c3{Pi}u-a3{Sigma}g+-b3{Sigma}u+ cascade dissociative emission by the electric dipole are obtained. The predissociation of the c3{Pi}u+ and c3{Pi}u- states both produce H(1s) atoms with an average Ek of ~4.1eV/atom, while the c3{Pi}u--b3{Sigma}u+ dissociative emissions by the magnetic dipole and electric quadrupole give an average Ek of ~1.0 and ~0.8eV/atom, respectively. The c3{Pi}u-a3{Sigma}g+-b3{Sigma}u+ cascade and dissociative emission gives an average Ek of ~1.3 eV/atom. On average, each H2 excited to the c3{Pi}u state in an H2-dominated atmosphere deposits ~7.1eV into the atmosphere while each H2 directly excited to the a3{Sigma}g+ and d3{Pi}u states contribute ~2.3 and ~3.3eV, respectively, to the atmosphere. The spectral distribution of the calculated continuum emission arising from the X1{Sigma}g+-c3{Pi}u excitation is significantly different from that of direct a3{Sigma}g+ or d3{Pi}u excitations. (5 data files).

[Excitation transfer between high-lying states in K2 in collisions with ground state K and H2 molecules].

PubMed

Shen, Xiao-Yan; Liu, Jing; Dai, Kang; Shen, Yi-Fan

2010-02-01

Pure potassium vapor or K-H2 mixture was irradiated in a glass fluorescence cell with pulses of 710 nm radiation from an OPO laser, populating K2 (1lambda(g)) state by two-photon absorption. Cross sections for 1lambda(g)-3lambda(g) transfer in K2 were determined using methods of molecular fluorescence. During the experiments with pure K vapor, the cell temperature was varied between 553 and 603 K. The K number density was determined spectroscopically by the white-light absorption measurement in the blue wing of the self-broadened resonance D2 line. The resulting fluorescence included a direct component emitted in the decay of the optically excitation and a sensitized component arising from the collisionally populated state. The decay signal of time-resolved fluorescence from1lambda(g) -->1 1sigma(u)+ transition was monitored. It was seen that just after the laser pulse the fluorescence of the photoexcited level decreased exponentially. The effective lifetimes of the 1lambda(g) state can be resolved. The plot of reciprocal of effective lifetimes of the 1lambda(g) state against K densities yielded the slope that indicated the total cross section for deactivation and the intercept that provided the radiative lifetime of the state. The radiative lifetime (20 +/- 2) ns was obtained. The cross section for deactivation of the K2(1lambda(g)) molecules by collisions with K is (2.5 +/- 0.3) x 10(-14) cm2. The time-resolved intensities of the K23lambda(g) --> 1 3sigma(u)+ (484 nm) line were measured. The radiative lifetime (16.0 +/- 3.2) ns and the total cross section (2.5 +/- 0.6) x 10(-14) cm2 for deactivation of the K2 (3lambda(g)) state can also be determined through the analogous procedure. The time-integrated intensities of 1lambda(g) --> 1 1sigma(u)+ and 3lambda(g) --> 1 3sigma(u)+ transitions were measured. The cross section (1.1 +/- 0.3) x10(-14) cm2 was obtained for K2 (1lambda(g))+ K --> K2 (3lambda(g)) + K collisions. During the experiments with K-H2 mixture, the cell temperature was kept constant at 553 K. The H2 pressure was varied between 40 and 400 Pa. The effects of K2-K collisions could not be neglected. These effects were subtracted out using the results of the pure K experiments. The cross section (2.7 +/- 1.1) x 10(-15) cm2 was obtained for K2 (1lambda(g)) + H2 --> K2 (3lambda(g))+H2 collisions. The cross section is (6.8 +/- 2.7) x 10(-15) cm2 for K2 (3lambda(g)) + H2 --> states out of K2 (3lambda(g)) + H2 collisions.

Yang Baxter and anisotropic sigma and lambda models, cyclic RG and exact S-matrices

NASA Astrophysics Data System (ADS)

Appadu, Calan; Hollowood, Timothy J.; Price, Dafydd; Thompson, Daniel C.

2017-09-01

Integrable deformation of SU(2) sigma and lambda models are considered at the classical and quantum levels. These are the Yang-Baxter and XXZ-type anisotropic deformations. The XXZ type deformations are UV safe in one regime, while in another regime, like the Yang-Baxter deformations, they exhibit cyclic RG behaviour. The associ-ated affine quantum group symmetry, realized classically at the Poisson bracket level, has q a complex phase in the UV safe regime and q real in the cyclic RG regime, where q is an RG invariant. Based on the symmetries and RG flow we propose exact factorizable S-matrices to describe the scattering of states in the lambda models, from which the sigma models follow by taking a limit and non-abelian T-duality. In the cyclic RG regimes, the S-matrices are periodic functions of rapidity, at large rapidity, and in the Yang-Baxter case violate parity.

Low-lying energy spectrum of the cerium dimer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nikolaev, A. V.; Skobeltsyn Institute of Nuclear Physics, Moscow State University, Vorob'evy Gory 1/2, 119991, Moscow

2011-07-15

The electronic structure of Ce{sub 2} is studied in a valence bond model with two 4f electrons localized at two cerium sites. It is shown that the low-lying energy spectrum of the simplest cerium chemical bond is determined by peculiarities of the occupied 4f states. The model allows for an analytical solution, which is discussed along with the numerical analysis. The energy spectrum is a result of the interplay between the 4f valence bond exchange, the 4f Coulomb repulsion, and the spin-orbit coupling. The calculated ground state is the even {Omega}={Lambda}={Sigma}=0 level, the lowest excitations situated at {approx}30 K aremore » the odd {Omega}={Lambda}={Sigma}=0 state and the {sup 3}6{sub 5} doublet ({Omega}={+-}5,{Lambda}={+-}6,{Sigma}={+-}1). The calculated magnetic susceptibility displays different behavior at high and low temperatures. In the absence of the spin-orbit coupling the ground state is the {sup 3}{Sigma}{sub g}{sup -} triplet. The results are compared with other many-electron calculations and experimental data.« less

A Study of Double-Charm and Charm-Strange Baryons inElectron-Positron Annihilations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Edwards, Adam J.; /SLAC

2007-10-15

In this dissertation I describe a study of double-charm and charm-strange baryons based on data collected with the BABAR Detector at the Stanford Linear Accelerator Center. In this study I search for new baryons and make precise measurements of their properties and decay modes. I seek to verify and expand upon double-charm and charm-strange baryon observations made by other experiments. The BABAR Detector is used to measure subatomic particles that are produced at the PEP-II storage rings. I analyze approximately 300 million e+e- {yields} c{bar c} events in a search for the production of double-charm baryons. I search for themore » double-charm baryons {Xi}{sup +}{sub cc} (containing the quarks ccd) and {Xi}{sup ++}{sub cc} (ccu) in decays to {Lambda}{sup +}{sub c}K{sup -}{pi}{sup +} and {Lambda}{sup +}{sub c}K{sup -}{pi}{sup +}{pi}{sup +}, respectively. No statistically significant signals for their production are found, and upper limits on their production are determined. Statistically significant signals for excited charm-strange baryons are observed with my analysis of approximately 500 million e+e- {yields} c{bar c} events. The charged charm-strange baryons {Xi}{sub c}(2970){sup +}, {Xi}{sub c}(3055){sup +}, {Xi}{sub c}(3123){sup +} are found in decays to {Lambda}{sup +}{sub c}K{sup -}{pi}{sup +}, the same decay mode used in the {Xi}{sup +}{sub cc} search. The neutral charm-strange baryon {Xi}{sub c}(3077){sup 0} is observed in decays to {Lambda}{sup +}{sub c}K{sub 8}{pi}{sup -}. I also search for excited charm-strange baryon decays to {Lambda}{sup +}{sub c}K{sub 8}, {Lambda}{sup +}{sub c}K{sup -}, {Lambda}{sup +}{sub c}K{sub 8}{pi}{sup -}{pi}{sup +}, and {Lambda}{sup +}{sub c}K{sup -}{pi}{sup -}{pi}{sup +}. No significant charm-strange baryon signals a f h these decay modes. For each excited charm-strange baryon state that I observe, I measure its mass, natural width (lifetime), and production rate. The properties of these excited charm-strange baryons and their decay modes provide constraints for phenomenological models of quark interactions through quantum chromodynamics. My discovery of the two new charm-strange baryons {Xi}{sub c}(3055){sup +} and {Xi}{sub c}(3123){sup +} influences our theoretical understanding of charm-strange baryon states.« less

Eta photoproduction in a combined analysis of pion- and photon-induced reactions

DOE PAGES

Ronchen, D.; Doring, M.; Haberzettl, H.; ...

2015-06-25

Themore » $$\\eta N$$ final state is isospin-selective and thus provides access to the spectrum of excited nucleons without being affected by excited $$\\Delta$$ states. To this end, the world database on eta photoproduction off the proton up to a center-of-mass energy of $$E\\sim 2.3$$ GeV is analyzed, including data on differential cross sections, and single and double polarization observables. resonance spectrum and its properties are determined in a combined analysis of eta and pion photoproduction off the proton together with the reactions $$\\pi N\\to \\pi N$$, $$\\eta N$$, $$K\\Lambda$$ and $$K\\Sigma$$. For the analysis, the so-called J\\"ulich coupled-channel framework is used, incorporating unitarity, analyticity, and effective three-body channels. Parameters tied to photoproduction and hadronic interactions are varied simultaneously. Furthermore, the influence of recent MAMI $T$ and $F$ asymmetry data on the eta photoproduction amplitude is discussed in detail.« less

Search for b\\to u Transitions in \\Bz \\to \\Dz \\Kstarz Decays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aubert, B.; Bona, M.; Karyotakis, Y.

We present a study of the decays B{sup 0} {yields} D{sup 0} K*{sup 0} and B{sup 0} {yields} {bar D}{sup 0} K*{sup 0} with K*{sup 0} {yields} K{sup +}{pi}{sup -}. The D{sup 0} and the {bar D}{sup 0} mesons are reconstructed in the final states f = K{sup +} {pi}{sup -}, K{sup +}{pi}{sup -}{pi}{sup 0}, K{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -} and their charge conjugates. Using a sample of 465 million B{bar B} pairs collected with the BABAR detector at PEP-II asymmetric-energy e{sup +}e{sup -} collider at SLAC, we measure the ratio R{sub ADS} {triple_bond} [{Lambda}({bar B}{sup 0} {yields} [f]{sub D}{barmore » K}*{sup 0}) + {Lambda}(B{sup 0} {yields} [{bar f}]{sub D}K*{sup 0})]/[{Lambda}({bar B}{sup 0} {yields} [{bar f}]{sub D}{bar K}*{sup 0}) + {Lambda}(B{sup 0} {yields} [f]{sub D}K*{sup 0})] for the three final states. We do not find significant evidence for a signal and set the following limits at 95% probability: R{sub ADS}(K{pi}) < 0.244, R{sub ADS}(K{pi}{pi}{sup 0}) < 0.181 and R{sub ADS}(K{pi}{pi}{pi}) < 0.391. From the combination of these three results, we find that the ratio r{sub S} between the b {yields} u and the b {yields} c amplitudes lies in the range [0.07; 0.41] at 95% probability.« less

Starspot evolution, differential rotation, and magnetic cycles in the chromospherically active binaries lambda andromedae, sigma Geminorum, II Pegasi, and V711 Tauri

NASA Technical Reports Server (NTRS)

Henry, Gregory W.; Eaton, Joel A.; Hamer, Jamesia; Hall, Douglas S.

1995-01-01

We have analyzed 15-19 yr of photoelectric photometry, obtained manually and with automated telescopes, of the chromospherically active binaries lambda And, sigma Gem, II Peg, and V711 Tau. These observations let us identify individual dark starspots on the stellar surfaces from periodic dimming of the starlight, follow the evolution of these spots, and search for long-term cyclic changes in the properties of these starspots that might reveal magnetic cycles analogous to the Sun's 11 yr sunspot cycle. We developed a computer code to fit a simple two-spot model to our observed light curves that allows us to extract the most easily determinable and most reliable spot parameters from the light curves, i.e., spot longitudes and radii. We then used these measured properties to identify individual spots and to chart their life histories by constructing migration and amplitude curves. We identified and followed 11 spots in lambda And, 16 in sigma Gem, 12 in II Peg, and 15 in V711 Tau. Lifetimes of individual spots ranged from a few months to longer than 6 yr. Differential rotation coefficients, estimated from the observed range of spot rotation periods for each star and defined by equation (2), were 0.04 for lambda And, 0.038 for sigma Gem, 0.005 for II Peg, and 0.006 for V711 Tau, versus 0.19 for the Sun. We searched for cyclic changes in mean brightness, B-V color index, and spot rotation period as evidence for long-term cycles. Of these, long-term variability in mean brightness appears to offer the best evidence for such cycles in these four stars. Cycles of 11.1 yr for lambda And, 8.5 yr for sigma Gem, 11 yr for II Peg, and 16 yr V711 Tau are implied by these mean brightness changes. Cyclic changes in spot rotation period were found in lambda And and possibly II Peg. Errors in B-V were too large for any long-term changes to be detectable.

Theoretical Study of the B(sup 3) Sigma(sup -, sub u) - X(sup3)Sigma(sub g, sup -) and B"(sup 3)Pi(sub u) - X(sup 3)Sigma(sub g, sup -) Band Systems of S(sub 2)

NASA Technical Reports Server (NTRS)

Pradhan, Atul D.; Partridge, Harry; Langhoff, Stephen R. (Technical Monitor)

1995-01-01

Multireference configuration-interaction (MRCI) wavefunctions and potential energy curves have been calculated for the X(sup 3)Sigma(sub g,sup -), B(sup 3)Sigma(sub u, Sup -) and B"(sup 3)Pi((sub u) states of S(sub 2) using correlation consistent Gaussian basis sets. These wavefunctions are utilized to compute the the transition dipole moments of the B(sup 3)Sigma(sub g, sup -) - X(sup 3) Sigma(sub g, sup -) and B"(sup 3)Pi(sub u) - X(sup 3)Sigma(sub g, sup -) systems. Oscillator strengths, transition probabilities, and radiative lifetimes are computed for the X-B system and comparison is made with experimental data.

Enhanced peculiar velocities in brane-induced gravity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wyman, Mark; Khoury, Justin

The mounting evidence for anomalously large peculiar velocities in our Universe presents a challenge for the {Lambda}CDM paradigm. The recent estimates of the large-scale bulk flow by Watkins et al. are inconsistent at the nearly 3{sigma} level with {Lambda}CDM predictions. Meanwhile, Lee and Komatsu have recently estimated that the occurrence of high-velocity merging systems such as the bullet cluster (1E0657-57) is unlikely at a 6.5-5.8{sigma} level, with an estimated probability between 3.3x10{sup -11} and 3.6x10{sup -9} in {Lambda}CDM cosmology. We show that these anomalies are alleviated in a broad class of infrared-modifed gravity theories, called brane-induced gravity, in which gravitymore » becomes higher-dimensional at ultralarge distances. These theories include additional scalar forces that enhance gravitational attraction and therefore speed up structure formation at late times and on sufficiently large scales. The peculiar velocities are enhanced by 24-34% compared to standard gravity, with the maximal enhancement nearly consistent at the 2{sigma} level with bulk flow observations. The occurrence of the bullet cluster in these theories is {approx_equal}10{sup 4} times more probable than in {Lambda}CDM cosmology.« less

Intensity formulas for triplet bands

NASA Technical Reports Server (NTRS)

Budo, A.

1982-01-01

Previous work in this area is surveyed and the mathematics involved in determining the quantitative intensity measurements in triplet bands is presented. Explicit expressions for the intensity distribution in the branches of the 3 Sigma-3 Pi and 1 Sigma-3Pi bands valid for all values of the coupling constant Y of the 3 Pi terms are given. The intensity distribution calculated according to the formulas given is compared with measurements of PH, 3 Pi-3 Sigma. Good quantitative agreement is obtained.

The electromagnetic Sigma-to-Lambda hyperon transition form factors at low energies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Granados, Carlos; Leupold, Stefan; Perotti, Elisabetta

Using dispersion theory the low-energy electromagnetic form factors for the transition of a Sigma to a Lambda hyperon are related to the pion vector form factor. The additionally required input, i.e. the two-pion-Sigma-Lambda amplitudes are determined from relativistic next-to-leading-order (NLO) baryon chiral perturbation theory including the baryons from the octet and optionally from the decuplet. Pion rescattering is again taken into account by dispersion theory. It turns out that the inclusion of decuplet baryons is not an option but a necessity to obtain reasonable results. The electric transition form factor remains very small in the whole low-energy region. The magneticmore » transition form factor depends strongly on one not very well determined low-energy constant of the NLO Lagrangian. Furthermore, one obtains reasonable predictive power if this low-energy constant is determined from a measurement of the magnetic transition radius. Such a measurement can be performed at the future Facility for Antiproton and Ion Research (FAIR).« less

The electromagnetic Sigma-to-Lambda hyperon transition form factors at low energies

DOE PAGES

Granados, Carlos; Leupold, Stefan; Perotti, Elisabetta

2017-06-09

Using dispersion theory the low-energy electromagnetic form factors for the transition of a Sigma to a Lambda hyperon are related to the pion vector form factor. The additionally required input, i.e. the two-pion-Sigma-Lambda amplitudes are determined from relativistic next-to-leading-order (NLO) baryon chiral perturbation theory including the baryons from the octet and optionally from the decuplet. Pion rescattering is again taken into account by dispersion theory. It turns out that the inclusion of decuplet baryons is not an option but a necessity to obtain reasonable results. The electric transition form factor remains very small in the whole low-energy region. The magneticmore » transition form factor depends strongly on one not very well determined low-energy constant of the NLO Lagrangian. Furthermore, one obtains reasonable predictive power if this low-energy constant is determined from a measurement of the magnetic transition radius. Such a measurement can be performed at the future Facility for Antiproton and Ion Research (FAIR).« less

Ab initio calculation of the electronic structures of the (7)Sigma+ ground and A (7)Pi and a (5)Sigma+ excited states of MnH.

PubMed

Tomonari, Mutsumi; Nagashima, Umpei; Hirano, Tsuneo

2009-04-21

Electronic structures and molecular constants of the ground (7)Sigma(+) and low-lying A (7)Pi and a (5)Sigma(+) electronic excited states of the MnH molecule were studied by multireference single and double excitation configuration interaction (MR-SDCI) with Davidson's correction (+Q) calculations under exact C(infinity v) symmetry using Slater-type basis sets. To correctly describe the (7)Sigma(+) electronic ground state, X (7)Sigma(+), at the MR-SDCI+Q calculation, we employed a large number of reference configurations in terms of the state-averaged complete active space self-consistent field (CASSCF) orbitals, taking into account the contribution from the B (7)Sigma(+) excited state. The A (7)Pi and a (5)Sigma(+) states can well be described by the MR-SDCI wave functions based on the CASSCF orbitals obtained for the lowest state only. In the MR-SDCI+Q, calculations of the X (7)Sigma(+), A (7)Pi, and a (5)Sigma(+) states required 16, 7, and 17 reference configurations, respectively. Molecular constants, i.e., r(e) and omega(e) of these states and excitation energy from the X (7)Sigma(+) state, obtained at the MR-SDCI+Q level, showed a good agreement with experimental values. The small remaining differences may be accounted for by taking relativistic effects into account.

CLAS N* Excitation Results from Pion and Kaon Electroproduction

DOE PAGES

Carman, Daniel S.

2018-05-24

The study of the structure of excited nucleonmore » $N^*$ states employing the electroproduction of exclusive reactions is an important avenue for exploring the nature of the non-perturbative strong interaction. The electrocouplings of $N^*$ states in the mass range below $W$=1.8~GeV have been determined from analyses of CLAS $$\\pi N$$, $$\\eta N$$, and $$\\pi \\pi N$$ data at four-momentum transfers $Q^2$ up to 5~GeV$^2$. The work has made it clear that consistent results from independent analyses of several exclusive channels with different couplings and non-resonant backgrounds but the same $N^*$ electroexcitation amplitudes, is essential to have confidence in the extracted results. In terms of hadronic couplings, many high-lying $N^*$ states preferentially decay through the $$\\pi \\pi N$$ channel, while couplings to $$\\pi N$$ final states become rather small. The resonance parameters determined from $$\\pi N$$ and $$\\pi \\pi N$$ electroproduction can be checked in independent studies of the $KY$ ($$Y = \\Lambda, \\Sigma^0$$) channels. Therefore, data from the $KY$ channels already measured with CLAS will play an important role in $N^*$ structure studies. These comparisons await the development of suitable reaction models. Starting in 2018, a program to study the structure of $N^*$ states in various exclusive electroproduction channels using the new CLAS12 spectrometer will get underway. These studies will probe the structure of $N^*$ states in the mass range up to $W$=3~GeV and $Q^2$ up to 12~GeV$^2$, thus providing a means to access $N^*$ structure information spanning a broad regime encompassing both low- and high-energy degrees of freedom.« less

CLAS N* Excitation Results from Pion and Kaon Electroproduction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carman, Daniel S.

The study of the structure of excited nucleonmore » $N^*$ states employing the electroproduction of exclusive reactions is an important avenue for exploring the nature of the non-perturbative strong interaction. The electrocouplings of $N^*$ states in the mass range below $W$=1.8~GeV have been determined from analyses of CLAS $$\\pi N$$, $$\\eta N$$, and $$\\pi \\pi N$$ data at four-momentum transfers $Q^2$ up to 5~GeV$^2$. The work has made it clear that consistent results from independent analyses of several exclusive channels with different couplings and non-resonant backgrounds but the same $N^*$ electroexcitation amplitudes, is essential to have confidence in the extracted results. In terms of hadronic couplings, many high-lying $N^*$ states preferentially decay through the $$\\pi \\pi N$$ channel, while couplings to $$\\pi N$$ final states become rather small. The resonance parameters determined from $$\\pi N$$ and $$\\pi \\pi N$$ electroproduction can be checked in independent studies of the $KY$ ($$Y = \\Lambda, \\Sigma^0$$) channels. Therefore, data from the $KY$ channels already measured with CLAS will play an important role in $N^*$ structure studies. These comparisons await the development of suitable reaction models. Starting in 2018, a program to study the structure of $N^*$ states in various exclusive electroproduction channels using the new CLAS12 spectrometer will get underway. These studies will probe the structure of $N^*$ states in the mass range up to $W$=3~GeV and $Q^2$ up to 12~GeV$^2$, thus providing a means to access $N^*$ structure information spanning a broad regime encompassing both low- and high-energy degrees of freedom.« less

Measurement of the Lambda b0 lifetime in Lambda b0-->J/psi Lambda 0 in pp collisions at square root s=1.96 TeV.

PubMed

Abulencia, A; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Ambrose, D; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arguin, J-F; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Bedeschi, F; Behari, S; Belforte, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Budroni, S; Burkett, K; Busetto, G; Bussey, P; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carrillo, S; Carlsmith, D; Carosi, R; Carron, S; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Ciljak, M; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Coca, M; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Cully, J C; Cyr, D; DaRonco, S; D'Auria, S; Davies, T; D'Onofrio, M; Dagenhart, D; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; Dell'Orso, M; Delli Paoli, F; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; DiTuro, P; Dörr, C; Donati, S; Donega, M; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, I; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Field, R; Flanagan, G; Foland, A; Forrester, S; Foster, G W; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Garberson, F; Garfinkel, A F; Gay, C; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, A; Gibson, K; Gimmell, J L; Ginsburg, C; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Griffiths, M; Grinstein, S; Grosso-Pilcher, C; Group, R C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Holloway, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ishizawa, Y; Ivanov, A; Iyutin, B; James, E; Jang, D; Jayatilaka, B; Jeans, D; Jensen, H; Jeon, E J; Jindariani, S; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Karchin, P E; Kato, Y; Kemp, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kovalev, A; Kraan, A C; Kraus, J; Kravchenko, I; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kusakabe, Y; Kwang, S; Laasanen, A T; Labarga, L; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; LeCompte, T; Lee, J; Lee, J; Lee, Y J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lin, C S; Lindgren, M; Lipeles, E; Liss, T M; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Loverre, P; Lu, R-S; Lucchesi, D; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; MacQueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Manca, G; Margaroli, F; Marginean, R; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Maruyama, T; Mastrandrea, P; Masubuchi, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyamoto, A; Moed, S; Moggi, N; Mohr, B; Moore, R; Morello, M; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Nachtman, J; Nagano, A; Naganoma, J; Nahn, S; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nigmanov, T; Nodulman, L; Norniella, O; Nurse, E; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagliarone, C; Palencia, E; Papadimitriou, V; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Piedra, J; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Portell, X; Poukhov, O; Pounder, N; Prokoshin, F; Pronko, A; Proudfoot, J; Ptochos, F; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ranjan, N; Rappoccio, S; Reisert, B; Rekovic, V; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Sabik, S; Safonov, A; Sakumoto, W K; Salamanna, G; Saltó, O; Saltzberg, D; Sánchez, C; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savard, P; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sfyrla, A; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Sjolin, J; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spinella, F; Spreitzer, T; Squillacioti, P; Stanitzki, M; Staveris-Polykalas, A; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sun, H; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Takikawa, K; Tanaka, M; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Tesarek, R J; Thom, J; Thompson, A S; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tsuchiya, R; Tsuno, S; Turini, N; Ukegawa, F; Unverhau, T; Uozumi, S; Usynin, D; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Veramendi, G; Veszpremi, V; Vidal, R; Vila, I; Vilar, R; Vine, T; Vollrath, I; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner, J; Wagner, W; Wallny, R; Wang, S M; Warburton, A; Waschke, S; Waters, D; Weinberger, M; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Yagil, A; Yamamoto, K; Yamaoka, J; Yamashita, T; Yang, C; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zhang, X; Zhou, J; Zucchelli, S

2007-03-23

We report a measurement of the Lambda b0 lifetime in the exclusive decay Lambda b0-->J/psi Lambda 0 in pp collisions at square root s=1.96 TeV using an integrated luminosity of 1.0 fb-1 of data collected by the CDF II detector at the Fermilab Tevatron. Using fully reconstructed decays, we measure tau(Lambda b0)=1.593(-0.078)(+0.083)(stat)+/-0.033(syst) ps. This is the single most precise measurement of tau(Lambda b0) and is 3.2sigma higher than the current world average.

Benchmarking electronic-state excitation cross sections for electron-N{sub 2} collisions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kato, Hidetoshi; Suzuki, Daisuke; Ohkawa, Mizuha

2010-04-15

We report differential cross sections for electron impact excitation of the a {sup 1{Pi}}{sub g}, C {sup 3{Pi}}{sub u}, E {sup 3{Sigma}}{sub g}{sup +}, a{sup ''} {sup 1{Sigma}}{sub g}{sup +}, b {sup 1{Pi}}{sub u}, c{sub 3} {sup 1{Pi}}{sub u}, o{sub 3} {sup 1{Pi}}{sub u}, b{sup '} {sup 1{Sigma}}{sub u}{sup +}, c{sub 4}{sup '} {sup 1{Sigma}}{sub u}{sup +}, G {sup 3{Pi}}{sub u}, and F {sup 3{Pi}}{sub u} electronic states in N{sub 2}. The incident electron energies are 20, 30, and 40 eV, while the scattered electron angles are 10 deg. and 20 deg. These kinematic conditions were specifically targeted in ordermore » to try and shed new light on the worrying discrepancies that exist in the literature for the a {sup 1{Pi}}{sub g}, C {sup 3{Pi}}{sub u}, E {sup 3{Sigma}}{sub g}{sup +}, and a{sup ''} {sup 1{Sigma}}{sub g}{sup +} cross sections, and in general the present measurements confirm that those from the more recent results of the University of California, Fullerton, and the Jet Propulsion Laboratory [M. A. Khakoo, P. V. Johnson, I. Ozkay, P. Yan, S. Trajmar, and I. Kanik, Phys. Rev. A 71, 062703 (2005); C. P. Malone, P. V. Johnson, I. Kanik, B. Ajdari, and M. A. Khakoo, Phys. Rev. A 79, 032704 (2009)] are reliable. In addition, we provide a rigorous cross-check for the remaining seven electronic states, where the only recent comprehensive study is from Khakoo and colleagues [Phys. Rev. A 77, 012704 (2008)]. Here, however, some of those cross sections are confirmed and others are not, suggesting that further work is still needed.« less

Experimental Study of the NaK 3(1)Pi State.

PubMed

Laub; Mazsa; Webb; La Civita J; Prodan; Jabbour; Namiotka; Huennekens

1999-02-01

We report the results of an optical-optical double resonance experiment to determine the NaK 3(1)Pi state potential energy curve. In the first step, a narrow band cw dye laser (PUMP) is tuned to line center of a particular 2(A)1Sigma+(v', J') <-- 1(X)1Sigma+(v", J") transition, and its frequency is then fixed. A second narrowband tunable cw Ti:Sapphirelaser (PROBE) is then scanned, while 3(1)Pi --> 1(X)1Sigma+ violet fluorescence is monitored. The Doppler-free signals accurately map the 3(1)Pi(v, J) ro-vibrational energy levels. These energy levels are then fit to a Dunham expansion to provide a set of molecular constants. The Dunham constants, in turn, are used to construct an RKR potential curve. Resolved 3(1)Pi(v, J) --> 1(X)1Sigma+(v", J") fluorescence scans are also recorded with both PUMP and PROBE laser frequencies fixed. Comparison between observed and calculated Franck-Condon factors is used to determine the absolute vibrational numbering of the 3(1)Pi state levels and to determine the variation of the 3(1)Pi --> 1(X)1Sigma+ transitiondipole moment with internuclear separation. The recent theoretical calculation of the NaK 3(1)Pi state potential reported by Magnier and Millié (1996, Phys. Rev. A 54, 204) is in excellent agreement with the present experimental RKR curve. Copyright 1999 Academic Press.

Studies of molecular physics in sodium-potassium: An analysis of the 4(3)Sigma+ state and interactions between the 2(A)(1)Sigma+ and 1(b)(3)Pi states

NASA Astrophysics Data System (ADS)

Burns, Patrick

2004-12-01

In this dissertation we report the results of three experiments designed to provide new information on the structure and interactions of the NaK molecule. Specifically these experiments investigate 2(A)1Sigma +(upsilonA, J) + M → 1(b)3 pi0(upsilonb, J) + M collisional excitation transfers (where M is a collision partner), hyperfine structure of the NaK 1(b)3pi and 1(b)3pi0 ˜ 2(A)1Sigma+ spin-orbit interactions, and the structure and spectra of the NaK 43Sigma+ state, respectively. In this first experiment, populations of collisionally populated levels were recorded near the NaK 1(b)3pi0(upsilon =18, J = 44) ˜ 2(A)1Sigma+ (upsilon = 20, J = 44) center of spin-orbit perturbation. Our data indicate that population is transferred from the pumped level, 2(A) 1Sigma+(upsilon = 20, J = 49), directly to the surrounding "daughter" levels [1(b)3Sigma 0(upsilon =18, J = 45--48) and 2(A)1Sigma +(upsilon = 20, J = 45--48)]. The relative populations of the daughter levels appear anomalous, as their populations do not monotonically decrease for levels further away in energy from the pumped level. We have measured the hyperfine structure of mutually perturbing ro-vibrational levels of the 1(b)3pi0 and 2(A)1Sigma + states of the NaK molecule, using the PFOODR method with co-propagating lasers. Unperturbed 1(b)3pi0 levels are split into four hyperfine components by the Fermi contact interaction b FI·S. Mixing between the 1(b)3pi0 and 2(A)1Sigma + levels imparts hyperfine structure to the nominally singlet component, and reduces the hyperfine splitting of the nominally triplet component, of the perturbed levels. We determined a value for the Fermi constant, bF= (0.00989 +/- 0.00027) cm-1, and the magnitude of the electronic part of the 1(b)3pi 0 ˜ 2(A)1Sigma+ spin-orbit coupling, |Hel| = (15.65 +/- 0.14) cm-1 , from an analysis of the measured hyperfine splittings of the mixed singlet-triplet levels. High-resolution spectra have been observed for numerous vibrational-rotational levels (upsilon, N) of the 43Sigma + state of NaK. A potential curve was obtained from the data using the inverse perturbation approximation method. Measured bound-free emission, 43Sigma+ → 1(a)3Sigma +, was used to determine both the absolute vibrational numbering and the transition dipole moment function M(R). Each (upsilon, N) level is typically split into three sets of sublevels by the Fermi contact interaction bFI·S. Further splitting (of order 0.004 cm-1) has been attributed to the spin-rotation interaction gammaN·S. The values of bF that fit the data best are ˜(0.99 +/- 0.04) x 10-2 cm-1, with weak dependence on upsilon. The best fit values of gamma are in the range 1--6 x 10-4 cm-1 and depend strongly on upsilon.

Observation of the $$\\Xi_b^0$$ Baryon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aaltonen, T.; /Helsinki Inst. of Phys.; Alvarez Gonzalez, B.

The observation of the bottom, strange baryon {Xi}{sup 0}{sub b} through the decay chain {Xi}{sup 0}{sub b} {yields} {Xi}{sup +}{sub c} {pi}{sup -}, where {Xi}{sup +}{sub c} {yields} {Xi}{sup -} {pi}{sup +} {pi}{sup +}, {Xi}{sup -} {yields} {Lambda} {yields} p {pi}{sup -}, is reported using data corresponding to an integrated luminosity of 4.2 ft{sup -1} from p{anti p} collisions at {radical}{ovr s} = 1.96 TeV recorded with the Collider Detector at Fermilab. A signal of 25.3{sup +5.6}{sub -5.4} candidates is observed whose probability of arising from a background fluctuation is 3.6 x 10{sup -12}, corresponding to 6.8 Gaussian standard deviations.more » The {Xi}{sup 0}{sub b} mass is measured to be 5787.8 {+-} 5.0(stat) {+-} 1.3(syst) MeV/c{sup 2}. In addition, the {Xi}{sup -}{sub b} is observed through the process {Xi}{sup -}{sub b} {yields} {Xi}{sup 0}{sub c} {pi}{sup -}, where {Xi}{sup 0}{sub c} {yields} {Xi}{sup -} {pi}{sup +}, {Xi}{sup -} {yields} {Lambda} {pi}{sup -}, and {Lambda} {yields} p {pi}{sup -}.« less

Simple model for lambda-doublet propensities in bimolecular reactions

NASA Technical Reports Server (NTRS)

Bronikowski, Michael J.; Zare, Richard N.

1990-01-01

A simple geometric model is presented to account for lambda-doublet propensities in bimolecular reactions A + BC - AB + C. It applies to reactions in which AB is formed in a pi state, and in which the unpaired molecular orbital responsible for lambda-doubling arises from breaking the B-C bond. The lambda-doublet population ratio is predicted to be 2:1 provided that: (1) the motion of A in the transition state determines the plane of rotation of AB; (2) the unpaired pi orbital lying initially along the B-C bond may be resolved into a projection onto the AB plane of rotation and a projection perpendicular to this plane; (3) there is no preferred geometry for dissociation of ABC. The 2:1 lambda-doublet ratio is the 'unconstrained dynamics prior' lambda-doublet distribution for such reactions.

Optical characterization of the oceanic unicellular cyanobacterium Synechococcus grown under a day-night cycle in natural irradiance

NASA Technical Reports Server (NTRS)

Stramski, Dariusz; Shalapyonok, Alexi; Reynolds, Rick A.

1995-01-01

The optical properties of the ocenanic cyanobacterium Synechococcus (clone WH8103) were examined in a nutrient-replete laboratory culture grown under a day-night cycle in natural irradiance. Measurements of the spectral absorption and beam attenuation coefficients, the size distribution of cells in suspension, and microscopic analysis of samples were made at intervals of 2-4 hours for 2 days. These measurements were used to calculate the optical properties at the level of a single 'mean' cell representative of the acutal population, specifically, the optical cross sections for spectral absorption bar-(sigma(sub a)), scattering bar-sigma(sub b))(lambda), and attentuation bar-(sigma(sub c))(lambda). In addition, concurrent determinations of chlorophyll a and particulate organic carbon allowed calculation of the Chl a- and C-specific optical coefficients. The refractive index of cells was derived from the observed data using a theory of light absorption and scattering by homogeneous spheres. Low irradiance because of cloudy skies resulted in slow division rates of cells in the culture. The percentage of dividing cells was unusually high (greater than 30%) throughout the experiment. The optical cross sections varied greatly over a day-night cycle, with a minimum near dawn or midmorning and maximum near dusk. During daylight hours, bar-(sigma(sub b)) and bar-(sigma(sub c)) can increase more than twofold and bar-(sigma(sub a) by as much as 45%. The real part of the refractive index n increaed during the day; changes in n had equal or greater effect than the varying size distribution on changes in bar-(sigma(sub c)) and bar-(sigma(sub b)). The contribution of changes in n to the increase of bar-(sigma(sub c))(660) during daylight hours was 65.7% and 45.1% on day 1 and 2, respectively. During the dark period, when bar-(sigma(sub c))(660) decreased by a factor of 2.9, the effect of decreasing n was dominant (86.3%). With the exception of a few hours during the second light period, the imaginary part of the refractive index n' showed little variation over a day-night cycle, and bar-(sigma(sub a)) was largely controlled by variations in cell size. The real part of the refractive index at lambda = 660 nm was correlated with the intracellular C concentration and the imaginary part at lambda = 678 nm with the intracellular Chl a concentration. The C-specfic attenuation coefficient showed significant diel variability, which has implications for the estimation of oceanic primary production from measurements of diel variability in beam attenuation. This study provides strong evidence that diel variability is an important component of the optical characterization of marine phytoplankton.

Explicit Substitutions and All That

NASA Technical Reports Server (NTRS)

Ayala-Rincon, Mauricio; Munoz, Cesar

2000-01-01

Explicit substitution calculi are extensions of the lambda-calculus where the substitution mechanism is internalized into the theory. This feature makes them suitable for implementation and theoretical study of logic-based tools such as strongly typed programming languages and proof assistant systems. In this paper we explore new developments on two of the most successful styles of explicit substitution calculi: the lambda sigma- and lambda S(e)-calculi.

Explicit Substitutions and All That

NASA Technical Reports Server (NTRS)

Ayala-Rincon, Mauricio; Munoz, Cesar; Busnell, Dennis M. (Technical Monitor)

2000-01-01

Explicit substitution calculi are extensions of the Lambda-calculus where the substitution mechanism is internalized into the theory. This feature makes them suitable for implementation and theoretical study of logic-based tools such as strongly typed programming languages and proof assistant systems. In this paper we explore new developments on two of the most successful styles of explicit substitution calculi: the lambda(sigma)- and lambda(s(e))-calculi.

Partially pre-calculated weights for the backpropagation learning regime and high accuracy function mapping using continuous input RAM-based sigma-pi nets.

PubMed

Neville, R S; Stonham, T J; Glover, R J

2000-01-01

In this article we present a methodology that partially pre-calculates the weight updates of the backpropagation learning regime and obtains high accuracy function mapping. The paper shows how to implement neural units in a digital formulation which enables the weights to be quantised to 8-bits and the activations to 9-bits. A novel methodology is introduced to enable the accuracy of sigma-pi units to be increased by expanding their internal state space. We, also, introduce a novel means of implementing bit-streams in ring memories instead of utilising shift registers. The investigation utilises digital "Higher Order" sigma-pi nodes and studies continuous input RAM-based sigma-pi units. The units are trained with the backpropagation learning regime to learn functions to a high accuracy. The neural model is the sigma-pi units which can be implemented in digital microelectronic technology. The ability to perform tasks that require the input of real-valued information, is one of the central requirements of any cognitive system that utilises artificial neural network methodologies. In this article we present recent research which investigates a technique that can be used for mapping accurate real-valued functions to RAM-nets. One of our goals was to achieve accuracies of better than 1% for target output functions in the range Y epsilon [0,1], this is equivalent to an average Mean Square Error (MSE) over all training vectors of 0.0001 or an error modulus of 0.01. We present a development of the sigma-pi node which enables the provision of high accuracy outputs. The sigma-pi neural model was initially developed by Gurney (Learning in nets of structured hypercubes. PhD Thesis, Department of Electrical Engineering, Brunel University, Middlessex, UK, 1989; available as Technical Memo CN/R/144). Gurney's neuron models, the Time Integration Node (TIN), utilises an activation that was derived from a bit-stream. In this article we present a new methodology for storing sigma-pi node's activations as single values which are averages. In the course of the article we state what we define as a real number; how we represent real numbers and input of continuous values in our neural system. We show how to utilise the bounded quantised site-values (weights) of sigma-pi nodes to make training of these neurocomputing systems simple, using pre-calculated look-up tables to train the nets. In order to meet our accuracy goal, we introduce a means of increasing the bandwidth capability of sigma-pi units by expanding their internal state-space. In our implementation we utilise bit-streams when we calculate the real-valued outputs of the net. To simplify the hardware implementation of bit-streams we present a method of mapping them to RAM-based hardware using 'ring memories'. Finally, we study the sigma-pi units' ability to generalise once they are trained to map real-valued, high accuracy, continuous functions. We use sigma-pi units as they have been shown to have shorter training times than their analogue counterparts and can also overcome some of the drawbacks of semi-linear units (Gurney, 1992. Neural Networks, 5, 289-303).

Observation of psi(3770) --> pi pi J/psi and measurement of Gamma ee[psi(2S)].

PubMed

Adam, N E; Alexander, J P; Berkelman, K; Cassel, D G; Crede, V; Duboscq, J E; Ecklund, K M; Ehrlich, R; Fields, L; Galik, R S; Gibbons, L; Gittelman, B; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Meyer, T O; Onyisi, P U E; Patterson, J R; Peterson, D; Phillips, E A; Pivarski, J; Riley, D; Ryd, A; Sadoff, A J; Schwarthoff, H; Shi, X; Shepherd, M R; Stroiney, S; Sun, W M; Urner, D; Wilksen, T; Weaver, K M; Weinberger, M; Athar, S B; Avery, P; Breva-Newell, L; Patel, R; Potlia, V; Stoeck, H; Yelton, J; Rubin, P; Cawlfield, C; Eisenstein, B I; Gollin, G D; Karliner, I; Kim, D; Lowrey, N; Naik, P; Sedlack, C; Selen, M; White, E J; Williams, J; Wiss, J; Asner, D M; Edwards, K W; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Gong, D T; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Li, S Z; Poling, R; Scott, A W; Smith, A; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Zweber, P; Ernst, J; Severini, H; Dytman, S A; Love, W; Mehrabyan, S; Mueller, J A; Savinov, V; Li, Z; Lopez, A; Mendez, H; Ramirez, J; Huang, G S; Miller, D H; Pavlunin, V; Sanghi, B; Shipsey, I P J; Adams, G S; Anderson, M; Cummings, J P; Danko, I; Napolitano, J; He, Q; Muramatsu, H; Park, C S; Thorndike, E H; Coan, T E; Gao, Y S; Liu, F; Artuso, M; Boulahouache, C; Blusk, S; Butt, J; Dorjkhaidav, O; Li, J; Menaa, N; Mountain, R; Nandakumar, R; Randrianarivony, K; Redjimi, R; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Zhang, K; Csorna, S E; Bonvicini, G; Cinabro, D; Dubrovin, M; Briere, R A; Chen, G P; Chen, J; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L

2006-03-03

We observe signals for the decays psi(3770) --> XJ/psi from data acquired with the CLEO detector operating at the CESR e+ e- collider with square root of s = 3773 MeV. We measure the following branching fractions Beta(psi(3770) --> XJ/psi and significances: (189 +/- 20 +/- 20) x 10(-5) (11.6sigma) for X = pi+ pi-, (80 +/- 25 +/- 16) x 10(-5) (3.4sigma) for X = pi0 pi0, and (87 +/- 33 +/- 22) x 10(-5) (3.5sigma) for X = eta, where the errors are statistical and systematic, respectively. The radiative return process e+ e- --> gamma psi(2S) populates the same event sample and is used to measure Gamma ee[psi(2S)] = (2.54 +/- 0.03 +/- 0.11) keV.

Differential cross sections for the electron impact excitation of the A {sup 3}{sigma}{sub u}{sup +}, B {sup 3}{pi}{sub g}, W {sup 3}{delta}{sub u}, B{sup '} {sup 3}{sigma}{sub u}{sup -}, a{sup '} {sup 1}{sigma}{sub u}{sup -}, a {sup 1}{pi}{sub g}, w {sup 1}{delta}{sub u}, and C {sup 3}{pi}{sub u} states of N{sub 2}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khakoo, M.A.; Ozkay, I.; Johnson, P.V.

2005-06-15

Measurements of differential cross sections for the electron-impact excitation of molecular nitrogen from the ground X {sup 1}{sigma}{sub g}{sup +}(v{sup ''}=0) level to the A {sup 3}{sigma}{sub u}{sup +}(v{sup '}), B {sup 3}{pi}{sub g}(v{sup '}), W {sup 3}{delta}{sub u}(v{sup '}), B{sup '} {sup 3}{sigma}{sub u}{sup -}(v{sup '}), a{sup '} {sup 1}{sigma}{sub u}{sup -}(v{sup '}), a {sup 1}{pi}{sub g}(v{sup '}), w {sup 1}{delta}{sub u}(v{sup '}), and C {sup 3}{pi}{sub u}(v{sup '}) levels are presented. The data are obtained at the incident energies of 10, 12.5, 15, 17.5, 20, 30, 50, and 100 eV over the angular range of 5 deg. -130more » deg. in 5 deg. intervals. The individual electronic state excitation differential cross sections are obtained by unfolding electron energy-loss spectra of molecular nitrogen using available semiempirical Frank-Condon factors. The data are compared to previous measurements and to available theory. We also make several important suggestions regarding future work that, like the present, relies on the unfolding of electron energy-loss spectra for obtaining differential cross sections.« less

Correlation Measurement of Lambda-anti-Lambda, Lambda-Lambda and anti-Lambda-anti-Lambda with the ATLAS detector at s=7 TeV

NASA Astrophysics Data System (ADS)

Cheng, Hok-Chuen

This thesis summaries the measurements of correlations between Lambda 0Lambda0, Lambda0Lambda 0, and Lambda0Lambda 0 hyperon pairs produced inclusively at the LHC, which are useful for a better understanding of the quark-antiquark pair production and jet fragmentation and hadronization processes. The analysis is based on hyperon pairs selected using the muon and minimum bias data samples collected at the ATLAS experiment from proton-proton collisions at a center-of-mass energy of 7 TeV in 2010. Excess Lambda0Lambda 0 are observed near the production threshold and are identified to be originated from the parton system in the string model in the MC sample, decaying either directly or through heavy strange resonances such as Sigma0 and Sigma*(1385). Dynamical correlations have been explored through a correlation function defined as the ratio of two-particle to single-particle densities. Positive correlation is observed for Lambda0Lambda0 and anticorrelation is observed for Lambda0Lambda 0 and Lambda0Lambda 0 for Q in [0,2] GeV. The structure replicates similar correlations in pp, pp, and pppp events in PYTHIA generator as predicted by the Lund string fragmentation model. Parameters of the "popcorn" mechanism implemented in the PYTHIA generator are tuned and are found to have little impact on the structure observed. The spin composition of the sample is extracted using a data-driven reference sample built by event mixing. Appropriate corrections have been made to the kinematic distributions in the reference sample by kinematic weighting to make sure that the detector effects are well modeled. A modified Pearson's chi2 test statistics is calculated for the costheta* distribution to determine the best-fitted A-value for data. The results are consistent with zero for both like-type and unlike-type hyperon pairs in Q ∈ [0,10] GeV and Q ∈ [1,10] GeV respectively. The data statistics in the range of Q ∈ [0, 1] GeV is currently too low for the estimation of the emitter size for Fermi-Dirac correlation.

Fully quantum-state resolved study of NO{sub 2} photodissociation. Correlated NO({sup 2}{Pi}{sub {Omega}}, {nu} = 0 J,A) + O({sup 3}P{sub j}) distributions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sanov, A.; Bieler, C.R.; Reisler, H.

1995-09-14

Relative O({sup 3}P{sub j} = 2.1.0) spin-orbit populations correlated with specific NO[{sup 2}{Pi}{sub {Omega}} = {1/2}, 3/2; {nu} = 0; f; {Lambda} = {Pi}(A{prime}), {Pi}(A{double_prime})] product states were obtained following photolysis of NO{sub 2} at excess energies E{sup {+-}} = 390, 425, and 1054 cm{sup -1}. These fully quantum state-resolved measurements were carried out by recording spatial profiles of recoiling NO({sup 2}{Pi}{sub {Omega}}, J, {Lambda}) products using polarized radiation for photolysis and state-selective laser ionization detection. The relative O({sup 3}P{sub j}) populations correlated with each NO({sup 2}{Pi}{sub {Omega}}, J, {Lambda}) state show marked fluctuations at each excess energy as amore » function of rotational state and {Lambda}-doublet component. The relative populations also fluctuate as a function of excess energy. The O({sup 3}P{sub j}) spin-orbit population ratios, when averaged over all measurements, exhibit distributions that are colder than statistical, in agreement with previous results. In particular, we find that, on average, O({sup 3}P{sub 1}):O({sup 3}P{sub 2}) population ratios correlated with the ground NO({sup 2}{Pi}{sub {1/2}}) state are colder than the corresponding ratios correlated with the excited NO({sup 2}{Pi}{sub 3/2}) spin-orbit state. These results are in agreement with the state-specific calculations of Katigiri and Kato. 45 refs., 12 figs., 3 tabs.« less

PWA prospects for K+Lambda and K+Sigma^0 photoproduction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biplab Dey, Michael E. McCracken, Curtis A. Meyer

2012-04-01

We present a status update on the CMU group PWA efforts in the strangeness (K{sup +}{Lambda}/K{sup +}{Sigma}{sup 0}) sector. The bulk of the currently available data comes from recently published CLAS g11a results, with extensive polarization data expected soon from the CLAS g8 and g9 set of experiments. We give a brief description of issues pertaining to different sign conventions for the polarization observables in the literature, and normalization discrepancies between the CLAS-g11a results and older high energy data from SLAC/CEA/DESY that used an untagged photon beam.

Theoretical study of the NO gamma system

NASA Technical Reports Server (NTRS)

Langhoff, Stephen R.; Bauschlicher, Charles W., Jr.; Partridge, Harry

1988-01-01

A systematic study of the NO gamma system with level of correlation treatment was carried out using large Gaussian basis sets to determine the potential curves for the X2Pi and A2Sigma(+) states of NO. It is shown that the A2Sigma-X2Pi electronic transition moment (gamma system) increases monotonically with decreasing internuclear distance and that the increase in the moment as r decreases is correlated with the increasing degree of diffuse character in the X2Pi state. The results of a study of the X2Pi and A2Sigma(+) dipole moment functions showed that the X2Pi vibrationally averaged dipole moments and the (1-0) and (2-0) vibration-rotation band intensities agree well with experimental data.

Measurement of the Lambdab0 lifetime in Lambdab0 --> Lambdac+pi- decays in pp collisions at square root of s = 1.96 TeV.

PubMed

Aaltonen, T; Adelman, J; Alvarez González, B; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Apresyan, A; Arisawa, T; Artikov, A; Asaadi, J; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Barria, P; Bartos, P; Bauer, G; Beauchemin, P-H; Bedeschi, F; Beecher, D; Behari, S; Bellettini, G; Bellinger, J; Benjamin, D; Beretvas, A; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Bridgeman, A; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Calancha, C; Camarda, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carls, B; Carlsmith, D; Carosi, R; Carrillo, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavaliere, V; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chou, J P; Chung, K; Chung, W H; Chung, Y S; Chwalek, T; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Compostella, G; Convery, M E; Conway, J; Corbo, M; Cordelli, M; Cox, C A; Cox, D J; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Cully, J C; Dagenhart, D; Datta, M; Davies, T; de Barbaro, P; De Cecco, S; Deisher, A; De Lorenzo, G; Dell'Orso, M; Deluca, C; Demortier, L; Deng, J; Deninno, M; d'Errico, M; Di Canto, A; di Giovanni, G P; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Dorigo, T; Dube, S; Ebina, K; Elagin, A; Erbacher, R; Errede, D; Errede, S; Ershaidat, N; Eusebi, R; Fang, H C; Farrington, S; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Ferrazza, C; Field, R; Flanagan, G; Forrest, R; Frank, M J; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garberson, F; Garcia, J E; Garfinkel, A F; Garosi, P; Gerberich, H; Gerdes, D; Gessler, A; Giagu, S; Giakoumopoulou, V; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C M; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Group, R C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, S R; Halkiadakis, E; Han, B-Y; Han, J Y; Happacher, F; Hara, K; Hare, D; Hare, M; Harr, R F; Hartz, M; Hatakeyama, K; Hays, C; Heck, M; Heinrich, J; Herndon, M; Heuser, J; Hewamanage, S; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Hou, S; Houlden, M; Hsu, S-C; Hughes, R E; Hurwitz, M; Husemann, U; Hussein, M; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; James, E; Jang, D; Jayatilaka, B; Jeon, E J; Jha, M K; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Kar, D; Karchin, P E; Kato, Y; Kephart, R; Ketchum, W; Keung, J; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, H W; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kreps, M; Kroll, J; Krop, D; Krumnack, N; Kruse, M; Krutelyov, V; Kuhr, T; Kulkarni, N P; Kurata, M; Kwang, S; Laasanen, A T; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; LeCompte, T; Lee, E; Lee, H S; Lee, J S; Lee, S W; Leone, S; Lewis, J D; Lin, C-J; Linacre, J; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, C; Liu, T; Lockyer, N S; Loginov, A; Lovas, L; Lucchesi, D; Lueck, J; Lujan, P; Lukens, P; Lungu, G; Lys, J; Lysak, R; MacQueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis-Katsikakis, A; Margaroli, F; Marino, C; Marino, C P; Martin, A; Martin, M S; Martin, V; Martínez, M; Martínez-Ballarín, R; Mastrandrea, P; Mathis, M; Mattson, M E; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzione, A; Mesropian, C; Miao, T; Mietlicki, D; Miladinovic, N; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyake, H; Moed, S; Moggi, N; Mondragon, M N; Moon, C S; Moore, R; Morello, M J; Morlock, J; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Nett, J; Neu, C; Neubauer, M S; Neubauer, S; Nielsen, J; Nodulman, L; Norman, M; Norniella, O; Nurse, E; Oakes, L; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Osterberg, K; Pagan Griso, S; Pagliarone, C; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramanov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Peiffer, T; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Pianori, E; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Potamianos, K; Poukhov, O; Prokoshin, F; Pronko, A; Ptohos, F; Pueschel, E; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Renton, P; Renz, M; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rodriguez, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Rutherford, B; Saarikko, H; Safonov, A; Sakumoto, W K; Santi, L; Sartori, L; Sato, K; Savoy-Navarro, A; Schlabach, P; Schmidt, A; Schmidt, E E; Schmidt, M A; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sforza, F; Sfyrla, A; Shalhout, S Z; Shears, T; Shepard, P F; Shimojima, M; Shiraishi, S; Shochet, M; Shon, Y; Shreyber, I; Simonenko, A; Sinervo, P; Sisakyan, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soha, A; Somalwar, S; Sorin, V; Squillacioti, P; Stanitzki, M; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Strycker, G L; Suh, J S; Sukhanov, A; Suslov, I; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tang, J; Tecchio, M; Teng, P K; Thom, J; Thome, J; Thompson, G A; Thomson, E; Tipton, P; Ttito-Guzmán, P; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Totaro, P; Tourneur, S; Trovato, M; Tsai, S-Y; Tu, Y; Turini, N; Ukegawa, F; Uozumi, S; van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Vellidis, C; Vidal, M; Vila, I; Vilar, R; Vogel, M; Volobouev, I; Volpi, G; Wagner, P; Wagner, R G; Wagner, R L; Wagner, W; Wagner-Kuhr, J; Wakisaka, T; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Weinelt, J; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Wilbur, S; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wolfe, H; Wright, T; Wu, X; Würthwein, F; Yagil, A; Yamamoto, K; Yamaoka, J; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yi, K; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanetti, A; Zeng, Y; Zhang, X; Zheng, Y; Zucchelli, S

2010-03-12

We report a measurement of the lifetime of the Lambda(b)(0) baryon in decays to the Lambda(c)(+)pi(-) final state in a sample corresponding to 1.1 fb(-1) collected in pp collisions at square root of s = 1.96 TeV by the CDF II detector at the Tevatron collider. Using a sample of about 3000 fully reconstructed Lambda(b)(0) events we measure tau(Lambda(b)(0)) = 1.401 +/- 0.046(stat) +/- 0.035(syst) ps (corresponding to ctau(Lambda(b)(0)) = 420.1 +/- 13.7(stat) +/- 10.6(syst) microm, where c is the speed of light). The ratio of this result and the world average B(0) lifetime yields tau(Lambda(b)(0))/tau(B(0)) = 0.918 +/- 0.038 (stat) and (syst), in good agreement with recent theoretical predictions.

Differential Cross Sections for the Electron Impact Excitation of the A(sup 3)(Sigma)(sub u)(sup +), B(sup 3)Pi(sub g), W(sup 3)(Delta)(sub u), B'(sup 3)(Sigma)(sub u)(sup -), a'(sup 1)Sigma(sub u)(sup -), a(sup 1)Pi(sub g), w(sup 1)Delta(sub u), and C(sup 3)Pi(sub u) States of N(sub 2)

NASA Technical Reports Server (NTRS)

Khakoo, M. A.; Johnson, P. V.; Ozkay, I.; Yan, P.; Trajmar, S.; Kanik, I.

2005-01-01

Measurements of differential cross sections for the electron-impact excitation of molecular nitrogen from the ground X(sup 1)(Sigma)(sub g)(sup +)(v''=0)level to the A(sup 3)(Sigma)(sub u)(sup +)(v'), B(sup 3)Pi(sub g)(v'), W(sup 3)(Delta)(sub u)(v'),B'(sup 3)(Sigma)(sub u)(sup -)(v'), a(sup 1)(Pi)(sub g)(v'), w(sup 1)(Delta)(sub u)(v'), and C(sup 3)(Pi)(sub u)(v') levels are presented. The data are obtained at the incident energies of 10, 12.5, 15, 17.5, 20, 30, 50, and 100 eV over the angular range of 5(deg)-130(deg) in 5(deg) intervals. The individual electronic state excitation differential cross sections are obtained by unfolding electron energy-loss spectra of molecular nitrogen using available semiempirical Frank-Condon factors. The data are compared to previous measurements and to available theory. We also make several important suggestions regarding future work that, like the present, relies on the unfolding of electron energy-loss spectra for obtaining differential cross sections.

Neutral-strange-particle production in 200-GeV/ c p /. pi. sup + / K sup + interactions on Au, Ag, and Mg

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brick, D.H.; Widgoff, M.; Beilliere, P.

1992-02-01

We have used the Fermilab 30-in. bubble-chamber--hybrid spectrometer to study neutral-strange-particle production in the interactions of 200-GeV/{ital c} protons and {pi}{sup +} and {ital K}{sup +} mesons with nuclei of gold, silver, and magnesium. Average multiplicities and inclusive cross sections for {ital K}{sup 0} and {Lambda} are measured, and a power law is found to give a good description of their {ital A} dependence. The exponent characterizing the {ital A} dependence is consistent with being the same for {ital K}{sup 0} and {Lambda} production, and also the same for proton and {pi}{sup +} beams. Average {ital K}{sup 0} and {Lambda}more » multiplicities, as well as their ratio, have been measured as functions of the numbers of projectile collisions {nu}{sub {ital p}} and secondary collisions {nu}{sub {ital s}} in the nucleus, and indicate that rescattering contributes significantly to enhancement of {Lambda} production but not to {ital K}{sup 0} production. The properties of events with multiple {ital K}{sup 0}'s or {Lambda}'s also corroborate this conclusion. {ital K}{sup 0} rapidities are in the central region and decrease gently with increasing {nu}{sub {ital p}}, while {Lambda} rapidities are in the target-fragmentation region and are independent of {nu}{sub {ital p}}. {ital K}{sup 0} and {Lambda} multiplicities increase with the rapidity loss of the projectile, but their rapidities do not.« less

Cesium frequency standard for lasers at. Sigma. = 1. 06. mu. m

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wallmeroth, K.; Letterer, R.

1990-07-15

High-resolution spectra of the {ital X}{sup 1}{Sigma}{sup +}{sub {ital g}}--{ital A}{sup 1}{Sigma}{sup +}{sub {ital u}} band of molecular cesium at {lambda}=1.06 {mu}m have been measured. An absolute wave-number reference table for lasers emitting at {Sigma} = 1.06 {mu}m has been established. The cesium resonances are calibrated with respect to the well-known molecular-iodine absorption lines at {Sigma} = 0.53 {mu}m. An accuracy of 10{sup {minus}7} has been achieved.

The nature of the bonding in XCO for X = Fe, Ni, and Cu

NASA Technical Reports Server (NTRS)

Bauschlicher, C. W., Jr.; Bagus, P. S.; Nelin, C. J.; Roos, B. O.

1986-01-01

The bonding in the (5,3)Sigma - and 3Delta states of FeCO, the (3,1)Sigma + , 3Delta, and 3Pi states of NiCO, and the 2Sigma + state of CuCO are analyzed using the constrained-space orbital-variation (CSOV) technique for both (CASSCF) and SCF wave functions. The bonding is discussed in terms of sigma repulsion between the metals 4s and the CO 5-sigma and CO-to-metal sigma donation when there is an empty or partly occupied d-sigma orbital and metal-to-CO 2pi(asterisk) backdonation. The bonding is compared for the different metals and between the different states.

Bonding without Tears.

ERIC Educational Resources Information Center

Akeroyd, F. Michael

1982-01-01

Discusses merits of using sigma-pi model of ethylene as a teaching aid in introductory organic chemistry. The nonmathematical treatment of sigma-pi bonding is then extended to such phenomena as conjugation, hyperconjugation, Markovnikoff addition, aromaticity, and aromatic substitution. (SK)

A Categorification of the Crystal Isomorphism B 1,1 B + B(Lambda i) = B(Lambdasigma (i) and a Graphical Calculus for the Shifted Symmetric Functions

NASA Astrophysics Data System (ADS)

Kvinge, Henry

We prove two results at the intersection of Lie theory and the representation theory of symmetric groups, Hecke algebras, and their generalizations. The first is a categorification of the crystal isomorphism B. (1,1) tensor B1,1 ⊕ B(Lambdai ) ≅ B(Lambdasigma (i)). Here B(Lambdai and B(Lambda sigma(i)) are two affine type highest weight crystals of weight Lambdai and Lambdasigma (i) respectively, sigma is a specific map from the Dynkin indexing set I to itself, and B1,1 is a Kirillov-Reshetikhin crystal. We show that this crystal isomorphism is in fact the shadow of a richer module-theoretic phenomenon in the representation theory of Khovanov-Lauda-Rouquier algebras of classical affine type. Our second result identifies the center EndH'( 1) of Khovanov's Heisenberg category H', as the algebra of shifted symmetric functions Lambda* of Okounkov and Olshanski, i.e. End H'(1) ≅ Lambda*. This isomorphism provides us with a graphical calculus for Lambda*. It also allows us to describe EndH'(1) in terms of the transition and co-transition measure of Kerov and the noncommutative probability spaces of Biane.

Predissociation of oxygen in the B3Sigma(u)(-) state

NASA Technical Reports Server (NTRS)

Chiu, S. S.-L.; Cheung, A. S.-C.; Finch, M.; Jamieson, M. J.; Yoshino, K.; Dalgarno, A.; Parkinson, W. H.

1992-01-01

The predissociation linewidths and level shifts of vibrational levels of three oxygen isotopic molecules (O2)-16, (O-16)(O-18), and (O2)-18 arising from the interactions of the B3Sigma(u)(-) state with the four repulsive states 5Pi(u), 3Sigma(u)(+), 3Pi(u), and 1Pi(u) have been calculated. A set of parameters characterizing these interactions has been determined. Good agreement between calculated and experimental predissociation widths and shifts has been obtained for all the three isotopic molecules.

Localized N, {lambda}, {sigma}, and {xi} single-particle potentials in finite nuclei calculated with SU{sub 6} quark-model baryon-baryon interactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kohno, M.; Fujiwara, Y.

Localized single-particle potentials for all octet baryons, N, {lambda}, {sigma}, and {xi}, in finite nuclei, {sup 12}C, {sup 16}O, {sup 28}Si, {sup 40}Ca, {sup 56}Fe, and {sup 90}Zr, are calculated using the quark-model baryon-baryon interactions. G matrices evaluated in symmetric nuclear matter in the lowest order Brueckner theory (LOBT) are applied to finite nuclei in local density approximation. Nonlocal potentials are localized by a zero-momentum Wigner transformation. Empirical single-particle properties of the nucleon and the {lambda} hyperon in a nuclear medium have been known to be explained semiquantitatively in the LOBT framework. Attention is focused in the present consideration onmore » predictions for the {sigma} and {xi} hyperons. The unified description for the octet baryon-baryon interactions by the SU{sub 6} quark model enables us to obtain less ambiguous extrapolation to the S=-1 and S=-2 sectors based on the knowledge in the NN sector than other potential models. The {sigma} mean field is shown to be weakly attractive at the surface, but turns out to be repulsive inside, which is consistent with the experimental evidence. The {xi} hyperon s.p. potential is also attractive at the nuclear surface region, and inside it fluctuates around zero. Hence {xi} hypernuclear bound states are unlikely. We also evaluate energy shifts of the {sigma}{sup -} and {xi}{sup -} atomic levels in {sup 28}Si and {sup 56}Fe, using the calculated s.p. potentials.« less

Electron-impact excitation of the a-italic /sup 3/. sigma. /sub g//sup +/, B-italic /sup 1/. sigma. /sub u//sup +/, c-italic /sup 3/Pi/sub u/, and C-italic /sup 1/Pi/sub u/ states of H/sub 2/

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khakoo, M.A.; Trajmar, S.

1986-07-01

Normalized differential and integral cross sections for electron-impact excitation of the dipole-allowed B-italic /sup 1/..sigma../sub u//sup +/,C-italic /sup 1/Pi/sub u/ and dipole-forbidden a-italic /sup 3/..sigma../sub g//sup +/,c-italic /sup 3/Pi/sub u/ states of molecular hydrogen have been determined by analysis of energy-loss spectra obtained with a crossed-beam apparatus at electron-impact energies of 20, 30, 40, and 60 eV and scattering angles ranging from 10/sup 0/ to 120/sup 0/. Normalization of the data was achieved by utilizing the elastic differential cross sections measured previously by us (preceding article). The cross sections are compared with other available theoretical and experimental data.

Theoretical study of the alkali and alkaline-earth monosulfides

NASA Technical Reports Server (NTRS)

Partridge, Harry; Langhoff, Stephen R.; Bauschlicher, Charles W., Jr.

1988-01-01

Ab initio calculations have been used to obtain accurate spectroscopic constants for the X2Pi and A2Sigma(+) states of the alkali sulfides and the X1Sigma(+), a3Pi, and A1Pi states of the alkaline-earth sulfides. In contrast to the alkali oxides, the alkali sulfides are found to have X2Pi ground states, due to the larger electrostatic interaction. Dissociation energies of 3.27 eV for BeS, 2.32 eV for MgS, 3.29 eV for CaS, and 3.41 eV for SrS have been obtained for the X1Sigma(+) states of the alkaline-earth sulfides, in good agreement with experimental results. Core correlation is shown to increase the Te values for the a3Pi and A1Pi states of MgS, CaS, and SrS.

Calculation of the {pi}{sup +}{Sigma}{sup +} and {pi}{sup +}{Xi}{sup 0} Scattering Lengths in Lattice QCD

DOE Office of Scientific and Technical Information (OSTI.GOV)

Torok, Aaron

The {pi}{sup +}{Sigma}{sup +} and {pi}{sup +}{Xi}{sup 0} scattering lengths were calculated in mixed-action Lattice QCD with domain-wall valence quarks on the asqtad-improved coarse MILC configurations at four light-quark masses, and at two light-quark masses on the fine MILC configurations. Heavy Baryon Chiral Perturbation Theory with two and three flavors of light quarks was used to perform the chiral extrapolations. To NNLO in the three-flavor chiral expansion, the kaon-baryon processes that were investigated show no signs of convergence. Using the two-flavor chiral expansion for extrapolation, the pion-hyperon scattering lengths are found to be a{sub {pi}}{sup +}{sub {Sigma}}{sup +} = -0.197{+-}0.017more » fm, and a{sub {pi}}{sup +}{sub {Xi}}{sup 0} = -0.098{+-}0.017 fm, where the comprehensive error includes statistical and systematic uncertainties.« less

The Local Supercluster as a test of cosmological models

NASA Technical Reports Server (NTRS)

Cen, Renyue

1994-01-01

The Local Supercluster kinematic properties (the Local Group infall toward the Virgo Cluster and galaxy density distribution about the Virgo Cluster) in various cosmological models are examined utilizing large-scale N-body (PM) simulations 500(exp 3) cells, 250(exp 3) particles, and box size of 400 h(exp -1) Mpc) and are compared to observations. Five models are investigated: (1) the standard, Cosmic Background Explorer Satellite (COBE)-normalized cold dark matter (CDM) model with omega = 1, h = 0.5, and sigma(sub 8) = 1.05; (2) the standard Hot Dark Matter (HDM) model with omega = 1, h = 0.75, and sigma(sub 8) = 1; (3) the tilted CDM model with omega = 1, h = 0.5, n = 0.7, and sigma(sub 8) = 0.5; (4) a CDM + lambda model with omega = 0.3, lambda = 0.7, h = 2/3, and sigma(sub 8) = 2/3; (5) the PBI model with omega = 0.2, h = 0.8, x = 0.1, m = -0.5, and sigma(sub 8) = 0.9. Comparison of the five models with the presently available observational measurements v(sub LG) = 85 - 305 km/s (with mean of 250 km/s), delta(n(sub g))/(n(sub g)-bar) = 1.40 + or - 0.35) suggests that an open universe with omega approximately 0.5 (with or without lambda) and sigma(sub 8) approximately 0.8 is preferred, with omega = 0.3-1.0 (with or without lambda) and sigma(sub 8) = 0.7-1.0 being the acceptable range. At variance with some previous claims based on either direct N-body or spherical nonlinear approaches, we find that a flat model with sigma(sub 8) approximately 0.7-1.0 seems to be reasonably consistent with observations. However, if one favors the low limit of v(sub LG) = 85 km/s, then an omega approximately 0.2-0.3 universe seems to provide a better fit, and flat (omega = 1) models are ruled out at approximately 95% confidence level. On the other hand, if the high limit of v(sub LG) = 350 km/s is closer to the truth, then it appears that omega approximately 0.7-0.8 is more consistent. This test is insensitive to the shape of the power spectrum, but rather sensitive to the normalization of the perturbation amplitude on the relevant scale (e.g., sigma(sub 8)) and omega. We find that neither linear nor nonlinear relations (with spherical symmetry) are good approximations for the relation between radial peculiar velocity and density perturbation, i.e., nonspherical effects and gravitational tidal field are important. The derived omega using either of the two relations is underestimated. In some cases, this error is as large as a factor of 2-4.

Optimized equation of the state of the square-well fluid of variable range based on a fourth-order free-energy expansion.

PubMed

Espíndola-Heredia, Rodolfo; del Río, Fernando; Malijevsky, Anatol

2009-01-14

The free energy of square-well (SW) systems of hard-core diameter sigma with ranges 1 < or = lambda < or = 3 is expanded in a perturbation series. This interval covers most ranges of interest, from short-ranged SW fluids (lambda approximately 1.2) used in modeling colloids to long ranges (lambda approximately 3) where the van der Waals classic approximation holds. The first four terms are evaluated by means of extensive Monte Carlo simulations. The calculations are corrected for the thermodynamic limit and care is taken to evaluate and to control the various sources of error. The results for the first two terms in the series confirm well-known independent results but have an increased estimated accuracy and cover a wider set of well ranges. The results for the third- and fourth-order terms are novel. The free-energy expansion for systems with short and intermediate ranges, 1 < or = lambda < or = 2, is seen to have properties similar to those of systems with longer ranges, 2 < or = lambda < or = 3. An equation of state (EOS) is built to represent the free-energy data. The thermodynamics given by this EOS, confronted against independent computer simulations, is shown to predict accurately the internal energy, pressure, specific heat, and chemical potential of the SW fluids considered and for densities 0 < or = rho sigma(3) < or = 0.9 including subcritical temperatures. This fourth-order theory is estimated to be accurate except for a small region at high density, rho sigma(3) approximately 0.9, and low temperature where terms of still higher order might be needed.

Accurate ab initio calculations which demonstrate a 3 Pi u ground state for Al2

NASA Technical Reports Server (NTRS)

Bauschlicher, Charles W., Jr.; Partridge, Harry; Langhoff, Stephen R.; Taylor, Peter R.; Walch, Stephen P.

1986-01-01

The spectroscopic parameters and separations between the three low-lying X 3 Pi u, A 3 Sigma g -, and a 1 Sigma g + states of Al2 are studied as a function of both the one-particle and n-particle basis set. Approximate correlation treatments are calibrated against full Cl calculations correlating the six valence electrons in a double-zeta plus two d-function basis set. Since the CASSCF/MRCI 3 Pi u to 3 Sigma g - separation is in excellent agreement wtih the FCI value, the MRCI calculations were carried out in an extended (20s13p6d4f)/(6s5p3d2f) gaussian basis. Including a small correction for relativistic effects, the best estimate is that 3 Sigma g - state lies 174/cm above the 3 Pi u ground state. The 1 Sigma g + state lies at least 2000/cm higher in energy. At the CPF level, inclusion of 2s and 2p correlation has little effect on D sub e, reduces T sub e by only 26/cm, and shortens the bond lengths by about 0.02 a sub o. Further strong support for a 3 Pi u ground state comes from the experimental absorption spectra, since both observed transitions can be convincingly assigned as 3 Pi u yields 3 Pi g. The (2) 3 Pi g state is observed to be sensitive to the level of correlation treatment, and to have its minimum shifted to shorter rho values, such that the strongest experimental absorption peak probably corresponds to the 0 yields 2 transition.

Kato type operators and Weyl's theorem

NASA Astrophysics Data System (ADS)

Duggal, B. P.; Djordjevic, S. V.; Kubrusly, Carlos

2005-09-01

A Banach space operator T satisfies Weyl's theorem if and only if T or T* has SVEP at all complex numbers [lambda] in the complement of the Weyl spectrum of T and T is Kato type at all [lambda] which are isolated eigenvalues of T of finite algebraic multiplicity. If T* (respectively, T) has SVEP and T is Kato type at all [lambda] which are isolated eigenvalues of T of finite algebraic multiplicity (respectively, T is Kato type at all [lambda][set membership, variant]iso[sigma](T)), then T satisfies a-Weyl's theorem (respectively, T* satisfies a-Weyl's theorem).

Rosenbluth Separation of the π 0 Electroproduction Cross Section Off the Neutron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mazouz, M.; Ahmed, Z.; Albataineh, H.

Here, we report the first longitudinal/transverse separation of the deeply virtual exclusivemore » $$\\pi^0$$ electroproduction cross section off the neutron and coherent deuteron. Furthemore, the corresponding four structure functions $$d\\sigma_L/dt$$, $$d\\sigma_T/dt$$, $$d\\sigma_{LT}/dt$$ and $$d\\sigma_{TT}/dt$$ are extracted as a function of the momentum transfer to the recoil system at $Q^2$=1.75 GeV$^2$ and $$x_B$$=0.36. The $$ed \\to ed\\pi^0$$ cross sections are found compatible with the small values expected from theoretical models. The $$en \\to en\\pi^0$$ cross sections show a dominance from the response to transversely polarized photons, and are in good agreement with calculations based on the transversity GPDs of the nucleon. By combining our results with previous measurements of $$\\pi^0$$ electroproduction off the proton, we present a flavor decomposition of the $u$ and $d$ quark contributions to the cross section.« less

Rosenbluth Separation of the π 0 Electroproduction Cross Section Off the Neutron

DOE PAGES

Mazouz, M.; Ahmed, Z.; Albataineh, H.; ...

2017-06-01

Here, we report the first longitudinal/transverse separation of the deeply virtual exclusivemore » $$\\pi^0$$ electroproduction cross section off the neutron and coherent deuteron. Furthemore, the corresponding four structure functions $$d\\sigma_L/dt$$, $$d\\sigma_T/dt$$, $$d\\sigma_{LT}/dt$$ and $$d\\sigma_{TT}/dt$$ are extracted as a function of the momentum transfer to the recoil system at $Q^2$=1.75 GeV$^2$ and $$x_B$$=0.36. The $$ed \\to ed\\pi^0$$ cross sections are found compatible with the small values expected from theoretical models. The $$en \\to en\\pi^0$$ cross sections show a dominance from the response to transversely polarized photons, and are in good agreement with calculations based on the transversity GPDs of the nucleon. By combining our results with previous measurements of $$\\pi^0$$ electroproduction off the proton, we present a flavor decomposition of the $u$ and $d$ quark contributions to the cross section.« less

Time-Resolved Spectroscopy of Active Binary Stars

NASA Technical Reports Server (NTRS)

Brown, Alexander

2000-01-01

This NASA grant covered EUVE observing and data analysis programs during EUVE Cycle 5 GO observing. The research involved a single Guest Observer project 97-EUVE-061 "Time-Resolved Spectroscopy of Active Binary Stars". The grant provided funding that covered 1.25 months of the PI's salary. The activities undertaken included observation planning and data analysis (both temporal and spectral). This project was awarded 910 ksec of observing time to study seven active binary stars, all but one of which were actually observed. Lambda-And was observed on 1997 Jul 30 - Aug 3 and Aug 7-14 for a total of 297 ksec; these observations showed two large complex flares that were analyzed by Osten & Brown (1999). AR Psc, observed for 350 ksec on 1997 Aug 27 - Sep 13, showed only relatively small flares that were also discussed by Osten & Brown (1999). EUVE observations of El Eri were obtained on 1994 August 24-28, simultaneous with ASCA X-ray spectra. Four flares were detected by EUVE with one of these also observed simultaneously, by ASCA. The other three EUVE observations were of the stars BY Dra (1997 Sep 22-28), V478 Lyr (1998 May 18-27), and sigma Gem (1998 Dec 10-22). The first two stars showed a few small flares. The sigma Gem data shows a beautiful complete flare with a factor of ten peak brightness compared to quiescence. The flare rise and almost all the decay phase are observed. Unfortunately no observations in other spectral regions were obtained for these stars. Analysis of the lambda-And and AR Psc observations is complete and the results were published in Osten & Brown (1999). Analysis of the BY Dra, V478 Lyr and sigma Gem EUVE data is complete and will be published in Osten (2000, in prep.). The El Eri EUV analysis is also completed and the simultaneous EUV/X-ray study will be published in Osten et al. (2000, in prep.). Both these latter papers will be submitted in summer 2000. All these results will form part of Rachel Osten's PhD thesis.

Two-Photon/Laser-Induced Fluorescence (TP/LIF) sensor

NASA Technical Reports Server (NTRS)

Bradshaw, John D.

1994-01-01

The Two-Photon/Laser-Induced Fluorescence (TP/LIF) technique is based on the stepwise excitation of the OH transitions, X(exp 2)II, v(exp '') = 0 yields X(exp 2)II, v(exp '') = 1 (lambda = 2.9 microns) and X(exp 2)II v(exp '') = 1 yields A(exp2)Sigma, v' = 0 (lambda = 345 nm) with background free fluorescence monitoring of the A(exp 2)Sigma, v' = 0 yields X(exp 2)II, v(exp '') = 0 transition near 309 nm. This technique has awaited the advent of a suitable mid-infrared (2.9 microns) laser source. Turnable mid-IR lasers now exist that are capable of meeting the specifications required of a high sensitivity TP/LIF OH sensor.

An experimental study of the intersystem crossing and reactions of C2(X1Sigmag+) and C2(a3Pi(u)) with O2 and NO at very low temperature (24-300 K).

PubMed

Páramo, Alejandra; Canosa, André; Le Picard, Sébastien D; Sims, Ian R

2006-03-09

A low-temperature gas-phase kinetics study of the reactions and collisional relaxation processes involving C2(X1Sigma(g)+) and C2(a3Pi(u)) in collision with O2 and NO partners at temperatures from 300 to 24 K is reported. The experiments employed a CRESU (Cinétique de Réaction en Ecoulement Supersonique Uniforme) apparatus to attain low temperatures. The C2 species were created using pulsed laser photolysis at 193 nm of mixtures containing C2Cl4 diluted in N2, Ar, or He carrier gas. C2(X1Sigma(g)+) molecules were detected via pulsed laser-induced fluorescence in the (D1Sigma(u)+ <-- X1Sigma(g)+) system, and C2(a3Pi(u)) molecules were detected via pulsed laser-induced fluorescence in the (d 3Pi(g) <-- a 3Pi(u)) system. Relaxation of 3C2 by intersystem crossing induced by oxygen was measured at temperatures below 200 K, and it was found that this process remains very efficient in the temperature range 50-200 K. Reactivity of C2(X1Sigma(g)+) with oxygen became very inefficient below room temperature. Using these two observations, it was found to be possible to obtain the C2(X1Sigma(g)+) state alone at low temperatures by addition of a suitable concentration of O2 and then study its reactivity with NO without any interference coming from the possible relaxation of C2(a3Pi(u)) to C2(X1Sigma(g)+) induced by this reagent. The rate coefficient for reaction of C2(X1Sigma(g)+) with NO was found to be essentially constant over the temperature range 36-300 K with an average value of (1.6 +/- 0.1) x 10(-10) cm3 molecule(-1) s(-1). Reactivity of C2(a3Pi(u)) with NO was found to possess a slight negative temperature dependence over the temperature range 50-300 K, which is in very good agreement with data obtained at higher temperatures.

The Theoretical Transition Probabilities Between the B(sup 3)Pi(sub g) and the A(sup 3)Sigma(Sup +, sub u), W(sup 3)Delta(sub u), B'(sup 3)Sigma(sup -, sub u) States of N2

NASA Technical Reports Server (NTRS)

Thuemmel, Helmar T.; Partridge, Harry; Huo, Winifred M.; Langhoff, Stephen (Technical Monitor)

1995-01-01

The electronic transition moment functions between the B(sup 3)Pi(sub g) and the A(sup 3)Sigma(sup +, sub u), W(sup 3)Delta(sub u), B'(sup 3)Sigma(sup -, sub u) states of N2 are studied using the internally contracted multireference configuration interaction (ICMRCI) method based upon complete active space SCF (CASSCF) reference wave-functions. The dependence of the moments on both the one and n-particle basis sets has been investigated in detail. The calculated radiative lifetimes for the vibrational levels of B(sup 3)Pi(sub g) are in excellent agreement with the most recent measurement of Euler and Pipkin (1983)

Ab initio multireference study of the BN molecule

NASA Technical Reports Server (NTRS)

Martin, J. M. L.; Lee, Timothy J.; Scuseria, Gustavo E.; Taylor, Peter R.

1992-01-01

The lowest 1Sigma(+) and 3Pi states of the BN molecule are studied using multireference configuration interaction (MRCI) and averaged coupled-pair functional (ACPF) methods and large atomic natural orbital (ANO) basis sets, as well as several coupled cluster methods. Our calculations strongly support a 3Pi ground state, but the a1Sigma(+) state lies only 381 +/- 100/cm higher. The a1Sigma(+) state wave function exhibits strong multireference character and, consequently, the predictions of the perturbationally-based single-reference CCSD(T) coupled cluster method are not as reliable in this case as the multireference results. The theoretical predictions for the spectroscopic constants of BN are in good agreement with experiment for the Chi3Pi state, but strongly suggest a misassignment of the fundamental vibrational frequency for the a1Sigma(+) state.

Lagrange constraint neural network for audio varying BSS

NASA Astrophysics Data System (ADS)

Szu, Harold H.; Hsu, Charles C.

2002-03-01

Lagrange Constraint Neural Network (LCNN) is a statistical-mechanical ab-initio model without assuming the artificial neural network (ANN) model at all but derived it from the first principle of Hamilton and Lagrange Methodology: H(S,A)= f(S)- (lambda) C(s,A(x,t)) that incorporates measurement constraint C(S,A(x,t))= (lambda) ([A]S-X)+((lambda) 0-1)((Sigma) isi -1) using the vector Lagrange multiplier-(lambda) and a- priori Shannon Entropy f(S) = -(Sigma) i si log si as the Contrast function of unknown number of independent sources si. Szu et al. have first solved in 1997 the general Blind Source Separation (BSS) problem for spatial-temporal varying mixing matrix for the real world remote sensing where a large pixel footprint implies the mixing matrix [A(x,t)] necessarily fill with diurnal and seasonal variations. Because the ground truth is difficult to be ascertained in the remote sensing, we have thus illustrated in this paper, each step of the LCNN algorithm for the simulated spatial-temporal varying BSS in speech, music audio mixing. We review and compare LCNN with other popular a-posteriori Maximum Entropy methodologies defined by ANN weight matrix-[W] sigmoid-(sigma) post processing H(Y=(sigma) ([W]X)) by Bell-Sejnowski, Amari and Oja (BSAO) called Independent Component Analysis (ICA). Both are mirror symmetric of the MaxEnt methodologies and work for a constant unknown mixing matrix [A], but the major difference is whether the ensemble average is taken at neighborhood pixel data X's in BASO or at the a priori sources S variables in LCNN that dictates which method works for spatial-temporal varying [A(x,t)] that would not allow the neighborhood pixel average. We expected the success of sharper de-mixing by the LCNN method in terms of a controlled ground truth experiment in the simulation of variant mixture of two music of similar Kurtosis (15 seconds composed of Saint-Saens Swan and Rachmaninov cello concerto).

Symmetric and anti-symmetric LS hyperon potentials from lattice QCD

NASA Astrophysics Data System (ADS)

Ishii, Noriyoshi; Murano, Keiko; Nemura, Hidekatsu; Sasaki, Kenji; Inoue, Takashi; HAL QCD Collaboration

2014-09-01

We present recent results of odd-parity hyperon-hyperon potentials from lattice QCD. By using HAL QCD method, we generate hyperon-hyperon potentials from Nambu-Bethe-Salpeter (NBS) wave functions generated by lattice QCD simulation in the flavor SU(3) limit. Potentials in the irreducible flavor SU(3) representations are combined to make a Lambda-N potential which has a strong symmetric LS potential and a weak anti-symmetric LS potential. We discuss a possible cancellation between symmetric and anti-symmetric LS (Lambda-N) potentials after the coupled Sigma-N sector is integrated out. We present recent results of odd-parity hyperon-hyperon potentials from lattice QCD. By using HAL QCD method, we generate hyperon-hyperon potentials from Nambu-Bethe-Salpeter (NBS) wave functions generated by lattice QCD simulation in the flavor SU(3) limit. Potentials in the irreducible flavor SU(3) representations are combined to make a Lambda-N potential which has a strong symmetric LS potential and a weak anti-symmetric LS potential. We discuss a possible cancellation between symmetric and anti-symmetric LS (Lambda-N) potentials after the coupled Sigma-N sector is integrated out. This work is supported by JSPS KAKENHI Grant Number 25400244.

Double-strangeness production in {bar p}Xe annihilation at low energy in the DIANA chamber

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barmin, V.V.; Barylov, V.G.; Chernukha, S.F.

1994-09-01

From the analysis of about 10{sup 5} annihilations of antiprotons at rest and in flight (0.4 - 0.9 GeV/c) on Xe nuclei, new results are presented for the final state K{sup 0}{sub s}SX (S = K{sup 0}{sub s}, K{sup {minus}}, {Lambda}, {Sigma}{sup 0}, {Sigma}{sup +-}). From these results and from earlier results for the final state K{sup +}SX, inclusive and semiinclusive yields are determined, giving virtually all strange channels. The effective strangeness contents were deduced to be 5.5% at rest and 5.3% in flight. In addition to 14 events reported earlier in the final states K{sup +}K{sup +}X and K{supmore » +}K{sup 0}{sub s}{Lambda}X and based on an analysis of 5.4 x 10{sup 5} annihilations, three new events were found in a further analysis of 10{sup 5} annihilations. The new events, together with the revised yields and momentum and mass distributions, are presented. The results confirm earlier results on the effective mass of {Lambda}{Lambda} and a determination of the preferable cascade process.« less

Soft X-Ray Absorption Spectroscopy of High-Abrasion-Furnace Carbon Black

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muramatsu, Yasuji; Harada, Ryusuke; Gullikson, Eric M.

2007-02-02

The soft x-ray absorption spectra of high-abrasion-furnace carbon black were measured to obtain local-structure/chemical-states information of the primary particles and/or crystallites. The soft x-ray absorption spectral features of carbon black represent broader {pi}* and {sigma}* peak structures compared to highly oriented pyrolytic graphite (HOPG). The subtracted spectra between the carbon black and HOPG, (carbon black) - (HOPG), show double-peak structures on both sides of the {pi}* peak. The lower-energy peak, denoted as the 'pre-peak', in the subtracted spectra and the {pi}*/{sigma}* peak intensity ratio in the absorption spectra clearly depend on the specific surface area by nitrogen adsorption (NSA). Therefore,more » it is concluded that the pre-peak intensity and the {pi}*/{sigma}* ratio reflect the local graphitic structure of carbon black.« less

A correlated ab initio study of the A2 pi <-- X2 sigma+ transition in MgCCH

NASA Technical Reports Server (NTRS)

Woon, D. E.

1997-01-01

The A2 pi <-- X2 sigma+ transition in MgCCH was studied with correlation consistent basis sets and single- and multireference correlation methods. The A2 pi excited state was characterized in detail; the x2 sigma+ ground state has been described elsewhere recently. The estimated complete basis set (CBS) limits for valence correlation, including zero-point energy corrections, are 22668, 23191, and 22795 for the RCCSD(T), MRCI, and MRCI + Q methods, respectively. A core-valence correction of +162 cm-1 shifts the RCCSD(T) value to 22830 cm-1, in good agreement with the experimental result of 22807 cm-1.

Gauss's law test of gravity at short range

NASA Technical Reports Server (NTRS)

Moody, M. V.; Paik, H. J.

1993-01-01

A null test of the gravitational inverse-square law can be performed by testing Gauss's law for the field. We have constructed a three-axis superconducting gravity gradiometer and carried out such a test. A lead pendulum weighing 1500 kg was used to produce a time-varying field. This experiment places a new (2-sigma) limit of alpha = (0.9 + or - 4.6) x 10 exp -4 at lambda of 1.5 m, where alpha and lambda are parameters for the generalized potential phi = -(GM/r)(l + alpha e exp -r/lambda).

From Ξb→Λbπ to Ξc→Λcπ

DOE PAGES

Gronau, Michael; Rosner, Jonathan L.

2016-04-11

Using a successful framework for describing S-wave hadronic decays of light hyperons induced by a subprocess s -> u((u) over bard), we presented recently a model-independent calculation of the amplitude and branching ratio for Xi(-)(b) -> Lambda(b)pi(-) in agreement with a LHCb measurement. The same quark process contributes to Xi(0)(c) -> Lambda(c)pi(-), while a second term from the subprocess cs -> cd has been related by Voloshin to differences among total decay rates of charmed baryons. We calculate this term and find it to have a magnitude approximately equal to the s -> u((u) over bard) term. We argue formore » a negligible relative phase between these two contributions, potentially due to final state interactions. However, we do not know whether they interfere destructively or constructively. For constructive interference one predicts B(Xi(0)(c) -> Lambda(c)pi(-)) = (1.94 +/- 0.70) x 10(-3) and B(Xi(+)(c) -> Lambda(c)pi(0)) = (3.86 +/- 1.35) x 10(-3). For destructive interference, the respective branching fractions are expected to be less than about 10(-4) and 2 x 10(-4). (C) 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP(3).« less

From Ξb→Λbπ to Ξc→Λcπ

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gronau, Michael; Rosner, Jonathan L.

Using a successful framework for describing S-wave hadronic decays of light hyperons induced by a subprocess s -> u((u) over bard), we presented recently a model-independent calculation of the amplitude and branching ratio for Xi(-)(b) -> Lambda(b)pi(-) in agreement with a LHCb measurement. The same quark process contributes to Xi(0)(c) -> Lambda(c)pi(-), while a second term from the subprocess cs -> cd has been related by Voloshin to differences among total decay rates of charmed baryons. We calculate this term and find it to have a magnitude approximately equal to the s -> u((u) over bard) term. We argue formore » a negligible relative phase between these two contributions, potentially due to final state interactions. However, we do not know whether they interfere destructively or constructively. For constructive interference one predicts B(Xi(0)(c) -> Lambda(c)pi(-)) = (1.94 +/- 0.70) x 10(-3) and B(Xi(+)(c) -> Lambda(c)pi(0)) = (3.86 +/- 1.35) x 10(-3). For destructive interference, the respective branching fractions are expected to be less than about 10(-4) and 2 x 10(-4). (C) 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP(3).« less

Shake for Sigma, Pray for Pi: Classroom Orbital Overlap Analogies

ERIC Educational Resources Information Center

Dicks, Andrew P.

2011-01-01

An introductory organic classroom demonstration is discussed where analogies are made between common societal hand contact and covalent bond formation. A handshake signifies creation of a [sigma] bond ("head-on" orbital overlap), whereas the action of praying illustrates "sideways" overlap and generation of a [pi] bond. The nature of orbital and…

Theoretical study of the A prime 5Sigma(+)g and C double prime 5Pi u states of N2 - Implications for the N2 afterglow

NASA Technical Reports Server (NTRS)

Partridge, Harry; Langhoff, Stephen R.; Bauschlicher, Charles W., Jr.; Schwenke, David W.

1988-01-01

Theoretical spectroscopic constants are reported for the A prime 5Sigma(+)g and C double prime 5Pi u states of N2 based on CASSCF/MRCI calculations using large ANO Gaussian basis sets. The calculated A prime Sigma(+)g potential differs qualitatively from previous calculations in that the inner well is significantly deeper (De = 3450/cm). This deeper well provides considerable support for the suggestion of Berkowitz et al. (1956) that A prime 5Sigma(+)g is the primary precursor state involved in the yellow Lewis-Rayleigh afterglow of N2.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roat, C

A measurement of {Beta}({Lambda}{sub c}{sup +} {yields} pK{sup -} {pi}{sup +}) is presented based on data collected with the BaBar detector at the Stanford Linear Accelerator Center. Branching fraction measurements represent a large portion of what is known about short-lived particles, the strong force that binds them, and the weak force that causes them to decay. While the majority of branching fraction measurements are done as ratios between two decay modes, it is the absolute measurements of a few particular decay modes that set the scale for these relative measurements. The {Lambda}{sub c}{sup +} particle is one of the fourmore » weakly decaying hadrons into which more than 90% of the known heavy quark hadrons will eventually decay. Thus, an absolute measurement of the branching fraction for {Lambda}{sub c}{sup +} {yields} pK{sup -}{pi}{sup +} is important for many studies of the heavy quark sector, from spectroscopy to B meson decays. The number of produced {Lambda}{sub c}{sup +}'s is inferred from the number of events reconstructed with an antiproton and an accompanying D meson. The final result of {Beta}({Lambda}{sub c}{sup +} {yields} pK{sup -} {pi}{sup +}) = [6.12 {+-} 0.31(stat.) {+-} 0.42(syst.)]% represents more than a two-fold improvement in precision over the world average. The dominant source of systematic uncertainty is the irreducible background of {Xi}{sub c} baryons.« less

Photoacoustic measurement of differential broadening of the Lambda doublets in NO(X 2Pi 1/2,v = 2-0) by Ar

NASA Technical Reports Server (NTRS)

Pine, A. S.

1989-01-01

A differential broadening of the Lambda doublets in the v = 2-0 overtone band of the 2pi1/2 ground electronic state of NO in an Ar buffer gas has been observed by photoacoustic spectroscopy using a tunable color-center laser. The broadening coefficients for the f symmetry components are larger than for the e symmetry components by up to about 6 percent for J of about 16.5. This differential depends on J and vanishes at low J, implicating the anisotropy of the unpaired electron Pi orbital in the plane of rotation. The 2Pi3/2 transitions are slightly broader than the 2Pi1/2 as a result of spin-flipping collisional relaxation. The observed line shapes also exhibit collisional or Dicke narrowing due to velocity-changing collisions.

Spectroscopic studies and structure of 3-methoxy-2 -[(2,4,4,6,6-pentachloro-1,3,5,2{lambda}{sup 5},4{lambda}{sup 5},6{lambda}{sup 5}-triazatriphosphin-2-yl)oxy] benzaldehyde

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oezay, H.; Yildiz, M., E-mail: myildiz@comu.edu.tr; Uenver, H.

2013-01-15

The compound called 3-methoxy-2- [(2,4,4,6,6-pentachloro-1,3,5,2{lambda}{sup 5},4{lambda}{sup 5},6{lambda}{sup 5}-triazatriphosphin-2-yl)oxy] benzaldehyde has been synthesized from the reaction of 2-hydroxy-3-methoxybenzaldehyde with hexachlorocyclotriphosphazene. It has been characterized by elemental analysis, MS, IR, {sup 1}H NMR, {sup 13}C NMR, {sup 31}P NMR and UV-visible spectroscopic techniques. The structure of the title compound has been determind by X-ray analysis. Crystals are orthorhombic, space group P2{sub 1}2{sub 1}2{sub 1}, Z = 4, a = 7.705(1), b = 12.624(1), c = 17.825(2) A, R{sub 1} = 0.0390 and wR{sub 2} = 0.1074 [I > 2{sigma}(I)], respectively.

Theoretical electronic transition moments for the Ballik-Ramsay, Fox-Herzberg, and Swan systems of C2

NASA Technical Reports Server (NTRS)

Cooper, D. M.

1981-01-01

Electronic transition moments and their variation with internuclear separation are calculated for the Ballik-Ramsay (b 3 Sigma g - a 3 Pi u), Fox-Herzberg (e 3 Pi g-a 3 Pi u) and Swan (d 3 Pi g-a 3 Pi u) band systems of C2, which appear in a variety of terrestrial and astrophysical sources. Electronic wave functions of the a 3 Pi u, b 2 Sigma g -, d 3 Pi g and e 3 Pi g states of C2 are obtained by means of a self-consistent field plus configuration interaction calculation using an atomic basis of 46 Slater-type orbitals, and theoretical potential energy curves and spectroscopic constants for the four electronic states were computed. The results obtained for both the potential energy curves and electronic transition moments are found to be in good agreement with experimental data.

Clar's sextet rule is a consequence of the sigma-electron framework.

PubMed

Maksić, Zvonimir B; Barić, Danijela; Müller, Thomas

2006-08-24

A number of condensed PAHs are examined to identify the underlying reasons governing empirical Clar's rule taking benzene as a limiting case. It is found that the so-called Clar's structures are the only minima on the MP2(fc) potential energy hypersurfaces, meaning that other conceivable valence isomers are nonexistent. The influence of the electron correlation energies to the stability of Clar's structures is substantial with predominating influence of the sigma-electrons. However, the contributions arising from the sigma- and pi-electron correlation energies are approximately the same, if Clar's structures are compared with some artificial pi-electron localized or graphite-like delocalized planar systems. Analysis of the Hartree-Fock (HF) energies provides a compelling evidence that the origin of stability of Clar's structures lies in a decrease of the positive T, V(ee) and V(nn) energy terms relative to some characteristic virtual "delocalized" or "localized" model geometries. Partitioning of the mixed and terms in the sigma- and pi-type contributions, by using the stockholder (SHR), equipartitioning (EQP) and standard pi (SPI) schemes, unequivocally shows that the driving force leading to Clar's structures are more favorable sigma-type interactions. All these conclusions hold for the archetypal benzene too, which could be considered as a limiting Clar system. Finally, the boundaries of Clar's hypothesis and some common misconceptions are briefly discussed. Perusal of the geometric parameters and pi-bond orders reveals that there are no benzene rings completely "vacant" or "fully occupied" by the pi-electrons, envisaged by Clar in his picture of condensed benzenoid compounds. Instead, there are six-membered rings with higher and lower total pi-electron density. The bond length anisotropy of the former rings is smaller. It is concluded that Clar's proposition is a useful rule of thumb providing qualitative information on the stability of the PAH systems, which in turn should not be overinterpreted.

OMEGA{sup -}, XI*{sup -}, SIGMA*{sup -}, and DELTA{sup -} decuplet baryon magnetic moments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Slaughter, Milton Dean

The properties of the ground-state U spin =(3/2) baryon decuplet magnetic moments DELTA{sup -}, XI*{sup -}, SIGMA*{sup -}, and OMEGA{sup -} and their ground-state spin-(1/2) cousins p, n, LAMBDA, SIGMA{sup +}, SIGMA{sup 0}, SIGMA{sup -}, XI{sup +}, and XI{sup -} have been studied for many years with a modicum of success. The magnetic moments of many are yet to be determined. Of the decuplet baryons, only the magnetic moment of the OMEGA{sup -} has been accurately determined. We calculate the magnetic moments of the physical decuplet U spin =(3/2) quartet members without ascribing any specific form to their quark structuremore » or intraquark interactions.« less

Relation between scattering and production amplitude--Case of intermediate {sigma}-particle in {pi}{pi}-system--

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ishida, Muneyuki; Ishida, Shin; Ishida, Taku

1998-05-29

The relation between scattering and production amplitudes are investigated, using a simple field theoretical model, from the general viewpoint of unitarity and the applicability of final state interaction (FSI-) theorem. The IA-method and VMW-method, which are applied to our phenomenological analyses [2,3] suggesting the {sigma}-existence, are obtained as the physical state representations of scattering and production amplitudes, respectively. Moreover, the VMW-method is shown to be an effective method to obtain the resonance properties from general production processes, while the conventional analyses based on the 'universality' of {pi}{pi}-scattering amplitude are powerless for this purpose.

A /sup 1/Pi--X /sup 1/. sigma. /sup +/ band system in CH/sup +/ and CD/sup +/: theoretical spectroscopic constants and lifetimes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elander, N.; Oddershede, J.; Beebe, N.H.F.

1977-08-15

Polarization propagator calculation of spectroscopic constants and radiative lifetimes for the A /sup 1/Pi--X /sup 1/..sigma../sup +/ band system are presented. The spectroscopic constants agree well with experimental and other theoretical values. We have also performed an iterative Rydberg-Klein-Rees (RKR) calculation of B/sub e/, ..omega../sub e/, and ..omega../sub e/x/sub e/ for the experimental X /sup 1/..sigma../sup +/ state.The calculated radiative lifetime for the A /sup 1/Pi state (v'=0) is 660 ns and 598 ns, with theoretical and experimental potential energy curves, respectively. This difference (about 60 ns) indicates the inaccuracy in the present calculation. Experimentally the most recent estimate ofmore » the A /sup 1/Pi (v'=0) state is 630 +- 50 ns, and theoretically the Yoshimine et al. transition moment gives tau (A /sup 1/Pi, v'=0) =722 ns.The radiative lifetimes calculated for CD/sup +/ are between 1.3% and 3.9% larger than the corresponding CH/sup +/ lifetimes.« less

Hard quark-quark scattering with exclusive reactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barton, D.S.; Bunce, G.M.; Carroll, A.S.

1984-07-19

We have begun a program designed to study hard quark-quark scattering with exclusive reactions, focusing on quasi-elastic two-body reactions with all possible quark flavor exchanges. Examples are ..pi../sup -/p ..-->.. ..pi../sup -/p, rho/sup -/p, ..pi../sup +/..delta../sup -/, K/sup +/..sigma../sup -/, or K..lambda... Of the two-body exclusives, only elastic scattering had been measured at such large t previous to our experiment. By comparing the relative importance of different final states, the energy dependence of the production ratios of these states, the prominence of resonances such as rho/sup -/ over background in this region, and measuring polarizations where accessible, we have collectedmore » a large body of data on hard scattering in a completely new domain. Previously, essential all short distance QCD tests have been for inclusive processes. We have taken data with both negative and positive incident beam at 10 GeV/c on a hydrogen target and will present the first results, for ..pi../sup -/p ..-->.. ..pi../sup -/p and rho/sup -/p at THETA/sub cm/ = 90/sup 0/, -t = 9 GeV/sup 2//c/sup 2/. The apparatus consists of a magnetic spectrometer, with Cerenkov particle identification, which selects stable charged particles (protons in this case) at high momentum near 90/sup 0/ in the center-of-mass. A large aperture array of PWCs observes the recoil particle or charged decay products. Cross sections are extremely low, approximately a 1 nb/(GeV/c)/sup 2/ for elastic scattering. We will report on a sample of more than 1000 ..pi../sup -/p elastic events, and on rho/sup -/p, where the rho/sup -/ decay distribution was observed. We find a surprisingly large rho/sup -/p cross section in this large momentum transfer region, with rho/sup -/p about half the elastic cross section, and a striking spin alignment of the rho/sup -/.« less

Dynamical coupled-channels study of {pi}N {right arrow} {pi pi}N reactions.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kamano, H.; Julia-Diaz, B.; Lee, T.-S. H.

As a step toward performing a complete coupled-channels analysis of the world data of {pi}N,{gamma}*N {yields} {pi}N,{eta}N,{pi}{pi}N reactions, the {pi}N {yields} {pi}{pi}N reactions are investigated starting with the dynamical coupled-channels model developed in Phys. Rev. C 76, 065201 (2007). The channels included are {pi}N,{eta}N, and {pi}{pi}N which has {pi}{Delta},{rho}N, and {sigma}N resonant components. The nonresonant amplitudes are generated from solving a set of coupled-channels equations with the meson-baryon potentials defined by effective Lagrangians. The resonant amplitudes are generated from 16 bare excited nucleon (N*) states that are dressed by the nonresonant interactions as constrained by the unitarity condition. The datamore » of total cross sections and {pi}N and {pi}{pi} invariant mass distributions of {pi} + p {yields} {pi} + {pi} + n, {pi} + {pi}0p and {pi} - p {yields} {pi} + {pi} - n, {pi} - {pi}0p,{pi}0{pi}0n reactions from threshold to the invariant mass W = 2 GeV can be described to a very large extent. We show the importance of the coupled-channels effects and the strong interference among the contributions from the {pi}{Delta},{sigma}N, and {rho}N channels. The large interference between the resonant and nonresonant amplitudes is also demonstrated. Possible future developments are discussed.« less

L(p) approximation capabilities of sum-of-product and sigma-pi-sigma neural networks.

PubMed

Long, Jinling; Wu, Wei; Nan, Dong

2007-10-01

This paper studies the L(p) approximation capabilities of sum-of-product (SOPNN) and sigma-pi-sigma (SPSNN) neural networks. It is proved that the set of functions that are generated by the SOPNN with its activation function in $L_{loc};p(\\mathcal{R})$ is dense in $L;p(\\mathcal{K})$ for any compact set $\\mathcal{K}\\subset \\mathcal{R};N$, if and only if the activation function is not a polynomial almost everywhere. It is also shown that if the activation function of the SPSNN is in ${L_{loc};\\infty(\\mathcal{R})}$, then the functions generated by the SPSNN are dense in $L;p(\\mathcal{K})$ if and only if the activation function is not a constant (a.e.).

The Effect of Solar Radiation on Molecular Nitrogen Emissions Originating in the Sunlit Thermosphere of Earth.

NASA Astrophysics Data System (ADS)

Hatfield, David Brooke

The vibrational distribution of N_2 triplet states in the sunlit upper thermosphere of Earth is measured and modeled for the first time. A comparison is made between measured and theoretical limb column emission rates for bands originating from each upper vibrational level of C^3Pi_ u(v) and A^3Sigma_sp {u}{+}(v). The measured column emission rates for the Second Positive (2PG) bands are 3.2 (+/-0.2), 3.2 (+/-0.2) and 0.6 (+0.0,-0.4) kRayleighs for bands originating from C^3Pi_ u(0<=qrm v<=q2) and 13.3 ( +/-0.2), 10.0 (+/-0.2), 3 (+0,-2) and 2 (+0,-2) kRayleighs for Vegard-Kaplan (VK) bands originating from A^3Sigma_sp{u}{+ }(0<=qrm v<=q3).. Predicted limb column emission rates for C ^3Pi_ u(v) are in excellent agreement with the measured 2PG intensities, but comparisons of predicted A^3Sigma_sp{u }{+}(v) column emissions to measured VK intensities are poor. Despite this discrepancy, the predicted sum of all A^3Sigma_sp {u}{+}(v) emission rates over all v compared well to the sum of measured VK intensities. This implies that the excitation rate into the N_2 triplet states is well understood, but that the cascade mechanisms are not as yet understood sufficiently to use dayglow N_2 band emissions as remote sensing probes of the sunlit thermosphere. The dayglow N_2 emissions are modeled by extending the existing auroral model to include resonance scattering of sunlight and replacing the precipitating auroral electrons with photoelectrons. The effects of solar resonance scattering on the X ^1Sigma_sp{g}{+}, A^3Sigma_sp{u }{+} and B^3Pi _ g states are presented as a function of A^3Sigma_sp{u}{+ } quenching rate. These theoretical predictions have important implications for the analysis of dayglow and auroral emissions. The effect of resonance scattering on the A^3Sigma_sp{u} {+} state is small, and will not be measurable under auroral conditions. This implies that the measured auroral vibrational population of the A^3 Sigma_sp{u}{+} state is valid for sunlit aurora. The population of B ^3Pi_ g(v = O) relative to other B^3Pi_ g(v) states is predicted to be enhanced by sunlight. A novel set of computer variables based on tree structures was created to manage the information used. These variables are described in detail and were found to be useful tools for the creation and extension of computer models treating diatomic species.

Asymmetry Studies in the Production of $$\\Lambda^0/\\bar \\Lambda^0$$, $$\\Xi^-/\\bar{\\Xi}^+$$ and $$\\Omega^-/\\bar{\\Omega}^+$$ Hyperons in 500 GeV/c $$\\pi^-$$ - Nucleon Interactions (in Portuguese)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Solano Salinas, Carlos Javier

Using data from fprmilab fixed-target experiment E791, we have measmed for the first time particle/antiparticle production asymmetries formore » $$\\Lambda^0 \\Xi^-$$ and $$\\Omega^-$$ hyperons in $$\\pi^-$$nucleon interactions at 500 GeV /c as joint functions of $$x_F$$ and $$p^2_{\\tau}$$ over the ranges $$-0.12 \\le x_F \\le 0.12$$ and $$0 \\le p^2_{\\tau} \\le 4 (GeV/c)^2$$. There is now direct evidence of a basic asymmetry, even at $$x_F$$ = 0.0, which may be due to associated production. In addition, there are leading-particle-type effects which are qualitativrly like what one would expect from rrcmnbination models or their alternatives. WP used the Dnal Parton Model (DPM) to cakulate the asymmetry for the $$\\Lambda^0$$ and compared with the Lund model (PYTHIA /JETSET) predictions and with om experimental results.« less

Rare azido-bridged manganese(II) systems: syntheses, crystal structures, and magnetic properties.

PubMed

Ghosh, A K; Ghoshal, D; Zangrando, E; Ribas, J; Ray Chaudhuri, N

2005-03-21

Two new polymeric azido-bridged manganese complexes of formulas [Mn(N3)2 (bpee)]n (1) and {[Mn(N3)(dpyo)Cl(H2O)2](H2O)}n (2) [bpee, trans-1,2-bis(4-pyridyl)ethylene; dpyo, 4,4'-dipyridyl N,N'-dioxide] have been synthesized and characterized by single-crystal X-ray diffraction analysis and low-temperature magnetic study. Both the complexes 1 and 2 crystallize in the triclinic system, space group P1, with a = 8.877(3) A, b = 11.036(3) A, c = 11.584(4) A, alpha = 72.62(2) degrees, beta = 71.06(2) degrees, gamma = 87.98(3) degrees, and Z = 1 and a = 7.060(3) A, b = 10.345(3) A, c = 11.697(4) A, alpha = 106.86(2) degrees, beta = 113.33(2) degrees, gamma = 96.39(3) degrees, and Z = 2, respectively. Complex 1 exhibits a 2D structure of [-Mn(N3)2-]n chains, connected by bpee ligands, whose pyridine rings undergo pi-pi and C-H...pi interactions. This facilitates the rare arrangement of doubly bridged azide ligands with one end-on and two end-to-end (EO-EE-EE) sequence. Complex 2 is a neutral 1D polymer built up by [Mn(N3)(dpyo)Cl(H2O)2] units and lattice water molecules. The metals are connected by single EE azide ligands, which are arranged in a cis position to the Mn(II) center. The 1D zipped chains are linked by H-bonds involving lattice water molecules and show pi-pi stacking of dpyo pyridine rings to form a supramolecular 2D layered structure. The magnetic studies were performed in 2-300 K temperature range, and the data were fitted by considering an alternating chain of exchange interactions with S = 5/2 (considered as classical spin) with the spin Hamiltonians H = -Ji sigma(S(3i)S(3i+1) + S(3i+1)S(3i+2)) - J2 sigmaS(3i-1)S(3i) and H = -Ji sigmaS(2i)S(2i+1) - J2 sigmaS(2i+1)S(2i+2) for complexes 1 and 2, respectively. Complex 2 exhibits small antiferromagnetic coupling between the metal centers, whereas 1 exhibits a new case of topological ferromagnetism, which is very unusual.

Slow photoelectron imaging spectroscopy of CCO- and CCS-.

PubMed

Garand, Etienne; Yacovitch, Tara I; Neumark, Daniel M

2008-08-21

High-resolution photodetachment spectra of CCO(-) and CCS(-) using slow photoelectron velocity-map imaging spectroscopy are reported. Well-resolved transitions to the neutral X (3)Sigma(-), a (1)Delta, b (1)Sigma(+), and A (3)Pi states are seen for both species. The electron affinities of CCO and CCS are determined to be 2.3107+/-0.0006 and 2.7475+/-0.0006 eV, respectively, and precise term energies for the a (1)Delta, b (1)Sigma(+), and A (3)Pi excited states are also determined. The two low-lying singlet states of CCS are observed for the first time, as are several vibronic transitions within the four bands. Analysis of hot bands finds the spin-orbit orbit splitting in the X (2)Pi ground state of CCO(-) and CCS(-) to be 61 and 195 cm(-1), respectively.

On existence of the {sigma}(600) Its physical implications and related problems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ishida, Shin

1998-05-29

We make a re-analysis of 1=0 {pi}{pi} scattering phase shift {delta}{sub 0}{sup 0} through a new method of S-matrix parametrization (IA; interfering amplitude method), and show a result suggesting strongly for the existence of {sigma}-particle-long-sought Chiral partner of {pi}-meson. Furthermore, through the phenomenological analyses of typical production processes of the 2{pi}-system, the pp-central collision and the J/{psi}{yields}{omega}{pi}{pi} decay, by applying an intuitive formula as sum of Breit-Wigner amplitudes, (VMW; variant mass and width method), the other evidences for the {sigma}-existence are given. The validity of the methods used in the above analyses is investigated, using a simple field theoretical model,more » from the general viewpoint of unitarity and the applicability of final state interaction (FSI-) theorem, especially in relation to the ''universality'' argument. It is shown that the IA and VMW are obtained as the physical state representations of scattering and production amplitudes, respectively. The VMW is shown to be an effective method to obtain the resonance properties from production processes, which generally have the unknown strong-phases. The conventional analyses based on the 'universality' seem to be powerless for this purpose.« less

Deploying Six Sigma in a health care system as a work in progress.

PubMed

Christianson, Jon B; Warrick, Louise H; Howard, Richard; Vollum, John

2005-11-01

An integrated health care system deployed Six Sigma in four clinical projects. The selected projects targeted Medicare profitability, emergency department cycle time reduction, clinic patient preparation, and medication safety. CROSS-PROJECT ANALYSIS: The six-month start-up period yielded several lessons. For example, the selection and sequence for implementing strategic performance improvement (PI) projects, and the decision to use Six Sigma methods, should be guided by an overall system of project portfolio management. Fairview Health Services (FHS) had begun with a partial deployment with the intent of using the experience to inform subsequent full deployment. Yet even before completing analyses of project outcomes, FHS decided to proceed with full deployment. Leaders developed strategic and communication plans, allocated resources, and provided for further training. In 2005, three years after the initial implementation period, Six Sigma implementation has continued. A systemwide method for setting priorities for PI projects is in place, supported by a Web-based system for managing, tracking, monitoring, and communicating results. Cultural change is a challenge in any environment where staff is rooted in a single PI methodology and is skeptical about the credibility of Six Sigma because of its tie to manufacturing. Health care organizations will need to find better ways to engage physicians, especially community physicians whose patients and clinical practices could be affected by Six Sigma projects.

Core-core and core-valence correlation

NASA Technical Reports Server (NTRS)

Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Taylor, Peter R.

1988-01-01

The effect of 1s core correlation on properties and energy separations are analyzed using full configuration-interaction (FCI) calculations. The Be1S - 1P, the C 3P - 5S,m and CH(+) 1Sigma(+) - 1Pi separations, and CH(+) spectroscopic constants, dipole moment, and 1Sigma(+) - 1Pi transition dipole moment have been studied. The results of the FCI calculations are compared to those obtained using approximate methods.

Publisher's Note: Branching ratio of the electromagnetic decay of the Σ+(1385) Phys. Rev. D 85, 052004 (2012)

NASA Astrophysics Data System (ADS)

Keller, D.; Hicks, K.; Adhikari, K. P.; Adikaram, D.; Amaryan, M. J.; Anghinolfi, M.; Baghdasaryan, H.; Ball, J.; Battaglieri, M.; Bedlinskiy, I.; Biselli, A. S.; Bookwalter, C.; Boiarinov, S.; Branford, D.; Briscoe, W. J.; Brooks, W. K.; Burkert, V. D.; Carman, D. S.; Celentano, A.; Chandavar, S.; Cole, P. L.; Contalbrigo, M.; Crede, V.; D'Angelo, A.; Daniel, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Djalali, C.; Doughty, D.; Dupre, R.; El Alaoui, A.; El Fassi, L.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Gabrielyan, M. Y.; Gevorgyan, N.; Gilfoyle, G. P.; Giovanetti, K. L.; Gohn, W.; Golovatch, E.; Gothe, R. W.; Graham, L.; Griffioen, K. A.; Guidal, M.; Guler, N.; Guo, L.; Hafidi, K.; Hakobyan, H.; Holtrop, M.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Jo, H. S.; Joo, K.; Khandaker, M.; Khetarpal, P.; Kim, A.; Kim, W.; Klein, F. J.; Kubarovsky, A.; Kubarovsky, V.; Kuleshov, S. V.; Lu, H. Y.; MacGregor, I. J. D.; Mao, Y.; Markov, N.; Mayer, M.; McKinnon, B.; Meyer, C. A.; Mineeva, T.; Mirazita, M.; Mokeev, V.; Moutarde, H.; Munevar, E.; Nadel-Turonski, P.; Nasseripour, R.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Osipenko, M.; Ostrovidov, A. I.; Paolone, M.; Pappalardo, L.; Paremuzyan, R.; Park, K.; Park, S.; Pasyuk, E.; Anefalos Pereira, S.; Pisano, S.; Pogorelko, O.; Pozdniakov, S.; Procureur, S.; Prok, Y.; Protopopescu, D.; Raue, B. A.; Ricco, G.; Rimal, D.; Ripani, M.; Ritchie, B. G.; Rosner, G.; Rossi, P.; Sabatié, F.; Saini, M. S.; Salgado, C.; Schott, D.; Schumacher, R. A.; Seraydaryan, H.; Sharabian, Y. G.; Smith, E. S.; Smith, G. D.; Sober, D. I.; Sokhan, D.; Stepanyan, S. S.; Stepanyan, S.; Stoler, P.; Strauch, S.; Taiuti, M.; Tang, W.; Taylor, C. E.; Tkachenko, S.; Vernarsky, B.; Vineyard, M. F.; Vlassov, A. V.; Voskanyan, H.; Voutier, E.; Watts, D. P.; Wood, M. H.; Zachariou, N.; Zana, L.; Zhao, B.; Zhao, Z. W.

2012-03-01

The CLAS detector was used to obtain the first ever measurement of the electromagnetic decay of the $\\Sigma^{*+}(1385)$ from the reaction $\\gamma p \\to K^0 \\Sigma^{*+}(1385)$. A real photon beam with a maximum energy of 3.8 GeV was incident on a liquid-hydrogen target, resulting in the photoproduction of the kaon and $\\Sigma^*$ hyperon. Kinematic fitting was used to separate the reaction channel from the background processes. The fitting algorithm exploited a new method to kinematically fit neutrons in the CLAS detector, leading to the partial width measurement of $250.0\\pm56.9(stat)^{+34.3}_{-41.2}(sys)$ keV. A U-spin symmetry test using the SU(3) flavor-multiplet representation yields predictions for the $\\Sigma^{*+}(1385)\\to\\Sigma^{+}\\gamma$ and $\\Sigma^{*0}(1385)\\to\\Lambda\\gamma$ partial widths that agree with the experimental measurements.

A new continuum model for suspensions of gyrotactic micro-organisms

NASA Technical Reports Server (NTRS)

Pedley, T. J.; Kessler, J. O.

1990-01-01

A new continuum model is formulated for dilute suspensions of swimming micro-organisms with asymmetric mass distributions. Account is taken of randomness in a cell's swimming direction, p, by postulating that the probability density function for p satisfies a Fokker-Planck equation analogous to that obtained for colloid suspensions in the presence of rotational Brownian motion. The deterministic torques on a cell, viscous and gravitational, are balanced by diffusion, represented by an isotropic rotary diffusivity Dr, which is unknown a priori, but presumably reflects stochastic influences on the cell's internal workings. When the Fokker-Planck equation is solved, macroscopic quantities such as the average cell velocity Vc, the particle diffusivity tensor D and the effective stress tensor sigma can be computed; Vc and D are required in the cell conservation equation, and sigma in the momentum equation. The Fokker-Planck equation contains two dimensionless parameters, lambda and epsilon; lambda is the ratio of the rotary diffusion time Dr-1 to the torque relaxation time B (balancing gravitational and viscous torques), while epsilon is a scale for the local vorticity or strain rate made dimensionless with B. In this paper we solve the Fokker-Planck equation exactly for epsilon = 0 (lambda arbitrary) and also obtain the first-order solution for small epsilon. Using experimental data on Vc and D obtained with the swimming alga, Chlamydomonas nivalis, in the absence of bulk flow, the epsilon = 0 results can be used to estimate the value of lambda for that species (lambda approximately 2.2; Dr approximately 0.13 s-1). The continuum model for small epsilon is then used to reanalyse the instability of a uniform suspension, previously investigated by Pedley, Hill & Kessler (1988). The only qualitatively different result is that there no longer seem to be circumstances in which disturbances with a non-zero vertical wavenumber are more unstable than purely horizontal disturbances. On the way, it is demonstrated that the only significant contribution to sigma, other than the basic Newtonian stress, is that derived from the stresslets associated with the cells' intrinsic swimming motions.

Dynamical coupled-channels study of {pi}N{yields}{pi}{pi}N reactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kamano, H.; Julia-Diaz, B.; Department d'Estructura i Constituents de la Materia and Institut de Ciencies del Cosmos, Universitat de Barcelona E-08028 Barcelona

As a step toward performing a complete coupled-channels analysis of the world data of {pi}N,{gamma}*N{yields}{pi}N,{eta}N,{pi}{pi}N reactions, the {pi}N{yields}{pi}{pi}N reactions are investigated starting with the dynamical coupled-channels model developed in Phys. Rev. C 76, 065201 (2007). The channels included are {pi}N,{eta}N, and {pi}{pi}N which has {pi}{delta},{rho}N, and {sigma}N resonant components. The nonresonant amplitudes are generated from solving a set of coupled-channels equations with the meson-baryon potentials defined by effective Lagrangians. The resonant amplitudes are generated from 16 bare excited nucleon (N*) states that are dressed by the nonresonant interactions as constrained by the unitarity condition. The data of total cross sectionsmore » and {pi}N and {pi}{pi} invariant mass distributions of {pi}{sup +}p{yields}{pi}{sup +}{pi}{sup +}n,{pi}{sup +}{pi}{sup 0}p and {pi}{sup -}p{yields}{pi}{sup +}{pi}{sup -}n,{pi}{sup -}{pi}{sup 0}p,{pi}{sup 0}{pi}{sup 0}n reactions from threshold to the invariant mass W=2 GeV can be described to a very large extent. We show the importance of the coupled-channels effects and the strong interference among the contributions from the {pi}{delta},{sigma}N, and {rho}N channels. The large interference between the resonant and nonresonant amplitudes is also demonstrated. Possible future developments are discussed.« less

Interactions of NO and CO with Pd and Pt atoms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, G.W.; Carter, E.A.

1991-03-21

The authors report ab initio generalized valence bond and correlation-consistent configuration interaction studies of CO and NO interacting with Pd and Pt atoms. They find dramatically different bonding mechanisms for the two ligands, which are easily understood in terms of changes in the electronic structure of the metal and the ligand. CO bonds to both Pd and pt by a {sigma} donor/{pi} back-bonding mechanism, yielding linear geometries. Their calculations predict that the ground ({sup 1}{Sigma}{sup +}) state of PdCO is bound by 27 kcal/mol, while the ground ({sup 1}{Sigma}{sup +}) state of PtCO is bound by only 18.5 kcal/mol. Bymore » contrast, PdNO and PtNO are both bent, with the dominant bonding involving a covalent {sigma} bond between a singly occupied metal d{sigma} orbital and the singly occupied NO 2{pi}* orbital. While the ground ({sup 2}A{prime}) state of PtNO is strongly bound (D{sub e}(Pt-NO) {approximately} 20 kcal/mol), NO binds very weakly to Pd (D{sub e}(Pd-NO) {le} 4 kcal/mol). Linear excited states ({sup 2}{Sigma} and {sup 2}{Pi}) of PtNO and PdNO are predicted to be only weakly bound or unbound. However, corresponding linear cationic states ({sup 1}{Sigma}{sup +} and {sup 3}{Pi}) are strongly bound, but the cationic bent ({sup 1}A{prime}) states are still the ground states of PtNO{sup +} and PdNO{sup +}. These stark contrasts, in which NO binds strongly to Pt but weakly to Pd while CO binds much more strongly to Pd, are due to the preference for closed-shell species to bind strongly to other closed-shell species (e.g., CO to Pd) and for radicals to bind strongly to other radicals (e.g., NO to Pt).« less

Apparatus and method for closed-loop control of reactor power in minimum time

DOEpatents

Bernard, Jr., John A.

1988-11-01

Closed-loop control law for altering the power level of nuclear reactors in a safe manner and without overshoot and in minimum time. Apparatus is provided for moving a fast-acting control element such as a control rod or a control drum for altering the nuclear reactor power level. A computer computes at short time intervals either the function: .rho.=(.beta.-.rho.).omega.-.lambda..sub.e '.rho.-.SIGMA..beta..sub.i (.lambda..sub.i -.lambda..sub.e ')+l* .omega.+l* [.omega..sup.2 +.lambda..sub.e '.omega.] or the function: .rho.=(.beta.-.rho.).omega.-.lambda..sub.e .rho.-(.lambda..sub.e /.lambda..sub.e)(.beta.-.rho.)+l* .omega.+l* [.omega..sup.2 +.lambda..sub.e .omega.-(.lambda..sub.e /.lambda..sub.e).omega.] These functions each specify the rate of change of reactivity that is necessary to achieve a specified rate of change of reactor power. The direction and speed of motion of the control element is altered so as to provide the rate of reactivity change calculated using either or both of these functions thereby resulting in the attainment of a new power level without overshoot and in minimum time. These functions are computed at intervals of approximately 0.01-1.0 seconds depending on the specific application.

The impact of new polarization data from Bonn, Mainz and Jefferson Laboratory on $$\\gamma p \\rightarrow \\pi N$$ multipoles

DOE PAGES

Anisovich, A. V.; Beck, R.; Döring, M.; ...

2016-09-16

New data on pion-photoproduction off the proton have been included in the partial wave analyses Bonn-Gatchina and SAID and in the dynamical coupled-channel approach Julich-Bonn. All reproduce the recent new data well: the double polarization data for E, G, H, P and T inmore » $$\\gamma p \\to \\pi^0 p$$ from ELSA, the beam asymmetry $$\\Sigma$$ for $$\\gamma p \\to \\pi^0 p$$ and $$\\pi^+ n$$ from Jefferson Laboratory, and the precise new differential cross section and beam asymmetry data $$\\Sigma$$ for $$\\gamma p \\to \\pi^0 p$$ from MAMI. The new fit results for the multipoles are compared with predictions not taking into account the new data. Lastly, the mutual agreement is improved considerably but still far from being perfect.« less

The impact of new polarization data from Bonn, Mainz and Jefferson Laboratory on $$\\gamma p \\rightarrow \\pi N$$ multipoles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anisovich, A. V.; Beck, R.; Döring, M.

New data on pion-photoproduction off the proton have been included in the partial wave analyses Bonn-Gatchina and SAID and in the dynamical coupled-channel approach Julich-Bonn. All reproduce the recent new data well: the double polarization data for E, G, H, P and T inmore » $$\\gamma p \\to \\pi^0 p$$ from ELSA, the beam asymmetry $$\\Sigma$$ for $$\\gamma p \\to \\pi^0 p$$ and $$\\pi^+ n$$ from Jefferson Laboratory, and the precise new differential cross section and beam asymmetry data $$\\Sigma$$ for $$\\gamma p \\to \\pi^0 p$$ from MAMI. The new fit results for the multipoles are compared with predictions not taking into account the new data. Lastly, the mutual agreement is improved considerably but still far from being perfect.« less

Neutrino Mass Bounds from 0{nu}{beta}{beta} Decays and Large Scale Structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keum, Y.-Y.; Department of Physics, National Taiwan University, Taipei, Taiwan 10672; Ichiki, K.

2008-05-21

We investigate the way how the total mass sum of neutrinos can be constrained from the neutrinoless double beta decay and cosmological probes with cosmic microwave background (WMAP 3-year results), large scale structures including 2dFGRS and SDSS data sets. First we discuss, in brief, on the current status of neutrino mass bounds from neutrino beta decays and cosmic constrain within the flat {lambda}CMD model. In addition, we explore the interacting neutrino dark-energy model, where the evolution of neutrino masses is determined by quintessence scalar filed, which is responsable for cosmic acceleration today. Assuming the flatness of the universe, the constraintmore » we can derive from the current observation is {sigma}m{sub {nu}}<0.87 eV at the 95% confidence level, which is consistent with {sigma}m{sub {nu}}<0.68 eV in the flat {lambda}CDM model.« less

Baryon-Baryon Interactions ---Nijmegen Extended-Soft-Core Models---

NASA Astrophysics Data System (ADS)

Rijken, T. A.; Nagels, M. M.; Yamamoto, Y.

We review the Nijmegen extended-soft-core (ESC) models for the baryon-baryon (BB) interactions of the SU(3) flavor-octet of baryons (N, Lambda, Sigma, and Xi). The interactions are basically studied from the meson-exchange point of view, in the spirit of the Yukawa-approach to the nuclear force problem [H. Yukawa, ``On the interaction of Elementary Particles I'', Proceedings of the Physico-Mathematical Society of Japan 17 (1935), 48], using generalized soft-core Yukawa-functions. These interactions are supplemented with (i) multiple-gluon-exchange, and (ii) structural effects due to the quark-core of the baryons. We present in some detail the most recent extended-soft-core model, henceforth referred to as ESC08, which is the most complete, sophisticated, and successful interaction-model. Furthermore, we discuss briefly its predecessor the ESC04-model [Th. A. Rijken and Y. Yamamoto, Phys. Rev. C 73 (2006), 044007; Th. A. Rijken and Y. Yamamoto, Ph ys. Rev. C 73 (2006), 044008; Th. A. Rijken and Y. Yamamoto, nucl-th/0608074]. For the soft-core one-boson-exchange (OBE) models we refer to the literature [Th. A. Rijken, in Proceedings of the International Conference on Few-Body Problems in Nuclear and Particle Physics, Quebec, 1974, ed. R. J. Slobodrian, B. Cuec and R. Ramavataram (Presses Universitè Laval, Quebec, 1975), p. 136; Th. A. Rijken, Ph. D. thesis, University of Nijmegen, 1975; M. M. Nagels, Th. A. Rijken and J. J. de Swart, Phys. Rev. D 17 (1978), 768; P. M. M. Maessen, Th. A. Rijken and J. J. de Swart, Phys. Rev. C 40 (1989), 2226; Th. A. Rijken, V. G. J. Stoks and Y. Yamamoto, Phys. Rev. C 59 (1999), 21; V. G. J. Stoks and Th. A. Rijken, Phys. Rev. C 59 (1999), 3009]. All ingredients of these latter models are also part of ESC08, and so a description of ESC08 comprises all models so far in principle. The extended-soft-core (ESC) interactions consist of local- and non-local-potentials due to (i) one-boson-exchanges (OBE), which are the members of nonets of pseudo-scalar-, vector-, scalar-, and axial-mesons, (ii) diffractive (i.e. multiple-gluon) exchanges, (iii) two pseudo-scalar exchange (PS-PS), and (iv) meson-pair-exchange (MPE). The OBE- and pair-vertices are regulated by gaussian form factors producing potentials with a soft behavior near the origin. The assignment of the cutoff masses for the BBM-vertices is dependent on the SU(3)-classification of the exchanged mesons for OBE, and a similar scheme for MPE. The ESC-models ESC04 and ESC08 describe the nucleon-nucleon (NN), hyperon-nucleon (YN), and hyperon-hyperon (YY) interactions in a unified way using broken SU(3)-symmetry. Novel ingredients in the OBE-sector in the ESC-models are the inclusion of (i) the axial-vector meson potentials, (ii) a zero in the scalar- and axial-vector meson form factors. These innovations made it possible for the first time to keep the meson coupling parameters of the model qualitatively in accordance with the predictions of the (3P_0) quark-antiquark creation (QPC) model. This is also the case for the F/(F+D)-ratios. Furthermore, the introduction of the zero helped to avoid the occurrence of unwanted bound states in Lambda N. Broken SU(3)-symmetry serves to connect the NN and the YN channels, which leaves after fitting NN only a few free parameters for the determination of the YN-interactions. In particular, the meson-baryon coupling constants are calculated via SU(3) using the coupling constants of the NN oplus YN-analysis as input. In ESC04 medium strong flavor-symmetry-breaking (FSB) of the coupling constants was investigated, using the (3}P_{0) -model with a Gell-Mann-Okubo hypercharge breaking for the BBM-coupling. In ESC08 the couplings are kept SU(3)-symmetric. The charge-symmetry-breaking (CSB) in the Lambda p and Lambda n channels, which is an SU(2) isospin breaking, is included in the OBE-, TME-, and MPE-potentials. In ESC04 and ESC08 simultaneous fits to the NN- and the YN- scattering data have been achieved, using different options for the ESC-model. In particularly in ESC08 with single-sets of parameters excellent fits were obtained for the NN- and YN-data. For example, in the case of ESC08a'' we have: (i) For the selected 4233 NN-data with energies 0 ≤ T_{lab} ≤ 350 MeV, excellent results were obtained having chi(2/N_{data}) = 1.094. (ii) For the usual set of 35 YN-data and 3 Sigma(+p) cross-sections from a recent KEK-experiment E289 [H. Kanda et al., AIP Conf. Proc. 842 (2006), 501; H. Kanda, Measurement of the cross sections of Sigma(=p) elastic scattering, Ph. D. thesis, Department of Physics, Faculty of Science, Kyoto University, March 2007] the fit has chi(2}/YN_{data) ≈ 0.83. (iii) For YY there is a weak LambdaLambda-interaction, which successfully matches with t he Nagara-event [H. Takahashi et al., Phys. Rev. Lett. 87 (2001), 212502]. (iv) The nuclear Sigma and Xi well-dephts satisfy U_Sigma > 0 and U_Xi < 0. The predictions for the S = -2 (LambdaLambda, Xi N, LambdaSigma, SigmaSigma)-channels are the occurrences of an S = -2 bound states in the Xi N((3S_1-^3D_1,) I = 0,1)-channels.

Relative transverse momentum distributions of bottom hadrons produced in 1.96 TeV proton-antiproton collisions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roy, Philippe; /McGill U.

2008-05-01

Fragmentation is the process by which bare quarks dress themselves up as hadrons. Since we cannot get reliable calculations of this process using perturbative quantum chromodynamics, the fragmentation properties of quarks must be obtained empirically. We report on the signal extraction and relative transverse momentum p{sub T} spectrum determination that will lead to a high precision measurement of relative fragmentation fractions of b quarks into B hadrons, in 1.96 TeV p{bar p} collisions. Using 1.9 fb{sup -1} of data taken with the CDF-II detector, we fully reconstruct 473 {+-} 42 B{sub s}{sup 0} {yields} D{sub s}{sup -} {pi}{sup +}, 15206more » {+-} 203 B{sup 0} {yields} D{sup -} {pi}{sup +}, 1483 {+-} 45 B{sup 0} {yields} D*{sup -}{pi}{sup +} and 4444 {+-} 297 {Lambda}{sub b}{sup 0} {yields} {Lambda}{sub c}{sup +}{pi}{sup -} candidate decays. In order to reduce systematic uncertainties, ratios of p{sub T} spectra are reported. We find that B{sub s} and B{sup 0} mesons are produced with similar p{sub T} and {Lambda}{sub b} baryons are produced with lower p{sub T} than B{sup 0} mesons. Our results are consistent with previous CDF measurements suggesting a difference between fragmentation processes observed at lepton and hadron colliders.« less

Cyclo-biphenalenyl biradicaloid molecular materials: conformation, rearrangement, magnetism, and thermochromism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Jingsong; Sumpter, Bobby G; Meunier, Vincent

2010-01-01

Cyclo-biphenalenyl biradicaloid molecular materials with chair- and boat-conformations are studied by restricted and broken-symmetry DFT using the M06 family of meta-GGA functionals. The global minima of these molecular materials are magnetically silent due to the sigma-bond connecting the two phenalenyls, while the sigma-bond may undergo low-barrier sigmatropic rearrangements via pi-pi bonded paramagnetic intermediates. The validation of theory is performed for the chair-conformation by comparing the sigma-bonded structures and the rearrangement barriers with experimental data. The boat-conformation is then studied using the validated functional. The electronic spectra of both chair- and boat-conformations are calculated and their applications in thermochromism are discussed.

Theoretical study of photoacidity of HCN: the effect of complexation with water.

PubMed

Muchová, Eva; Spirko, Vladimir; Hobza, Pavel; Nachtigallová, Dana

2006-11-14

The character of the hydrogen bonding and the excited state proton transfer (ESPT) in the model system HCN...H(2)O is investigated. The PES of the two lowest excited states of the H(2)O...HCN complex was calculated using the CASPT2 method. The nonadiabatic coupling of the two states of the (pi-->pi*) and (pi-->sigma*) character is responsible for the excited state proton/hydrogen transfer. Compared to the ground state, the barrier for this process is significantly smaller. An increased number of water molecules in the complex with cyclic hydrogen-bonded network causes a large blue shift of the state of the (pi-->sigma*) character. The question of the dissociation of the complex in its excited state is also addressed.

Osmotic pressure and virial coefficients of star and comb polymer solutions: dissipative particle dynamics.

PubMed

Wang, Tzu-Yu; Fang, Che-Ming; Sheng, Yu-Jane; Tsao, Heng-Kwong

2009-03-28

The effects of macromolecular architecture on the osmotic pressure pi and virial coefficients (B(2) and B(3)) of star and comb polymers in good solvents are studied by dissipative particle dynamics simulations for both dilute and semiconcentrated regimes. The dependence of the osmotic pressure on polymer concentration is directly calculated by considering two reservoirs separated by a semipermeable, fictitious membrane. Our simulation results show that the ratios A(n+1) identical with B(n+1)/R(g)(3n) are essentially constant and A(2) and A(3) are arm number (f) dependent, where R(g) is zero-density radius of gyration. The value of dimensionless virial ratio g = A(3)/A(2)(2) increases with arm number of stars whereas it is essentially arm number independent for comb polymers. In semiconcentrated regime the scaling relation between osmotic pressure and volume fraction, pi proportional to phi(lambda), still holds for both star and comb polymers. For comb polymers, the exponent lambda is close to lambda(*) (approximately = 2.73 for linear chains) and is independent of the arm number. However, for star polymers, the exponent lambda deviates from lambda(*) and actually grows with increasing the arm number. This may be attributed to the significant ternary interactions near the star core in the many-arm systems.

Isoscalar π π , K K ¯ , η η scattering and the σ , f 0 , f 2 mesons from QCD

DOE Office of Scientific and Technical Information (OSTI.GOV)

Briceno, Raul A.; Dudek, Jozef J.; Edwards, Robert G.

We present the first lattice QCD study of coupled isoscalarmore » $$\\pi\\pi,K\\overline{K},\\eta\\eta$$ $S$- and $D$-wave scattering extracted from discrete finite-volume spectra computed on lattices which have a value of the quark mass corresponding to $$m_\\pi\\sim391$$ MeV. In the $J^P=0^+$ sector we find analogues of the experimental $$\\sigma$$ and $$f_0(980)$$ states, where the $$\\sigma$$ appears as a stable bound-state below $$\\pi\\pi$$ threshold, and, similar to what is seen in experiment, the $$f_0(980)$$ manifests itself as a dip in the $$\\pi\\pi$$ cross section in the vicinity of the $$K\\overline{K}$$ threshold. For $J^P=2^+$ we find two states resembling the $$f_2(1270)$$ and $$f_2'(1525)$$, observed as narrow peaks, with the lighter state dominantly decaying to $$\\pi\\pi$$ and the heavier state to $$K\\overline{K}$$. The presence of all these states is determined rigorously by finding the pole singularity content of scattering amplitudes, and their couplings to decay channels are established using the residues of the poles.« less

Isoscalar π π , K K ¯ , η η scattering and the σ , f 0 , f 2 mesons from QCD

DOE PAGES

Briceno, Raul A.; Dudek, Jozef J.; Edwards, Robert G.; ...

2018-03-23

We present the first lattice QCD study of coupled isoscalarmore » $$\\pi\\pi,K\\overline{K},\\eta\\eta$$ $S$- and $D$-wave scattering extracted from discrete finite-volume spectra computed on lattices which have a value of the quark mass corresponding to $$m_\\pi\\sim391$$ MeV. In the $J^P=0^+$ sector we find analogues of the experimental $$\\sigma$$ and $$f_0(980)$$ states, where the $$\\sigma$$ appears as a stable bound-state below $$\\pi\\pi$$ threshold, and, similar to what is seen in experiment, the $$f_0(980)$$ manifests itself as a dip in the $$\\pi\\pi$$ cross section in the vicinity of the $$K\\overline{K}$$ threshold. For $J^P=2^+$ we find two states resembling the $$f_2(1270)$$ and $$f_2'(1525)$$, observed as narrow peaks, with the lighter state dominantly decaying to $$\\pi\\pi$$ and the heavier state to $$K\\overline{K}$$. The presence of all these states is determined rigorously by finding the pole singularity content of scattering amplitudes, and their couplings to decay channels are established using the residues of the poles.« less

Synthesis and electrochemical studies of charge-transfer complexes of thiazolidine-2,4-dione with σ and π acceptors

NASA Astrophysics Data System (ADS)

Singh, Prashant; Kumar, Pradeep; Katyal, Anju; Kalra, Rashmi; Dass, Sujata K.; Prakash, Satya; Chandra, Ramesh

2010-03-01

In the present work, we report the synthesis and characterization of novel charge-transfer complexes of thiazolidine-2,4-dione (TZD) with sigma acceptor (iodine) and pi acceptors (chloranil, dichlorodicyanoquinone, picric acid and duraquinone). We also evaluated their thermal and electrochemical properties and we conclude that these complexes are frequency dependent. Charge-transfer complex between thiazolidine-2,4-dione and iodine give best conductivity. In conclusion, complex with sigma acceptors are more conducting than with pi acceptors.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shevchenko, N. V.; Mares, J.; Gal, A.

Coupled-channels three-body calculations of an I=1/2,J{sup {pi}}=0{sup -} KNN quasibound state in the KNN-{pi}{sigma}N system were performed and the dependence of the resulting three-body energy on the two-body KN-{pi}{sigma} interaction was investigated. Earlier results of binding energy B{sub K{sup -}}{sub pp}{approx}50-70 MeV and width {gamma}{sub K{sup -}}{sub pp}{approx}100 MeV are confirmed [N. V. Shevchenko et al., Phys. Rev. Lett. 98, 082301 (2007)]. It is shown that a suitably constructed energy-independent complex KN potential gives a considerably shallower and narrower three-body quasibound state than the full coupled-channels calculation. Comparison with other calculations is made.

Measurement of CP Asymmetries and Branching Fractions in B0 -> pi+ pi-, B0 -> K+ pi-, B0 -> pi0 pi0, B0 -> K0 pi0 and Isospin Analysis of B -> pi pi Decays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aubert, Bernard; Bona, M.; Karyotakis, Y.

2008-08-01

The authors present preliminary results of improved measurements of the CP-violating asymmetries and branching fractions in the decays B{sup 0} {yields} {pi}{sup +}{pi}{sup -}, B{sup 0} {yields} K{sup +}{pi}{sup -}, B{sup 0} {yields} {pi}{sup 0}{pi}{sup 0}, and B{sup 0} {yields} K{sup 0}{pi}{sup 0}. This update includes all data taken at the {Upsilon}(4S) resonance by the BABAR experiment at the asymmetric PEP-II B-meson factory at SLAC, corresponding to 467 {+-} 5 million B{bar B} pairs. They find S{sub {pi}{pi}} = -0.68 {+-} 0.10 {+-} 0.03, C{sub {pi}{pi}} = -0.25 {+-} 0.08 {+-} 0.02, {Alpha}{sub K{sub {pi}}} = -0.107 {+-} 0.016{sub -0.004},{supmore » +0.006}, C{sub {pi}{sup 0}{pi}{sup 0}} = -0.43 {+-} 0.26 {+-} 0.05, {Beta}(B{sup 0} {yields} {pi}{sup 0}{pi}{sup 0}) = (1.83 {+-} 0.21 {+-} 0.13) x 10{sup -6}, {Beta}(B{sup 0} {yields} K{sup 0}{pi}{sup 0}) = (10.1 {+-} 0.6 {+-} 0.4) x 10{sup -6}, where the first error is statistical and the second is systematic. They observe CP violation with a significance of 6.7{sigma} in B{sup 0} {yields} {pi}{sup -} and 6.1{sigma} in B{sup 0} {yields} K{sup +}{pi}{sup -}. Constraints on the Unitarity Triangle angle {alpha} are determined from the isospin relation between all B {yields} {pi}{pi} rates and asymmetries.« less

Environmental fate and biodegradability of benzene derivatives as studied in a model aquatic ecosystem.

PubMed Central

Lu, P Y; Metcalf, R L

1975-01-01

A model aquatic ecosystem is devised for studying relatively volatile organic compounds and simulating direct discharge of chemical wastes into aquatic ecosystems. Six simple benzene derivatives (aniline, anisole, benzoic acid, chlorobenzene, nitrobenzene, and phthalic anhydride) and other important specialty chemicals: hexachlorobenzene, pentachlorophenol, 2,6-diethylaniline, and 3,5,6-trichloro-2-pyridinol were also chosen for study of environmental behavior and fate in the model aquatic ecosystem. Quantitative relationships of the intrinsic molecular properties of the environmental micropollutants with biological responses are established, e.g., water solubility, partition coefficient, pi constant, sigma constant, ecological magnification, biodegradability index, and comparative detoxication mechanisms, respectively. Water solubility, pi constant, and sigma constant are the most significant factors and control the biological responses of the food chain members. Water solubility and pi constant control the degree of bioaccumulation, and sigma constant limits the metabolism of the xenobiotics via microsomal detoxication enzymes. These highly significant correlations should be useful for predicting environmental fate of organic chemicals. PMID:1157796

High resolution spectroscopic study of Be Λ 10

DOE PAGES

Gogami, T.; Chen, C.; Kawama, D.; ...

2016-03-10

Spectroscopy of amore » $$^{10}_{\\Lambda}$$Be hypernucleus was carried out at JLab Hall C using the $$(e,e^{\\prime}K^{+})$$ reaction. A new magnetic spectrometer system (SPL+HES+HKS), specifically designed for high resolution hypernuclear spectroscopy, was used to obtain an energy spectrum with a resolution of 0.78 MeV (FWHM). The well-calibrated spectrometer system of the present experiment using the $$p(e,e^{\\prime}K^{+})\\Lambda,\\Sigma^{0}$$ reactions allowed us to determine the energy levels, and the binding energy of the ground state peak (mixture of 1$$^{-}$$ and 2$$^{-}$$ states) was obtained to be B$$_{\\Lambda}$$=8.55$$\\pm$$0.07(stat.)$$\\pm$$0.11(sys.) MeV. Furthermore, the result indicates that the ground state energy is shallower than that of an emulsion study by about 0.5 MeV which provides valuable experimental information on charge symmetry breaking effect in the $$\\Lambda N$$ interaction.« less

Multichannel 0 → 2 and 1 → 2 transition amplitudes for arbitrary spin particles in a finite volume

DOE PAGES

Hansen, Maxwell; Briceno, Raul

2015-10-01

We present a model-independent, non-perturbative relation between finite-volume matrix elements and infinite-volumemore » $$\\textbf{0}\\rightarrow\\textbf{2}$$ and $$\\textbf{1}\\rightarrow\\textbf{2}$$ transition amplitudes. Our result accommodates theories in which the final two-particle state is coupled to any number of other two-body channels, with all angular momentum states included. The derivation uses generic, fully relativistic field theory, and is exact up to exponentially suppressed corrections in the lightest particle mass times the box size. This work distinguishes itself from previous studies by accommodating particles with any intrinsic spin. To illustrate the utility of our general result, we discuss how it can be implemented for studies of $$N+\\mathcal{J}~\\rightarrow~(N\\pi,N\\eta,N\\eta',\\Sigma K,\\Lambda K)$$ transitions, where $$\\mathcal{J}$$ is a generic external current. The reduction of rotational symmetry, due to the cubic finite volume, manifests in this example through the mixing of S- and P-waves when the system has nonzero total momentum.« less

Reference Values for Spirometry Derived Using Lambda, Mu, Sigma (LMS) Method in Korean Adults: in Comparison with Previous References.

PubMed

Jo, Bum Seak; Myong, Jun Pyo; Rhee, Chin Kook; Yoon, Hyoung Kyu; Koo, Jung Wan; Kim, Hyoung Ryoul

2018-01-15

The present study aimed to update the prediction equations for spirometry and their lower limits of normal (LLN) by using the lambda, mu, sigma (LMS) method and to compare the outcomes with the values of previous spirometric reference equations. Spirometric data of 10,249 healthy non-smokers (8,776 females) were extracted from the fourth and fifth versions of the Korea National Health and Nutrition Examination Survey (KNHANES IV, 2007-2009; V, 2010-2012). Reference equations were derived using the LMS method which allows modeling skewness (lambda [L]), mean (mu [M]), and coefficient of variation (sigma [S]). The outcome equations were compared with previous reference values. Prediction equations were presented in the following form: predicted value = e{a + b × ln(height) + c × ln(age) + M - spline}. The new predicted values for spirometry and their LLN derived using the LMS method were shown to more accurately reflect transitions in pulmonary function in young adults than previous prediction equations derived using conventional regression analysis in 2013. There were partial discrepancies between the new reference values and the reference values from the Global Lung Function Initiative in 2012. The results should be interpreted with caution for young adults and elderly males, particularly in terms of the LLN for forced expiratory volume in one second/forced vital capacity in elderly males. Serial spirometry follow-up, together with correlations with other clinical findings, should be emphasized in evaluating the pulmonary function of individuals. Future studies are needed to improve the accuracy of reference data and to develop continuous reference values for spirometry across all ages. © 2018 The Korean Academy of Medical Sciences.

Scalar resonances in a unitary {pi}{pi} S-wave model for D{sup +} {r_arrow} {pi}{sup+}{pi}{sup-}{pi}{sup+}.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boito, D. R.; Dedonder, J.-P.; El-Bennich, B.

We propose a model for D{sup +} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup +} decays following experimental results which indicate that the two-pion interaction in the S wave is dominated by the scalar resonances f{sub 0}(600)/{sigma} and f{sub 0}(980). The weak decay amplitude for D{sup +} {yields} R{pi}{sup +}, where R is a resonance that subsequently decays into {pi}{sup +}{pi}{sup -}, is constructed in a factorization approach. In the S wave, we implement the strong decay R {yields} {pi}{sup +}{pi}{sup -} by means of a scalar form factor. This provides a unitary description of the pion-pion interaction in the entire kinematically allowedmore » mass range m{sub {pi}{pi}}{sup 2} from threshold to about 3 GeV{sup 2}. In order to reproduce the experimental Dalitz plot for D{sup +} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup +}, we include contributions beyond the S wave. For the P wave, dominated by the {rho}(770){sup 0}, we use a Breit-Wigner description. Higher waves are accounted for by using the usual isobar prescription for the f{sub 2}(1270) and {rho}(1450){sup 0}. The major achievement is a good reproduction of the experimental m{sub {pi}{pi}}{sup 2} distribution, and of the partial as well as the total D{sup +} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup +} branching ratios. Our values are generally smaller than the experimental ones. We discuss this shortcoming and, as a by-product, we predict a value for the poorly known D {yields} {sigma} transition form factor at q{sup 2} = m{sub {pi}}{sup 2}.« less

Scalar resonances in a unitary {pi}{pi} S-wave model for D{sup +}{yields}{pi}{sup +}{pi}{sup -}{pi}{sup +}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boito, D. R.; Instituto de Fisica, Universidade de Sao Paulo, C.P. 66318, 05315-970, Sao Paulo, SP; Dedonder, J.-P.

We propose a model for D{sup +}{yields}{pi}{sup +}{pi}{sup -}{pi}{sup +} decays following experimental results which indicate that the two-pion interaction in the S wave is dominated by the scalar resonances f{sub 0}(600)/{sigma} and f{sub 0}(980). The weak decay amplitude for D{sup +}{yields}R{pi}{sup +}, where R is a resonance that subsequently decays into {pi}{sup +}{pi}{sup -}, is constructed in a factorization approach. In the S wave, we implement the strong decay R{yields}{pi}{sup +}{pi}{sup -} by means of a scalar form factor. This provides a unitary description of the pion-pion interaction in the entire kinematically allowed mass range m{sub {pi}}{sub {pi}}{sup 2}more » from threshold to about 3 GeV{sup 2}. In order to reproduce the experimental Dalitz plot for D{sup +}{yields}{pi}{sup +}{pi}{sup -}{pi}{sup +}, we include contributions beyond the S wave. For the P wave, dominated by the {rho}(770){sup 0}, we use a Breit-Wigner description. Higher waves are accounted for by using the usual isobar prescription for the f{sub 2}(1270) and {rho}(1450){sup 0}. The major achievement is a good reproduction of the experimental m{sub {pi}}{sub {pi}}{sup 2} distribution, and of the partial as well as the total D{sup +}{yields}{pi}{sup +}{pi}{sup -}{pi}{sup +} branching ratios. Our values are generally smaller than the experimental ones. We discuss this shortcoming and, as a by-product, we predict a value for the poorly known D{yields}{sigma} transition form factor at q{sup 2}=m{sub {pi}}{sup 2}.« less

Coupled-cavity drift-tube linac

DOEpatents

Billen, James H.

1996-01-01

A coupled-cavity drift-tube linac (CCDTL) combines features of the Alvarez drift-tube linac (DTL) and the .pi.-mode coupled-cavity linac (CCL). In one embodiment, each accelerating cavity is a two-cell, 0-mode DTL. The center-to-center distance between accelerating gaps is .beta..lambda., where .lambda. is the free-space wavelength of the resonant mode. Adjacent accelerating cavities have oppositely directed electric fields, alternating in phase by 180 degrees. The chain of cavities operates in a .pi./2 structure mode so the coupling cavities are nominally unexcited. The CCDTL configuration provides an rf structure with high shunt impedance for intermediate velocity charged particles, i.e., particles with energies in the 20-200 MeV range.

Coupled-cavity drift-tube linac

DOEpatents

Billen, J.H.

1996-11-26

A coupled-cavity drift-tube linac (CCDTL) combines features of the Alvarez drift-tube linac (DTL) and the {pi}-mode coupled-cavity linac (CCL). In one embodiment, each accelerating cavity is a two-cell, 0-mode DTL. The center-to-center distance between accelerating gaps is {beta}{lambda}, where {lambda} is the free-space wavelength of the resonant mode. Adjacent accelerating cavities have oppositely directed electric fields, alternating in phase by 180 degrees. The chain of cavities operates in a {pi}/2 structure mode so the coupling cavities are nominally unexcited. The CCDTL configuration provides an rf structure with high shunt impedance for intermediate velocity charged particles, i.e., particles with energies in the 20-200 MeV range. 5 figs.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sirunyan, Albert M; et al.

Measurements are presented of the lifetimes of the Bmore » $^0$, B$$^0_\\mathrm{s}$$, $$\\Lambda^0_\\mathrm{b}$$, and B$$_\\mathrm{c}^+$$ hadrons using the decay channels B$$^0\\to$$J/$$\\psi$$K*(892)$^0$, B$$^0\\to$$J/$$\\psi$$K$$^0_\\mathrm{S}$$, B$$^0_\\mathrm{s}\\to$$J/$$\\psi \\pi^+\\pi^-$$, B$$^0_\\mathrm{s}\\to$$J/$$\\psi\\phi$$(1020), $$\\Lambda^0_\\mathrm{b}\\to$$J/$$\\psi\\Lambda^0$$, and B$$_\\mathrm{c}\\to$$J/$$\\psi\\pi^+$$. The data sample, corresponding to an integrated luminosity of 19.7 fb$$^{-1}$$, was collected by the CMS detector at the LHC in proton-proton collisions at $$\\sqrt{s}=$$ 8 TeV. The B$^0$ lifetime is measured to be 453.0 $$\\pm$$ 1.6 (stat) $$\\pm$$ 1.8 (syst) $$\\mu$$m in J/$$\\psi$$K*(892)$^0$ and 457.8 $$\\pm$$ 2.7 (stat) $$\\pm$$ 2.8 (syst) $$\\mu$$m in J/$$\\psi$$K$$^0_\\mathrm{S}$$, which results in a combined measurement of $$c\\tau_{\\mathrm{B}^0} = $$454.1 $$\\pm$$ 1.4 (stat) $$\\pm$$ 1.7 (syst) $$\\mu$$m. The effective lifetime of the B$$^0_\\mathrm{s}$$ meson is measured in two decay modes, with contributions from different amounts of the heavy and light eigenstates. This results in two different measured lifetimes: $$c\\tau_{\\mathrm{B}^0_\\mathrm{s} \\to \\mathrm{J}/\\psi \\pi^+\\pi^-} =$$ 502.7 $$\\pm$$ 10.2 (stat) $$\\pm$$ 3.4 (syst) $$\\mu$$m and $$c\\tau_{\\mathrm{B}^0_\\mathrm{s} \\to \\mathrm{J}/\\psi\\phi(1020)} = $$443.9 $$\\pm$$ 2.0 (stat) $$\\pm$$ 1.5 (syst) $$\\mu$$m. The $$\\Lambda^0_\\mathrm{b}$$ lifetime is found to be 442.9 $$\\pm$$ 8.2 (stat) $$\\pm$$ 2.8 (syst) $$\\mu$$m. The precision from each of these channels is as good as or better than previous measurements. The B$$_\\mathrm{c}^+$$ lifetime, measured with respect to the B$^+$ to reduce the systematic uncertainty, is 162.3 $$\\pm$$ 7.8 (stat) $$\\pm$$ 4.2 (syst) $$\\pm$$ 0.1 $$(\\tau_{\\mathrm{B}^+})$$ $$\\mu$$m. All results are in agreement with current world-average values.« less

Measurement of b hadron lifetimes in pp collisions at $$\\sqrt{s} =$$ 8 TeV

DOE PAGES

Sirunyan, Albert M; et al.

2018-06-07

Measurements are presented of the lifetimes of the Bmore » $^0$, B$$^0_\\mathrm{s}$$, $$\\Lambda^0_\\mathrm{b}$$, and B$$_\\mathrm{c}^+$$ hadrons using the decay channels B$$^0\\to$$J/$$\\psi$$K*(892)$^0$, B$$^0\\to$$J/$$\\psi$$K$$^0_\\mathrm{S}$$, B$$^0_\\mathrm{s}\\to$$J/$$\\psi \\pi^+\\pi^-$$, B$$^0_\\mathrm{s}\\to$$J/$$\\psi\\phi$$(1020), $$\\Lambda^0_\\mathrm{b}\\to$$J/$$\\psi\\Lambda^0$$, and B$$_\\mathrm{c}\\to$$J/$$\\psi\\pi^+$$. The data sample, corresponding to an integrated luminosity of 19.7 fb$$^{-1}$$, was collected by the CMS detector at the LHC in proton-proton collisions at $$\\sqrt{s}=$$ 8 TeV. The B$^0$ lifetime is measured to be 453.0 $$\\pm$$ 1.6 (stat) $$\\pm$$ 1.8 (syst) $$\\mu$$m in J/$$\\psi$$K*(892)$^0$ and 457.8 $$\\pm$$ 2.7 (stat) $$\\pm$$ 2.8 (syst) $$\\mu$$m in J/$$\\psi$$K$$^0_\\mathrm{S}$$, which results in a combined measurement of $$c\\tau_{\\mathrm{B}^0} = $$454.1 $$\\pm$$ 1.4 (stat) $$\\pm$$ 1.7 (syst) $$\\mu$$m. The effective lifetime of the B$$^0_\\mathrm{s}$$ meson is measured in two decay modes, with contributions from different amounts of the heavy and light eigenstates. This results in two different measured lifetimes: $$c\\tau_{\\mathrm{B}^0_\\mathrm{s} \\to \\mathrm{J}/\\psi \\pi^+\\pi^-} =$$ 502.7 $$\\pm$$ 10.2 (stat) $$\\pm$$ 3.4 (syst) $$\\mu$$m and $$c\\tau_{\\mathrm{B}^0_\\mathrm{s} \\to \\mathrm{J}/\\psi\\phi(1020)} = $$443.9 $$\\pm$$ 2.0 (stat) $$\\pm$$ 1.5 (syst) $$\\mu$$m. The $$\\Lambda^0_\\mathrm{b}$$ lifetime is found to be 442.9 $$\\pm$$ 8.2 (stat) $$\\pm$$ 2.8 (syst) $$\\mu$$m. The precision from each of these channels is as good as or better than previous measurements. The B$$_\\mathrm{c}^+$$ lifetime, measured with respect to the B$^+$ to reduce the systematic uncertainty, is 162.3 $$\\pm$$ 7.8 (stat) $$\\pm$$ 4.2 (syst) $$\\pm$$ 0.1 $$(\\tau_{\\mathrm{B}^+})$$ $$\\mu$$m. All results are in agreement with current world-average values.« less

Measurement of b hadron lifetimes in pp collisions at $$\\sqrt{s} = 8$$ $$\\,\\text {Te}\\text {V}$$

DOE PAGES

Sirunyan, A. M.; Tumasyan, A.; Adam, W.; ...

2018-06-07

Here, measurements are presented of the lifetimes of the Bmore » $^0$, B$$^0_\\mathrm{s}$$, $$\\Lambda^0_\\mathrm{b}$$, and B$$_\\mathrm{c}^+$$ hadrons using the decay channels B$$^0\\to$$J/$$\\psi$$K*(892)$^0$, B$$^0\\to$$J/$$\\psi$$K$$^0_\\mathrm{S}$$, B$$^0_\\mathrm{s}\\to$$J/$$\\psi \\pi^+\\pi^-$$, B$$^0_\\mathrm{s}\\to$$J/$$\\psi\\phi$$(1020), $$\\Lambda^0_\\mathrm{b}\\to$$J/$$\\psi\\Lambda^0$$, and B$$_\\mathrm{c}\\to$$J/$$\\psi\\pi^+$$. The data sample, corresponding to an integrated luminosity of 19.7 fb$$^{-1}$$, was collected by the CMS detector at the LHC in proton-proton collisions at $$\\sqrt{s}=$$ 8 TeV. The B$^0$ lifetime is measured to be 453.0 $$\\pm$$ 1.6 (stat) $$\\pm$$ 1.8 (syst) $$\\mu$$m in J/$$\\psi$$K*(892)$^0$ and 457.8 $$\\pm$$ 2.7 (stat) $$\\pm$$ 2.8 (syst) $$\\mu$$m in J/$$\\psi$$K$$^0_\\mathrm{S}$$, which results in a combined measurement of $$c\\tau_{\\mathrm{B}^0} = $$454.1 $$\\pm$$ 1.4 (stat) $$\\pm$$ 1.7 (syst) $$\\mu$$m. The effective lifetime of the B$$^0_\\mathrm{s}$$ meson is measured in two decay modes, with contributions from different amounts of the heavy and light eigenstates. This results in two different measured lifetimes: $$c\\tau_{\\mathrm{B}^0_\\mathrm{s} \\to \\mathrm{J}/\\psi \\pi^+\\pi^-} =$$ 502.7 $$\\pm$$ 10.2 (stat) $$\\pm$$ 3.4 (syst) $$\\mu$$m and $$c\\tau_{\\mathrm{B}^0_\\mathrm{s} \\to \\mathrm{J}/\\psi\\phi(1020)} = $$443.9 $$\\pm$$ 2.0 (stat) $$\\pm$$ 1.5 (syst) $$\\mu$$m. The $$\\Lambda^0_\\mathrm{b}$$ lifetime is found to be 442.9 $$\\pm$$ 8.2 (stat) $$\\pm$$ 2.8 (syst) $$\\mu$$m. The precision from each of these channels is as good as or better than previous measurements. The B$$_\\mathrm{c}^+$$ lifetime, measured with respect to the B$^+$ to reduce the systematic uncertainty, is 162.3 $$\\pm$$ 7.8 (stat) $$\\pm$$ 4.2 (syst) $$\\pm$$ 0.1 $$(\\tau_{\\mathrm{B}^+})$$ $$\\mu$$m. All results are in agreement with current world-average values.« less

Measurement of b hadron lifetimes in pp collisions at $$\\sqrt{s} = 8$$ $$\\,\\text {Te}\\text {V}$$

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sirunyan, A. M.; Tumasyan, A.; Adam, W.

Here, measurements are presented of the lifetimes of the Bmore » $^0$, B$$^0_\\mathrm{s}$$, $$\\Lambda^0_\\mathrm{b}$$, and B$$_\\mathrm{c}^+$$ hadrons using the decay channels B$$^0\\to$$J/$$\\psi$$K*(892)$^0$, B$$^0\\to$$J/$$\\psi$$K$$^0_\\mathrm{S}$$, B$$^0_\\mathrm{s}\\to$$J/$$\\psi \\pi^+\\pi^-$$, B$$^0_\\mathrm{s}\\to$$J/$$\\psi\\phi$$(1020), $$\\Lambda^0_\\mathrm{b}\\to$$J/$$\\psi\\Lambda^0$$, and B$$_\\mathrm{c}\\to$$J/$$\\psi\\pi^+$$. The data sample, corresponding to an integrated luminosity of 19.7 fb$$^{-1}$$, was collected by the CMS detector at the LHC in proton-proton collisions at $$\\sqrt{s}=$$ 8 TeV. The B$^0$ lifetime is measured to be 453.0 $$\\pm$$ 1.6 (stat) $$\\pm$$ 1.8 (syst) $$\\mu$$m in J/$$\\psi$$K*(892)$^0$ and 457.8 $$\\pm$$ 2.7 (stat) $$\\pm$$ 2.8 (syst) $$\\mu$$m in J/$$\\psi$$K$$^0_\\mathrm{S}$$, which results in a combined measurement of $$c\\tau_{\\mathrm{B}^0} = $$454.1 $$\\pm$$ 1.4 (stat) $$\\pm$$ 1.7 (syst) $$\\mu$$m. The effective lifetime of the B$$^0_\\mathrm{s}$$ meson is measured in two decay modes, with contributions from different amounts of the heavy and light eigenstates. This results in two different measured lifetimes: $$c\\tau_{\\mathrm{B}^0_\\mathrm{s} \\to \\mathrm{J}/\\psi \\pi^+\\pi^-} =$$ 502.7 $$\\pm$$ 10.2 (stat) $$\\pm$$ 3.4 (syst) $$\\mu$$m and $$c\\tau_{\\mathrm{B}^0_\\mathrm{s} \\to \\mathrm{J}/\\psi\\phi(1020)} = $$443.9 $$\\pm$$ 2.0 (stat) $$\\pm$$ 1.5 (syst) $$\\mu$$m. The $$\\Lambda^0_\\mathrm{b}$$ lifetime is found to be 442.9 $$\\pm$$ 8.2 (stat) $$\\pm$$ 2.8 (syst) $$\\mu$$m. The precision from each of these channels is as good as or better than previous measurements. The B$$_\\mathrm{c}^+$$ lifetime, measured with respect to the B$^+$ to reduce the systematic uncertainty, is 162.3 $$\\pm$$ 7.8 (stat) $$\\pm$$ 4.2 (syst) $$\\pm$$ 0.1 $$(\\tau_{\\mathrm{B}^+})$$ $$\\mu$$m. All results are in agreement with current world-average values.« less

Role of the N*(1535) in {eta}{sup '} production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cao Xu; Graduate School, Chinese Academy of Sciences, Beijing 100049; Lee Xiguo

2008-09-15

We study the near-threshold {eta}{sup '} production mechanism in nucleon-nucleon and {pi}N collisions under the assumption that subthreshold resonance N*(1535) is predominant. In an effective Lagrangian approach that gives a reasonable description to the pN{yields}pN{eta} and {pi}{sup -}p{yields}n{eta} reactions, we find that the excitation of N*(1535) resonance from the t-channel {pi} exchange makes the dominate contribution to the pN{yields}pN{eta}{sup '} process, and a value of 6.5 for the ratio of {sigma}(pn{yields}pn{eta}{sup '}) to {sigma}(pp{yields}pp{eta}{sup '}) is predicted. A strongcoupling strength of N*(1535) to {eta}{sup '}N (g{sub {eta}{sup '}}{sub NN*}{sup 2}/4{pi}=1.1) is extracted from a combined analysis to pp{yields}pp{eta}{sup '} andmore » {pi}N{yields}N{eta}{sup '}, and the possible implication to the intrinsic component of N*(1535) is explored.« less

The C(2)1pi(u) state of Na2 molecule studied by polarization labelling spectroscopy method.

PubMed

Jastrzebski, W; Kowalczyk, P; Camacho, J J; Pardo, A; Poyato, J M

2001-08-01

The C1pi(u) <-- X1sigma(g)+ system of Na2 is studied by the polarization labelling spectroscopy technique. Accurate molecular constants are derived for the observed levels nu = 0-12, J = 12-100 in the C1pi(u) state.

Spectroscopy of light tetraquark states

NASA Astrophysics Data System (ADS)

Prelovsek, S.; Draper, T.; Lang, C. B.; Limmer, M.; Liu, K. F.; Mathur, N.; Mohler, D.

We address the question whether the lightest scalar mesons sigma and kappa are tetraquarks, as is strongly supported by many phenomenological studies. We present a search for possible light tetraquark states with J^PC=0^++ and I=0, 1/2, 3/2, 2 on the lattice. The spectrum is determined using the generalized eigenvalue method with a number of tetraquark interpolators at the source and the sink. In all the channels, we unavoidably find lowest scattering states pi(k)pi(-k) or K(k)pi(-k) with back-to-back momentum k=0,2*pi/L,.. . However, we find an additional light state in the I=0 and I=1/2 channels, which may be related to the observed resonances sigma and kappa with a strong tetraquark component. In the exotic repulsive channels I=2 and I=3/2, where no resonance is observed, we find no light state in addition to the scattering states.

Energy of the ground and 2{sup +} excited states of {sub {lambda}}{sub {lambda}}{sup 10}Be: A partial ten-body model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shoeb, Mohammad; Sonika

2009-08-15

The energies of the ground and excited 2{sup +} states of {sub {lambda}}{sub {lambda}}{sup 10}Be have been calculated variationally in the Monte Carlo framework. The hypernucleus is treated as a partial ten-body problem in the {lambda}{lambda}+{alpha}{alpha} model where nucleonic degrees of freedom of {alpha}'s are taken into consideration ignoring the antisymmetrization between two {alpha}'s. The central two-body {lambda}N and {lambda}{lambda} and the three-body dispersive and two-pion exchange {lambda}NN forces, constrained by the {lambda}p scattering data and the observed ground state energies of {sub {lambda}}{sup 5}He and {sub {lambda}}{sub {lambda}}{sup 6}He, are employed. The product-type trial wave function predicts binding energymore » for the ground state considerably less than for the event reported by Danysz et al.; however, it is consistent with the value deduced assuming a {gamma} ray of 3.04 MeV must have escaped undetected in the decay of the product {sub {lambda}}{sup 9}Be* {yields} {sub {lambda}}{sup 9}Be+{gamma} of the emulsion event {sub {lambda}}{sub {lambda}}{sup 10}Be{yields} {pi}{sup -}+p+{sub {lambda}}{sup 9}Be* and for the excited 2{sup +} state closer to the value measured in the Demachi-Yanagi event. The hypernucleus {sub {lambda}}{sub {lambda}}{sup 10}Be has an oblate shape in the excited state. These results are consistent with the earlier four-body {alpha} cluster model approach where {alpha}'s are assumed to be structureless entities.« less

Multidimensional intermolecular dynamics from tunable far-infrared laser spectroscopy: Angular-radial coupling in the intermolecular potential of argon--H sub 2 O

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cohen, R.C.; Saykally, R.J.

1991-12-01

Five new vibration--rotation tunneling states of Ar--H{sub 2}O (the {Sigma} and {Pi}(1{sub 11}) and the {Sigma} and {Pi}(2{sub 12}) internal rotor states and the {ital n}=1, {Pi}(1{sub 01}) stretching-internal rotor combination level) have been accessed by tunable far-infrared laser spectroscopy. The measured vibrational band origins of transitions to these states are within 2% of predictions made from an anisotropic three-dimensional intermolecular potential surface (denoted AW1) derived from a nonlinear least-squares fit to previous far-infrared spectral data (J. Phys. Chem. {bold 94}, 7991(1990)). This provides strong evidence that the AW1 intermolecular potential surface incorporates much of the essential physics of themore » intermolecular forces which bind the cluster. However, larger deviations from the predictions are found in the observed rotational term values. A detailed analysis of these deviations clearly demonstrates the need for even stronger angular-radial coupling in the Ar--H{sub 2}O intermolecular potential than the already substantial coupling present in the AW1 surface. Specifically, the presently observed {Sigma}(1{sub 11}) state and the {ital n}=1, {Sigma}(0{sub 00}) state are found to be approximately 65:35 mixtures of the basis states which represent pure stretching and internal rotation. The {Sigma}(2{sub 12}) level is found to be mixed just as strongly with {ital n}=2, {Sigma}(1{sub 01}). The formalism for accurately deperturbing vibration--rotation--tunneling states coupled by Coriolis interactions used in the above analysis is presented.« less

Differential cross sections for excitation of H 2 by low-energy electron impact

DOE PAGES

Hargreaves, Leigh R.; Bhari, S.; Adjari, B.; ...

2017-10-31

Experimental and theoretical differential cross sections (DCS) for the electron-impact excitation of molecular hydrogen to themore » $$B{}^{1}{{\\rm{\\Sigma }}}_{u}^{+}$$, $$c{}^{3}{{\\rm{\\Pi }}}_{u}$$, $$a{}^{3}{{\\rm{\\Sigma }}}_{g}^{+}$$, $$C{}^{1}{{\\rm{\\Pi }}}_{u}$$, and the $$E(F){}^{1}{{\\rm{\\Sigma }}}_{g}^{+}$$ states are presented at incident energies near to threshold. The experimental DCSs were taken at incident energies of 14, 15, 16 and 17.5 eV and for scattering angles from 10° to 130°. In conclusion, the theoretical DCSs are from the convergent close-coupling method which has recently successfully modeled differential electron scattering from H 2 when compared with available experiment at energies of 17.5 eV and above.« less

Differential cross sections for excitation of H 2 by low-energy electron impact

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hargreaves, Leigh R.; Bhari, S.; Adjari, B.

Experimental and theoretical differential cross sections (DCS) for the electron-impact excitation of molecular hydrogen to themore » $$B{}^{1}{{\\rm{\\Sigma }}}_{u}^{+}$$, $$c{}^{3}{{\\rm{\\Pi }}}_{u}$$, $$a{}^{3}{{\\rm{\\Sigma }}}_{g}^{+}$$, $$C{}^{1}{{\\rm{\\Pi }}}_{u}$$, and the $$E(F){}^{1}{{\\rm{\\Sigma }}}_{g}^{+}$$ states are presented at incident energies near to threshold. The experimental DCSs were taken at incident energies of 14, 15, 16 and 17.5 eV and for scattering angles from 10° to 130°. In conclusion, the theoretical DCSs are from the convergent close-coupling method which has recently successfully modeled differential electron scattering from H 2 when compared with available experiment at energies of 17.5 eV and above.« less

On the uniqueness of the constrained space orbital variation (CSOV) technique

NASA Technical Reports Server (NTRS)

Bauschlicher, C. W., Jr.

1986-01-01

Several CSOV analyses are performed for the 1Sigma(+) state of NiCO, and it is shown that the importance of the CO sigma donation, Ni pi back donation, and interunit polarizations are virtually independent of the order of the CSOV steps, provided that the open-shell 3d sigma and 4s Ni orbitals are orthogonalized to the CO. This order of orthogonalization is consistent with the polarization of the Ni observed in the unconstrained SCF wavefunction. If instead the CO is orthogonalized to the open-shell Ni orbitals, the frozen orbital repulsion and entire CSOV analysis becomes unphysical. A comparison of the SCF and CAS SCF descriptions for the NiCO 1Sigma(+) state shows the importance of the s to d promotion and sd hybridization in reducing the repulsion and increasing the Ni to CO pi bonding. For LiF, CSOV analyses starting from both the neutral and ionic asymptotes show the bonding to be predominantly Li(+) - F(-). These examples show the uniqueness of the CSOV decomposition.

An Ab Initio Study of the Low-Lying Doublet States of AgO and AgS

NASA Technical Reports Server (NTRS)

Bauschlicher, Charles W., Jr.; Partridge, Harry; Langhoff, Stephen R.

1990-01-01

Spectroscopic constants (D(sub o), r(sub e), mu(sub e), T(sub e)) are determined for the doublet states of AgO and AgS below approx. = 30000/cm. Large valence basis sets are employed in conjunction with relativistic effective core potentials (RECPs). Electron correlation is included using the modified coupled-pair functional (MCPF) and multireference configuration interaction (MRCI) methods. The A(sup 2)Sigma(sup +) - X(sup 2)Pi band system is found to occur in the near infrared (approx. = 9000/cm) and to be relatively weak with a radiative lifetime of 900 microns for A(sup 2)Sigma(sup +) (upsilon = 0). The weakly bound C(sup 2)Pi state (our notation), the upper state of the blue system, is found to require high levels of theoretical treatment to determine a quantitatively accurate potential. The red system is assigned as a transition from the C(sup 2)Pi state to the previously unobserved A(sup 2)Sigma(sup +) state. Several additional transitions are identified that should be detectable experimentally. A more limited study is performed for the vertical excitation spectrum of AgS. In addition, a detailed all-electron study of the X(sup 2)Pi and A(sup 2)Sigma(sup +) states of AgO is carried out using large atomic natural orbital (ANO) basis sets. Our best calculated D(sub o) value for AgO is significantly less than the experimental value, which suggests that there may be some systematic error in the experimental determination.

Hard-sphere mixture excess free energy at infinite size ratio

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tukur, N.M.; Hamad, E.Z.; Mansoori, G.A.

1999-02-01

This article presents the exact limiting value of the derivative of the excess Helmholtz energy, A{sup E}, with respect to molecular size at constant temperature, density and composition for a binary mixture of hard spheres with an infinite size ratio ({sigma}{sub 11}/{sigma}{sub 22}{r_arrow}{infinity}); i.e., lim{sub {sigma}{sub 22}{r_arrow}0}[({partial_derivative}A{sub hs}{sup E}/RT)/{partial_derivative}{sigma}{sub 22}]{sub T,{rho},x,{sigma}{sub 11}}=({pi}/2){rho}x{sub 1}x{sub 2}{sigma}{sub 11}{sup 2}/(1{minus}({pi}/6){rho}x{sub 1}{sigma}{sub 11}{sup 3}). This limiting value is compared with the Mansoori{endash}Carnahan{endash}Starling{endash}Leland (MCSL) and also used to test the limits of some commonly used models in estimating the excess free energy of solvents in mixtures or polymer solutions. The models evaluated include the van Laar,more » Wilson, Edmond{endash}Ogston, Flory{endash}Huggins, Lacome{endash}Sanchez, Scott{endash}Magat, and Chen {ital et al.} It is shown that while the MCSL equation of state produces the same limiting value as the exact value reported here the other mixture models deviate from the exact value. This expression may be utilized to correct the mixture theories at their infinite size ratio limits. {copyright} {ital 1999 American Institute of Physics.}« less

Assignment of polarization-dependent peaks in carbon K-edge spectra from biogenic and geologic aragonite.

PubMed

Zhou, Dong; Metzler, Rebecca A; Tyliszczak, Tolek; Guo, Jinghua; Abrecht, Mike; Coppersmith, Susan N; Gilbert, P U P A

2008-10-16

Many biominerals, including mollusk and echinoderm shells, avian eggshells, modern and fossil bacterial sediments, planktonic coccolithophores, and foraminifera, contain carbonates in the form of biogenic aragonite or calcite. Here we analyze biogenic and geologic aragonite using different kinds of surface- and bulk-sensitive X-ray absorption near-edge structure (XANES) spectroscopy at the carbon K-edge, as well as high-resolution scanning transmission X-ray microscopy (STXM). Besides the well-known main pi* and sigma* carbonate peaks, we observed and fully characterized four minor peaks, at energies between the main pi* and sigma* peaks. As expected, the main peaks are similar in geologic and biogenic aragonite, while the minor peaks differ in relative intensity. In this and previous work, the minor peaks appear to be the ones most affected in biomineralization processes, hence the interest in characterizing them. Peak assignment was achieved by correlation of polarization-dependent behavior of the minor peaks with that of the main pi* and sigma* peaks. The present characterization provides the background for future studies of aragonitic biominerals.

Test of universal rise of hadronic total cross sections based on {pi}p, Kp and pp, pp scatterings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ishida, Muneyuki; Igi, Keiji; Theoretical Physics Laboratory, RIKEN, Wako, Saitama 351-0198

Recently, there have been several evidences that the hadronic total cross section {sigma}{sub tot} is proportional to Blog{sup 2}s, which is consistent with the Froissart unitarity bound. The COMPETE Collaboration has further assumed {sigma}{sub tot}{approx_equal}Blog{sup 2}(s/s{sub 0})+Z to extend its universal rise with the common values of B and s{sub 0} for all hadronic scatterings to reduce the number of adjustable parameters. It was suggested that the coefficient B was universal in the arguments of the color glass condensate of QCD in recent years. However, there has been no rigorous proof yet based only on QCD. We attempt to investigatemore » the value of B for {pi}{sup {+-}}p, K{sup {+-}}p and pp, pp scatterings, respectively, through the search for the simultaneous best fit to the experimental {sigma}{sub tot} and {rho} ratios at high energies. The {sigma}{sub tot} at the resonance- and intermediate-energy regions has also been exploited as a duality constraint based on the special form of the finite-energy sum rule. We estimate the values of B, s{sub 0}, and Z individually for {pi}{sup {+-}}p, K{sup {+-}}p and pp, pp scatterings without using the universality hypothesis. It turns out that the values of B are mutually consistent within 1 standard deviation. It has to be stressed that we cannot obtain such a definite conclusion without the duality constraint. It is also interesting to note that the values of Z for {pi}p, Kp, and p(p)p approximately satisfy the ratio 2 ratio 2 ratio 3 predicted by the quark model. The obtained value of B for p(p)p is B{sub pp}=0.280{+-}0.015 mb, which predicts {sigma}{sub tot}{sup pp}=108.0{+-}1.9 mb and {rho}{sup pp}=0.131{+-}0.0025 at the LHC energy {radical}(s)=14 TeV.« less

The Zeeman effect in the (0,0) band of the A 7Pi-X 7Sigma(+) transition of manganese monohydride, MnH.

PubMed

Steimle, Timothy C; Wang, Hailing; Gengler, Jamie J; Stoll, Michael; Meijer, Gerard

2008-10-28

The Zeeman tuning of the P(1)(0) line (nu=17 568.35 cm(-1)) of the A (7)Pi-X (7)Sigma(+) (0,0) band of manganese monohydride, MnH, has been investigated. The laser induced fluorescence spectrum of a supersonic molecular beam sample was recorded at a resolution of approximately 40 MHz and with field strengths of up to 362.0 mT. The observed spectrum was successfully fitted using a traditional effective Zeeman Hamiltonian to determine an effective magnetic g-factor for the J=2 level of the F(1)-spin component of the A (7)Pi(v=0) state. Spectral predictions of the P(1)(0) line at field strengths used in magnetic trapping experiments are presented.

Cyclo-biphenalenyl biradicaloid molecular materials: conformation, tautomerization, magnetism, and thermochromism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Jingsong; Sumpter, Bobby G; Meunier, Vincent

2011-01-01

Phenalenyl and its derivatives have recently attracted a great deal of interest as a result of a 2-electron multicenter (2e/mc) covalent pi-pi bonding between two pi-stacked phenalenyl units. The 2e/mc bonded pi-dimers are close in energy to the sigma-dimers of phenalenyl and therefore fickle properties may emerge from bond fluctuation, yielding smart pi-functional materials. Here we examine the valence tautomerization of two cyclo-biphenalenyl biradicaloid molecular materials with chair- and boat-conformations by spin-restricted (R) and unrestricted (U) DFT using the M06 and B3LYP functionals. We found that the chair-conformation involves a 2e/4c pi-pi bonded structure while the boat-conformation involves a 2e/12cmore » pi-pi bonded structure on their potential energy surfaces. The global minimum for the chair-conformation is the sigma-bonded structure while it is the pi-pi bonded structure for the boat-conformation. The chair-conformation exhibits a stepwise [3,3]-sigmatropic rearrangement, and calculations predict a negligible paramagnetic susceptibility near room temperature. In comparison, the paramagnetism of the boat-conformation should be observable by SQUID and/or ESR. According to the difference of the global minima of the two conformations and the parameterized UV-Vis calculations, the color of the chair-conformation is expected to become darker while that of the boat-conformation become lighter with increasing temperature.« less

Comparison of the resonance-enhanced multiphoton ionization spectra of pyrrole and 2,5-dimethylpyrrole: Building toward an understanding of the electronic structure and photochemistry of porphyrins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beames, Joseph M.; Nix, Michael G. D.; Hudson, Andrew J.

The photophysical properties of porphyrins have relevance for their use as light-activated drugs in cancer treatment and sensitizers in solid-state solar cells. However, the appearance of their UV-visible spectra is usually explained inadequately by qualitative molecular-orbital theories. We intend to gain a better insight into the intense absorption bands, and excited-state dynamics, that make porphyrins appropriate for both of these applications by gradually building toward an understanding of the macrocyclic structure, starting with studies of smaller pyrrolic subunits. We have recorded the (1+1) and (2+1) resonance-enhanced multiphoton ionization (REMPI) spectra of pyrrole and 2,5-dimethylpyrrole between 25 600 cm{sup -1} (390more » nm) and 48 500 cm{sup -1} (206 nm). We did not observe a (1+1) REMPI signal through the optically bright {sup 1}B{sub 2} ({pi}{pi}*) and {sup 1}A{sub 1} ({pi}{pi}*) states in pyrrole due to ultrafast deactivation via conical intersections with the dissociative {sup 1}A{sub 2} ({pi}{sigma}*) and {sup 1}B{sub 1} ({pi}{sigma}{sup *}) states. However, we did observe (2+1) REMPI through Rydberg states with a dominant feature at 27 432 cm{sup -1} (two-photon energy, 54 864 cm{sup -1}) assigned to a 3d(leftarrow){pi} transition. In contrast, 2,5-dimethylpyrrole has a broad and structured (1+1) REMPI spectrum between 36 000 and 42 500 cm{sup -1} as a result of vibronic transitions to the {sup 1}B{sub 2} ({pi}{pi}*) state, and it does not show the 3d(leftarrow){pi} Rydberg transition via (2+1) REMPI. We have complemented the experimental studies by a theoretical treatment of the excited states of both molecules using time-dependent density functional theory (TD-DFT) and accounted for the contrasting features in the spectra. TD-DFT modeled the photochemical activity of both the optically dark {sup 1}{pi}{sigma}* states (dissociative) and optically bright {sup 1}{pi}{pi}* states well, predicting the barrierless deactivation of the {sup 1}B{sub 2} ({pi}{pi}*) state of pyrrole and the bound minimum of the {sup 1}B{sub 2} ({pi}{pi}*) state in 2,5-dimethylpyrrole. However, the quantitative agreement between vibronic transition energies and the excited-state frequencies calculated by TD-DFT was hampered by inaccurate modeling of Rydberg orbital mixing with the valence states, caused by the lack of an asymptotic correction to the exchange-correlation functionals used.« less

Relative Band Oscillator Strengths for Carbon Monoxide: Alpha (1)Pi-Chi (1)Sigma(+) Transitions

NASA Technical Reports Server (NTRS)

Federman, S. R.; Menningen, K. L.; Lee, Wei; Stoll, J. B.

1997-01-01

Band oscillator strengths for CO transitions between the electronic states A (l)Pi and X(1)Sigma(+) were measured via absorption with a synchrotron radiation source. When referenced to the well-characterized (5,0) band oscillator strength, our relative values for the (7,0) to (11,0) bands are most consistent with the recent experiments of Chan et al. and the theoretical predictions of Kirby & Cooper. Since the results from various laboratory techniques and theory now agree, analyses of interstellar CO based on absorption from A-X bands are no longer hindered by uncertainties in oscillator strength.

A Study of the X(sup 2) Sigma(sup +) and A(sup 2) Pi States of MgAr(sup +) and MgKr(sup +)

NASA Technical Reports Server (NTRS)

Bauschlicher, Charles W., Jr.; Partridge, Harry; Langhoff, Stephen R. (Technical Monitor)

1995-01-01

The ground (sup 2)Sigma(sup +) and lowest excited (sup 2)Pi states of MgAr(sup +) and MgKr(sup +) are studied using the singles and doubles configuration interaction (SDCI) approach, in conjunction with large basis sets. The effect of Mg core correlation and core polarization are accounted for using the core-polarization potential (CPP) approach. Franck-Condon factors, oscillator strengths, radiative lifetimes, dissociation energies, bond lengths, and excitation energies are reported. The computed results are in good agreement with the available experimental data.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simard, G.; et al.

We report constraints on cosmological parameters from the angular power spectrum of a cosmic microwave background (CMB) gravitational lensing potential map created using temperature data from 2500 degmore » $^2$ of South Pole Telescope (SPT) data supplemented with data from Planck in the same sky region, with the statistical power in the combined map primarily from the SPT data. We fit the corresponding lensing angular power spectrum to a model including cold dark matter and a cosmological constant ($$\\Lambda$$CDM), and to models with single-parameter extensions to $$\\Lambda$$CDM. We find constraints that are comparable to and consistent with constraints found using the full-sky Planck CMB lensing data. Specifically, we find $$\\sigma_8 \\Omega_{\\rm m}^{0.25}=0.598 \\pm 0.024$$ from the lensing data alone with relatively weak priors placed on the other $$\\Lambda$$CDM parameters. In combination with primary CMB data from Planck, we explore single-parameter extensions to the $$\\Lambda$$CDM model. We find $$\\Omega_k = -0.012^{+0.021}_{-0.023}$$ or $$M_{\

Dynamics of the Trans-Neptune Region: Apsidal Waves in the Kuiper Belt

NASA Technical Reports Server (NTRS)

Ward, William R.; Hahn, Joseph M.

1998-01-01

The role of apsidal density waves propagating in a primordial trans-Neptune disk (i.e., Kuiper belt) is investigated. It is shown that Neptune launches apsidal waves at its secular resonance near 40 AU that propagate radially outward, deeper into the particle disk. The wavelength of apsidal waves is considerably longer than waves that might be launched at Lindblad resonances, because the pattern speed, g(sub s), resulting from the apsis precession of Neptune is much slower than its mean motion, Omega(sub s). If the early Kuiper belt had a sufficient surface density, sigma, the disk's wave response to Neptune's secular perturbation would have spread the disturbing torque radially over a collective scale lambda(sub *) approx. = r(2(mu)(sub d)Omega/ absolute value of r dg/dr)(sup 1/2), where mu(sub d)equivalent pi(sigma)r(exp 2)/(1 solar mass) and Omega(r) and g(r) are respectively the mean motion and precession frequency of the disk particles. This results in considerably smaller eccentricities at resonance than had the disk particles been treated as noninteracting test particles. Consequently, particles are less apt to be excited into planet-crossing orbits, implying that the erosion timescales reported by earlier test-particle simulations of the Kuiper belt may be underestimated. It is also shown that the torque the disk exerts upon the planet (due to its gravitational attraction for the disk's spiral wave pattern) damps the planet's eccentricity and further inhibits the planet's ability to erode the disk. Key words: celestial mechanics, stellar dynamics - comets: general minor planets, asteroids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hartfiel, Brandon; /SLAC

The physics of this note is divided into two parts. The first part measures the {Lambda}{sub c} {yields} {pi}kp continuum momentum spectrum at a center of mass energy of 10.54 GeV/c. The data sample consists of 15,400 {Lambda}{sub c} baryons from 9.46 fb{sup -1} of integrated luminosity. With more than 13 times more data than the best previous measurement, we are able to exclude some of the simpler, one parameter fragmentation functions. In the second part, we add the {Lambda}{sub c} {yields} K{sup 0}p mode, and look for events with a {Lambda}{sub c}{sup +} and a {bar {Lambda}}{sub c}{sup -}more » in order to look for ''popcorn'' mesons formed between the baryon and antibaryon. We add on-resonance data, with a kinematic cut to eliminate background from B decays, as well as BaBar run 3 and 4 data to increase the total data size to 219.70 fb{sup -1}. We find 619 events after background subtraction. After a subtraction of 1.06 {+-} .09 charged pions coming from decays of known resonances to {Lambda}{sub c} + {eta}{pi}, we are left with 2.63 {+-} .21 additional charged pions in each of these events. This is significantly higher than the .5 popcorn mesons per baryon pair used in the current tuning of Pythia 6.2, the most widely used Monte Carlo generator. The extra mesons we find appear to be the first direct evidence of popcorn mesons, although some of them could be arising from hypothetical unresolved, unobserved charmed baryon resonances contributing decay mesons to our data. To contribute a significant fraction, this hypothesis requires a large number of such broad unresolved states and seems unlikely, but can not be completely excluded.« less

The nature of the metal-CO interaction and bonding

NASA Technical Reports Server (NTRS)

Bagus, P. S.; Nelin, C. J.; Bauschlicher, C. W., Jr.

1984-01-01

The adsorption of CO on metal surfaces is represented by molecular orbital cluster models of CO at an on top site and adsorbed normal to the surface carbon end down. Ab initio SCF and MCSCF calculations are performed for several clusters. The new constrained space orbital variation CSOV approach is used to analyze the bonding and to compare CO adsorption on Al, representative of sp metals, with that on Cu, representative of transition metals. There is a large repulsion between the superposed free CO and metal charge distributions which is considerably smaller for Cu than for Al because there are fewer valence sigma electrons for Cu than for Al. The CSOV analysis shows that the metal to CO pi donation is much more important than the CO to metal sigma donation. It is also shown that for Cu, the d pi contribution to the metal pi donation is larger than the valence 4p pi contribution. The d pi donation is compared between Fe, Ni, and Cu and this donation and the metal-CO interaction are found to be different in the order Fe greater than Ni greater than Cu.

Direct Comparison of Brookhaven Reflectivity Measurements with Free-Electron Theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bane, Karl L.F.

2010-12-13

The reflectivity at normal incidence of copper and aluminum samples was recently measured over a large frequency range at Brookhaven by one of us (JT). Then using the Kramers-Kroning integrals, and assuming the free-electron model of conductivity, the dependence of conductivity on frequency was obtained. The results seemed to suggest, for example, that the dc conductivities of the copper and evaporated aluminum samples are a factor of 3 lower than expected. We propose in this report, instead, directly fitting the free-electron model to the low frequency end of the reflectivity data. This fitting does not depend on the higher frequencymore » results and on Kramers-Kronig integrations, but it does assume that the data at the low frequency end is sufficiently accurate. Note that for our LCLS wakefield studies, it is only over these (relatively) low frequencies that we need to know the electrical properties of the metals. The equations that relate reflectivity R with the free electron parameters dc conductivity {sigma} and relaxation time {tau} are: (1) {tilde {sigma}} = {sigma}/1-ikc{tau}; (2) {tilde n} = {radical} {tilde {epsilon}} = {radical}(1+4{pi}i{tilde k}c/{omega}); and (3) R = |{tilde n}-1/{tilde n} + 1|{sup 2}. The parameters are ac conductivity {tilde {sigma}}, index of refraction {tilde n}, dielectric constant {tilde {epsilon}}, and wave number k = {omega}/c, with {omega} frequency and c the speed of light. In Fig. 1 we show the ideal behavior of R for a reasonably good conducting metal, where {sigma} = 0.12 x 10{sup 17}/s and {tau} = 0.55 x 10{sup -14} s (solid line); these parameters are, respectively, 2% ({sigma}) and 20% ({tau}) of the nominal values for copper. The parameters were chosen so that the important features of R(k) could be seen easily in one plot. We see 3 distinct regions: (1) for low frequencies, k {approx}< 1/c{tau}, R continually decreases, with positive curvature, and with a low frequency asymptote of (1 - {radical}2kc/{pi}{sigma}); (2) for intermediate frequencies the reflectivity is nearly constant, R {approx} (1 - {radical}1/{pi}{sigma}{tau}); (3) for k {approx}> k{sub p} = {radical}4{pi}{sigma}/c{sup 2}{tau}, the plasma frequency of the metal, R quickly drops to zero. The dashed lines in Fig. 1 give the analytic guideposts for the 3 regions. Note that it is only in the first and part of the second region that we can expect the free electron model to have validity in real metals; at higher frequencies the effects of absorption bands and other physics will distort the R(k) curve. In principle, knowing R accurately in the entire 1st region suffices for obtaining the free-electron parameters {sigma} and {tau}; in practice, however, knowing it also in the 2nd region gives us more confidence in the model and especially in the value of {tau}.« less

Frequency-scanning particle size spectrometer

NASA Technical Reports Server (NTRS)

Fymat, A. L. (Inventor)

1979-01-01

A particle size spectrometer having a fixed field of view within the forward light scattering cone at an angle theta sub s between approximately 100 and 200 minutes of arc (preferably at 150 minutes), a spectral range extending approximately from 0.2 to 4.0 inverse micrometers, and a spectral resolution between about 0.1 and 0.2 inverse micrometers (preferably toward the lower end of this range of spectral resolution), is employed to determine the distribution of particle sizes, independently of the chemical composition of the particles, from measurements of incident light, at each frequency, sigma (=1/lambda), and scattered light, I(sigma).

Dynamical coupled-channel model of meson production reactions in the nucleon resonance region.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matsuyama, A.; Sato, T.; Lee, T.-S. H.

A dynamical coupled-channel model is presented for investigating the nucleon resonances (N*) in the meson production reactions induced by pions and photons. Our objective is to extract the N* parameters and to investigate the meson production reaction mechanisms for mapping out the quark-gluon substructure of N* from the data. The model is based on an energy-independent Hamiltonian which is derived from a set of Lagrangians by using a unitary transformation method. The constructed model Hamiltonian consists of (a) {Gamma}V for describing the vertex interactions N*{leftrightarrow}MB,{pi}{pi}N with MB={gamma}N,{pi}N,{epsilon}N,{pi}{Delta},{rho}N,{sigma}N, and {rho}{leftrightarrow}{pi}{pi} and {sigma}{leftrightarrow}{pi}{pi}, (b) v22 for the non-resonant MB{yields}M'B' and {pi}{pi}{yields}{pi}{pi} interactions,more » (c) vMB,{pi}{pi}N for the non-resonant MB{yields}{pi}{pi}N transitions, and (d) v{pi}{pi}N,{pi}{pi}N for the non-resonant {pi}{pi}N{yields}{pi}{pi}N interactions. By applying the projection operator techniques, we derive a set of coupled-channel equations which satisfy the unitarity conditions within the channel space spanned by the considered two-particle MB states and the three-particle {pi}{pi}N state. The resulting amplitudes are written as a sum of non-resonant and resonant amplitudes such that the meson cloud effects on the N* decay can be explicitly calculated for interpreting the extracted N* parameters in terms of hadron structure calculations. We present and explain in detail a numerical method based on a spline-function expansion for solving the resulting coupled-channel equations which contain logarithmically divergentone-particle-exchange driving terms {sup (E)}{sub M B, M' B'} resulted from the {pi}{pi}N unitarity cut. This method is convenient, and perhaps more practical and accurate than the commonly employed methods of contour rotation/deformation, for calculating the two-pion production observables. For completeness in explaining our numerical procedures, we also present explicitly the formula for efficient calculations of a very large number of partial-wave matrix elements which are the input to the coupled-channel equations. Results for two pion photo-production are presented to illustrate the dynamical consequence of the one-particle-exchange driving term Z{sup (E)}{sub M B, M' B'} of the coupled-channel equations. We show that this mechanism, which contains the effects due to {pi}{pi}N unitarity cut, can generate rapidly varying structure in the reaction amplitudes associated with the unstable particle channels {pi}{Delta}, {rho}N, and {sigma}N, in agreement with the analysis of Aaron and Amado [Phys. Rev. D13 (1976) 2581]. It also has large effects in determining the two-pion production cross sections. Our results indicate that cautions must be taken to interpret the N* parameters extracted from using models which do not include {pi}{pi}N cut effects. Strategies for performing a complete dynamical coupled-channel analysis of all of available data of meson photo-production and electro-production are discussed.« less

{chi}{sub cJ} decays to h{sup +}h{sup -}h{sup 0}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Athar, S. B.; Patel, R.; Potlia, V.

2007-02-01

Using a sample of 3x10{sup 6} {psi}(2S) decays recorded by the CLEO detector, we study three-body decays of the {chi}{sub c0}, {chi}{sub c1}, and {chi}{sub c2} produced in radiative decays of the {psi}(2S). We consider the final states {pi}{sup +}{pi}{sup -}{eta}, K{sup +}K{sup -}{eta}, pp{eta}, {pi}{sup +}{pi}{sup -}{eta}{sup '}, K{sup +}K{sup -}{pi}{sup 0}, pp{pi}{sup 0}, {pi}{sup +}K{sup -}K{sub S}{sup 0}, and K{sup +}p{lambda}, measuring branching fractions or placing upper limits. For {chi}{sub c1}{yields}{pi}{sup +}{pi}{sup -}{eta}, K{sup +}K{sup -}{pi}{sup 0}, and {pi}{sup +}K{sup -}K{sub S}{sup 0} our observed samples are large enough to indicate the largest contributions to the substructure.

Pion-nucleon scattering in the Roper channel from lattice QCD

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lang, Christian B.; Leskovec, L.; Padmanath, M.

We present a lattice QCD study ofmore » $$N\\pi$$ scattering in the positive-parity nucleon channel, where the puzzling Roper resonance $N^*(1440)$ resides in experiment. The study is based on the PACS-CS ensemble of gauge configurations with $$N_f=2+1$$ Wilson-clover dynamical fermions, $$m_\\pi \\simeq 156~$$MeV and $$L\\simeq 2.9~$$fm. In addition to a number of $qqq$ interpolating fields, we implement operators for $$N\\pi$$ in $p$-wave and $$N\\sigma$$ in $s$-wave. In the center-of-momentum frame we find three eigenstates below 1.65 GeV. They are dominated by $N(0)$, $$N(0)\\pi(0)\\pi(0)$$ (mixed with $$N(0)\\sigma(0)$$) and $$N(p)\\pi(-p)$$ with $$p\\simeq 2\\pi/L$$, where momenta are given in parentheses. This is the first simulation where the expected multi-hadron states are found in this channel. The experimental $$N\\pi$$ phase-shift would -- in the approximation of purely elastic $$N\\pi$$ scattering -- imply an additional eigenstate near the Roper mass $$m_R\\simeq 1.43~$$GeV for our lattice size. We do not observe any such additional eigenstate, which indicates that $$N\\pi$$ elastic scattering alone does not render a low-lying Roper. Coupling with other channels, most notably with $$N\\pi\\pi$$, seems to be important for generating the Roper resonance, reinforcing the notion that this state could be a dynamically generated resonance. Our results are in line with most of previous lattice studies based just on $qqq$ interpolators, that did not find a Roper eigenstate below $1.65~$GeV. As a result, the study of the coupled-channel scattering including a three-particle decay $$N\\pi\\pi$$ remains a challenge.« less

Pion-nucleon scattering in the Roper channel from lattice QCD

DOE PAGES

Lang, Christian B.; Leskovec, L.; Padmanath, M.; ...

2017-01-31

We present a lattice QCD study ofmore » $$N\\pi$$ scattering in the positive-parity nucleon channel, where the puzzling Roper resonance $N^*(1440)$ resides in experiment. The study is based on the PACS-CS ensemble of gauge configurations with $$N_f=2+1$$ Wilson-clover dynamical fermions, $$m_\\pi \\simeq 156~$$MeV and $$L\\simeq 2.9~$$fm. In addition to a number of $qqq$ interpolating fields, we implement operators for $$N\\pi$$ in $p$-wave and $$N\\sigma$$ in $s$-wave. In the center-of-momentum frame we find three eigenstates below 1.65 GeV. They are dominated by $N(0)$, $$N(0)\\pi(0)\\pi(0)$$ (mixed with $$N(0)\\sigma(0)$$) and $$N(p)\\pi(-p)$$ with $$p\\simeq 2\\pi/L$$, where momenta are given in parentheses. This is the first simulation where the expected multi-hadron states are found in this channel. The experimental $$N\\pi$$ phase-shift would -- in the approximation of purely elastic $$N\\pi$$ scattering -- imply an additional eigenstate near the Roper mass $$m_R\\simeq 1.43~$$GeV for our lattice size. We do not observe any such additional eigenstate, which indicates that $$N\\pi$$ elastic scattering alone does not render a low-lying Roper. Coupling with other channels, most notably with $$N\\pi\\pi$$, seems to be important for generating the Roper resonance, reinforcing the notion that this state could be a dynamically generated resonance. Our results are in line with most of previous lattice studies based just on $qqq$ interpolators, that did not find a Roper eigenstate below $1.65~$GeV. As a result, the study of the coupled-channel scattering including a three-particle decay $$N\\pi\\pi$$ remains a challenge.« less

The p({gamma}, {pi}{sup 0}) reaction in the {Delta}(1232) region

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davidson, R.M.; Gutenberg, J.; Mukhopadhyay, N.C.

Linearly polarized photons from the Laser Electron Gamma Source (LEGS) have been used by Blanpied et al. to study the p({gamma}, {pi}{sup 0}) reaction, looking for the E2 transition amplitude in the nucleon to Delta(1232) excitation. These authors contrast their measured cross-section ratio d{sigma}{parallel}/d{sigma}{perpendicular}, with expectations of earlier analyses, by the authors and Wittman (DMW), by Nozawa et al. (NBL), and using the multipoles of Behrends and Donnachie directly, and find {open_quotes}large discrepancies{close_quotes} among them. Here the authors clarify these discrepancies. The crucial difference between DMW and NBL calculations is the inclusion of the u-channel {Delta} contribution in DMW, omittedmore » in NBL. The authors find for a fair, though not perfect, agreement with the new data: E{sub 1+}{sup {pi}}{sup 0} {r_arrow}2.1E{sub 1+}{sup {pi}}{sup 0}, keeping other multipoles fixed.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carvalho De Gouvea, Andre Luiz

ln this thesis the polarization of themore » $$\\Xi^-$$ hyperon and the $$\\Xi^+$$ antihyperon produced in the Fermilab Experiment E791 was determined by the analysis of the weak decay $$\\Xi^- \\to \\Lambda^0 + \\pi^-$$. For $$\\Xi^-$$ produced in the interaction between a 500 GeV/c $$\\pi^-$$ beam and a unpolarized carbon (platinum) target in the region $$p_t$$ > 0.8 GeV/c and $$X_F$$ > 0, -10.9% ± 1.5% (-14.7% ± 3.1%) polarization was obtained perpendicular to the production plane and -5.92% ± 1.69% (-2.41%±3.53% $$\\approx O$$) polarization was measured for $$\\Xi^+$$. Evidence was also found for a polarized $$\\Omega^-$$ hyperon produced in the same experiment in the region $$X_F$$ >0, after analysis of the weak decay $$\\Omega^- \\to \\Lambda^0 + K^-$$.« less

Finding New Math Identities by Computer

NASA Technical Reports Server (NTRS)

Bailey, David H.; Chancellor, Marisa K. (Technical Monitor)

1996-01-01

Recently a number of interesting new mathematical identities have been discovered by means of numerical searches on high performance computers, using some newly discovered algorithms. These include the following: pi = ((sup oo)(sub k=0))(Sigma) (1 / 16) (sup k) ((4 / 8k+1) - (2 / 8k+4) - (1 / 8k+5) - (1 / 8k+6)) and ((17 pi(exp 4)) / 360) = ((sup oo)(sub k=1))(Sigma) (1 + (1/2) + (1/3) + ... + (1/k))(exp 2) k(exp -2), zeta(3, 1, 3, 1, ..., 3, 1) = (2 pi(exp 4m) / (4m+2)! where m = number of (3,1) pairs. and where zeta(n1,n2,...,nr) = (sub k1 (is greater than) k2 (is greater than) ... (is greater than) kr)(Sigma) (1 / (k1 (sup n1) k2 (sup n2) ... kr (sup nr). The first identity is remarkable in that it permits one to compute the n-th binary or hexadecimal digit of pu directly, without computing any of the previous digits, and without using multiple precision arithmetic. Recently the ten billionth hexadecimal digit of pi was computed using this formula. The third identity has connections to quantum field theory. (The first and second of these been formally established; the third is affirmed by numerical evidence only.) The background and results of this work will be described, including an overview of the algorithms and computer techniques used in these studies.

Er{sup 3+}-doped strontium lithium bismuth borate glasses for broadband 1.5 {mu}m emission - optical properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rajesh, D.; Balakrishna, A.; Ratnakaram, Y. C.

2013-02-05

Strontium lithium bismuth borate glasses (SLBiB) doped with various concentrations of Er{sup 3+} were prepared using conventional melt quench technique and investigated their optical properties. The amorphous nature of the prepared glass samples was confirmed by X-ray diffraction and SEM analysis. Optical properties were studied by measuring the optical absorption and near infrared luminescence spectra at room temperature. Judd-Ofelt (J-O) theory has been applied for the f.f transitions of Er{sup 3+} ions to evaluate J-O intensity parameters, {Omega}{lambda} ({lambda} = 2, 4 and 6). Using the J-O intensity parameters, radiative properties such as transition probabilities (A{sub R}), branching ratios ({beta})more » and radiative lifetimes ({tau}) are estimated for certain transitions. From the emission spectra, peak emission-cross sections ({sigma}{sub p}) and products of stimulated emission cross-section and full width at half maximum ({sigma}{sub p} Multiplication-Sign FWHM) were calculated for the observed emission transition, {sup 4}I{sub 13/2}{yields}{sup 4}I{sub 15/2}.« less

Ab initio investigation of the ground and low-lying states of the diatomic fluorides TiF, VF, CrF, and MnF.

PubMed

Koukounas, Constantine; Kardahakis, Stavros; Mavridis, Aristides

2004-06-22

The electronic structure of the ground and low-lying states of the diatomic fluorides TiF, VF, CrF, and MnF was examined by multireference and coupled cluster methods in conjunction with extended basis sets. For a total of 34 states we report binding energies, spectroscopic constants, dipole moments, separation energies, and charge distributions. In addition, for all states we have constructed full potential curves. The suggested ground state binding energies of TiF(X (4)Phi), VF(X (5)Pi), CrF(X (6)Sigma(+)), and MnF(X (7)Sigma(+)) are 135, 130, 110, and 108 kcal/mol, respectively, with first excited states A (4)Sigma(-), A (5)Delta, A (6)Pi, and a (5)Sigma(+) about 2, 3, 23, and 19 kcal/mol higher. In essence all our numerical findings are in harmony with experimental results. For all molecules and states studied it is clear that the in situ metal atom (M) shows highly ionic character, therefore the binding is described realistically by M(+)F(-). (c) 2004 American Institute of Physics.

Theoretical study of the diatomic alkali and alkaline-earth oxides

NASA Technical Reports Server (NTRS)

Langhoff, S. R.; Bauschlicher, C. W., Jr.; Partridge, H.

1986-01-01

Theoretical dissociation energies for the ground states of the alkali and alkaline earth oxides are presented that are believed to be accurate to 0.1 eV. The 2 Pi - 2 Sigma + separations for the alkali oxides are found to be more sensitive to basis set than to electron correlation. Predicted 2 Pi ground states for LiO and NaO and 2 Sigma + ground states for RbO and CsO are found to be in agreement with previous theoretical and experimental work. For KO, a 2 Sigma + state is found at both the numerical Hartree-Fock (NHF) level and at the singles plus doubles configuration interaction level using a Slater basis set that is within 0.02 eV of the NHF limit. It is found that an accurate balanced treatment of the two states requires correlating the electrons on both the metal and oxide ion.

Theoretical nuclear physics

NASA Astrophysics Data System (ADS)

Rost, E.; Shephard, J. R.

1992-08-01

This report discusses the following topics: Exact 1-loop vacuum polarization effects in 1 + 1 dimensional QHD; exact 1-fermion loop contributions in 1 + 1 dimensional solitons; exact scalar 1-loop contributions in 1 + 3 dimensions; exact vacuum calculations in a hyper-spherical basis; relativistic nuclear matter with self-consistent correlation energy; consistent RHA-RPA for finite nuclei; transverse response functions in the (triangle)-resonance region; hadronic matter in a nontopological soliton model; scalar and vector contributions to (bar p)p yields (bar lambda)lambda reaction; 0+ and 2+ strengths in pion double-charge exchange to double giant-dipole resonances; and nucleons in a hybrid sigma model including a quantized pion field.

{sigma} Hyperons in the Nucleus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bart, S.; Chrien, R. E.; Franklin, W. A.

1999-12-20

A search for {sigma} hypernuclear states in p -shell hypernuclei has been performed with the Moby Dick spectrometer and the low energy separated beam (LESB-2) at the Brookhaven Alternating Gradient Synchrotron (BNL AGS). Unlike some previously published reports, no narrow states have been observed for targets of {sup 6}Li and {sup 9}Be in (K{sup -}, {pi}{sup {+-}}) reactions, either for bound state or continuum regions. Together with the previously reported J=0 , T=1/2 bound state in {sup 4}{sub {sigma}} He , these results demonstrate the crucial role of isospin in {sigma} hypernuclei. (c) 1999 The American Physical Society.

Modeling polymer-induced interactions between two grafted surfaces: comparison between interfacial statistical associating fluid theory and self-consistent field theory.

PubMed

Jain, Shekhar; Ginzburg, Valeriy V; Jog, Prasanna; Weinhold, Jeffrey; Srivastava, Rakesh; Chapman, Walter G

2009-07-28

The interaction between two polymer grafted surfaces is important in many applications, such as nanocomposites, colloid stabilization, and polymer alloys. In our previous work [Jain et al., J. Chem. Phys. 128, 154910 (2008)], we showed that interfacial statistical associating fluid density theory (iSAFT) successfully calculates the structure of grafted polymer chains in the absence/presence of a free polymer. In the current work, we have applied this density functional theory to calculate the force of interaction between two such grafted monolayers in implicit good solvent conditions. In particular, we have considered the case where the segment sizes of the free (sigma(f)) and grafted (sigma(g)) polymers are different. The interactions between the two monolayers in the absence of the free polymer are always repulsive. However, in the presence of the free polymer, the force either can be purely repulsive or can have an attractive minimum depending upon the relative chain lengths of the free (N(f)) and grafted polymers (N(g)). The attractive minimum is observed only when the ratio alpha = N(f)/N(g) is greater than a critical value. We find that these critical values of alpha satisfy the following scaling relation: rho(g) square root(N(g)) beta(3) proportional to alpha(-lambda), where beta = sigma(f)/sigma(g) and lambda is the scaling exponent. For beta = 1 or the same segment sizes of the free and grafted polymers, this scaling relation is in agreement with those from previous theoretical studies using self-consistent field theory (SCFT). Detailed comparisons between iSAFT and SCFT are made for the structures of the monolayers and their forces of interaction. These comparisons lead to interesting implications for the modeling of nanocomposite thermodynamics.

Slopes of $pi$-meson spectra in the K $Yields$ 3$pi$ decays (in Russian)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kapustnikov, A.A.

1973-12-01

The strong violation ( approximates 35%) of the rule DELTA T = 1/2 on the Dalitz piot for the K yields 3 pi decays is considered in the framework of the nonlinear realization of the chiral SU(2) x SU(2) symmetry. The Lagrangian without derivatives obtained previously is used to describe the contact weak K pi interaction. It is postulated that the enhancement of effects related to the electromagnetic mass differences of pi and K mesons in the K yields 3 pi amplitudes is due to the PCAC modification: partial delta A = constant pi (1 - 2 alpha lambda /supmore » 2/ KK). At alpha = 0.8 the predictions of the model are shown to coincide with the experiment. (auth)« less

Orientation observed by Zeeman spectra of dissociated atoms and the interference in photoexcitations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kimura, Yasuyuki; Kasahara, Shunji; Kato, Hajime

2003-06-01

In a magnetic field, the wave number of a pump laser light polarized along the field was fixed to the isolated Cs{sub 2}D {sup 1}{sigma}{sub u}{sup +}(v=46, J=54)(leftarrow)X {sup 1}{sigma}{sub g}{sup +}(v=0, J=55) line, and the excitation spectrum of the dissociated Cs(6p {sup 2}P{sub 3/2}) atoms was measured by scanning the wave number of a probe laser light polarized perpendicular to the field. The population of each sublevel 6p {sup 2}P{sub 3/2,m{sub j}} of the dissociated atoms was determined from the line intensities in the m{sub j}-resolved excitation spectrum. The unequal population between the 6p {sup 2}P{sub 3/2,+verticalbarm{sub j}}{sub verticalbar}more » and 6p {sup 2}P{sub 3/2,-verticalbarm{sub j}}{sub verticalbar} levels (atomic orientation) was observed and it was enhanced as the magnetic-field strength was increased. The atomic orientation is shown to be induced by the interference between the indirect predissociation, which occurs by a combination of the spin-orbit coupling of the D {sup 1}{sigma}{sub u}{sup +} state with the (2){sup 3}{pi}{sub 0u} state and the L-uncoupling and Zeeman interactions between the (2){sup 3}{pi}{sub 0u} and dissociative (2){sup 3}{sigma}{sub u}{sup +} states, and the dissociation following a direct excitation to the (2){sup 3}{sigma}{sub u}{sup +} state, which is allowed by spin-orbit coupling of the (2){sup 3}{sigma}{sub u}{sup +} state with the B {sup 1}{pi}{sub u} state. It is demonstrated that the atomic orientation is produced by the photodissociation in the presence of an external magnetic field even when all degenerated molecular M=J,...,0,...,-J sublevels are excited by a light polarized linearly along the field.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ata, Metin; Baumgarten, Falk; Bautista, Julian

We present measurements of the Baryon Acoustic Oscillation (BAO) scale in redshift-space using the clustering of quasars. We consider a sample of 147,000 quasars from the extended Baryon Oscillation Spectroscopic Survey (eBOSS) distributed over 2044 square degrees with redshiftsmore » $0.8 < z < 2.2$ and measure their spherically-averaged clustering in both configuration and Fourier space. Our observational dataset and the 1400 simulated realizations of the dataset allow us to detect a preference for BAO that is greater than 2.5$$\\sigma$$. We determine the spherically averaged BAO distance to $z = 1.52$ to 4.4 per cent precision: $$D_V(z=1.52)=3855\\pm170 \\left(r_{\\rm d}/r_{\\rm d, fid}\\right)\\ $$Mpc. This is the first time the location of the BAO feature has been measured between redshifts 1 and 2. Our result is fully consistent with the prediction obtained by extrapolating the Planck flat $$\\Lambda$$CDM best-fit cosmology. All of our results are consistent with basic large-scale structure (LSS) theory, confirming quasars to be a reliable tracer of LSS, and provide a starting point for numerous cosmological tests to be performed with eBOSS quasar samples. We combine our result with previous, independent, BAO distance measurements to construct an updated BAO distance-ladder. Using these BAO data alone and marginalizing over the length of the standard ruler, we find $$\\Omega_{\\Lambda} > 0$$ at 6.5$$\\sigma$$ significance when testing a $$\\Lambda$$CDM model with free curvature.« less

The rotational spectrum of the CH radical in its a 4Sigma(-) state, studied by far-infrared laser magnetic resonance

NASA Technical Reports Server (NTRS)

Nelis, Thomas; Brown, John M.; Evenson, Kenneth M.

1990-01-01

The CH radical has been detected in its a 4Sigma(-) state by the technique of laser magnetic resonance at far-infrared wavelengths. Spectra relating to different spin components of the first three rotational transitions have been recorded. The molecule was generated either by the reaction of F atoms with CH4, with a trace of added oxygen or by the reaction of O atoms with C2H2. The observed resonances have been analyzed and fitted to determine the parameters of an effective Hamiltonian for a molecule in a 4Sigma state. The principal quantities determined are the rotational constant B0 = 451 138.434(94) MHz and the spin-spin parameter lambda(0) = 2785.83(18) MHz. Proton hyperfine parameters have also been determined.

Living the Creed: How Chapters of Sigma Lambda Beta International Fraternity, Inc., Contribute to Civic Engagement

ERIC Educational Resources Information Center

Del Real, Manuel

2017-01-01

National associations such as the Association of American Colleges and Universities (AAC&U) and Campus Compact create initiatives that promote service-learning and campus based service programs to improve civic engagement in higher education; they often fail to include Greek-letter organizations, especially Latino Greek-letter organizations,…

Constraints on Cosmological Parameters from the Angular Power Spectrum of a Combined 2500 deg$^2$ SPT-SZ and Planck Gravitational Lensing Map

DOE PAGES

Simard, G.; et al.

2018-06-20

We report constraints on cosmological parameters from the angular power spectrum of a cosmic microwave background (CMB) gravitational lensing potential map created using temperature data from 2500 degmore » $^2$ of South Pole Telescope (SPT) data supplemented with data from Planck in the same sky region, with the statistical power in the combined map primarily from the SPT data. We fit the corresponding lensing angular power spectrum to a model including cold dark matter and a cosmological constant ($$\\Lambda$$CDM), and to models with single-parameter extensions to $$\\Lambda$$CDM. We find constraints that are comparable to and consistent with constraints found using the full-sky Planck CMB lensing data. Specifically, we find $$\\sigma_8 \\Omega_{\\rm m}^{0.25}=0.598 \\pm 0.024$$ from the lensing data alone with relatively weak priors placed on the other $$\\Lambda$$CDM parameters. In combination with primary CMB data from Planck, we explore single-parameter extensions to the $$\\Lambda$$CDM model. We find $$\\Omega_k = -0.012^{+0.021}_{-0.023}$$ or $$M_{\

Constraints on Cosmological Parameters from the Angular Power Spectrum of a Combined 2500 deg$^2$ SPT-SZ and Planck Gravitational Lensing Map

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simard, G.; et al.

We report constraints on cosmological parameters from the angular power spectrum of a cosmic microwave background (CMB) gravitational lensing potential map created using temperature data from 2500 degmore » $^2$ of South Pole Telescope (SPT) data supplemented with data from Planck in the same sky region, with the statistical power in the combined map primarily from the SPT data. We fit the corresponding lensing angular power spectrum to a model including cold dark matter and a cosmological constant ($$\\Lambda$$CDM), and to models with single-parameter extensions to $$\\Lambda$$CDM. We find constraints that are comparable to and consistent with constraints found using the full-sky Planck CMB lensing data. Specifically, we find $$\\sigma_8 \\Omega_{\\rm m}^{0.25}=0.598 \\pm 0.024$$ from the lensing data alone with relatively weak priors placed on the other $$\\Lambda$$CDM parameters. In combination with primary CMB data from Planck, we explore single-parameter extensions to the $$\\Lambda$$CDM model. We find $$\\Omega_k = -0.012^{+0.021}_{-0.023}$$ or $$M_{\

Baryon masses and σ terms in SU(3) BChPT×1/N c

DOE PAGES

Fernando, Ishara P.; Alarcon-Soriano, Jose-Manuel; Goity, Jose Luis

2018-04-27

Baryon masses and nucleonmore » $$\\sigma$$ terms are studied with the effective theory that combines the chiral and $$1/N_c$$ expansions for three flavors. In particular the connection between the deviation of the Gell-Mann-Okubo relation and the $$\\sigma$$ term associated with the scalar density $$\\bar u u+\\bar d d-2\\bar s s$$ is emphasized. The latter is at lowest order related to a mass combination whose low value has given rise to a $$\\sigma$$ term puzzle. It is shown that while the nucleon $$\\sigma$$ terms have a well behaved low energy expansion, that mass combination is affected by large higher order corrections non-analytic in quark masses. Lastly, adding to the analysis lattice QCD baryon masses, it is found that $$\\sigma_{\\pi N}=69(10)$$~MeV and $$\\sigma_s$$ has natural magnitude within its relative large uncertainty.« less

Baryon masses and σ terms in SU(3) BChPT×1/N c

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fernando, Ishara P.; Alarcon-Soriano, Jose-Manuel; Goity, Jose Luis

Baryon masses and nucleonmore » $$\\sigma$$ terms are studied with the effective theory that combines the chiral and $$1/N_c$$ expansions for three flavors. In particular the connection between the deviation of the Gell-Mann-Okubo relation and the $$\\sigma$$ term associated with the scalar density $$\\bar u u+\\bar d d-2\\bar s s$$ is emphasized. The latter is at lowest order related to a mass combination whose low value has given rise to a $$\\sigma$$ term puzzle. It is shown that while the nucleon $$\\sigma$$ terms have a well behaved low energy expansion, that mass combination is affected by large higher order corrections non-analytic in quark masses. Lastly, adding to the analysis lattice QCD baryon masses, it is found that $$\\sigma_{\\pi N}=69(10)$$~MeV and $$\\sigma_s$$ has natural magnitude within its relative large uncertainty.« less

The lowest ionization potentials of Al2

NASA Technical Reports Server (NTRS)

Bauschlicher, Charles W., Jr.; Barnes, Leslie A.; Taylor, Peter R.

1988-01-01

Potential curves for the lowest two electronic states (X 2 sigma g + and A 2 pi u) of Al2(+) were computed using complete active space SCF/multireference CI wave functions and large Gaussian basis sets. The lowest observable vertical ionization potential (to Al2(+) X 2 sigma g +) of the Al2 X 3 pi u ground state is calculated to occur around 6.1 eV, in excellent agreement with the experimental range of 6.0 to 6.42 eV obtained in recent cluster ionization studies by Cox and co-workers. The second vertical ionization potential (to Al2(+) A 2 pi u) occurs near 6.4 eV, also within the experimental range. The adiabatic IP of 5.90 eV is in good agreement with the value of 5.8 to 6.1 eV deduced by Hanley and co-workers from the difference in thresholds between collision induced dissociation processes of Al3(+). The computed IP values are somewhat larger than those deduced from branching ratios in cluster fragmentation experiments by Jarrold and co-workers. The observation of an ionization threshold below 6.42 eV is shown to be incompatible with an Al2 ground electronic state assignment of 3 sigma g -, but the separation between the two lowest states of Al2 is so small that it is likely that both are populated in the experiments, so that this does not provide unambiguous support for the recent theoretical assignment of the ground state as 3 pi u.

Accounting for the differences in the structures and relative energies of the highly homoatomic np pi-np pi (n > or = 3)-bonded S2I4 2+, the Se-I pi-bonded Se2I4 2+, and their higher-energy isomers by AIM, MO, NBO, and VB methodologies.

PubMed

Brownridge, Scott; Crawford, Margaret-Jane; Du, Hongbin; Harcourt, Richard D; Knapp, Carsten; Laitinen, Risto S; Passmore, Jack; Rautiainen, J Mikko; Suontamo, Reijo J; Valkonen, Jussi

2007-02-05

The bonding in the highly homoatomic np pi-np pi (n > or = 3)-bonded S2I42+ (three sigma + two pi bonds), the Se-I pi-bonded Se2I42+ (four sigma + one pi bonds), and their higher-energy isomers have been studied using modern DFT and ab initio calculations and theoretical analysis methods: atoms in molecules (AIM), molecular orbital (MO), natural bond orbital (NBO), and valence bond (VB) analyses, giving their relative energies, theoretical bond orders, and atomic charges. The aim of this work was to seek theory-based answers to four main questions: (1) Are the previously proposed simple pi*-pi* bonding models valid for S2I42+ and Se2I42+? (2) What accounts for the difference in the structures of S2I42+ and Se2I42+? (3) Why are the classically bonded isolobal P2I4 and As2I4 structures not adopted? (4) Is the high experimentally observed S-S bond order supported by theoretical bond orders, and how does it relate to high bond orders between other heavier main group elements? The AIM analysis confirmed the high bond orders and established that the weak bonds observed in S2I42+ and Se2I42+ are real and the bonding in these cations is covalent in nature. The full MO analysis confirmed that S2I42+ contains three sigma and two pi bonds, that the positive charge is essentially equally distributed over all atoms, that the bonding between S2 and two I2+ units in S2I42+ is best described by two mutually perpendicular 4c2e pi*-pi* bonds, and that in Se2I42+, two SeI2+ moieties are joined by a 6c2e pi*-pi* bond, both in agreement with previously suggested models. The VB treatment provided a complementary approach to MO analysis and provided insight how the formation of the weak bonds affects the other bonds. The NBO analysis and the calculated AIM charges showed that the minimization of the electrostatic repulsion between EI2+ units (E = S, Se) and the delocalization of the positive charge are the main factors that explain why the nonclassical structures are favored for S2I42+ and Se2I42+. The difference in the structures of S2I42+ and Se2I42+ is related to the high strength of the S-S pi bond compared to the weak S-I sigma bond and the additional stabilization from increased delocalization of positive charge in the structure of S2I42+ compared to the structure of Se2I42+. The investigation of the E2X42+ series (E = S, Se, Te; X = Cl, Br, I) revealed that only S2I42+ adopts the highly np pi-np pi (n > or = 3)-bonded structure, while all other dications favor the pi-bonded Se2I42+ structure. Theoretical bond order calculations for S2I42+ confirm the previously presented experimentally based bond orders for S-S (2.1-2.3) and I-I (1.3-1.5) bonds. The S-S bond is determined to have the highest reported S-S bond order in an isolated compound and has a bond order that is either similar to or slightly less than the Si-Si bond order in the proposed triply bonded [(Me3Si)2CH]2(iPr)SiSi triple bond SiSi(iPr)[CH(SiMe3)2]2 depending on the definition of bond orders used.

Einstein coefficients for rotational lines of the (0,0) band of the NO A2sigma(+)-X2Pi system

NASA Technical Reports Server (NTRS)

Reisel, John R.; Carter, Campbell D.; Laurendeau, Normand M.

1992-01-01

A summary of the spectroscopic equations necessary for prediction of the molecular transition energies and the Einstein A and B coefficients for rovibronic lines of the gamma(0,0) band of nitric oxide (NO) is presented. The calculated molecular transition energies are all within 0.57/cm of published experimental values; in addition, over 95 percent of the calculated energies give agreement with measured results within 0.25/cm. Einstein coefficients are calculated from the band A00 value and the known Hoenl-London factors and are tabulated for individual rovibronic transitions in the NO A2sigma(+)-X2Pi(0,0) band.

A correlated ab initio study of linear carbon-chain radicals CnH (n = 2-7)

NASA Technical Reports Server (NTRS)

Woon, D. E.; Loew, G. H. (Principal Investigator)

1995-01-01

Linear carbon-chain radicals CnH for n = 2-7 have been studied with correlation consistent valence and core-valence basis sets and the coupled cluster method RCCSD(T). Equilibrium structures, rotational constants, and dipole moments are reported and compared with available experimental data. The ground state of the even-n series changes from 2 sigma+ to 2 pi as the chain is extended. For C4H, the 2 sigma+ state was found to lie only 72 cm-1 below the 2 pi state in the estimated complete basis set limit for valence correlation. The C2H- and C3H- anions have also been characterized.

Infrared renormalons and single meson production in proton-proton collisions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahmadov, A. I.; Aydin, Coskun; Hakan, Yilmaz A.

2009-07-01

In this article, we investigate the contribution of the higher-twist Feynman diagrams to the large-p{sub T} inclusive pion production cross section in proton-proton collisions and present the general formulas for the higher-twist differential cross sections in the case of the running coupling and frozen coupling approaches. The structure of infrared renormalon singularities of the higher-twist subprocess cross section and the resummed expression (the Borel sum) for it are found. We compared the resummed higher-twist cross sections with the ones obtained in the framework of the frozen coupling approach and leading-twist cross section. We obtain, that ratio R=({sigma}{sub {pi}{sup +}}{sup HT}){supmore » res}/({sigma}{sub {pi}{sup +}}{sup HT}){sup 0}, for all values of the transverse momentum p{sub T} of the pion identically equivalent to ratio r=({delta}{sub {pi}}{sup HT}){sup res}/({delta}{sub {pi}}{sup HT}){sup 0}. It is shown that the resummed result depends on the choice of the meson wave functions used in calculation. Phenomenological effects of the obtained results are discussed.« less

Improved Laboratory Values of the H{sub 2} Lyman and Werner Lines for Constraining Time Variation of the Proton-to-Electron Mass Ratio

DOE Office of Scientific and Technical Information (OSTI.GOV)

Salumbides, E. J.; Khramov, A.; Wolf, A. L.

2008-11-28

Two distinct high-accuracy laboratory spectroscopic investigations of the H{sub 2} molecule are reported. Anchor lines in the EF{sup 1}{sigma}{sub g}{sup +}-X{sup 1}{sigma}{sub g}{sup +} system are calibrated by two-photon deep-UV Doppler-free spectroscopy, while independent Fourier-transform spectroscopic measurements are performed that yield accurate spacings in the B{sup 1}{sigma}{sub u}{sup +}-EF{sup 1}{sigma}{sub g}{sup +} and I{sup 1}{pi}{sub g}-C{sup 1}{pi}{sub u} systems. From combination differences accurate transition wavelengths for the B-X Lyman and the C-X Werner lines can be determined with accuracies better than {approx}5x10{sup -9}, representing a major improvement over existing values. This metrology provides a practically exact database to extract amore » possible variation of the proton-to-electron mass ratio based on H{sub 2} lines in high-redshift objects. Moreover, it forms a rationale for equipping a future class of telescopes, carrying 30-40 m dishes, with novel spectrometers of higher resolving powers.« less

The Measurement of Strong-Interaction Effects in High-Z Sigma Hyperonic Atoms.

NASA Astrophysics Data System (ADS)

Phillips, William Clarke

Strong-interaction effects have been observed in the X-ray spectra of atoms formed with Sigma ^- in lead and tungsten. In the experiment, performed at the Alternating Gradient Synchrotron of Brookhaven National Laboratory, negative kaons were brought to rest in a novel laminar target consisting of thin sheets of high-Z material in a liquid hydrogen bath. The geometry of the target was designed to optimize the production of high-Z Sigma^- atoms and the detection of their subsequent de-excitation X rays. A method of identifying the energetic pi^+ from the production reaction K^-+ p toSigma^- +pi^+ resulted in a factor of 15 improvement in the signal-to -noise ratio of the Sigma^- atom X-rays over that of previous experiments. The X-ray spectra were recorded by three high-resolution intrinsic Ge detectors and analyzed for shifts, broadenings, and yield reductions of the final X-ray transitions before absorption of the Sigma^- into the nucleus. A lineshape function which reflected the non-Gaussian response of the X-ray spectroscopy system was developed for this analysis. The results are(UNFORMATTED TABLE OR EQUATION FOLLOWS)eqalign {Sigma^- - W (10to9): varepsilon = 650 +/- 30 eV,&quadGamma = 380 +/- 70 eV,quad %Y = .98 +/- .04cr Sigma^- - Pb (10to9): varepsilon = 510 +/- 50 eV,&quadGamma = 290 +/- 140 eV, quad %Y = .53 +/- .04cr} (TABLE/EQUATION ENDS)where varepsilon = E_{rm meds} - E_{rm calc }, Gamma is the Lorentzian FWHM, and %Y is the ratio (measured yield)/(yield calculated with no strong interaction). Optical model calculations with a = (0.928 + i0.022) fm are able to reproduce all observed effects in the Sigma^--W spectra. Such calculations with a = (0.247 + i0.039) fm reproduce the observed shift and width of the (10to9) transition in Sigma^--Pb, but fail to reproduce the observed yield reduction. It is doubtful if the current status of the theory of Sigma ^--N interactions can explain this discrepancy.

Ligand-to-ligand charge-transfer transitions of platinum(II) complexes with arylacetylide ligands with different chain lengths: spectroscopic characterization, effect of molecular conformations, and density functional theory calculations.

PubMed

Tong, Glenna So Ming; Law, Yuen-Chi; Kui, Steven C F; Zhu, Nianyong; Leung, King Hong; Phillips, David Lee; Che, Chi-Ming

2010-06-11

The complexes [Pt(tBu(3)tpy){C[triple bond]C(C(6)H(4)C[triple bond]C)(n-1)R}](+) (n = 1: R = alkyl and aryl (Ar); n = 1-3: R = phenyl (Ph) or Ph-N(CH(3))(2)-4; n = 1 and 2, R = Ph-NH(2)-4; tBu(3)tpy = 4,4',4''-tri-tert-butyl-2,2':6',2''-terpyridine) and [Pt(Cl(3)tpy)(C[triple bond]CR)](+) (R = tert-butyl (tBu), Ph, 9,9'-dibutylfluorene, 9,9'-dibutyl-7-dimethyl-amine-fluorene; Cl(3)tpy = 4,4',4''-trichloro-2,2':6',2''-terpyridine) were prepared. The effects of substituent(s) on the terpyridine (tpy) and acetylide ligands and chain length of arylacetylide ligands on the absorption and emission spectra were examined. Resonance Raman (RR) spectra of [Pt(tBu(3)tpy)(C[triple bond]CR)](+) (R = n-butyl, Ph, and C(6)H(4)-OCH(3)-4) obtained in acetonitrile at 298 K reveal that the structural distortion of the C[triple bond]C bond in the electronic excited state obtained by 502.9 nm excitation is substantially larger than that obtained by 416 nm excitation. Density functional theory (DFT) and time-dependent DFT (TDDFT) calculations on [Pt(H(3)tpy)(C[triple bond]CR)](+) (R = n-propyl (nPr), 2-pyridyl (Py)), [Pt(H(3)tpy){C[triple bond]C(C(6)H(4)C[triple bond]C)(n-1)Ph}](+) (n = 1-3), and [Pt(H(3)tpy){C[triple bond]C(C(6)H(4)C[triple bond]C)(n-1)C(6)H(4)-N(CH(3))(2)-4}](+)/+H(+) (n = 1-3; H(3)tpy = nonsubstituted terpyridine) at two different conformations were performed, namely, with the phenyl rings of the arylacetylide ligands coplanar ("cop") with and perpendicular ("per") to the H(3)tpy ligand. Combining the experimental data and calculated results, the two lowest energy absorption peak maxima, lambda(1) and lambda(2), of [Pt(Y(3)tpy)(C[triple bond]CR)](+) (Y = tBu or Cl, R = aryl) are attributed to (1)[pi(C[triple bond]CR)-->pi*(Y(3)tpy)] in the "cop" conformation and mixed (1)[d(pi)(Pt)-->pi*(Y(3)tpy)]/(1)[pi(C[triple bond]CR)-->pi*(Y(3)tpy)] transitions in the "per" conformation. The lowest energy absorption peak lambda(1) for [Pt(tBu(3)tpy){C[triple bond]C(C(6)H(4)C[triple bond]C)(n-1)C(6)H(4)-H-4}](+) (n = 1-3) shows a redshift with increasing chain length. However, for [Pt(tBu(3)tpy){C[triple bond]C(C6H4C[triple bond]C)(n-1)C(6)H(4)-N(CH(3))(2)-4}](+) (n = 1-3), lambda(1) shows a blueshift with increasing chain length n, but shows a redshift after the addition of acid. The emissions of [Pt(Y(3)tpy)(C[triple bond]CR)](+) (Y = tBu or Cl) at 524-642 nm measured in dichloromethane at 298 K are assigned to the (3)[pi(C[triple bond]CAr)-->pi*(Y(3)tpy)] excited states and mixed (3)[d(pi)(Pt)-->pi*(Y(3)tpy)]/(3)[pi(C[triple bond]C)-->pi*(Y(3)tpy)] excited states for R = aryl and alkyl groups, respectively. [Pt(tBu(3)tpy){C[triple bond]C(C(6)H(4)C[triple bond]C)(n-1)C(6)H(4)-N(CH(3))(2)-4}](+) (n = 1 and 2) are nonemissive, and this is attributed to the small energy gap between the singlet ground state (S(0)) and the lowest triplet excited state (T(1)).

Interferometric apparatus for ultra-high precision displacement measurement

NASA Technical Reports Server (NTRS)

Zhao, Feng (Inventor)

2004-01-01

A high-precision heterodyne interferometer measures relative displacement by creating a thermally-insensitive system generally not subject to polarization leakage. By using first and second light beams separated by a small frequency difference (.DELTA.f), beams of light at the first frequency (f.sub.0) are reflected by co-axial mirrors, the first mirror of which has a central aperture through which the light is transmitted to and reflected by the second mirror. Prior to detection, the light beams from the two mirrors are combined with light of the second and slightly different frequency. The combined light beams are separated according to the light from the mirrors. The change in phase (.DELTA..phi.) with respect to the two signals is proportional to the change in distance of Fiducial B by a factor of wavelength (.lambda.) divided by 4.pi. (.DELTA.L=.lambda..DELTA..phi.1/(4.pi.)). In a second embodiment, a polarizing beam splitting system can be used.

Measurement of the eta-meson mass using psi(2S) --> etaJ/psi.

PubMed

Miller, D H; Sanghi, B; Shipsey, I P J; Xin, B; Adams, G S; Anderson, M; Cummings, J P; Danko, I; Ge, J Y; Hu, D; Moziak, B; Napolitano, J; He, Q; Insler, J; Muramatsu, H; Park, C S; Thorndike, E H; Yang, F; Artuso, M; Blusk, S; Khalil, S; Li, J; Menaa, N; Mountain, R; Nisar, S; Randrianarivony, K; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Bonvicini, G; Cinabro, D; Dubrovin, M; Lincoln, A; Asner, D M; Edwards, K W; Naik, P; Briere, R A; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Adam, N E; Alexander, J P; Cassel, D G; Duboscq, J E; Ehrlich, R; Fields, L; Gibbons, L; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Mohapatra, D; Onyisi, P U E; Patterson, J R; Peterson, D; Riley, D; Ryd, A; Sadoff, A J; Shi, X; Stroiney, S; Sun, W M; Wilksen, T; Athar, S B; Patel, R; Yelton, J; Rubin, P; Eisenstein, B I; Karliner, I; Lowrey, N; Selen, M; White, E J; Wiss, J; Mitchell, R E; Shepherd, M R; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Poling, R; Scott, A W; Zweber, P; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Ernst, J; Ecklund, K M; Severini, H; Love, W; Savinov, V; Lopez, A; Mehrabyan, S; Mendez, H; Ramirez, J

2007-09-21

We measure the mass of the eta meson using psi(2S) --> etaJ/psi events acquired with the CLEO-c detector operating at the CESR e(+)e(-) collider. Using the four decay modes eta --> gamma gamma, 3pi(0), pi(+)pi(-)pi(0), and pi(+)pi(-)gamma, we find M(eta) = 547.785 +/- 0.017 +/- 0.057 MeV, in which the first uncertainty is statistical and the second systematic. This result has an uncertainty comparable to the two most precise previous measurements and is consistent with that of NA48, but is inconsistent at the level of 6.5 sigma with the much smaller mass obtained by GEM.

Photoproduction of Λ and Σ 0 hyperons using linearly polarized photons

DOE PAGES

Paterson, C. A.; Ireland, D. G.; Livingston, K.; ...

2016-06-08

Measurements of polarization observables for the reactionsmore » $$\\vec{\\gamma} p \\rightarrow K^+ \\Lambda$$ and $$\\vec{\\gamma} p \\rightarrow K^+ \\Sigma^0$$ have been performed. This is part of a programme of measurements designed to study the spectrum of baryon resonances. The accurate measurement of several polarization observables provides tight constraints for phenomenological fits. Beam-recoil observables for the $$\\vec{\\gamma} p \\rightarrow K^+ \\Sigma^0$$ reaction have not been reported before now. Furthermore, the measurements were carried out using linearly polarized photon beams and the CLAS detector at the Thomas Jefferson National Accelerator Facility. The energy range of the results is 1.71GeV.« less

Dynamical coupled-channels study of pi N --> pi pi N reactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kamano, Hiroyuki; Julia Diaz, Bruno; Lee, Tsung-Shung

2009-01-01

As a step toward performing a complete coupled-channels analysis of the world data of pi N, gamma^* N --> pi N, eta N, pi pi N reactions, the pi N --> pi pi N reactions are investigated starting with the dynamical coupled-channels model developed in Phys. Rev. C76, 065201 (2007). The channels included are pi N, eta N, and pi pi N which has pi Delta, rho N, and sigma N resonant components. The non-resonant amplitudes are generated from solving a set of coupled-channels equations with the meson-baryon potentials defined by effective Lagrangians. The resonant amplitudes are generated from 16more » bare excited nucleon (N^*) states which are dressed by the non-resonant interactions as constrained by the unitarity condition. The available total cross section data of pi^+ p --> pi^+ pi^+ n, pi^+ pi^0 and pi^- p --> pi^+ pi^- n, pi^- pi^0 n, pi^0 pi^0 n can be reproduced to a very large extent both in magnitudes and energy-dependence. Possible improvements of the model are investigated, in p« less

A Dependence Study of $$\\Xi^{*0}$$ and $$\\bar{\\Xi}^{*0}$$ in 250 GeV/c $$\\pi^-$$. $K^-$ -nucleon Interactions (in Portuguese)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seixas de Rezende, Fabio Antonio; /Rio de Janeiro, CBPF

A direct measurement of the mass number (A) dependence of the production of the hyperon {Xi}*{sup 0} and its opposite {bar {Xi}}*{sup 0} in {pi}{sup -}, K{sup -} beam-nucleon interactions at 250 GeV/c is reported. The data derive from the experiment E769 at Fermilab. The results were obtained for different targets: Be, Al, Cu and W. It was observed the data are found to be well described by the parametrization {sigma}{sub A} = {sigma}{sub 0}A{sup {alpha}}, {alpha} being calculated for different beams. The results obtained are compared with those results of E769 experiment. The results shown here are preliminary.

Calculated hydroxyl A2 sigma --> X2 pi (0, 0) band emission rate factors applicable to atmospheric spectroscopy

NASA Technical Reports Server (NTRS)

Cageao, R. P.; Ha, Y. L.; Jiang, Y.; Morgan, M. F.; Yung, Y. L.; Sander, S. P.

1997-01-01

A calculation of the A2 sigma --> X2 pi (0, 0) band emission rate factors and line center absorption cross sections of OH applicable to its measurement using solar resonant fluorescence in the terrestrial atmosphere is presented in this paper. The most accurate available line parameters have been used. Special consideration has been given to the solar input flux because of its highly structured Fraunhofer spectrum. The calculation for the OH atmospheric emission rate factor in the solar resonant fluorescent case is described in detail with examples and intermediate results. Results of this calculation of OH emission rate factors for individual rotational lines are on average 30% lower than the values obtained in an earlier work.

A Correlated Ab Initio Study of Linear Carbon-Chain Radicals C(sub n)H (n=2-7)

NASA Technical Reports Server (NTRS)

Woon, David E.

1995-01-01

Linear carbon-chain radicals C(sub n) H for n = 2-7 have been studied with correlation consistent valence and core-valence basis sets and the coupled cluster method RCCSD(T). Equilibrium structures, rotational constants, and dipole moments are reported and compared with available experimental data. The ground state of the even-n series changes from 2Sigma(+) to 2Pi as the chain is extended. For C4H, the 2Sigma(+) state was found to lie only 72 cm(exp -1) below the 2Pi state in the estimated complete basis set limit for valence correlation. The C2H(-) and C3H(-) anions have also been characterized.

Mutation induction in bacteria after heavy ion irradiation

NASA Technical Reports Server (NTRS)

Horneck, G.; Kozubek, S.

1994-01-01

From a compilation of experimental data on the mutagenic effects of heavy ions in bacteria, main conclusions have been drawn as follows: (1) The mutagenic efficacy of heavy ions in bacteria depends on physical and biological variables. Physical variables are the radiation dose, energy and charge of the ion; the biological variables are the bacterial strain, the repair genotype of bacteria, and the endpoint investigated (type of mutation, induction of enzymes related to mutagenesis); (2) The responses on dose or fluence are mainly linear or linear quadratic. The quadratic component, if found for low LET radiation, is gradually reduced with increasing LET; (3) At low values of Z and LET the cross section of mutation induction sigma m (as well as SOS response, sigma sos. and lambda phage induction, sigma lambda versus LET curves can be quite consistently described by a common function which increases up to approximately 100 keV/mu m. For higher LET values, the sigma(m) versus LET curves show the so-called 'hooks' observed also for other endpoints; (4) For light ions (Z is less than or equal to 4), the cross sections mostly decrease with increasing ion energy, which is probably related to the decrease of the specific energy departed by the ion inside the sensitive volume (cell). For ions in the range of Z = 10, sigma(m) is nearly independent on the ion energy. For heavier ions (Z is greater than or equal to 16), sigma(m) increases with the energy up to a maximum or saturation around 10 MeV/u. The increment becomes steeper with increasing atomic number of the ion. It correlates with the increasing track radius of the heavy ion; (5) The mutagenic efficiency per lethal event changes slightly with ion energy, if Z is small indicating a rough correlation between cellular lethality and mutation induction, only. For ions of higher Z this relation increases with energy, indicating a change in the 'mode' of radiation action from 'killing-prone' to 'mutation-prone'; and (6) Repair genotype substantially influences the radiation induced mutagenesis. Different mechanisms of mutation induction and/or different types of biologically significant lesions in wild type cells compared to repair deficient strains are a likely explanation.

Inversion of the anomalous diffraction approximation for variable complex index of refraction near unity. [numerical tests for water-haze aerosol model

NASA Technical Reports Server (NTRS)

Smith, C. B.

1982-01-01

The Fymat analytic inversion method for retrieving a particle-area distribution function from anomalous diffraction multispectral extinction data and total area is generalized to the case of a variable complex refractive index m(lambda) near unity depending on spectral wavelength lambda. Inversion tests are presented for a water-haze aerosol model. An upper-phase shift limit of 5 pi/2 retrieved an accurate peak area distribution profile. Analytical corrections using both the total number and area improved the inversion.

Measurement of absolute hadronic branching fractions of D mesons and e+e- -->DD cross sections at Ec.m.=3773 MeV.

PubMed

He, Q; Muramatsu, H; Park, C S; Park, W; Thorndike, E H; Coan, T E; Gao, Y S; Liu, F; Artuso, M; Boulahouache, C; Blusk, S; Butt, J; Dambasuren, E; Dorjkhaidav, O; Li, J; Menaa, N; Mountain, R; Nandakumar, R; Randrianarivony, K; Redjimi, R; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Zhang, K; Csorna, S E; Bonvicini, G; Cinabro, D; Dubrovin, M; Briere, R A; Chen, G P; Chen, J; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Adam, N E; Alexander, J P; Berkelman, K; Cassel, D G; Crede, V; Duboscq, J E; Ecklund, K M; Ehrlich, R; Fields, L; Gibbons, L; Gittelman, B; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Hsu, L; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Meyer, T O; Onyisi, P U E; Patterson, J R; Peterson, D; Phillips, E A; Pivarski, J; Riley, D; Ryd, A; Sadoff, A J; Schwarthoff, H; Shi, X; Shepherd, M R; Stroiney, S; Sun, W M; Urner, D; Weaver, K M; Wilksen, T; Weinberger, M; Athar, S B; Avery, P; Breva-Newell, L; Patel, R; Potlia, V; Stoeck, H; Yelton, J; Rubin, P; Cawlfield, C; Eisenstein, B I; Gollin, G D; Karliner, I; Kim, D; Lowrey, N; Naik, P; Sedlack, C; Selen, M; Williams, J; Wiss, J; Edwards, K W; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Gong, D T; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Li, S Z; Poling, R; Scott, A W; Smith, A; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Zweber, P; Ernst, J; Mahmood, A H; Severini, H; Asner, D M; Dytman, S A; Love, W; Mehrabyan, S; Mueller, J A; Savinov, V; Li, Z; Lopez, A; Mendez, H; Ramirez, J; Huang, G S; Miller, D H; Pavlunin, V; Sanghi, B; Shipsey, I P J; Adams, G S; Chasse, M; Cravey, M; Cummings, J P; Danko, I; Napolitano, J

2005-09-16

Using 55.8 pb(-1) of e+e- collisions recorded at the psi(3770) resonance with the CLEO-c detector at CESR, we determine absolute hadronic branching fractions of charged and neutral D mesons using a double tag technique. Among measurements for three D0 and six D+ modes, we obtain reference branching fractions B(D0-->K-pi+)=(3.91+/-0.08+/-0.09)% and B(D+-->K-pi+pi+)=(9.5+/-0.2+/-0.3)%, where the uncertainties are statistical and systematic, respectively. Final state radiation is included in these branching fractions by allowing for additional, unobserved, photons in the final state. Using a determination of the integrated luminosity, we also extract the cross sections sigma(e+e- -->D0D0)=(3.60+/-0.07(+0.07)(-0.05)) nb and sigma(e+e- -->D+D-)=(2.79+/-0.07(+0.10)(-0.04)) nb.

Multinucleon pion absorption in the sup 4 He(. pi. sup + , ppp ) n reaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weber, P.; McAlister, J.; Olszewski, R.

1991-04-01

Three-proton emission cross sections for the {sup 4}He({pi}{sup +},{ital ppp}){ital n} reaction were measured at an incident pion kinetic energy of {ital T}{sub {pi}}{sup +}=165 MeV over a wide angular range in a kinematically complete experiment. Angular correlations, missing momentum distributions, and energy spectra are compared with three- and four-body phase-space Monte Carlo calculations. The results provide strong evidence that most of the three-proton coincidences result from three-nucleon absorption. From phase-space integration the total three-nucleon absorption cross section is estimated to be {sigma}{sup 3{ital N}}=4.8{plus minus}1.0 mb. The cross section involving four nucleons is small and is estimated to bemore » {sigma}{sup 4{ital N}}{lt}2 mb. On the scale of the total absorption cross section in {sup 4}He, multinucleon pion absorption seems to represent only a small fraction.« less

On the equivalence of some spectral sequences for Serre fibrations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Onishchenko, Aleksandr Yu; Popelenskii, Fedor Yu

2011-04-30

Several different constructions of a spectral sequence for a Serre fibration {pi}:E{yields}B over a compact simply connected manifold B are considered in this paper. Namely, we consider the spectral sequence for the minimal model ({Lambda}Vx{Lambda}W,d) of the fibration, along with the spectral sequences arising from the Cech filtration in the complexes C*(U,A*{sub PL}({pi}{sup -1}(U))) and C*(U,S*({pi}{sup -1}(U))), where U=(U) is a covering of the base B. It is known that all these spectral sequences have the same terms E{sub 2}*{sup ,}*=H*(X)xH{sup *}(F) and converge to the cohomology of the total space E. A new natural isomorphism of these spectral sequencesmore » is constructed in every term E{sub r} with r{>=}2. It is also proved that in the case of a smooth locally trivial fibration these spectral sequences are isomorphic to the spectral sequences of the complex of smooth forms {Omega}*(E) and of the Cech-de Rham complex. It is therefore established that all these constructions give the same spectral sequence, starting from the E{sub 2} term. Bibliography: 9 titles.« less

On the equivalence of some spectral sequences for Serre fibrations

NASA Astrophysics Data System (ADS)

Onishchenko, Aleksandr Yu; Popelenskii, Fedor Yu

2011-04-01

Several different constructions of a spectral sequence for a Serre fibration \\pi\\colon E \\to B over a compact simply connected manifold B are considered in this paper. Namely, we consider the spectral sequence for the minimal model (\\Lambda V\\otimes \\Lambda W,d) of the fibration, along with the spectral sequences arising from the Čech filtration in the complexes \\check{C}^*(\\mathscr{U}, A_{PL}^*(\\pi^{-1}(U))) and \\check{C}^*(\\mathscr{U}, S^*(\\pi^{-1}(U))), where \\mathscr{U}=\\{U\\} is a covering of the base B. It is known that all these spectral sequences have the same terms E_2^{*,*}=H^*(X)\\otimes H^*(F) and converge to the cohomology of the total space E. A new natural isomorphism of these spectral sequences is constructed in every term E_r with r\\ge2. It is also proved that in the case of a smooth locally trivial fibration these spectral sequences are isomorphic to the spectral sequences of the complex of smooth forms \\Omega^*(E) and of the Čech-de Rham complex. It is therefore established that all these constructions give the same spectral sequence, starting from the E_2 term. Bibliography: 9 titles.

Molecular Line and Continuum Opacities for Modeling of Extrasolar Giant Planet and Cool Stellar Atmospheres

NASA Technical Reports Server (NTRS)

Weck, P. F.; Schweitzer, A.; Stancil, P. C.; Hauschildt, P. H.; Kirby, K.; Yamaguchi, Y.; Allen, W. D.

2002-01-01

The molecular line and continuum opacities are investigated in the atmospheres of cool stars and Extrasolar Giant Planets (EGPs). Using a combination of ab inito and experimentally derived potential curves and dipole transition moments, accurate data have been calculated for rovibrationally-resolved oscillator strengths and photodissociation cross sections in the B' (sup 2)Sigma+ (left arrow) X (sup 2)Sigma+ and A (sup 2)Pi (left arrow) X (sup 2)Sigma+ band systems in MgH. We also report our progress on the study of the electronic structure of LiCl and FeH.

Directional properties in photodissociation: a probe for the symmetry and geometry of excited states of dimethylnitrosamine and tert-butyl nitrite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lavi, R.; Schwartz-Lavi, I.B.; Rosenwaks, S.

1987-10-08

The rotational alignment, ..lambda..-doubling, and spin-orbit populations of the NO fragment following the photodissociation of (CH/sub 3/)/sub 2/NNO and (CH/sub 3/)/sub 3/CONO in different absorption bands are determined. The results for the S/sub 1/(n..pi..*) withdraws S/sub 0/ and S/sub 2/(..pi pi..*) withdraws S/sub 0/ transitions in both molecules indicate planarity of the fragmentation processes and an A'' symmetry of the S/sub 1/ state. For the S/sub 2/(..pi pi..*) withdraws S/sub 0/ transition in (CH/sub 3/)/sub 2/NNO the results imply an A' symmetry of the S/sub 2/ state. The values obtained for the alignment are indicative of the difference between themore » directions of the transition dipole moment for the S/sub 1/(n..pi..*) withdraws S/sub 0/ and the S/sub 2/(..pi pi..*) withdraws S/sub 0/ transitions.« less

Global analysis of data on the spin-orbit-coupled A {sup 1{Sigma}}{sub u}{sup +} and b {sup 3{Pi}}{sub u} states of Cs{sub 2}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bai, Jianmei; Ahmed, E. H.; Beser, B.

2011-03-15

We present experimentally derived potential curves and spin-orbit interaction functions for the strongly perturbed A {sup 1{Sigma}}{sub u}{sup +} and b {sup 3{Pi}}{sub u} states of the cesium dimer. The results are based on data from several sources. Laser-induced fluorescence Fourier transform spectroscopy (LIF FTS) was used some time ago in the Laboratoire Aime Cotton primarily to study the X {sup 1{Sigma}}{sub g}{sup +} state. More recent work at Tsinghua University provides information from moderate resolution spectroscopy on the lowest levels of the b {sup 3{Pi}}{sub 0u}{sup {+-}} state as well as additional high-resolution data. From Innsbruck University, we havemore » precision data obtained with cold Cs{sub 2} molecules. Recent data from Temple University was obtained using the optical-optical double resonance polarization spectroscopy technique, and finally, a group at the University of Latvia has added additional LIF FTS data. In the Hamiltonian matrix, we have used analytic potentials (the expanded Morse oscillator form) with both finite-difference (FD) coupled-channel and discrete variable representation (DVR) calculations of the term values. Fitted diagonal and off-diagonal spin-orbit functions are obtained and compared with ab initio results from Temple and Moscow State universities.« less

ABSOLUTE INTEGRAL CROSS SECTIONS AND PRODUCT BRANCHING RATIOS FOR THE VIBRATIONALLY SELECTED ION-MOLECULE REACTIONS: N{sub 2}{sup +}(X {sup 2}{Sigma}{sub g}{sup +}; v {sup +} = 0-2) + CH{sub 4}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu Yuntao; Chang, Yih Chung; Lu Zhou

Absolute vibrationally selected integral cross sections ({sigma}{sub v+}'s) for the ion-molecule reaction N{sub 2}{sup +}(X {sup 2}{Sigma}{sub g}{sup +}; v {sup +} = 0-2) + CH{sub 4} have been measured by using the newly developed vacuum ultraviolet (VUV) laser pulsed field ionization-photoion (PFI-PI) double-quadrupole-double-octopole ion guide apparatus. By employing a novel electric field pulsing scheme to the VUV laser PFI-PI source, we have been able to prepare reactant N{sub 2}{sup +} ions in single-vibrational quantum states with not only high intensity and high purity but also high kinetic energy resolution, allowing integral cross section measurements to be conducted in themore » center-of-mass kinetic energies (E{sub cm}'s) from 0.05 to 10.00 eV. Three primary product channels corresponding to the formations of CH{sub 3}{sup +}, CH{sub 2}{sup +}, and N{sub 2}H{sup +} were identified. After correcting for the secondary reactions involving CH{sub 3}{sup +} and CH{sub 2}{sup +}, we have determined the {sigma}{sub v+} values of the formation of these primary product ions, {sigma}{sub v+}(CH{sub 3}{sup +}), {sigma}{sub v+}(CH{sub 2}{sup +}), and {sigma}{sub v+}(N{sub 2}H{sup +}), and their branching ratios, [{sigma}{sub v+}(CH{sub 3}{sup +}): {sigma}{sub v+}(CH{sub 2}{sup +}): {sigma}{sub v+}(N{sub 2}H{sup +})]/{sigma}{sub v+}(CH{sub 3}{sup +} + CH{sub 2}{sup +} + N{sub 2}H{sup +}), v {sup +} = 0-2, in the E{sub cm} range of 0.05-10.00 eV, where {sigma}{sub v+}(CH{sub 3}{sup +} + CH{sub 2}{sup +} + N{sub 2}H{sup +}) = {sigma}{sub v+}(CH{sub 3}{sup +}) + {sigma}{sub v+}(CH{sub 2}{sup +}) + {sigma}{sub v+}(N{sub 2}H{sup +}). The branching ratios are found to be nearly independent of the v {sup +} state and E{sub cm}. Complex v {sup +}-state and E{sub cm} dependences for {sigma}{sub v+}(CH{sub 3}{sup +}), {sigma}{sub v+}(CH{sub 2}{sup +}), and {sigma}{sub v+}(N{sub 2}H{sup +}) along with vibrational inhibition for the formation of these product ions are observed. The vibrational effects on the {sigma}{sub v+} values are sufficiently large to warrant the inclusion of the vibrationally excited reactions N{sub 2}{sup +}(X {sup 2}{Sigma}{sub g}{sup +}; v {sup +} {>=} 1) + CH{sub 4} for a more realistic modeling of the ion and neutral densities observed in the atmosphere of Titan. The cross-sectional data obtained in the present study are also useful for benchmarking theoretical calculations on ion-neutral collision dynamics.« less

Dependence of the Normalized Radar Cross Section of Water Waves on Bragg Wavelength-Wind Speed Sensitivity

NASA Technical Reports Server (NTRS)

Long, David G.; Collyer, R. Scott; Reed, Ryan; Arnold, David V.

1996-01-01

Measurements of the normalized radar cross section (sigma(sup o)) made by the YSCAT ultrawideband scatterometer during an extended deployment on the Canada Centre for Inland Waters(CCIW) Research Tower located at Lake Ontario are analyzed and compared with anemometer wind measurements to study the sensitivity of (sigma(sup o)) to the wind speed as a function of the Bragg wavelength. This paper concentrates on upwind and downwind azimuth angles in the wind speed range of 4.5-12 m/s. While YSCAT collected measurements of sigma(sup o) at a variety of frequencies and incidence angles, this paper focuses on frequencies of 2.0, 3.05, 5.30, 10.02, and 14.0 GHz and incidence angles within the Bragg regime, 30-50 deg. Adopting a power law model to describe the relationship between sigma(sup o) and wind speed, both wind speed exponents and upwind/downwind (u/d) ratios of sigma(sup o) are found using least squares linear regression. The analysis of the wind speed exponents and u/d ratios show that shorter Bragg wavelengths (Lambda less than 4 cm) are the most sensitive to wind speed and direction. Additionally, vertical polarization (V-pol) sigma(sup o) is shown to be more sensitive to wind speed than horizontal polarization (H-pol) sigma(sup o), while the H-pol u/d ratio is larger than the V-pol u/d ratio.

Study of. lambda. parameters and crossover phenomena in SU(N) x SU(N) sigma models in two dimensions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shigemitsu, J; Kogut, J B

1981-01-01

The spin system analogues of recent studies of the string tension and ..lambda.. parameters of SU(N) gauge theories in 4 dimensions are carried out for the SU(N) x SU(N) and O(N) models in 2 dimensions. The relations between the ..lambda.. parameters of both the Euclidean and Hamiltonian formulation of the lattice models and the ..lambda.. parameter of the continuum models are obtained. The one loop finite renormalization of the speed of light in the lattice Hamiltonian formulations of the O(N) and SU(N) x SU(N) models is calculated. Strong coupling calculations of the mass gaps of these spin models are donemore » for all N and the constants of proportionality between the gap and the ..lambda.. parameter of the continuum models are obtained. These results are contrasted with similar calculations for the SU(N) gauge models in 3+1 dimensions. Identifying suitable coupling constants for discussing the N ..-->.. infinity limits, the numerical results suggest that the crossover from weak to strong coupling in the lattice O(N) models becomes less abrupt as N increases while the crossover for the SU(N) x SU(N) models becomes more abrupt. The crossover in SU(N) gauge theories also becomes more abrupt with increasing N, however, at an even greater rate than in the SU(N) x SU(N) spin models.« less

Pi-metal complexes of tetrapyrrolic systems. A novel coordination mode in "porphyrin-like" chemistry.

PubMed

Cuesta, Luciano; Sessler, Jonathan L

2009-09-01

The coordination chemistry of porphyrins and related tetrapyrrolic ligands has traditionally centered around the ability of these systems to form pyrrole N-ligated complexes via the formation of sigma bonds, either within the N(4) core or displaced above it. In fact, such sigma-complexes are known with almost every metal cation in the periodic table. However, a growing number of pi-complexes derived from tetrapyrrolic ligands have been reported in recent years. The underlying coordination mode, while still novel in the context of "porphyrin-like" chemistry, is already being recognized for the effects it can impart over the reactivity, as well as the spectroscopic, redox, electronic, and optical properties of various oligopyrrolic macrocycles. This critical review summarizes accomplishments made in this fast-emerging field (59 references).

Volcanic Signatures in Estimates of Stratospheric Aerosol Size, Distribution Width, Surface Area, and Volume Deduced from Global Satellite-Based Observations

NASA Technical Reports Server (NTRS)

Bauman, J. J.; Russell, P. B.

2000-01-01

Volcanic signatures in the stratospheric aerosol layer are revealed by two independent techniques which retrieve aerosol information from global satellite-based observations of particulate extinction. Both techniques combine the 4-wavelength Stratospheric Aerosol and Gas Experiment (SAGE) II extinction measurements (0.385 <= lambda <= 1.02 microns) with the 7.96 micron and 12.82 micron extinction measurements from the Cryogenic Limb Array Etalon Spectrometer (CLAES) instrument. The algorithms use the SAGE II/CLAES composite extinction spectra in month-latitude-altitude bins to retrieve values and uncertainties of particle effective radius R(sub eff), surface area S, volume V and size distribution width sigma(sub R). The first technique is a multi-wavelength Look-Up-Table (LUT) algorithm which retrieves values and uncertainties of R(sub eff) by comparing ratios of extinctions from SAGE II and CLAES (e.g., E(sub lambda)/E(sub 1.02) to pre-computed extinction ratios which are based on a range of unimodal lognormal size distributions. The pre-computed ratios are presented as a function of R(sub eff) for a given sigma(sub g); thus the comparisons establish the range of R(sub eff) consistent with the measured spectra for that sigma(sub g). The fact that no solutions are found for certain sigma(sub g) values provides information on the acceptable range of sigma(sub g), which is found to evolve in response to volcanic injections and removal periods. Analogous comparisons using absolute extinction spectra and error bars establish the range of S and V. The second technique is a Parameter Search Technique (PST) which estimates R(sub eff) and sigma(sub g) within a month-latitude-altitude bin by minimizing the chi-squared values obtained by comparing the SAGE II/CLAES extinction spectra and error bars with spectra calculated by varying the lognormal fitting parameters: R(sub eff), sigma(sub g), and the total number of particles N(sub 0). For both techniques, possible biases in retrieved-parameters caused by assuming a unimodal functional form are removed using correction factors computed from representative in situ measurements of bimodal size distributions. Some interesting features revealed by the LUT and PST retrievals include: (1) Increases in S and V (but not R(sub eff)) after the Ruiz and Kelut injections, (2) Increases in S, V, R(sub eff) after Pinatubo, (3) Post-Pinatubo increases in S, V, and R(sub eff) that are more rapid in the tropics than elsewhere, (4) Mid-latitude post-Pinatubo increases in R(sub eff) that lag increases in S and V, (5) S and V returning to pre-Pinatubo values sooner than R(sub eff) does, (6) Sharp increases in sigma(sub g), after Pinatubo and slight increases in sigma(sub g) after Ruiz, Etna, Kelut, Spurr and Rabaul, and (7) Gradual declines in the heights at which R(sub eff), S and V peak after Pinatubo.

FORECAST FOR THE PLANCK PRECISION ON THE TENSOR-TO-SCALAR RATIO AND OTHER COSMOLOGICAL PARAMETERS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burigana, C.; Gruppuso, A.; Mandolesi, N.

2010-11-20

The Planck satellite, successfully launched on 2009 May 14 to measure with unprecedented accuracy the primary cosmic microwave background (CMB) anisotropies, is operating as expected. The Standard Model of the Universe ('concordance' model) provides the current realistic context to analyze the CMB and other cosmological/astrophysical data, inflation in the early universe being part of it. The Planck performance for the crucial primordial parameter r, the tensor-to-scalar ratio related to primordial B-mode polarization, will depend on the quality of data analysis and interpretation. The Ginzburg-Landau (G-L) approach to inflation allows us to take high benefit of the CMB data. The fourth-degreemore » double-well inflaton potential gives an excellent fit to the current CMB+LSS data. We evaluate the Planck precision to the recovery of cosmological parameters, taking into account a reasonable toy model for residuals of systematic effects of instrumental and astrophysical origin based on publicly available information. We use and test two relevant models: the {Lambda}CDMr model, i.e., the standard {Lambda}CDM model augmented by r, and the {Lambda}CDMrT model, where the scalar spectral index, n{sub s} , and r are related through the theoretical 'banana-shaped' curve r = r(n{sub s}) coming from the G-L theory with a double-well inflaton potential. In the latter case, the analytical expressions for n{sub s} and r are imposed as a hard constraint in a Monte Carlo Markov Chain (MCMC) data analysis. We consider two C{sub l}-likelihoods (with and without B modes) and take into account the white noise sensitivity of Planck (LFI and HFI) in the 70, 100, and 143 GHz channels as well as the residuals from systematic errors and foregrounds. We also consider a cumulative channel of the three mentioned. We produce the sky (mock data) for the CMB multipoles C{sup TT}{sub l} , C{sup TE}{sub l} , C{sup EE}{sub l} , and C{sup BB}{sub l} from the {Lambda}CDMr and {Lambda}CDMrT models and obtain the cosmological parameter marginalized likelihood distributions for the two models. Foreground residuals affect only the cosmological parameters sensitive to the B modes. As expected, the likelihood r distribution is more clearly peaked near the fiducial value (r = 0.0427) in the {Lambda}CDMrT model than in the {Lambda}CDMr model. The best value for r in the presence of residuals turns out to be about r {approx_equal} 0.04 for both the {Lambda}CDMr and the {Lambda}CDMrT models. The {Lambda}CDMrT model is very stable; its distributions do not change by including residuals and the B modes. For r we find 0.028 < r < 0.116 at a 95% confidence level (CL) with the best value r = 0.04. We also compute the B mode detection probability by the most sensitive HFI-143 channel. At the level of foreground residual equal to 30% of our toy model, only a 68% CL (1{sigma}) detection is very likely. For a 95% CL detection (2{sigma}), the level of foreground residual should be reduced to 10% or lower of the adopted toy model. The lower bounds (and most probable value) we infer for r support the searching of CMB B-mode polarization in the current data as well as the planned CMB missions oriented toward B polarization.« less

VizieR Online Data Catalog: Vela Junior (RX J0852.0-4622) HESS image (HESS+, 2018)

NASA Astrophysics Data System (ADS)

H. E. S. S. Collaboration; Abdalla, H.; Abramowski, A.; Aharonian, F.; Ait Benkhali, F.; Akhperjanian, A. G.; Andersson, T.; Anguener, E. O.; Arakawa, M.; Arrieta, M.; Aubert, P.; Backes, M.; Balzer, A.; Barnard, M.; Becherini, Y.; Becker Tjus, J.; Berge, D.; Bernhard, S.; Bernloehr, K.; Blackwell, R.; Boettcher, M.; Boisson, C.; Bolmont, J.; Bordas, P.; Bregeon, J.; Brun, F.; Brun, P.; Bryan, M.; Buechele, M.; Bulik, T.; Capasso, M.; Carr, J.; Casanova, S.; Cerruti, M.; Chakraborty, N.; Chalme-Calvet, R.; Chaves, R. C. G.; Chen, A.; Chevalier, J.; Chretien, M.; Coffaro, M.; Colafrancesco, S.; Cologna, G.; Condon, B.; Conrad, J.; Cui, Y.; Davids, I. D.; Decock, J.; Degrange, B.; Deil, C.; Devin, J.; Dewilt, P.; Dirson, L.; Djannati-Atai, A.; Domainko, W.; Donath, A.; Drury, L. O'c.; Dutson, K.; Dyks, J.; Edwards, T.; Egberts, K.; Eger, P.; Ernenwein, J.-P.; Eschbach, S.; Farnier, C.; Fegan, S.; Fernandes, M. V.; Fiasson, A.; Fontaine, G.; Foerster, A.; Funk, S.; Fuessling, M.; Gabici, S.; Gajdus, M.; Gallant, Y. A.; Garrigoux, T.; Giavitto, G.; Giebels, B.; Glicenstein, J. F.; Gottschall, D.; Goyal, A.; Grondin, M.-H.; Hahn, J.; Haupt, M.; Hawkes, J.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hervet, O.; Hinton, J. A.; Hofmann, W.; Hoischen, C.; Holler, M.; Horns, D.; Ivascenko, A.; Iwasaki, H.; Jacholkowska, A.; Jamrozy, M.; Janiak, M.; Jankowsky, D.; Jankowsky, F.; Jingo, M.; Jogler, T.; Jouvin, L.; Jung-Richardt, I.; Kastendieck, M. A.; Katarzynski, K.; Katsuragawa, M.; Katz, U.; Kerszberg, D.; Khangulyan, D.; Khelifi, B.; Kieffer, M.; King, J.; Klepser, S.; Klochkov, D.; Kluzniak, W.; Kolitzus, D.; Komin, Nu.; Kosack, K.; Krakau, S.; Kraus, M.; Krueger, P. P.; Laffon, H.; Lamanna, G.; Lau, J.; Lees, J.-P.; Lefaucheur, J.; Lefranc, V.; Lemiere, A.; Lemoine-Goumard, M.; Lenain, J.-P.; Leser, E.; Lohse, T.; Lorentz, M.; Liu, R.; Lopez-Coto, R.; Lypova, I.; Marandon, V.; Marcowith, A.; Mariaud, C.; Marx, R.; Maurin, G.; Maxted, N.; Mayer, M.; Meintjes, P. J.; Meyer, M.; Mitchell, A. M. W.; Moderski, R.; Mohamed, M.; Mohrmann, L.; Mora, K.; Moulin, E.; Murach, T.; Nakashima, S.; de Naurois, M.; Niederwanger, F.; Niemiec J.; Oakes, L.; O'Brien, P.; Odaka, H.; Oettl, S.; Ohm, S.; Ostrowski, M.; Oya, I.; Padovani, M.; Panter, M.; Parsons, R. D.; Paz Arribas, M.; Pekeur, N. W.; Pelletier, G.; Perennes, C.; Petrucci, P.-O.; Peyaud, B.; Piel, Q.; Pita, S.; Poon, H.; Prokhorov, D.; Prokoph, H.; Puehlhofer, G.; Punch, M.; Quirrenbach, A.; Raab, S.; Reimer, A.; Reimer, O.; Renaud, M.; de Los Reyes, R.; Richter, S.; Rieger, F.; Romoli, C.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Saito, S.; Salek, D.; Sanchez, D. A.; Santangelo, A.; Sasaki, M.; Schlickeiser, R.; Schuessler, F.; Schulz, A.; Schwanke, U.; Schwemmer, S.; Seglar-Arroyo, M.; Settimo, M.; Seyffert, A. S.; Shafi, N.; Shilon, I.; Simoni, R.; Sol, H.; Spanier, F.; Spengler, G.; Spies, F.; Stawarz, L.; Steenkamp, R.; Stegmann, C.; Stycz, K.; Sushch, I.; Takahashi, T.; Tavernet, J.-P.; Tavernier, T.; Taylor, A. M.; Terrier, R.; Tibaldo, L.; Tiziani, D.; Tluczykont, M.; Trichard, C.; Tsuji, N.; Tuffs, R.; Uchiyama, Y.; van der, Walt D. J.; van Eldik, C.; van Rensburg, C.; van Soelen, B.; Vasileiadis, G.; Veh, J.; Venter, C.; Viana, A.; Vincent, P.; Vink, J.; Voisin, F.; Voelk, H. J.; Vuillaume, T.; Wadiasingh, Z.; Wagner, S. J.; Wagner, P.; Wagner, R. M.; White, R.; Wierzcholska, A.; Willmann, P.; Woernlein, A.; Wouters, D.; Yang, R.; Zabalza, V.; Zaborov, D.; Zacharias, M.; Zanin, R.; Zdziarski, A. A.; Zech, A.; Zefi, F.; Ziegler, A.; Zywucka, N.

2018-03-01

skymap.fit: H.E.S.S. excess skymap in FITS format of the region comprising Vela Junior and its surroundings. The excess map has been corrected for the gradient of exposure and smoothed with a Gaussian function of width 0.08° to match the analysis point spread function, matching the procedure applied to derive the maps in Fig. 1. sp_stat.txt: H.E.S.S. spectral points and fit parameters for Vela Junior (H.E.S.S. data points in Fig. 3 and Tab. A.2 and H.E.S.S. spectral fit parameters in Tab. 4). The errors in this file represent statistical uncertainties at 1 sigma confidence level. The covariance matrix of the fit is also included in the format: c11 c12 c_13 c21 c22 c_23 c31 c32 c_33 where the subindices represent the following parameters of the power-law with exponential cut-off (ECPL) formula in Tab. 2: 1: flux normalization (Phi0) 2: spectral index (Gamma) 3: inverse of the cutoff energy (lambda=1/Ecut) The units for the covariance matrix are the same as for the fit parameters. Notice that, while the fit parameters section of the file shows E_cut as parameter, the fit was done in lambda=1/Ecut; hence the covariance matrix shows the values for lambda in TeV-1. sp_syst.txt: H.E.S.S. spectral points and fit parameters for Vela Junior (H.E.S.S. data points in Fig. 3 and Tab. A.2 and H.E.S.S. spectral fit parameters in Tab. 4). The errors in this file represent systematic uncertainties at 1 sigma confidence level. The integral fluxes for several energy ranges are also included. (4 data files).

The clustering of the SDSS-IV extended Baryon Oscillation Spectroscopic Survey DR14 quasar sample: First measurement of Baryon Acoustic Oscillations between redshift 0.8 and 2.2

DOE PAGES

Ata, Metin; Baumgarten, Falk; Bautista, Julian; ...

2017-10-11

We present measurements of the Baryon Acoustic Oscillation (BAO) scale in redshift-space using the clustering of quasars. We consider a sample of 147,000 quasars from the extended Baryon Oscillation Spectroscopic Survey (eBOSS) distributed over 2044 square degrees with redshiftsmore » $0.8 < z < 2.2$ and measure their spherically-averaged clustering in both configuration and Fourier space. Our observational dataset and the 1400 simulated realizations of the dataset allow us to detect a preference for BAO that is greater than 2.5$$\\sigma$$. We determine the spherically averaged BAO distance to $z = 1.52$ to 4.4 per cent precision: $$D_V(z=1.52)=3855\\pm170 \\left(r_{\\rm d}/r_{\\rm d, fid}\\right)\\ $$Mpc. This is the first time the location of the BAO feature has been measured between redshifts 1 and 2. Our result is fully consistent with the prediction obtained by extrapolating the Planck flat $$\\Lambda$$CDM best-fit cosmology. All of our results are consistent with basic large-scale structure (LSS) theory, confirming quasars to be a reliable tracer of LSS, and provide a starting point for numerous cosmological tests to be performed with eBOSS quasar samples. We combine our result with previous, independent, BAO distance measurements to construct an updated BAO distance-ladder. Using these BAO data alone and marginalizing over the length of the standard ruler, we find $$\\Omega_{\\Lambda} > 0$$ at 6.5$$\\sigma$$ significance when testing a $$\\Lambda$$CDM model with free curvature.« less

Charm production by muons and its role in scale-noninvariance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gollin, G D

1981-01-01

Interactions of 209 GeV muons in the Multimuon Spectrometer at Fermilab have yielded more than 8 x 10/sup 4/ events with two muons in the final state. After reconstruction and cuts, the data contain 20,072 events with (81 +- 10)% attributed to the diffractive production of charmed states decaying to muons. The cross section for diffractive charm muoproduction is 6.9(+1.9,-1.4) nb where the error includes systematic uncertainties. Extrapolated to Q/sup 2/ = 0 with sigma(Q/sup 2/) = sigma(0)(1 + Q/sup 2//..lambda../sup 2/)/sup -2/, the effective cross section for 178 (100) GeV photons is 750(+180,-130) (560(+200,-120)) nb and the parameter ..lambda..more » is 3.3 +- 0.2 (2.9 +- 0.2) GeV/c. The ..nu.. dependence of the cross section is similar to that of the photon-gluon-fusion model. A first determination of the structure function for diffractive charm production indicates that charm accounts for approximately 1/3 of the scale-noninvariance observed in inclusive muon-nucleon scattering at low Bjorken x. Okubo-Zweig-Iizuka selection rules and unitarity allow the muon data to set a 90%-confidence lower limit on the psi N total cross section of 0.9 mb.« less

The Discovery of a High-Redshift Quasar without Emission Lines from Sloan Digital Sky Survey Commissioning Data.

PubMed

Fan; Strauss; Gunn; Lupton; Carilli; Rupen; Schmidt; Moustakas; Davis; Annis; Bahcall; Brinkmann; Brunner; Csabai; Doi; Fukugita; Heckman; Hennessy; Hindsley; Ivezic; Knapp; Lamb; Munn; Pauls; Pier; Rockosi; Schneider; Szalay; Tucker; York

1999-12-01

We report observations of a luminous unresolved object at redshift z=4.62, with a featureless optical spectrum redward of the Lyalpha forest region, discovered from Sloan Digital Sky Survey commissioning data. The redshift is determined by the onset of the Lyalpha forest at lambda approximately 6800 Å and a Lyman limit system at lambda=5120 Å. A strong Lyalpha absorption system with weak metal absorption lines at z=4.58 is also identified in the spectrum. The object has a continuum absolute magnitude of -26.6 at 1450 Å in the rest frame (h0=0.5, q0=0.5) and therefore cannot be an ordinary galaxy. It shows no radio emission (the 3 sigma upper limit of its flux at 6 cm is 60 µJy), indicating a radio-to-optical flux ratio at least as small as that of the radio-weakest BL Lacertae objects known. It is also not linearly polarized to a 3 sigma upper limit of 4% in the observed I band. Therefore, it is either the most distant BL Lac object known to date, with very weak radio emission, or a new type of unbeamed quasar, whose broad emission line region is very weak or absent.

Optical spectroscopy of lanthanide ions in ZnO-TeO2 glasses.

PubMed

Rolli, R; Wachtler, K; Wachtler, M; Bettinelli, M; Speghini, A; Ajò, D

2001-09-01

Zinc tellurite glasses of compositions 19ZnO-80TeO2-1Ln2O3 with Ln = Eu, Er, Nd and Tm were prepared by melt quenching. The absorption spectra were measured and from the experimental oscillator strengths of the f-->f transitions the Judd-Ofelt parameters ohm(lambda) were obtained. The values of the ohm(lambda) parameters are in the range usually observed for oxide glasses. For Nd3+ and Er3+, luminescence spectra in the near infrared were measured and the stimulated emission cross sections sigma(p) were evaluated for some laser transitions. The high values of sigma(p), especially for Nd3+, make them possible candidates for optical applications. Fluorescence line narrowing (FLN) spectra of the Eu3+ doped glass were measured at 20 K, and the energies of the Stark components of the 7F1 and 7F2 states were obtained. A crystal field analysis was carried out assuming a C2v site symmetry. The behaviour of the crystal field ratios B22/B20 and B44/B40 agrees reasonably well with the values calculated using the geometric model proposed by Brecher and Riseberg. The crystal field strength at the Eu3+ sites appears to be very low compared to other oxide glasses.

Method and source for producing a high concentration of positively charged molecular hydrogen or deuterium ions

DOEpatents

Ehlers, K.W.; Leung, K.N.

1983-07-26

One principal object of the present invention is to provide a novel method and apparatus for generating a high concentration of H/sub 2//sup +/ or D/sub 2//sup +/ ions by using a new and improved multicusp ion source. The basic principle in achieving a high percentage of H/sub 2//sup +/ or D/sub 2//sup +/ ions is to extract them from the source as soon as they are produced. Otherwise they will react with background gas molecules to form tri-atomic ions H/sub 3//sup +/ or D/sub 3//sup +/ or be dissociated by electrons. The former reaction H/sub 2//sup +/ + H/sub 2/ ..-->.. H/sub 3//sup +/ + H can have a very short mean free path length lambda. Assuming a background neutral gas density of approximately 3.3 x 10/sup 13/ cm/sup -3/ and a cross-section sigma of approximately 6 x 10/sup -15/ cm/sup 2/, lambda = (n/sub 0/ sigma)/sup -1/ is estimated to be about 5 cm. Thus the distance traversed by the H/sub 2//sup +/ ion before it arrives at the extractor electrode cannot exceed this value. This in turn sets a limit on the length of the source chamber.

On the Bonding in Fe2(CO)9

NASA Technical Reports Server (NTRS)

Bauschlicher, Charles W., Jr.

1986-01-01

The bonding in Fe2(CO)9 is analyzed using an self consistend field (SCF) wave function for a large basis set. There is no direct Fe-Fe metal-metal bond. The bridging CO's hold the two Fe(CO)3 fragments together by a sigma donation into the empty Fe-Fe d pi orbital and metal donation from the d pi* orbital into the CO 2pi* orbital. The bonding of the terminal CO is similar to that in Ni(CO)4 and the equatorial groups in Fe(CO)5.

Pion Elastic Scattering and the (pion Pion' Proton) Reaction on HELIUM-4 in the DELTA(3,3) Region

NASA Astrophysics Data System (ADS)

Jones, Mark Kevin

This dissertation presents measurements and analyses of pi^+ and pi ^{-} elastic scattering, and ( pi^{+}, pi^ {+^'}p) and ( pi^{-},pi^{-^ '}p) reactions on ^4 He. Both experiments were done at the Los Alamos Meson Physics Facility using the Energetic Pion Channel and Spectrometer. The ^4He( pi,pi) elastic scattering cross sections were measured for pi^{+} scattering at scattering angles theta _{lab} = 110^circ -170^circ and five incident energies between T_{pi } = 90 and 180 MeV. Elastic pi ^{-} cross sections were measured only at T_{pi} = 180 MeV. The ^4He(pi, pi' p) angular correlation functions were measured for pi^{+} and pi^{-} at T_{pi} = 180 and theta_{pi^' } = 30^circ, 40 ^circ, 60^circ , 80^circ and at T _pi = 140 MeV and theta_{pi^'} = 40^circ. Using scintillators at eight angles the protons were detected in coincidence with the inelastically scattered pions. In the ^4He(pi, pi^' p) experiment unexpectedly large ratios R_{pi p} = {sigma(pi^{+}, pi^{+} p)}over{sigma( pi^{-},pi^{-} p)} of up to 50 were observed near the quasi -free angle in the angular correlation functions summed over 30.5 to 39.5 MeV in ^4He excitation energy. The (pi,pi' p) data were analyzed by a distorted wave impulse approximation code 3DEE (Ch 82), (Re 82). 3DEE models the ( pi,pi' p) reaction as a pion -induced proton knock-out and includes distortions in the incident pion, the outgoing pion, and the emitted proton waves. The calculations give R_{pi p} between 6 and 9 at all proton and pion angles. The pi^{+} calculations reproduce the absolute pi^ {+} cross sections fairly well. The pi^{-} calculations have a peak in the angular correlation function near the quasi-free angle, in contrast to the pi^ {-} data which displays a flat distribution. At proton angles near 180^circ in the center of mass of the struck mass 4 system, the measured pi^{-} cross sections are larger than the pi^ {+} cross section which is the reverse of the ratio at 0^circ. These features of the measured pi^- cross sections indicate that interference between a quasi -free process and another process is important in the ( pi,pi^' p) reaction. The measurement of ^4He( pi,pi) elastic scattering data at theta_pi = 110 ^circ-170^circ extends the angular range of previous ^4He(pi,pi) data measured at EPICS. The experiment provides high quality elastic scattering data at backward angles. The pi^{-} elastic cross section at T_pi = 180 MeV measured for this dissertation when extrapolated to theta _{cm} = 180^circ is about a factor of two smaller than the cross section measured previously at CERN (Ref. (Bi 78)). The data were analyzed using a microscopic optical model and by a phase shift fit.

Structural and luminescence studies on pi...pi and Pt...Pt interactions in mixed chloro-isocyanide cyclometalated platinum(II) complexes.

PubMed

Díez, Alvaro; Forniés, Juan; Larraz, Carmen; Lalinde, Elena; López, José A; Martín, Antonio; Moreno, M Teresa; Sicilia, Violeta

2010-04-05

[Pt(bzq)Cl(CNR)] [bzq = benzoquinolinate; R = tert-butyl ((t)Bu 1), 2-6-dimethylphenyl (Xyl 2), 2-naphthyl (2-Np 3)] complexes have been synthesized and structurally and photophysically characterized. 1 was found to co-crystallize in two distinct pseudopolymorphs: a red form, which exhibits an infinite 1D-chain ([1](infinity)) and a yellow form, which contains discrete dimers ([1](2)), both stabilized by interplanar pi...pi (bzq) and short Pt...Pt bonding interactions. Complex 3, generated through the unexpected garnet-red double salt isomer [Pt(bzq)(CN-2-Np)(2)][Pt(bzq)Cl(2)] 4, crystallizes as yellow Pt...Pt dimers ([3](2)), while 2 only forms pi...pi (bzq) contacting dimers. Their electronic absorption and luminescence behaviors have been investigated. According to Time-Dependent Density Functional Theory (TD-DFT) calculations, the lowest-lying absorption (CH(2)Cl(2)) has been attributed to combined (1)ILCT and (1)MLCT/(1)ML'CT (L = bzq, L' = CNR) transitions, the latter increasing from 1 to 3. In solid state, while the yellow form [1](2) exhibits a green (3)MLCT unstructured emission only at 77 K, the 1-D form [1](infinity) displays a characteristic low-energy red emission (672 nm, 298 K; 744 nm, 77 K) attributed to a mixed (3)MMCT [d(sigma*)-->p(sigma)]/(3)MMLCT [dsigma*(M(2))-->sigma(pi*)(bzq)] excited state. However, upon exposure to standard atmospheric conditions, [1](infinity) shows an irreversible change to an orange-ochre solid, whose emissive properties are similar to those of the crude 1. Complexes 2 and 3 (77 K) exhibit a structured emission from discrete fragments ((3)LC/(3)MLCT), whereas the luminescence of the garnet-red salt 4 is dominated by a low energy emission (680 nm, 298 K; 730 nm, 77 K) arising from a (3)MMLCT excited state. Solvent (CH(2)Cl(2), toluene, 2-MeTHF and CH(3)CN) and concentration-dependent emission studies at 298 K and at 77 K are also reported for 1-3. In CH(2)Cl(2) solution, the low phosphorescent emission band is ascribed to bzq intraligand charge transfer (3)ILCT mixed with metal-to-ligand (L = bzq, L' = CNR) charge transfer (3)MLCT/(3)ML'CT character with the Pt to CNR contribution increasing from 1 to 3, according to computational studies.

The role of pressure in rubber elasticity.

PubMed

Bower, A F; Weiner, J H

2004-06-22

We describe a series of molecular dynamics computations that reveal an intimate connection at the atomic scale between difference stress (which resists stretches) and pressure (which resists volume changes) in an idealized elastomer, in contrast to the classical theory of rubber elasticity. Our simulations idealize the elastomer as a "pearl necklace," in which the covalent bonds are stiff linear springs, while nonbonded atoms interact through a Lennard-Jones potential with energy epsilon(LJ) and radius sigma(LJ). We calculate the difference stress t(11)-(t(22)+t(33))/2 and mean stress (t(11)+t(22)+t(33))/3 induced by a constant volume extension in the x(1) direction, as a function of temperature T and reduced density rho(*)=Nsigma(IJ) (3)/nu. Here, N is the number of atoms in the simulation cell and nu is the cell volume. Results show that for rho(*)<1, the difference stress is purely entropic and is in good agreement with the classical affine network model of rubber elasticity, which neglects nonbonded interactions. However, data presented by van Krevelen [Properties of Polymers, 3rd ed. (Elsevier, Amsterdam, 1990), p. 79] indicate that rubber at standard conditions corresponds to rho(*)=1.2. For rho(*)>1, the system is entropic for kT/epsilon(LJ)>2, but at lower temperatures the difference stress contains an additional energy component, which increases as rho(*) increases and temperature decreases. Finally, the model exhibits a glass transition for rho(*)=1.2 and kT/epsilon(LJ) approximately 2. The atomic-scale processes responsible for generating stress are explored in detail. Simulations demonstrate that the repulsive portion of the Lennard-Jones potential provides a contribution sigma(nbr)>0 to the difference stress, the attractive portion provides sigma(nba) approximately 0, while the covalent bonds provide sigma(b)<0. In contrast, their respective contributions to the mean stress satisfy Pi(nbr)<0, Pi(nba)>0, and Pi(b)<0. Analytical calculations, together with simulations, demonstrate that mean and difference stresses are related by sigma(nbr)=-APi(nbr)P(2)(theta(b)), sigma(b)=BPi(b)P(2)(theta(b)), where P(2)(theta(b)) is a measure of the anisotropy of the orientation of the covalent bonds, and A and B are coefficients that depend weakly on rho(*) and temperature. For high values of rho(*), we find that [sigma(nbr)]>[sigma(b)], and in this regime our model predicts behavior that is in good agreement with experimental data of D.L. Quested et al. [J. Appl. Phys. 52, 5977 (1981)] for the influence of pressure on the difference stress induced by stretching solithane. (c) 2004 American Institute of Physics.

Search for Exotic Baryons in 800 GeV pp{yields}p{xi}{sup {+-}}{pi}{sup {+-}}X Reactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Christian, D.C.; Gottschalk, E.E.; Gutierrez, G.

We report the results of a high-statistics, sensitive search for narrow baryon resonances decaying to {xi}{sup -}{pi}{sup -}, {xi}{sup -}{pi}{sup +}, {xi}{sup +}{pi}{sup -}, and {xi}{sup +}{pi}{sup +}. The only resonances observed are the well known {xi}{sup 0}(1530) and {xi}{sup 0}(1530). No evidence is found for the states near 1862 MeV, previously reported by NA49 [Phys. Rev. Lett. 92, 042003 (2003)]. At the 95% confidence level, we find the upper limit for the production of a Gaussian enhancement with {sigma}=7.6 MeV in the {xi}{sup -}{pi}{sup -} effective mass spectrum to be 0.3% of the number of observed {xi}{sup 0}(1530){yields}{xi}{sup -}{pi}{supmore » +}. We find similarly restrictive upper limits for an enhancement at 1862 MeV in the {xi}{sup -}{pi}{sup +}, {xi}{sup +}{pi}{sup -}, and {xi}{sup +}{pi}{sup +} mass spectra.« less

Two-component duality and flavoring in the P+f model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dash, J.W.; Jones, S.T.; Martin, A.

We show that modern Regge fits to rising ..pi..N total cross sections sigma/sub piN/ using the Harari-Freund P+f model of diffraction are not consistent with two-component duality. If a conventional Pomeron is chosen (dominant j-plane pole plus weak cuts), the resulting f is ''dual'' to the resonances plus one-half the background. Conversely, constraining the f-pole amplitude by duality does not allow a reasonable fit to sigma/sub piN/. In contrast, the P-f identity model of diffraction is shown to satisfy a modified form of two-component duality. We show that by incorporating flavoring renormalization, the P+f picture can be made consistent withmore » duality. The unflavored P intercept is 0.91 and the flavored P intercept is 1.1. Significant absorptive j-plane cuts are also required, though these are small enough to be consistent with dominant short-range order. Thus flavoring, which is so essential in P-f identity phenomenology, seems to play a positive role in diffraction scattering generally.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zabawa, P.; Wakim, A.; Haruza, M.

We report production of ultracold X {sup 1}{Sigma}{sup +}(v{sup ''}=0) NaCs molecules via photoassociation. We utilize a combination of spectroscopic techniques to determine formation pathways and label ground-state samples. Efficient free-bound excitation occurs due to coupling between B {sup 1}{Pi} and neighboring electronic states in the Na 3S+Cs 6P complex. An f-wave shape resonance contributes to formation of a rotationally pure sample of X {sup 1}{Sigma}{sup +}(v{sup ''}=0,J{sup ''}=1) molecules.

On the Statistical Analysis of X-ray Polarization Measurements

NASA Technical Reports Server (NTRS)

Strohmayer, T. E.; Kallman, T. R.

2013-01-01

In many polarimetry applications, including observations in the X-ray band, the measurement of a polarization signal can be reduced to the detection and quantification of a deviation from uniformity of a distribution of measured angles of the form alpha plus beta cosine (exp 2)(phi - phi(sub 0) (0 (is) less than phi is less than pi). We explore the statistics of such polarization measurements using both Monte Carlo simulations as well as analytic calculations based on the appropriate probability distributions. We derive relations for the number of counts required to reach a given detection level (parameterized by beta the "number of sigma's" of the measurement) appropriate for measuring the modulation amplitude alpha by itself (single interesting parameter case) or jointly with the position angle phi (two interesting parameters case). We show that for the former case when the intrinsic amplitude is equal to the well known minimum detectable polarization (MDP) it is, on average, detected at the 3sigma level. For the latter case, when one requires a joint measurement at the same confidence level, then more counts are needed, by a factor of approximately equal to 2.2, than that required to achieve the MDP level. We find that the position angle uncertainty at 1sigma confidence is well described by the relation sigma(sub pi) equals 28.5(degrees) divided by beta.

High-resolution photoabsorption cross sections of E1Pi - X1Sigma(+) vibrational bands of CO-12 and CO-13

NASA Technical Reports Server (NTRS)

Stark, G.; Smith, P. L.; Ito, K.; Yoshino, K.

1992-01-01

Photodissociation following absorption of extreme-ultraviolet photons is an important factor in determining the abundance and isotropic fractionation of CO in diffuse and translucent interstellar clouds. The principal channel for destruction of CO-13 in such clouds begins with absorption in the (1,0) vibrational band of the E1Pi - X1Sigma(+) system; similarly, absorption in the (0,0) band begins a significant destruction channel for CO-12. Reliable modeling of the CO fractionation process depends critically upon the accuracy of the photoabsorption cross section for these bands. We have measured the cross sections for the relevant isotropic species and for the (1,0) band of CO-12. Our results, which are uncertain by about 10 percent, are for the most part larger than previous measurements.

Rate coefficients for the reactions of C2(a(3)Pi(u)) and C2(X(1)Sigma(g)(+)) with various hydrocarbons (CH4, C2H2, C2H4, C2H6, and C3H8): a gas-phase experimental study over the temperature range 24-300 K.

PubMed

Páramo, Alejandra; Canosa, André; Le Picard, Sébastien D; Sims, Ian R

2008-10-02

The kinetics of reactions of C2(a(3)Pi(u)) and C2(X(1)Sigma(g)(+)) with various hydrocarbons (CH4, C2H2, C2H4, C2H6, and C3H8) have been studied in a uniform supersonic flow expansion over the temperature range 24-300 K. Rate coefficients have been obtained by using the pulsed laser photolysis-laser induced fluorescence technique, where both radicals were produced at the same time but detected separately. The reactivity of the triplet state was found to be significantly lower than that of the singlet ground state for all reactants over the whole temperature range of the study. Whereas C2(X(1)Sigma(g)(+)) reacts with a rate coefficient close to the gas kinetic limit with all hydrocarbons studied apart from CH4, C2(a(3)Pi(u)) appears to be more sensitive to the molecular and electronic structure of the reactant partners. The latter reacts at least one order of magnitude faster with unsaturated hydrocarbons than with alkanes, and the rate coefficients increase very significantly with the size of the alkane. Results are briefly discussed in terms of their potential astrophysical impact.

Intramolecular charge transfer of 4-(dimethylamino)benzonitrile probed by time-resolved fluorescence and transient absorption: No evidence for two ICT states and a {pi}{sigma}{sup *} reaction intermediate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zachariasse, Klaas A.; Druzhinin, Sergey I.; Senyushkina, Tamara

2009-12-14

For the double exponential fluorescence decays of the locally excited (LE) and intramolecular charge transfer (ICT) states of 4-(dimethylamino)benzonitrile (DMABN) in acetonitrile (MeCN) the same times {tau}{sub 1} and {tau}{sub 2} are observed. This means that the reversible LE<-->ICT reaction, starting from the initially excited LE state, can be adequately described by a two state mechanism. The most important factor responsible for the sometimes experimentally observed differences in the nanosecond decay time, with {tau}{sub 1}(LE)<{tau}{sub 1}(ICT), is photoproduct formation. By employing a global analysis of the LE and ICT fluorescence response functions with a time resolution of 0.5 ps/channel inmore » 1200 channels reliable kinetic and thermodynamic data can be obtained. The arguments presented in the literature in favor of a {pi}{sigma}* state with a bent CN group as an intermediate in the ICT reaction of DMABN are discussed. From the appearance of an excited state absorption (ESA) band in the spectral region between 700 and 800 nm in MeCN for N,N-dimethylanilines with CN, Br, F, CF{sub 3}, and C(=O)OC{sub 2}H{sub 2} p-substituents, it is concluded that this ESA band cannot be attributed to a {pi}{sigma}{sup *} state, as only the C-C{identical_to}N group can undergo the required 120 deg. bending.« less

Length Scale and Gravity Effects on Microgravity Boiling Heat Transfer

NASA Technical Reports Server (NTRS)

Kim, Jungho; McQuillen, John; Balombin, Joe

2002-01-01

Boiling is a complex phenomenon where hydrodynamics, heat transfer, mass transfer, and interfacial phenomena are tightly interwoven. An understanding of boiling and critical heat flux in microgravity environments is of importance to space based hardware and processes such as heat exchange, cryogenic fuel storage and transportation, electronic cooling, and material processing due to the large amounts of heat that can be removed with relatively little increase in temperature. Although research in this area has been performed in the past four decades, the mechanisms by which heat is removed from surfaces in microgravity are still unclear. In earth gravity, buoyancy is an important parameter that affects boiling heat transfer through the rate at which bubbles are removed from the surface. A simple model describing the bubble departure size based on a quasistatic force balance between buoyancy and surface tension is given by the Fritz [I] relation: Bo(exp 1/2) = 0.0208 theta where Bo is the ratio between buoyancy and surface tension forces. For small, rapidly growing bubbles, inertia associated with the induced liquid motion can also cause bubble departure. In microgravity, the magnitude of effects related to natural convection and buoyancy are small and physical mechanisms normally masked by natural convection in earth gravity such as Marangoni convection can substantially influence the boiling and vapor bubble dynamics. CHF (critical heat transfer) is also substantially affected by microgravity. In 1 g environments, Bo has been used as a correlating parameter for CHF. Zuber's CHF model for an infinite horizontal surface assumes that vapor columns formed by the merger of bubbles become unstable due to a Helmholtz instability blocking the supply of liquid to the surface. The jets are spaced lambda(sub D) apart, where lambda(sub D) = 2pi square root of 3[(sigma)/(g(rho(sub l) - rho(sub v)](exp 1/2) = 2pi square root of 3 L Bo(exp -1/2) = square root of 3 lambda(sub c) and is the wavelength that amplifies most rapidly. The critical wavelength, lambda(sub c), is the wavelength below which a vapor layer underneath a liquid layer is stable. For heaters with Bo smaller than about 3 (heaters smaller than lambda(sub D)), the above model is not applicable, and surface tension effects dominate. Bubble coalescence is thought to be the mechanism for CHF under these conditions. Small Bo can result by decreasing the size of a heater in earth gravity, or by operating a large heater in a lower gravity environment. In the microgravity of space, even large heaters can have low Bo, and models based on Helmholtz instability should not be applicable. The macrolayer model of Haramura and Katto is dimensionally equivalent to Zuber's model and has the same dependence on gravity, so it should not be applicable as well. The goal of this work is to determine how boiling heat transfer mechanisms in a low-g environment are altered from those at higher gravity levels. Boiling data using a microheater array was obtained under gravity environments ranging from 1.8 g to 0.02 g with heater sizes ranging from 2.7 mm to 1 mm. The boiling behavior for 2.7 mm at 0.02 g looked quite similar to boiling on the 1 mm heater at 1 g-the formation of a large primary bubble surrounded by smaller satellite bubbles was observed under both conditions. The similarity suggests that for heaters smaller than some fraction of I(sub c), coalescence and surface tension dominate boiling heat transfer. It also suggests that microgravity boiling can be studied by studying boiling on very small heaters.

Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Parameter Results

NASA Technical Reports Server (NTRS)

Hinshaw, G.; Larson, D.; Komatsu, E.; Spergel, D. N.; Bennett, C. L.; Dunkley, J.; Nolta, M. R.; Halpern, M.; Hill, R. S.; Odegard, N.;

Periodic intensity variations in sulfur emissions from the Io plasma torus

NASA Technical Reports Server (NTRS)

Woodward, R. Carey, Jr.; Scherb, Frank; Roesler, Fred L.

1994-01-01

In November and December 1988, we acquired 157 spectra of (S II) lambda 6731 emissions from the Io plasma torus with a Fabry-Perot interferometer at the McMath-Pierce Solar Telescope facility on Kitt Peak. A major goal of this experiment was to extend our earlier studies of intensity variations in the plasma torus. Our earlier analysis (F. L. Roesler, F. Scherb, and R. J. Oliversen, 1984, of (S III) lambda 9531 emission spectra acquired in April 1982 had shown that the intensity of torus emissions varied periodically with a period of 10.20 +/- 0.06 hr (1-sigma uncertainty level), slightly longer than Jupiter's System 3 rotational period of 9.925 hr. We present here an reanalysis of our 1982 data revealing, in addition to the 10.20-hr period, a clear secondary periodicity at 9.95 +/- 0.906 hr. By constrast, we show that our new (S II) lambda 6731 data have a single period of 10.14 +/- 0.03 hr. which is neither the System 3 period nor the proposed 'System 4' period of 10.224 hr.

Periodic intensity variations in sulfur emissions from the Io plasma torus

NASA Astrophysics Data System (ADS)

Woodward, R. Carey, Jr.; Scherb, Frank; Roesler, Fred L.; Oliversen, Ronald J.

1994-09-01

In November and December 1988, we acquired 157 spectra of (S II) lambda 6731 emissions from the Io plasma torus with a Fabry-Perot interferometer at the McMath-Pierce Solar Telescope facility on Kitt Peak. A major goal of this experiment was to extend our earlier studies of intensity variations in the plasma torus. Our earlier analysis (F. L. Roesler, F. Scherb, and R. J. Oliversen, 1984, of (S III) lambda 9531 emission spectra acquired in April 1982 had shown that the intensity of torus emissions varied periodically with a period of 10.20 +/- 0.06 hr (1-sigma uncertainty level), slightly longer than Jupiter's System 3 rotational period of 9.925 hr. We present here an reanalysis of our 1982 data revealing, in addition to the 10.20-hr period, a clear secondary periodicity at 9.95 +/- 0.906 hr. By constrast, we show that our new (S II) lambda 6731 data have a single period of 10.14 +/- 0.03 hr. which is neither the System 3 period nor the proposed 'System 4' period of 10.224 hr.

Topological, total, and elastic cross sections for K/sup +/p,. pi. /sup +/p, and pp interactions at 147 GeV/c

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brick, D.; Rudnicka, H.; Shapiro, A.M.

1982-06-01

The Fermilab hybrid 30-in. bubble-chamber spectrometer was exposed to a tagged 147-GeV/c positive beam containing ..pi../sup +/, K/sup +/, and p. A sample of 3003 K/sup +/p, 19 410 pp, and 20 745 ..pi../sup +/p interactions is used to derive sigma/sub n/, , f/sub 2//sup tsc/c, and /D for each beam particle. These values are compared to values obtained at other, mostly lower, beam momenta. The overall dependence of on E/sub a/, the available center-of-mass energy, for these three reactions as well as ..pi../sup -/p and pp interactions has been determined.

Formation of intermediate products during the resonance stepwise polarization of dibenzyl ketone and benzil molecules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Polevoi, A.V.; Matyuk, V.M.; Grigor'eva, G.A.

1987-07-01

The processes resulting in the intramolecular redistribution of energy in electronically excited S/sub ..pi pi..*/ states of dibenzyl ketone and benzil molecules have been investigated by laser mass spectrometry. The decisive role of dissociation under the conditions of the resonance stepwise photoionization of these molecules upon excitation by radiation with lambda = 266 nm has been demonstrated. The ionization potentials of the molecules and the appearance potentials of fragment ions from dibenzyl ketone and benzil have been determined on the basis of an analysis of photoionization efficiency curves.

Observation of J/psi-->3gamma.

PubMed

Adams, G S; Anderson, M; Cummings, J P; Danko, I; Hu, D; Moziak, B; Napolitano, J; He, Q; Insler, J; Muramatsu, H; Park, C S; Thorndike, E H; Yang, F; Artuso, M; Blusk, S; Khalil, S; Li, J; Mountain, R; Nisar, S; Randrianarivony, K; Sultana, N; Skwarnicki, T; Stone, S; Wang, J C; Zhang, L M; Bonvicini, G; Cinabro, D; Dubrovin, M; Lincoln, A; Naik, P; Rademacker, J; Asner, D M; Edwards, K W; Reed, J; Briere, R A; Ferguson, T; Ma, J S Y; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Alexander, J P; Cassel, D G; Duboscq, J E; Ehrlich, R; Fields, L; Galik, R S; Gibbons, L; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Hunt, J M; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Ledoux, J; Mahlke-Krüger, H; Mohapatra, D; Onyisi, P U E; Patterson, J R; Peterson, D; Riley, D; Ryd, A; Sadoff, A J; Shi, X; Stroiney, S; Sun, W M; Wilksen, T; Athar, S B; Patel, R; Yelton, J; Rubin, P; Eisenstein, B I; Karliner, I; Mehrabyan, S; Lowrey, N; Selen, M; White, E J; Wiss, J; Mitchell, R E; Shepherd, M R; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Poling, R; Scott, A W; Zweber, P; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Libby, J; Powell, A; Wilkinson, G; Ecklund, K M; Love, W; Savinov, V; Mendez, H; Ge, J Y; Miller, D H; Shipsey, I P J; Xin, B

2008-09-05

We report the first observation of the decay J/psi-->3gamma. The signal has a statistical significance of 6sigma and corresponds to a branching fraction of B(J/psi-->3gamma)=(1.2+/-0.3+/-0.2)x10;{-5}, in which the errors are statistical and systematic, respectively. The measurement uses psi(2S)-->pi;{+}pi;{-}J/psi events acquired with the CLEO-c detector operating at the CESR e;{+}e;{-} collider.

N* resonances from K $$\\Lambda$$ Λ amplitudes in sliced bins in energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anisovich, A. V.; Burkert, V.; Hadžimehmedović, M.

The two reactionsmore » $$\\gamma p\\to K^+\\Lambda$$ and $$\\pi^-p\\to K^0\\Lambda$$ are analyzed to determine the leading photoproduction multipoles and the pion-induced partial wave amplitudes in slices of the invariant mass. The multipoles and the partial-wave amplitudes are simultaneously fitted in a multichannel Laurent+Pietarinen model (L+P model), which determines the poles in the complex energy plane on the second Riemann sheet close to the physical axes. The results from the L+P fit are compared with the results of an energy-dependent fit based on the Bonn-Gatchina (BnGa) approach. The study confirms the existence of several poles due to nucleon resonances in the region at about 1.9\\,GeV with quantum numbers $J^P = 1/2^+$, $3/2^+, 1/2^-, 3/2^-, 5/2^-$.« less

N* resonances from K $$\\Lambda$$ Λ amplitudes in sliced bins in energy

DOE PAGES

Anisovich, A. V.; Burkert, V.; Hadžimehmedović, M.; ...

2017-12-22

The two reactionsmore » $$\\gamma p\\to K^+\\Lambda$$ and $$\\pi^-p\\to K^0\\Lambda$$ are analyzed to determine the leading photoproduction multipoles and the pion-induced partial wave amplitudes in slices of the invariant mass. The multipoles and the partial-wave amplitudes are simultaneously fitted in a multichannel Laurent+Pietarinen model (L+P model), which determines the poles in the complex energy plane on the second Riemann sheet close to the physical axes. The results from the L+P fit are compared with the results of an energy-dependent fit based on the Bonn-Gatchina (BnGa) approach. The study confirms the existence of several poles due to nucleon resonances in the region at about 1.9\\,GeV with quantum numbers $J^P = 1/2^+$, $3/2^+, 1/2^-, 3/2^-, 5/2^-$.« less

Heavy baryons as polarimeters at colliders

DOE PAGES

Galanti, Mario; Giammanco, Andrea; Grossman, Yuval; ...

2015-11-10

In new-physics processes that produce b or c jets, a measurement of the initial b or c-quark polarization could provide crucial information about the structure of the new physics. In the heavy-quark limit, the b and c-quark polarizations are preserved in the lightest baryons they hadronize into, Lambda(b) and Lambda(c), respectively. We revisit the prediction for the polarization retention after the hadronization process and extend it to the case of transverse polarization. We show how ATLAS and CMS can measure the b-quark polarization using semileptonic Lambda(b) decays, and the c-quark polarization using Lambda(+)(c) -> pK(-)pi(+) decays. For calibrating both measurementsmore » we suggest to use t (t) over bar samples in which these polarizations can be measured with precision of order 10% using 100thfb(-1) of data in Run 2 of the LHC. Measurements of the transverse polarization in QCD events at ATLAS, CMS and LHCb are motivated as well. The proposed measurements give access to nonperturbative QCD parameters relevant to the dynamics of the hadronization process.« less

Measurements of the exclusive decays of the upsilon(5S) to meson final states and improved B(s)* mass measurement.

PubMed

Aquines, O; Li, Z; Lopez, A; Mendez, H; Ramirez, J; Huang, G S; Miller, D H; Pavlunin, V; Sanghi, B; Shipsey, I P J; Xin, B; Adams, G S; Anderson, M; Cummings, J P; Danko, I; Napolitano, J; He, Q; Insler, J; Muramatsu, H; Park, C S; Thorndike, E H; Coan, T E; Gao, Y S; Liu, F; Stroynowski, R; Artuso, M; Blusk, S; Butt, J; Li, J; Menaa, N; Mountain, R; Nisar, S; Randrianarivony, K; Redjimi, R; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Zhang, K; Csorna, S E; Bonvicini, G; Cinabro, D; Dubrovin, M; Lincoln, A; Asner, D M; Edwards, K W; Briere, R A; Brock, I; Chen, J; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Adam, N E; Alexander, J P; Berkelman, K; Cassel, D G; Duboscq, J E; Ecklund, K M; Ehrlich, R; Fields, L; Galik, R S; Gibbons, L; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Meyer, T O; Onyisi, P U E; Patterson, J R; Peterson, D; Phillips, E A; Pivarski, J; Riley, D; Ryd, A; Sadoff, A J; Schwarthoff, H; Shi, X; Stroiney, S; Sun, W M; Wilksen, T; Weinberger, M; Athar, S B; Avery, P; Breva-Newell, L; Patel, R; Potlia, V; Stoeck, H; Yelton, J; Rubin, P; Cawlfield, C; Eisenstein, B I; Karliner, I; Kim, D; Lowrey, N; Naik, P; Sedlack, C; Selen, M; White, E J; Wiss, J; Shepherd, M R; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Gong, D T; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Poling, R; Scott, A W; Smith, A; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Zweber, P; Ernst, J; Arms, K; Severini, H; Dytman, S A; Love, W; Mehrabyan, S; Savinov, V

2006-04-21

Using 420 pb(-1) of data collected on the upsilon(5S) resonance with the CLEO III detector, we reconstruct B mesons in 25 exclusive decay channels to measure or set upper limits on the decay rate of upsilon(5S) into B meson final states. We measure the inclusive B cross section to be sigma(upsilon(5S) --> BB(X)) = (0.177 +/- 0.030 +/- 0.016) nb and make the first measurements of the production rates of sigma(upsilon(5S) --> B*B*) = (0.131 +/- 0.025 +/- 0.014) nb and sigma(upsilon(5S) --> BB*) = (0.043 +/- 0.016 +/- 0.006) nb, respectively. We set 90% confidence level limits of sigma(upsilon(5S) -->BB) < 0.038 nb, sigma(upsilon(5S) --> B(*)B(*)pi) < 0.055 nb and sigma(upsilon(5S) --> BBpipi) < 0.024 nb. We also extract the most precise value of the B(s)* mass to date, M(B(s)*) = (5411.7 +/- 1.6 +/- 0.6) MeV/c2.

Rotational level-dependent collisional broadening and line shift of the A2Sigma(+)-X2Pi (1,0) band of OH in hydrogen-air combustion gases

NASA Technical Reports Server (NTRS)

Kessler, W. J.; Allen, M. G.; Davis, S. J.

1993-01-01

Measurements of the collisional broadening and line shift of the (1,0) band of the A2Sigma(+)-X2Pi system of OH are reported in atmospheric pressure hydrogen-air combustion gases. The measurements were made using a single-mode, narrow linewidth, frequency-doubled ring dye laser operating near 283 nm. The OH was generated in the combustion gases of a flat flame H2-air burner. Collisional broadening parameters for equilibrium mixtures of H2, O2, H2O, and N2 were obtained spanning a range of fuel/air equivalence ratios from 0.6 to 1.6 and temperatures from 1500 to 2050 K. Measurements were obtained spanning rotational quantum numbers from 4.5 to 16.5. The collision induced frequency shift was determined to be 0.1 that of the collisional broadening.

A shock-tube determination of the SiO /A 1 Pi - X 1 Sigma +/ transition moment

NASA Technical Reports Server (NTRS)

Park, C.; Arnold, J. O.

1978-01-01

The sum of the squares of the electronic transition moments for the A 1 Pi - X 1 Sigma + band system of SiO has been determined from absorption measurements conducted in the reflected-shock region of a shock tube. The test gas was produced by shock-heating a mixture of N2O, SiCl4, and Ar, and the spectra were recorded photographically in the 260-290-nm wavelength range. The values of the sum as a function of internuclear distance between 2.8 and 3.3 Bohr were determined by comparing the measured absorption spectrum with that produced by a line-by-line synthetic-spectrum calculation which accounted for instrumental broadening. The value of the sum so deduced at an internuclear distance of 3.0 Bohr was 1.0 + or - 0.3 atomic units.

Infrared laser absorption spectroscopy of the nu4 (sigma u) fundamental and associated nu11(pi u) hot band of C7 - Evidence for alternating rigidity in linear carbon clusters

NASA Technical Reports Server (NTRS)

Heath, J. R.; Saykally, R. J.

1991-01-01

The first characterization of the bending potential of the C7 cluster is reported via the observation of the v = 1(1) and v = 2 deg levels of the nu11 (pi u) bend as hot bands associated with the nu4 (sigma u) antisymmetric stretch fundamental. The lower state hot band rotational constants are measured to be 1004.4(1.3) and 1123.6(9.0) MHz, constituting a 9.3 and 22 percent increase over the ground state rotational constant, 918.89 (41) MHz. These large increases are strong quartic and sextic centrifugal distortion constants determined for the ground and nu 4 = 1 states are found to be anomalously large and negative, evidencing strong perturbations between stretching and bending modes.

Core-core and core-valence correlation

NASA Technical Reports Server (NTRS)

Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Taylor, Peter R.

1988-01-01

The effect of (1s) core correlation on properties and energy separations was analyzed using full configuration-interaction (FCI) calculations. The Be 1 S - 1 P, the C 3 P - 5 S and CH+ 1 Sigma + or - 1 Pi separations, and CH+ spectroscopic constants, dipole moment and 1 Sigma + - 1 Pi transition dipole moment were studied. The results of the FCI calculations are compared to those obtained using approximate methods. In addition, the generation of atomic natural orbital (ANO) basis sets, as a method for contracting a primitive basis set for both valence and core correlation, is discussed. When both core-core and core-valence correlation are included in the calculation, no suitable truncated CI approach consistently reproduces the FCI, and contraction of the basis set is very difficult. If the (nearly constant) core-core correlation is eliminated, and only the core-valence correlation is included, CASSCF/MRCI approached reproduce the FCI results and basis set contraction is significantly easier.

Angular distribution, kinetic energy distributions, and excitation functions of fast metastable oxygen fragments following electron impact of CO2

NASA Technical Reports Server (NTRS)

Misakian, M.; Mumma, M. J.; Faris, J. F.

1975-01-01

Dissociative excitation of CO2 by electron impact was studied using the methods of translational spectroscopy and angular distribution analysis. Earlier time of flight studies revealed two overlapping spectra, the slower of which was attributed to metastable CO(a3 pi) fragments. The fast peak is the focus of this study. Threshold energy, angular distribution, and improve time of flight measurements indicate that the fast peak actually consists of five overlapping features. The slowest of the five features is found to consist of metastable 0(5S) produced by predissociation of a sigma u + state of CO2 into 0(5S) + CO(a3 pi). Oxygen Rydberg fragments originating directly from a different sigma u + state are believed to make up the next fastest feature. Mechanisms for producing the three remaining features are discussed.

Energetics of a strongly correlated Fermi gas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tan, Shina

2008-12-15

The energy of the two-component Fermi gas with the s-wave contact interaction is a simple linear functional of its momentum distribution: E{sub internal}=h{sup 2}{omega}C/4{pi}am+{sigma}{sub k{sigma}}(h{sup 2}k{sup 2}/2m)(n{sub k{sigma}}= -C/k{sup 4}) where the external potential energy is not included, a is the scattering length, {omega} is the volume, n{sub k{sigma}} is the average number of fermions with wave vector k and spin {sigma}, and C{identical_to}lim{sub k{yields}}{sub {infinity}}k{sup 4}n{sub k{up_arrow}}=lim{sub k{yields}}{sub {infinity}}k{sup 4}n{sub k{down_arrow}}. This result is a universal identity. Its proof is facilitated by a novel mathematical idea, which might be of utility in dealing with ultraviolet divergences in quantum fieldmore » theories. Other properties of this Fermi system, including pair correlations and the dimer-fermion scattering length, are also studied.« less

Random walks on cubic lattices with bond disorder

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ernst, M.H.; van Velthoven, P.F.J.

1986-12-01

The authors consider diffusive systems with static disorder, such as Lorentz gases, lattice percolation, ants in a labyrinth, termite problems, random resistor networks, etc. In the case of diluted randomness the authors can apply the methods of kinetic theory to obtain systematic expansions of dc and ac transport properties in powers of the impurity concentration c. The method is applied to a hopping model on a d-dimensional cubic lattice having two types of bonds with conductivity sigma and sigma/sub 0/ = 1, with concentrations c and 1-c, respectively. For the square lattice the authors explicitly calculate the diffusion coefficient D(c,sigma)more » as a function of c, to O(c/sup 2/) terms included for different ratios of the bond conductivity sigma. The probability of return at long times is given by P/sub 0/(t) approx. (4..pi..D(c,sigma)t)/sup -d/2/, which is determined by the diffusion coefficient of the disordered system.« less

Microwave properties and characterization of co-evaporated BSCCO thin films

NASA Technical Reports Server (NTRS)

Miranda, F. A.; Chorey, C. M.; Stan, M. A.; Nordgren, C. E.; Kwor, R. Y.; Kalkur, T. S.

1993-01-01

An extensive characterization of Bi-Sr-Ca-Cu-O (BSCCO) thin films deposited by co-evaporation on LaAlO3 and SrTiO3 substrates was performed. The films had a T(sub c) (R = O) of approximately 78 K, and were predominantly c-axis oriented, with critical current densities (J(sub c)) at 4.5 K of 1.6 x 10(exp 6) and 1.1 x 10(exp 6) A cm(sup -2), for the samples on SrTiO3 and LaAlO3, respectively. The microwave properties of the films were examined by three techniques. The complex conductivity sigma(sub *) = sigma(sub 1) - j(sigma(sub 2)) and the magnetic penetration depth (A) were measured by power transmission at 30.6 GHz; the surface resistance (R(sub s)) was measured using a cavity resonator at 58.9 GHz, and the transmission line losses were determined by measuring the quality factor (Q) of a linear microstrip resonator at 10.4 and 20.2 GHz. The complex conductivity for the film on LaAlO3 was determined to be (2.0-j10) x 10(exp 5) S/m at 77 K. It was observed that in the superconducting state sigma(sub 1) deviates from both the Bardeen-Cooper-Schrieffer (BCS) theory and the two-fluid model. Values of lambda were found to be approximately 2.0 and 1.1 microns at 77 K and 20 K respectively, and were obtained for the film on LaAlO3. The value of lambda at 20 K was approximately three times larger than that of BSCCO single crystals. R(sub s) values of 865 and 1391 mOmega were obtained for the films on SrTiO3 and LaAlO3, respectively, at 77 K and 58.9 GHz. Unloaded Q factors at 20 K of approximately 1100 and 800 at 10.4 and 20.2 GHz respectively, were measured for the BSCCO resonator. Unloaded Q values of 290 and 405 at 20 K were obtained at 10.4 GHz and 20.2 GHz respectively, for an all gold (Au) resonator.

Infrared identification of the {sigma}-complex of Cl-C{sub 6}H{sub 6} in the reaction of chlorine atom and benzene in solid para-hydrogen

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bahou, Mohammed; Witek, Henryk; Lee, Yuan-Pern

2013-02-21

The reaction of a chlorine atom with benzene (C{sub 6}H{sub 6}) is important in organic chemistry, especially in site-selective chlorination reactions, but its product has been a subject of debate for five decades. Previous experimental and theoretical studies provide no concrete conclusion on whether the product is a {pi}- or {sigma}-form of the Cl-C{sub 6}H{sub 6} complex. We took advantage of the diminished cage effect of para-hydrogen (p-H{sub 2}) to produce Cl in situ to react with C{sub 6}H{sub 6} (or C{sub 6}D{sub 6}) upon photolysis of a Cl{sub 2}/C{sub 6}H{sub 6} (or C{sub 6}D{sub 6})/p-H{sub 2} matrix at 3.2more » K. The infrared spectrum, showing intense lines at 1430.5, 833.6, 719.8, 617.0, and 577.4 cm{sup -1}, and several weaker ones for Cl-C{sub 6}H{sub 6}, and the deuterium shifts of observed new lines unambiguously indicate that the product is a 6-chlorocyclohexadienyl radical, i.e., the {sigma}-complex of Cl-C{sub 6}H{sub 6}. Observation of the {sigma}-complex rather than the {pi}-complex indicates that the {sigma}-complex is more stable in solid p-H{sub 2} at 3.2 K. The spectral information is crucial for further investigations of the Cl + C{sub 6}H{sub 6} reaction either in the gaseous or solution phase.« less

Amplitude Analysis of B0 to K^ pi^-pi^0 and Evidence of Direct CP Violation in B to K^* pi decays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lees, J.P.

We analyze the decay B{sup 0} {yields} K{sup +} {pi}{sup -} {pi}{sup 0} with a sample of 454 million B{bar B} events collected by the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC, and extract the complex amplitudes of seven interfering resonances over the Dalitz plot. These results are combined with amplitudes measured in B{sup 0} {yields} K{sup 0}{sub s}{pi}{sup +}{pi}{sup -} decays to construct isospin amplitudes from B{sup 0} {yields} K{sup *}{pi} and B{sup 0} {yields} {rho}K decays. We measure the phase of the isospin amplitude {Phi}{sub 3/2}, useful in constraining the CKM unitarity triangle angle {gamma}more » and evaluate a CP rate asymmetry sum rule sensitive to the presence of new physics operators. We measure direct CP violation in B{sup 0} {yields} K{sup *+}{pi}{sup -} decays at the level of 3 {sigma} when measurements from both B{sup 0} {yields} K{sup +}{pi}{sup -}{pi}{sup 0} and B{sup 0} {yields} K{sup 0}{sub s}{pi}{sup +}{pi}{sup -} decays are combined.« less

Optical–SZE scaling relations for DES optically selected clusters within the SPT-SZ Survey

DOE PAGES

Saro, A.; Bocquet, S.; Mohr, J.; ...

2017-03-15

We study the Sunyaev-Zel'dovich effect (SZE) signature in South Pole Telescope (SPT) data for an ensemble of 719 optically identified galaxy clusters selected from 124.6 degmore » $^2$ of the Dark Energy Survey (DES) science verification data, detecting a stacked SZE signal down to richness $$\\lambda\\sim20$$. The SZE signature is measured using matched-filtered maps of the 2500 deg$^2$ SPT-SZ survey at the positions of the DES clusters, and the degeneracy between SZE observable and matched-filter size is broken by adopting as priors SZE and optical mass-observable relations that are either calibrated using SPT selected clusters or through the Arnaud et al. (2010, A10) X-ray analysis. We measure the SPT signal to noise $$\\zeta$$-$$\\lambda$$, relation and two integrated Compton-$y$ $$Y_\\textrm{500}$$-$$\\lambda$$ relations for the DES-selected clusters and compare these to model expectations accounting for the SZE-optical center offset distribution. For clusters with $$\\lambda > 80$$, the two SPT calibrated scaling relations are consistent with the measurements, while for the A10-calibrated relation the measured SZE signal is smaller by a factor of $$0.61 \\pm 0.12$$ compared to the prediction. For clusters at $$20 < \\lambda < 80$$, the measured SZE signal is smaller by a factor of $$\\sim$$0.20-0.80 (between 2.3 and 10~$$\\sigma$$ significance) compared to the prediction, with the SPT calibrated scaling relations and larger $$\\lambda$$ clusters showing generally better agreement. We quantify the required corrections to achieve consistency, showing that there is a richness dependent bias that can be explained by some combination of contamination of the observables and biases in the estimated masses. We discuss possible physical effects, as contamination from line-of-sight projections or from point sources, larger offsets in the SZE-optical centering or larger scatter in the $$\\lambda$$-mass relation at lower richnesses.« less

Optical–SZE scaling relations for DES optically selected clusters within the SPT-SZ Survey

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saro, A.; Bocquet, S.; Mohr, J.

We study the Sunyaev-Zel'dovich effect (SZE) signature in South Pole Telescope (SPT) data for an ensemble of 719 optically identified galaxy clusters selected from 124.6 degmore » $^2$ of the Dark Energy Survey (DES) science verification data, detecting a stacked SZE signal down to richness $$\\lambda\\sim20$$. The SZE signature is measured using matched-filtered maps of the 2500 deg$^2$ SPT-SZ survey at the positions of the DES clusters, and the degeneracy between SZE observable and matched-filter size is broken by adopting as priors SZE and optical mass-observable relations that are either calibrated using SPT selected clusters or through the Arnaud et al. (2010, A10) X-ray analysis. We measure the SPT signal to noise $$\\zeta$$-$$\\lambda$$, relation and two integrated Compton-$y$ $$Y_\\textrm{500}$$-$$\\lambda$$ relations for the DES-selected clusters and compare these to model expectations accounting for the SZE-optical center offset distribution. For clusters with $$\\lambda > 80$$, the two SPT calibrated scaling relations are consistent with the measurements, while for the A10-calibrated relation the measured SZE signal is smaller by a factor of $$0.61 \\pm 0.12$$ compared to the prediction. For clusters at $$20 < \\lambda < 80$$, the measured SZE signal is smaller by a factor of $$\\sim$$0.20-0.80 (between 2.3 and 10~$$\\sigma$$ significance) compared to the prediction, with the SPT calibrated scaling relations and larger $$\\lambda$$ clusters showing generally better agreement. We quantify the required corrections to achieve consistency, showing that there is a richness dependent bias that can be explained by some combination of contamination of the observables and biases in the estimated masses. We discuss possible physical effects, as contamination from line-of-sight projections or from point sources, larger offsets in the SZE-optical centering or larger scatter in the $$\\lambda$$-mass relation at lower richnesses.« less

Quantitative test for concave aspheric surfaces using a Babinet compensator.

PubMed

Saxena, A K

1979-08-15

A quantitative test for the evaluation of surface figures of concave aspheric surfaces using a Babinet compensator is reported. A theoretical estimate of the sensitivity is 0.002lambda for a minimum detectable phase change of 2 pi x 10(-3) rad over a segment length of 1.0 cm.

Weak convergence of a projection algorithm for variational inequalities in a Banach space

NASA Astrophysics Data System (ADS)

Iiduka, Hideaki; Takahashi, Wataru

2008-03-01

Let C be a nonempty, closed convex subset of a Banach space E. In this paper, motivated by Alber [Ya.I. Alber, Metric and generalized projection operators in Banach spaces: Properties and applications, in: A.G. Kartsatos (Ed.), Theory and Applications of Nonlinear Operators of Accretive and Monotone Type, in: Lecture Notes Pure Appl. Math., vol. 178, Dekker, New York, 1996, pp. 15-50], we introduce the following iterative scheme for finding a solution of the variational inequality problem for an inverse-strongly-monotone operator A in a Banach space: x1=x[set membership, variant]C andxn+1=[Pi]CJ-1(Jxn-[lambda]nAxn) for every , where [Pi]C is the generalized projection from E onto C, J is the duality mapping from E into E* and {[lambda]n} is a sequence of positive real numbers. Then we show a weak convergence theorem (Theorem 3.1). Finally, using this result, we consider the convex minimization problem, the complementarity problem, and the problem of finding a point u[set membership, variant]E satisfying 0=Au.

The Asymmetry Parameter and Branching Ratio of Sigma Plus Radiative Decay

DOE Office of Scientific and Technical Information (OSTI.GOV)

Foucher, Maurice Emile

1992-05-01

We have measured the asymmetry parameter and branching ratio of themore » $$\\Sigma^+$$ radiative decay. This high statistics experiment (FNAL 761) was performed in the Proton Center charged hyperon beam at Fermi National Accelerator Laboratory in Batavia, Illinois. We find for the asymmetry parameter -0.720 $$\\pm$$ 0.086 $$\\pm$$ 0.045 where the first error is statistical and the second is systematic. This result is based on a sample of 34754 $$\\pm$$ 212 events. We find a preliminary value for the branching ratio $$Br ( \\Sigma^+ \\to p\\gamma )$$ $$/ Br ( \\Sigma^+ \\to p \\pi^0 )$$ = (2.14 $$\\pm$$ 0.07 $$\\pm$$ 0.11) x $$10^{-3}$$ where the first error is statistical and the second is systematic. This result is based on a sample of 31040 $$\\pm$$ 650 events. Both results are in agreement with previous low statistics measurements.« less

Weak decays and double beta decay

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nicholson, H.W.

1983-08-01

Work to measure the ..sigma../sup +/ 0 degree differential cross section in the reaction K/sup -/p ..-->.. ..sigma../sup +/..pi../sup -/ at several incident K/sup -/ momenta between 600 and 800 MeV/c as well as the asymmetries in the decays of polarized ..sigma../sup +/'s into protons and neutral pions and of polarized ..sigma../sup -/'s into neutrons and negative pions in collaboration with experimenters from Yale, Brookhaven, and the University of Pittsburgh (Brookhaven experiment 702) has been completed. Data from this experiment is currently being analyzed at Yale. Work is currently underway to develop and construct an experiment to search for neutrinolessmore » double beta decay in thin foils of Mo/sup 100/ in collaboration with experimenters from Lawrence Berkeley Laboratory. Development work on the solid state silicon detectors should be complete in the next six months and construction should e well underway within the next year.« less

Exact moduli space metrics for hyperbolic vortex polygons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krusch, S.; Speight, J. M.

2010-02-15

Exact metrics on some totally geodesic submanifolds of the moduli space of static hyperbolic N-vortices are derived. These submanifolds, denoted as {sigma}{sub n,m}, are spaces of C{sub n}-invariant vortex configurations with n single vortices at the vertices of a regular polygon and m=N-n coincident vortices at the polygon's center. The geometric properties of {sigma}{sub n,m} are investigated, and it is found that {sigma}{sub n,n-1} is isometric to the hyperbolic plane of curvature -(3{pi}n){sup -1}. The geodesic flow on {sigma}{sub n,m} and a geometrically natural variant of geodesic flow recently proposed by Collie and Tong ['The dynamics of Chern-Simons vortices', Phys.more » Rev. D Part. Fields Gravit. Cosmol. 78, 065013 (2008);e-print arXiv:hep-th/0805.0602] are analyzed in detail.« less

{pi} junction and spontaneous current state in a superfluid Fermi gas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kashimura, Takashi; Tsuchiya, Shunji; CREST

2011-07-15

We discuss an idea to realize a spontaneous current in a superfluid Fermi gas. When a polarized Fermi superfluid (N{sub {up_arrow}}>N{sub {down_arrow}}, where N{sub {sigma}} is the number of atoms in the hyperfine state described by pseudospin {sigma}={up_arrow},{down_arrow}) is loaded onto a ring-shaped trap with a weak potential barrier, some excess atoms ({Delta}N=N{sub {up_arrow}}-N{sub {down_arrow}}) are localized around the barrier. As shown in our previous paper [T. Kashimura, S. Tsuchiya, and Y. Ohashi, Phys. Rev. A 82, 033617 (2010)], this polarized potential barrier works as a {pi} junction in the sense that the superfluid order parameter changes its sign acrossmore » the barrier. Because of this, the phase of the superfluid order parameter outside the junction is shown to be twisted by {pi} along the ring, which naturally leads to a circulating supercurrent. While the ordinary supercurrent state is obtained as a metastable state, this spontaneous current state is shown to be more stable than the case with no current. Our results indicate that localized excess atoms would be useful for the manipulation of the superfluid order parameter in cold Fermi gases.« less

Heavier alkali-metal monosulfides (KS, RbS, CsS, and FrS) and their cations.

PubMed

Lee, Edmond P F; Wright, Timothy G

2005-10-08

The heavier alkali-metal monosulfides (KS, RbS, CsS, and FrS) have been studied by high-level ab initio calculations. The RCCSD(T) method has been employed, combined with large flexible valence basis sets. All-electron basis sets are used for potassium and sulfur, with effective core potentials being used for the other metals, describing the core electrons. Potential-energy curves are calculated for the lowest two neutral and cationic states: all neutral monosulfide species have a (2)Pi ground state, in contrast with the alkali-metal monoxide species, which undergo a change in the electronic ground state from (2)Pi to (2)Sigma(+) as the group is descended. In the cases of KS, RbS, and CsS, spin-orbit curves are also calculated. We also calculate potential-energy curves for the lowest (3)Sigma(-) and (3)Pi states of the cations. From the potential-energy curves, spectroscopic constants are derived, and for KS the spectroscopic results are compared to experimental spectroscopic values. Ionization energies, dissociation energies, and heats of formation are also calculated; for KS, we explore the effects of relativity and basis set extrapolation on these values.

Ground-state energies of the nonlinear sigma model and the Heisenberg spin chains

NASA Technical Reports Server (NTRS)

Zhang, Shoucheng; Schulz, H. J.; Ziman, Timothy

1989-01-01

A theorem on the O(3) nonlinear sigma model with the topological theta term is proved, which states that the ground-state energy at theta = pi is always higher than the ground-state energy at theta = 0, for the same value of the coupling constant g. Provided that the nonlinear sigma model gives the correct description for the Heisenberg spin chains in the large-s limit, this theorem makes a definite prediction relating the ground-state energies of the half-integer and the integer spin chains. The ground-state energies obtained from the exact Bethe ansatz solution for the spin-1/2 chain and the numerical diagonalization on the spin-1, spin-3/2, and spin-2 chains support this prediction.

Theoretical studies of chemisorption and dimer model systems: Moller-Plesset and configuration interaction calculations on PdH, PdC, PdO, PdF, Pd sub 2 , and PdCO

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schwerdtfeger, P.; McFeaters, J.S.; Moore, J.J.

1991-01-01

Ab initio SCF studies have been performed to study the molecular properties of several single-bonded palladium compounds, PdH, PdC, PdO, PdF, Pd{sub 2}, and PdCO, which are important in surface and materials science. Electron correlation effects were evaluated by a second- and third-order Moller-Plesset (MP) perturbation theory and a size-consistency-corrected configuration interaction with single and double substitutions (CISC). Relativistic effects were investigated for PdH and PdF. The ground state of PdC has been calculated at the CISC level to be a {sup 3}{Pi} state which is only 0.26 eV below the {sup 3}{Sigma}{sup {minus}} state (previously assigned ground state) andmore » 0.51 eV below the {sup 1}{Sigma}{sup +} state. PdC is predicted to be stable in the gas phase, and the possibility of preparing this compound is investigated. The bonding in CO chemisorbed on palladium is studied by using the model Pd-CO system. The effect of d{sub {pi}}-{pi}{sup *} back-bonding, discussed at the Hartree-Fock and CI level, is compared with results from multiple-scattering {Chi}{alpha} calculations. The C-O stretching frequency shift for CO on palladium was analyzed at various levels of theory, and the results indicated that the decrease in the CO force constant associated with chemisorption is not solely the result of d{sub {pi}}-{pi}{sup *} back-bonding.« less

Photodissociation of cis-, trans-, and 1,1-dichloroethylene in the ultraviolet range: characterization of Cl((2)P(J)) elimination.

PubMed

Hua, Linqiang; Zhang, Xiaopeng; Lee, Wei-Bin; Chao, Meng-Hsuan; Zhang, Bing; Lin, King-Chuen

2010-01-14

By using photofragment velocity imaging detection coupled with a (2 + 1) resonance-enhanced multiphoton ionization technique, the elimination channel of spin-orbit chlorine atoms in photodissociation of cis-, trans-, and 1,1-dichloroethylene at two photolysis wavelengths of 214.5 and 235 nm is investigated. Translational energy and angular distributions of Cl((2)P(J)) fragmentation are acquired. The Cl((2)P(J)) fragments are produced by two competing channels. The fast dissociation component with higher translational energy is characterized by a Gaussian distribution, resulting from a curve crossing of the initially excited (pi, pi*) state to nearby repulsive (pi, sigma*) and/or (n, sigma*). In contrast, the slow component with a lower translational energy is characterized by a Boltzmann distribution, which dissociates on the vibrationally hot ground state relaxed from the (pi, pi*) state via internal conversion. cis-C(2)H(2)Cl(2) is found to have a larger branching of Boltzmann component than the other two isomers. The fraction of available energy partitioning into translation increases along the trend of cis- < trans- < 1,1-C(2)H(2)Cl(2). This trend may be fitted by a rigid radical model and interpreted by means of a torque generated during the C-Cl bond cleavage. The anisotropy parameters are determined, and the transition dipole moments are expected to be essentially along the C horizontal lineC bond axis. The results are also predicted theoretically. The relative quantum yields of Cl((2)P(J)) have a similar value for the three isomers at the two photolysis wavelengths.

Properties of heavy flavoured hadrons at CDF

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fernandez, Juan Pablo; /Madrid, CIEMAT

We present recent CDF results on the properties of hadrons containing heavy quarks. These include the measurements of mass, lifetime and relative cross section of the B{sub c} meson and an updated measurement of the B{sub s}{sup 0} and {Lambda}{sub b}{sup 0} lifetime. We also summarize new measurements of the mass of the {Sigma}{sub b} baryon. We expect more results from the Tevatron which will accumulate more data until the end of Run II currently scheduled to conclude in 2010.

Bonding in tris(. eta. sup 5 -cyclopentadienyl) actinide complexes. 3. Interaction of. pi. -neutral,. pi. -acidic, and. pi. -basic ligands with (. eta. sup 5 -C sub 5 H sub 5 ) sub 3 U sup 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bursten, B.E.; Rhodes, L.F.; Strittmater

1989-04-12

A qualitative treatment of the bonding in Cp{sub 3}M (Cp = {eta}{sup 5}-C{sub 5}H{sub 5}) compounds under C{sub 3{upsilon}} symmetry reveals that the Cp{sub 3}{sup 3{minus}} ligand field contains a high-lying a{sub 2} orbital which is restricted by symmetry to interact only with metals that contain f orbitals. Quantitative investigation of the electronic structure of 5f{sup 3} Cp{sub 3}U via X{alpha}-SW molecular orbital calculations with quasi-relativistic corrections reveals that the Cp ligands donate electron density primarily into the U 6d orbitals while the three principally metal-based valence electrons are housed in the 5f orbitals. Electronic structure calculations of Cl{sub 3}Umore » show that although Cl can be considered isolobal with Cp, it is a poorer donor ligand. Calculations of Cp{sub 3}U bonded to a fourth ligand L (L = H, CO, NO, OH) indicate that the {sigma}-bonding framework is essentially the same for {pi}-neutral (H), {pi}-acidic (CO, NO), or {pi}-basic (OH) ligands: Electron density is donated from the {sigma} orbital of the fourth ligand into a uranium orbital that is primarily 6d{sub z{sup 2}} in character with minor contributions from the 5f{sub z{sup 3}} orbital, the 7p{sub z} orbital, and the 7s orbital. In the {pi}-bonding framework, the U 5f orbitals are responsible for back-donation into the {pi}* orbitals of CO an NO, while acceptance of electron density from the {pi} orbitals of OH involves the U 6d orbitals and, to a lesser extent, the U 5f orbitals. The bonding scheme of Cp{sub 3}UNO suggests that this molecule may prove to be a rather unusual example of a linear NO{sup {minus}} ligand.« less

Experimental studies on the effect of (Lambda-Cyhalothrin) insecticide on lungs and the ameliorating effect of plant extracts (Ginseng (Panax Ginseng) and garlic (Allium sativum L.) on asthma development in albino rats.

PubMed

Mohi El-Din, Mouchira M; Mostafa, Amna M; Abd-Elkader, Aml

2014-04-16

Lambda-cyhalothrin (LTC) is a synthetic pyrethroid insecticide for agricultural and public health applications. This study was to determine the pathological alterations of LTC in lungs, which has not previously been studied, and the ameliorating effects of plant extracts (ginseng and garlic) on the development of asthma in albino rats. Four groups (gps) of albino rats, (n = 20, average body weight = 200 gm with an age of 4 months), were formed. Gp 1 was kept as control. Gp 2 was injected intraperitoneally (i.p.) with LTC at a dose of 1/6 LD50 that is 9.34 mg/kg body weight (w.t.) daily for 21 days (d). Gp 3 & 4 were injected (i.p.) with ginseng at the dose of 200 mg/kg b.wt and garlic (Allium sativum L.) at the dose of 100 mg/kg b.wt., respectively, one hour before being given LTC at a dose of 1/6 LD50 (9.34 mg/kg b.wt.) daily. Each groups were divided into two sacrificed, at 15 and 21 d p.i. Blood and lung samples were collected for hematological and histopathological examinations. Hematological findings showed that the animals in gps 2 and 3, which were treated for 21 days, showed a significant difference in RBC counts (P > .001), Hb (P > .007), PCV% (P > .004), (P > .008) in comparison with the control group. Signs of cough and nasal discharge were seen in gp 2, which became mild in gp 4. Grossly, the lungs showed congestion and consolidation in gp 2. Histopathologically, macroabscesses and interstitial alveolitis were seen in gp 2, which led to obstruction in the lumen of the bronchioles at 21 d p.i. Meanwhile, thickening in the interalveolar septa with mononuclear cells was seen in gps. 3 and 4 at 21d p.i. The study shows 3 gps of rats injected with LHC alone or combined with garlic and ginseng extract, each group were divided into two sacrificed (15 and 21 d p.i.). Lambda cyhalothrin causes bronchial obstruction in the lungs of the rats (15 and 21 d p.i), which decreased into mild to moderate interstitial inflammation in the rats given garlic and ginseng, respectively.

Experimental studies on the effect of (Lambda-Cyhalothrin) insecticide on lungs and the ameliorating effect of plant extracts (Ginseng (Panax Ginseng) and garlic (Allium sativum L.) on asthma development in albino rats

PubMed Central

2014-01-01

Background Lambda-cyhalothrin (LTC) is a synthetic pyrethroid insecticide for agricultural and public health applications. This study was to determine the pathological alterations of LTC in lungs, which has not previously been studied, and the ameliorating effects of plant extracts (ginseng and garlic) on the development of asthma in albino rats. Methods Four groups (gps) of albino rats, (n = 20, average body weight = 200 gm with an age of 4 months), were formed. Gp 1 was kept as control. Gp 2 was injected intraperitoneally (i.p.) with LTC at a dose of 1/6 LD50 that is 9.34 mg/kg body weight (w.t.) daily for 21 days (d). Gp 3 & 4 were injected (i.p.) with ginseng at the dose of 200 mg/kg b.wt and garlic (Allium sativum L.) at the dose of 100 mg/kg b.wt., respectively, one hour before being given LTC at a dose of 1/6 LD50 (9.34 mg/kg b.wt.) daily. Each groups were divided into two sacrificed, at 15 and 21 d p.i. Blood and lung samples were collected for hematological and histopathological examinations. Results Hematological findings showed that the animals in gps 2 and 3, which were treated for 21 days, showed a significant difference in RBC counts (P > .001), Hb (P > .007), PCV% (P > .004), (P > .008) in comparison with the control group. Signs of cough and nasal discharge were seen in gp 2, which became mild in gp 4. Grossly, the lungs showed congestion and consolidation in gp 2. Histopathologically, macroabscesses and interstitial alveolitis were seen in gp 2, which led to obstruction in the lumen of the bronchioles at 21 d p.i. Meanwhile, thickening in the interalveolar septa with mononuclear cells was seen in gps. 3 and 4 at 21d p.i. Conclusions The study shows 3 gps of rats injected with LHC alone or combined with garlic and ginseng extract, each group were divided into two sacrificed (15 and 21 d p.i.). Lambda cyhalothrin causes bronchial obstruction in the lungs of the rats (15 and 21 d p.i), which decreased into mild to moderate interstitial inflammation in the rats given garlic and ginseng, respectively. PMID:24739272

DOE Office of Scientific and Technical Information (OSTI.GOV)

dos Reis, Alberto Correa

This work a presents a measurement of the total cross section for the charmed baryonmore » $$\\Lambda_c$$ times the branching fraction of the mode $$\\Lambda_c \\to pK\\bar{\\mu}$$, for the kinematical region $$x_F$$ > O in $$\\pi$$-nucleus interactions at 250 GeV/c. This measurement is made with data from the experiment E769, collected during 1987/1988 at the FERMILAB Tagged Photon Laboratory. A segmented target of berillium, aluminum, copper and tungsten was used. Based on the A dependence measurement, made by E769, and on the available branching fractions, the total cross section per nucleon is calculated. The result is compared with other experiments and with some theoretical predictions inspired on QCD.« less

KINETIC ENERGY DISTRIBUTION OF H(1s) FROM H{sub 2} X {sup 1}{Sigma}{sup +} {sub g}-a {sup 3}{Sigma}{sup +} {sub g} EXCITATION AND LIFETIMES AND TRANSITION PROBABILITIES OF a {sup 3}{Sigma}{sup +} {sub g}(v, J)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu Xianming; Johnson, Paul V.; Malone, Charles P.

Dissociative excitation of molecular hydrogen plays an important role in the heating of outer planet upper thermospheres. This paper addresses the role of one of the triplet states involved in the process. H{sub 2} excited to the a {sup 3}{Sigma}{sup +} {sub g} state, or higher triplet-ungerade states, is dissociated via the a {sup 3}{Sigma}{sup +} {sub g}-b {sup 3}{Sigma}{sup +} {sub u} continuum. The kinetic energy distribution of H(1s) produced from direct X {sup 1}{Sigma}{sup +} {sub g}-a {sup 3}{Sigma}{sup +} {sub g}(v, J) excitation by electrons is investigated by an accurate theoretical evaluation of spontaneous transition probabilities ofmore » the a {sup 3}{Sigma}{sup +} {sub g}(v, J)-b {sup 3}{Sigma}{sup +} {sub u} continuum transition. It is shown that the X {sup 1}{Sigma}{sup +} {sub g}(0)-a {sup 3}{Sigma}{sup +} {sub g}(v, J) excitation primarily produces H(1s) atoms with kinetic energies lower than 2 eV. In addition to the continuum a {sup 3}{Sigma}{sup +} {sub g}(v, J)-b {sup 3}{Sigma}{sup +} {sub u} transition probabilities, spontaneous emission lifetimes of the a {sup 3}{Sigma}{sup +} {sub g}(v, J) (v = 0-20, J {<=} 14) levels have been calculated by considering both the a {sup 3}{Sigma}{sup +} {sub g}-b {sup 3}{Sigma}{sup +} {sub u} and a {sup 3}{Sigma}{sup +} {sub g}-c {sup 3}{Pi} {sub u} transitions. The calculated lifetimes show a moderately strong rotational dependence, and the lifetimes for the J = 0 rotational level of the low v levels agree well with previous calculations and experimental measurements. Calculations of the a {sup 3}{Sigma}{sup +} {sub g}-b {sup 3}{Sigma}{sup +} {sub u} continuum emission spectra from electron impact X {sup 1}{Sigma}{sup +} {sub g}-a {sup 3}{Sigma}{sup +} {sub g} excitation are included.« less

Student View: What Do Good Teachers Do?

ERIC Educational Resources Information Center

Educational Horizons, 2012

2012-01-01

Students know what good teaching looks like--but educators rarely ask them. See what these high school students, who are members of the Future Educators Association[R] and want to be teachers themselves, said. FEA is a part of the PDK family of education associations, which includes Pi Lambda Theta. Get insider advice on good teaching from some…

Experimental medium energy physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barnes, P.D.

1991-01-01

This report discusses the following topics: Search for the H Dibaryon at the AGS; Hypernuclear Weak Decay Studies at the AGS; Relativistic Proton-Nucleus and Heavy Ion-Nucleus Collisions at the SPS; Hyperon-Antihyperon Production studies at LEAR; Hyperon Photoproduction at CEBAF; Double Lambda Hypernuclei; Weak Decay of Light Hypernuclei; and {pi}{sup 0}/{gamma}Detection with the CMU Scintillator Arrays.

Modelling of N2 Vegard-Kaplan and LBH emissions in the planetary atmospheres

NASA Astrophysics Data System (ADS)

Jain, Sonal Kumar; Bhardwaj, Anil

The N_{2} triplet band emissions are common features in the dayglow of Earth. Recent discoveries of N _{2} Vegard-Kaplan (VK) band emissions on Mars by SPICAM/Mars-Express and N _{2} VK and LBH band emissions on Titan by Cassini's UVIS have led planetary scientists to look for the processes governing the N _{2} triplet and singlet band emissions in different planetary atmospheres. We have developed a model to calculate N _{2} triplet and Lyman-Birge-Hopefield (LBH) band emissions in the dayglow of Venus, Mars, Titan, and Pluto. The Steady state photoelectron fluxes and volume excitation rates have been calculated using the Analytical Yield Spectra (AYS) technique. Since interstate cascading is important for triplet and singlet states of N _{2}, the population of any given level of N _{2} triplet and singlet states is calculated under statistical equilibrium considering direct excitation, cascading, and quenching effects. Relative population of all vibrational levels of each triplet and singlet states is calculated in the model. Line of sight intensities and height-integrated overhead intensities have been calculated for VK ( A(3Sigma_u^+) - X(1Sigma^+_g) ), first positive ( B(3Pi_g) - A(3Sigma^+_u) ), second positive ( C(3Pi_u) - B(3Pi_g) ), Wu-Benesch (W(3Delta_u) - B(3Pi_g) ), B '-> B, E -> B, E-> C, E-> A, and LBH (a(1Pi_g) - X(1Sigma^+_g) ) bands of N _{2}. The N _{2} VK band span wavelength range from far ultraviolet to visible, and some transitions even originate at wavelength more than 1000 nm. Our calculations show that the overhead intensity of VK bands in the wavelength range 400-800, 300-190, 200-300, and 150-200 nm are 22%, 39%, 35%, and 4% of the total VK band emission. On Titan, the calculated intensities of N _{2} VK and LBH bands in 150-190 and 120-190 nm wavelength range, respectively, are in good agreement with the Cassini-UVIS observation. On Mars, calculated intensities of N _{2} VK bands are in agreement with the SPICAM observed limb profile of N _{2} VK (0-6) when the N _{2} density in Martian upper atmosphere is reduced by a factor of 3. Calculations are also carried out on Venus using this model. Calculated intensities on Venus are about factor of 10 higher than that on Mars. On Pluto, the predicted limb intensities of N _{2} VK and LBH bands for New Horizons flyby condition peak at radial distance of 2000 km with a value of about 5 and 9.5 R, respectively for solar zenith angle 60(°) . The results will presented and discussed.

Experimental and theoretical study of the pyrrole cluster photochemistry: Closing the {pi}{sigma}{sup *} dissociation pathway by complexation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poterya, Viktoriya; Profant, Vaclav; Farnik, Michal

Photolysis of size selected pyrrole clusters has been investigated and compared to the photolysis of an isolated pyrrole molecule. Experimentally, size distributions of different mean cluster sizes (n=3 and n>>5) have been prepared in supersonic expansions and the clusters were photolyzed at 243 and 193 nm. The kinetic energy distributions of the H photofragments have been measured. The distributions exhibit a bimodal character with fast and slow H-fragment peaks similar to the spectra of the bare molecule. However, with increasing cluster size the slow component gains intensity with respect to the fast one. A similar effect is observed with increasingmore » the excitation energy from 243 to 193 nm. Theoretical calculations at the CASSCF/CASPT2 level have been performed for bare and complexed pyrroles (pyrrole is complexed with an argon atom and with another pyrrole unit). Combination of theoretical and experimental approaches leads to the conclusion that the direct dissociative pathway along the {pi}{sigma}{sup *} potential energy surface in the N-H stretch coordinate is closed by the presence of the solvent molecule. This pathway is an important channel leading to the fast H atoms in the dissociation of the bare molecule. The solvent molecule influences significantly the electronic structure in the Rydberg-type {pi}{sigma}{sup *} state while it has little influence on the valence states. The slow channel is mostly populated by the out-of-plane deformation mode which is also not influenced by solvation. We have also studied other possible reaction channels in pyrrole clusters (hydrogen transfer, dimerization). The present study shows that more insight into the bulk behavior of biologically relevant molecules can be gained from cluster studies.« less

Molecules in high spin states III: the millimeter/submillimeter-wave spectrum of the MnCl radical (X (7)Sigma(+)).

PubMed

Halfen, D T; Ziurys, L M

2005-02-01

The pure rotational spectrum of the MnCl radical (X (7)Sigma(+)) has been recorded in the range 141-535 GHz using millimeter-submillimeter direct absorption spectroscopy. This work is the first time the molecule has been studied with rotational resolution in its ground electronic state. MnCl was synthesized by the reaction of manganese vapor, produced in a Broida-type oven, with Cl(2). Transitions of both chlorine isotopomers were measured, as well as lines originating in several vibrationally excited states. The presence of several spin components and manganese hyperfine interactions resulted in quite complex spectra, consisting of multiple blended features. Because 42 rotational transitions were measured for Mn(35)Cl over a wide range of frequencies with high signal-to-noise, a very accurate set of rotational, fine structure, and hyperfine constants could be determined with the aid of spectral simulations. Spectroscopic constants were also determined for Mn(37)Cl and several vibrationally excited states. The values of the spin-rotation and spin-spin parameters were found to be relatively small (gamma=11.2658 MHz and lambda=1113.10 MHz for Mn(35)Cl); in the case of lambda, excited electronic states contributing to the second-order spin-orbit interaction may be canceling each other. The Fermi contact hyperfine term was found to be large in manganese chloride with b(F)(Mn(35)Cl)=397.71 MHz, a result of the manganese 4s character mixing into the 12sigma orbital. This orbital is spsigma hybridized, and contains some Mn 4psigma character, as well. Hence, it also contributes to the dipolar constant c, which is small and positive for this radical (c=32.35 MHz for Mn(35)Cl). The hyperfine parameters in MnCl are similar to those of MnH and MnF, suggesting that the bonding in these three molecules is comparable.

Structural, electronic, and optical properties of representative Cu-flavonoid complexes.

PubMed

Lekka, Ch E; Ren, Jun; Meng, Sheng; Kaxiras, Efthimios

2009-05-07

We present density functional theory (DFT) results on the structural, electronic, and optical properties of Cu-flavonoid complexes for molar ratios 1:1, 1:2, and 1:3. We find that the preferred chelating site is close to the 4-oxo group and in particular the 3-4 site followed by the 3'-4' dihydroxy group in ring B. For the Cu-quercetin complexes, the large bathochromic shift of the first absorbance band upon complexation, which is in good agreement with experimental UV-vis spectra, results from the reduction of the electronic energy gap. The HOMO states for these complexes are characterized by pi-bonding between the Cu d orbitals and the C, O p orbitals except for the case of 1:1 complex (spin minority), which corresponds to sigma-type bonds. The LUMO states are attributed to the contribution of Cu p(z) orbitals. Consequently, the main features of the first optical absorption maxima are essentially due to pi --> pi transitions, while the 1:1 complex exhibits also sigma --> pi transitions. Our optical absorption calculations based on time-dependent DFT demonstrate that the 1:1 complex is responsible for the spectroscopic features at pH 5.5, whereas the 1:2 complex is mainly the one responsible for the characteristic spectra at pH 7.4. These theoretical predictions explain in detail the behavior of the optical absorption for the Cu-flavonoid complexes observed in experiments and are thus useful in elucidating the complexation mechanism and antioxidant activity of flavonoids.

Observation of CH A (sup 2)Delta approaches X (sup 2)Pi(sub r) and B (sup 2)Sigma(sup -) approaches X (sup 2)Pi(sub r) emissions in gas-phase collisions of fast O((sup 3)P) atoms with acetylene

NASA Technical Reports Server (NTRS)

Orient, O. J.; Chutjian, A.; Murad, E.

1995-01-01

Optical emissions in single-collision, beam-beam reactions of fast (3-22 eV translational energy) O(P-3) atoms with C2H2 have been measured in the wavelength range 300-850 nm. Two features were observed, one with a peak wavelength at 431 nm, corresponding to the CH A (sup 2)Delta yields X (sup 2)Pi(sub r) transition, and a second weaker emission in the range 380-400 nm corresponding to the B (sup 2)Sigma(sup -) yields X (sup 2)Pi(sub r) transition. Both the A yields X and B yields X emissions were fit to a synthetic spectrum of CH(A) at a vibrational temperature T(sub v) of 10,000 K (0.86 eV) and a rotational temperature T(r) of approximately 5000 K (0.43 eV); and CH(B) to T(sub v) = 2500 K (0.22 eV) and T(sub r) = 1000 K (0.09 eV). The energy threshold for the A yields X emission was measured to be 7.3 +/- 0.4 eV (lab) or 4.5 +/- 0.2 eV (c.m.). This agrees with the energy threshold of 7.36 eV (lab) for the reaction O(P-3) + C2H2 yields CH(A) + HCO.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zabawa, P.; Wakim, A.; Neukirch, A.

We demonstrate that a photoassociation resonance detuned less than a wave number below the Cs 6 {sup 2}P{sub 3/2} atomic line can be used to create a deeply bound molecular sample of ultracold polar NaCs. We assign 1 {sup 1}{Sigma}{sup +} (v=4,5,6,11,19) vibrational levels utilizing a pulsed depletion spectroscopic method (scanning {approx}700 cm{sup -1} at a time) in which we observe the 1 {sup 1}{Sigma}{sup +}{yields}2 {sup 1}{Sigma}{sup +}-1 {sup 3{Pi}} vibrational progression. These data are compared with results from a hot-molecule collision-enhanced laser-induced fluorescence experiment and shown to be in good agreement. This technique is a powerful tool tomore » experimentally determine the population distribution in any ultracold molecular system.« less

Evidence for an exotic S= -2, Q= -2 baryon resonance in proton-proton collisions at the CERN SPS.

PubMed

Alt, C; Anticic, T; Baatar, B; Barna, D; Bartke, J; Betev, L; Białkowska, H; Billmeier, A; Blume, C; Boimska, B; Botje, M; Bracinik, J; Bramm, R; Brun, R; Buncić, P; Cerny, V; Christakoglou, P; Chvala, O; Cramer, J G; Csató, P; Darmenov, N; Dimitrov, A; Dinkelaker, P; Eckardt, V; Farantatos, G; Filip, P; Flierl, D; Fodor, Z; Foka, P; Freund, P; Friese, V; Gál, J; Gaździcki, M; Georgopoulos, G; Gładysz, E; Hegyi, S; Höhne, C; Kadija, K; Karev, A; Kniege, S; Kolesnikov, V I; Kollegger, T; Korus, R; Kowalski, M; Kraus, I; Kreps, M; van Leeuwen, M; Lévai, P; Litov, L; Makariev, M; Malakhov, A I; Markert, C; Mateev, M; Mayes, B W; Melkumov, G L; Meurer, C; Mischke, A; Mitrovski, M; Molnár, J; Mrówczyński, St; Pálla, G; Panagiotou, A D; Panayotov, D; Perl, K; Petridis, A; Pikna, M; Pinsky, L; Pühlhofer, F; Reid, J G; Renfordt, R; Retyk, W; Roland, C; Roland, G; Rybczyński, M; Rybicki, A; Sandoval, A; Sann, H; Schmitz, N; Seyboth, P; Siklér, F; Sitar, B; Skrzypczak, E; Stefanek, G; Stock, R; Ströbele, H; Susa, T; Szentpétery, I; Sziklai, J; Trainor, T A; Varga, D; Vassiliou, M; Veres, G I; Vesztergombi, G; Vranić, D; Wetzler, A; Włodarczyk, Z; Yoo, I K; Zaranek, J; Zimányi, J

2004-01-30

Results of resonance searches in the Xi(-)pi(-), Xi(-)pi(+), Xi;(+)pi(-), and Xi;(+)pi(+) invariant mass spectra in proton-proton collisions at sqrt[s]=17.2 GeV are presented. Evidence is shown for the existence of a narrow Xi(-)pi(-) baryon resonance with mass of 1.862+/-0.002 GeV/c(2) and width below the detector resolution of about 0.018 GeV/c(2). The significance is estimated to be above 4.2sigma. This state is a candidate for the hypothetical exotic Xi(--)(3/2) baryon with S=-2, I=3 / 2, and a quark content of (dsdsū). At the same mass, a peak is observed in the Xi(-)pi(+) spectrum which is a candidate for the Xi(0)(3/2) member of this isospin quartet with a quark content of (dsus[-]d). The corresponding antibaryon spectra also show enhancements at the same invariant mass.

Quantum scattering studies of spin-orbit effects in the Cl({sup 2}P) + HCl {yields} ClH + Cl({sup 2}P) reaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schatz, G.C.; McCabe, P.; Connor, J.N.L.

1998-07-01

The authors present quantum scattering calculations for the Cl + HCl {yields} ClH + Cl reaction in which they include the three electronic states that correlate asymptotically to the ground state of Cl({sup 2}P) + HCl(X{sup 1}{Sigma}{sup +}). The potential surfaces and couplings are taken from the recent work of C.S. Maierle, G.C. Schatz, M.S. Gordon, P. McCabe and J.N.L. Connor, J. Chem. Soc. Farad. Trans. (1997). They are based on extensive ab initio calculations for geometries in the vicinity of the lowest energy saddle point, and on an electrostatic expansion (plus empirical dispersion and repulsion) for long range geometriesmore » including the van der Waals wells. Spin-orbit coupling has been included using a spin-orbit coupling parameter {lambda} that is assumed to be independent of nuclear geometry, and Coriolis interactions are incorporated accurately. The scattering calculations use a hyperspherical coordinate coupled channel method in full dimensionality. AJ-shifting approximation is employed to convert cumulative reaction probabilities for total angular momentum quantum number J = 1/2 into state selected and thermal rate coefficients. Two issues have been studied: (a) the influence of the magnitude of {lambda} on the fine-structure resolved cumulative probabilities and rate coefficients (the authors consider {lambda}`s that vary from 0 to {+-}100% of the true Cl value), and (b) the transition state resonance spectrum, and its variation with {lambda} and with other parameters in the calculations. Cl + HCl is a simple hydrogen transfer reaction which serves as a canonical model both for heavy-light-heavy atom reactions, and for the reactions of halogen atoms with closed shell molecules.« less

CCKT Calculation of e-H Total Cross Sections

NASA Technical Reports Server (NTRS)

Bhatia, Aaron K.; Schneider, B. I.; Temkin, A.; Fisher, Richard R. (Technical Monitor)

2002-01-01

We are in the process of carrying out calculations of e-H total cross sections using the 'complex-correlation Kohn-T' (CCKT) method. In a later paper, we described the methodology more completely, but confined calculations to the elastic scattering region, with definitive, precision results for S-wave phase shifts. Here we extend the calculations to the (low) continuum (1 much less than k(exp 2) much less than 3) using a Green's function formulation. This avoids having to solve integro-differential equations; rather we evaluate indefinite integrals involving appropriate Green's functions and the (complex) optical potential to find the scattering function u(r). From the asymptotic form of u(r) we extract a T(sub L) which is a complex number. From T(sub L), elastic sigma(sub L)(elastic) = 4pi(2L+1)((absolute value of T(sub L))(exp 2)), and total sigma (sub L)(total) = 4pi/k(2L+1)Im(T(sub L)) cross sections follow.

Observation of Psi(3770)-->gammachi(c1)-->gammagammaJ/Psi.

PubMed

Coan, T E; Gao, Y S; Liu, F; Artuso, M; Boulahouache, C; Blusk, S; Butt, J; Dorjkhaidav, O; Li, J; Menaa, N; Mountain, R; Nandakumar, R; Randrianarivony, K; Redjimi, R; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Zhang, K; Csorna, S E; Bonvicini, G; Cinabro, D; Dubrovin, M; Lincoln, A; Briere, R A; Chen, G P; Chen, J; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Adam, N E; Alexander, J P; Berkelman, K; Cassel, D G; Crede, V; Duboscq, J E; Ecklund, K M; Ehrlich, R; Fields, L; Galik, R S; Gibbons, L; Gittelman, B; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Meyer, T O; Onyisi, P U E; Patterson, J R; Peterson, D; Phillips, E A; Pivarski, J; Riley, D; Ryd, A; Sadoff, A J; Schwarthoff, H; Shi, X; Shepherd, M R; Stroiney, S; Sun, W M; Urner, D; Wilksen, T; Weaver, K M; Weinberger, M; Athar, S B; Avery, P; Breva-Newell, L; Patel, R; Potlia, V; Stoeck, H; Yelton, J; Rubin, P; Cawlfield, C; Eisenstein, B I; Gollin, G D; Karliner, I; Kim, D; Lowrey, N; Naik, P; Sedlack, C; Selen, M; White, E J; Williams, J; Wiss, J; Asner, D M; Edwards, K W; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Gong, D T; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Li, S Z; Poling, R; Scott, A W; Smith, A; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Zweber, P; Ernst, J; Severini, H; Dytman, S A; Love, W; Mehrabyan, S; Mueller, J A; Savinov, V; Li, Z; Lopez, A; Mendez, H; Ramirez, J; Huang, G S; Miller, D H; Pavlunin, V; Sanghi, B; Shipsey, I P J; Adams, G S; Anderson, M; Cummings, J P; Danko, I; Napolitano, J; He, Q; Muramatsu, H; Park, C S; Thorndike, E H

2006-05-12

From e(+)e(-) collision data acquired with the CLEO detector at the Cornell Electron Storage Ring, we observe the non-DD(_) decay Psi(3770))-->gammachi(c1) with a statistical significance of 6.6 standard deviations, using the two-photon cascades to J/Psi and J/Psi-->l(+)l(-). We determine sigma(e(=)e(-)-->Psi(3770))xBeta(Psi(3770)-->gammachi(c1))=(18.0 +/- 3.3 +/- 2.5) pb and branching fraction Beta(Psi(3770)-->gammachi(c1)=(2.8 +/- 0.5+/-0.4) x 10(-3). We set 90% C.L. upper limits for the transition to chi(c2) (chi(c0)): sigma x Beta<5.7 pb (<282 pb) and Beta<0.9 x 10(-3) (<44 x 10(-3)). We also determine Gamma(Psi(3770)gammachi(c1))/Gamma(Psi(3770)-->pi(+)pi(-)J/Psi)=1.5 +/- 0.3 +/- 0.3 (>1.0 at 90% C.L.), which bears upon the interpretation of X(3872).

Simulation of the A-X and B-X transition emission spectra of the InBr molecule for diagnostics in low-pressure plasmas

NASA Astrophysics Data System (ADS)

Briefi, S.; Fantz, U.

2011-04-01

Inductively coupled low-pressure discharges containing InBr have been investigated spectroscopically. In order to obtain plasma parameters such as the vibrational and rotational temperature of the InBr molecule, the emission spectra of the A\\,^3\\!\\Pi_{0^+}\\rightarrow X\\,^1\\!\\Sigma_{0}^+ and the B\\,^3\\! \\Pi_{1}\\rightarrow X\\,^1\\!\\Sigma_{0}^+ transitions have been simulated. The program is based on the molecular constants and takes into account vibrational states up to v = 24. The required Franck-Condon factors and vibrationally resolved transition probabilities have been computed solving the Schrödinger equation using the Born-Oppenheimer approximation. The ground state density of the InBr molecule in the plasma has been determined from absorption spectra using effective transition probabilities for the A-X and B-X transition according to the vibrational population. The obtained densities agree well with densities derived from an Arrhenius type vapour pressure equation.

Implications of R parity violating Yukawa couplings in {delta}S=1 semileptonic decays of K mesons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mir, Azeem; Tahir, Farida; Haseeb, Mahnaz Q.

2007-12-01

We present a class of constraints on products and combinations of Yukawa couplings for R parity violating (Re{sub p}) and lepton flavor conserving as well as violating semileptonic decays of K mesons into light pseudoscalar mesons along with two charged leptons at 1{sigma} and 2{sigma} levels. We compare the constraints obtained by semileptonic rare decays with pure leptonic rare decays and find that most of these bounds are now improved over the existing ones. We also study the forward-backward asymmetry in the decays of K{sup +}{yields}{pi}{sup +}l{sup +}l{sup -} (l=e and {mu}) in the absence of tensor terms. The asymmetrymore » is found to be up to O(10{sup -3}) (O(10{sup -1})) for the electron and muon modes, respectively. The asymmetry is found to be as large as O(10{sup -1}) in the case of K{sup +}{yields}{pi}{sup +}{mu}{sup +}{mu}{sup -}.« less

The C4H radical and the diffuse interstellar bands. An ab initio study

NASA Technical Reports Server (NTRS)

Kolbuszewski, Marcin

1994-01-01

An ab initio study of the low-lying electronic states of C4H has been presented where the species studied has a chi(2)sigma(+) ground state and two low lying pi states. Based on the vertical and adiabatic excitation energies between those states it is suggested that the 4428 A diffuse interstellar band is not carried by C4H. The application of the particle in a box model shows strong coincidences between the strong DIB's and predicted wavelengths of pi-pi transitions in C(2n)H series. Based on those coincidences, it is suggested the C(2n)H species as good candidates for carriers of diffuse interstellar bands.

Bonding Properties of a Novel Inorganometallic Complex, Ru(SnPh(3))(2)(CO)(2)(iPr-DAB) (iPr-DAB = N,N'-Diisopropyl-1,4-diaza-1,3-butadiene), and its Stable Radical-Anion, Studied by UV-Vis, IR, and EPR Spectroscopy, (Spectro-) Electrochemistry, and Density Functional Calculations.

PubMed

Aarnts, Maxim P.; Wilms, Maikel P.; Peelen, Karin; Fraanje, Jan; Goubitz, Kees; Hartl, Frantisek; Stufkens, Derk J.; Baerends, Evert Jan; Vlcek, Antonín

1996-09-11

Ru(SnPh(3))(2)(CO)(2)(iPr-DAB) was synthesized and characterized by UV-vis, IR, (1)H NMR, (13)C NMR, (119)Sn NMR, and mass (FAB(+)) spectroscopies and by single-crystal X-ray diffraction, which proved the presence of a nearly linear Sn-Ru-Sn unit. Crystals of Ru(SnPh(3))(2)(CO)(2)(iPr-DAB).3.5C(6)H(6) form in the triclinic space group P&onemacr; in a unit cell of dimensions a = 11.662(6) Å, b = 13.902(3) Å, c = 19.643(2) Å, alpha = 71.24(2) degrees, beta = 86.91(4) degrees, gamma = 77.89(3) degrees, and V = 2946(3) Å(3). One-electron reduction of Ru(SnPh(3))(2)(CO)(2)(iPr-DAB) produces the stable radical-anion [Ru(SnPh(3))(2)(CO)(2)(iPr-DAB)](*-) that was characterized by IR, and UV-vis spectroelectrochemistry. Its EPR spectrum shows a signal at g = 1.9960 with well resolved Sn, Ru, and iPr-DAB (H, N) hyperfine couplings. DFT-MO calculations on the model compound Ru(SnH(3))(2)(CO)(2)(H-DAB) reveal that the HOMO is mainly of sigma(Sn-Ru-Sn) character mixed strongly with the lowest pi orbital of the H-DAB ligand. The LUMO (SOMO in the reduced complex) should be viewed as predominantly pi(H-DAB) with an admixture of the sigma(Sn-Ru-Sn) orbital. Accordingly, the lowest-energy absorption band of the neutral species will mainly belong to the sigma(Sn-Ru-Sn)-->pi(iPr-DAB) charge transfer transition. The intrinsic strength of the Ru-Sn bond and the delocalized character of the three-center four-electron Sn-Ru-Sn sigma-bond account for the inherent stability of the radical anion.

Alternative Careers for Educators. A Workshop Presented by Pi Lambda Theta's Iota Chapter at Indiana University.

ERIC Educational Resources Information Center

Kiewitt, Eva L., Ed.

This document summarizes a workshop to assist persons considering preparation in education to realistically look at the use of the wide range of skills and competencies developed in a teacher education program. The first section is an introduction that discusses the purposes of the workshop. The second section is the keynote address, A Look at…

Student-Industry Plan for Action.

ERIC Educational Resources Information Center

National Association of Manufacturers, New York, NY. Education Committee.

The guidelines for a student-industry action committee represent an attempt by the authors to reverse the trend of mistrust demonstrated by the American public toward business and industry. Twelve chapter presidents of Delta Sigma Pi, a university business fraternity, met initially with representatives of the National Association of Manufacturers…

Power spectrum, correlation function, and tests for luminosity bias in the CfA redshift survey

NASA Technical Reports Server (NTRS)

Park, Changbom; Vogeley, Michael S.; Geller, Margaret J.; Huchra, John P.

1994-01-01

We describe and apply a method for directly computing the power spectrum for the galaxy distribution in the extension of the Center for Astrophysics Redshift Survey. Tests show that our technique accurately reproduces the true power spectrum for k greater than 0.03 h Mpc(exp -1). The dense sampling and large spatial coverage of this survey allow accurate measurement of the redshift-space power spectrum on scales from 5 to approximately 200 h(exp -1) Mpc. The power spectrum has slope n approximately equal -2.1 on small scales (lambda less than or equal 25 h(exp -1) Mpc) and n approximately -1.1 on scales 30 less than lambda less than 120 h(exp -1) Mpc. On larger scales the power spectrum flattens somewhat, but we do not detect a turnover. Comparison with N-body simulations of cosmological models shows that an unbiased, open universe CDM model (OMEGA h = 0.2) and a nonzero cosmological constant (CDM) model (OMEGA h = 0.24, lambda(sub zero) = 0.6, b = 1.3) match the CfA power spectrum over the wavelength range we explore. The standard biased CDM model (OMEGA h = 0.5, b = 1.5) fails (99% significance level) because it has insufficient power on scales lambda greater than 30 h(exp -1) Mpc. Biased CDM with a normalization that matches the Cosmic Microwave Background (CMB) anisotropy (OMEGA h = 0.5, b = 1.4, sigma(sub 8) (mass) = 1) has too much power on small scales to match the observed galaxy power spectrum. This model with b = 1 matches both Cosmic Background Explorer Satellite (COBE) and the small-scale power spect rum but has insufficient power on scales lambda approximately 100 h(exp -1) Mpc. We derive a formula for the effect of small-scale peculiar velocities on the power spectrum and combine this formula with the linear-regime amplification described by Kaiser to compute an estimate of the real-space power spectrum. Two tests reveal luminosity bias in the galaxy distribution: First, the amplitude of the pwer spectrum is approximately 40% larger for the brightest 50% of galaxies in volume-limited samples that have M(sub lim) greater than M*. This bias in the power spectrum is independent of scale, consistent with the peaks-bias paradigm for galaxy formation. Second, the distribution of local density around galaxies shows that regions of moderate and high density contain both very bright (M less than M* = -19.2 + 5 log h) and fainter galaxies, but that voids preferentially harbor fainter galaxies (approximately 2 sigma significance level).

A comparison of the bonding in Cr(NO)4 and Ni(CO)4

NASA Technical Reports Server (NTRS)

Bauschlicher, C. W., Jr.; Siegbahn, P. E. M.

1986-01-01

The bonding in Cr(NO)4 is very ionic, with about 1.5 electrons donated from the Cr to the NO 2pi orbitals. There is also a NO sigma donation of about 0.5 electrons to the Cr, yielding a net charge of Cr of about 1. A large MCSCF expansion is needed to describe both the ionic and covalent contributions to the Cr 3d-NO 2pi bonding. This bonding is compared to that in the isoelectronic Ni(CO)4.

Electronic structure and reactivity of three-coordinate iron complexes.

PubMed

Holland, Patrick L

2008-08-01

[Reaction: see text]. The identity and oxidation state of the metal in a coordination compound are typically thought to be the most important determinants of its reactivity. However, the coordination number (the number of bonds to the metal) can be equally influential. This Account describes iron complexes with a coordination number of only three, which differ greatly from iron complexes with octahedral (six-coordinate) geometries with respect to their magnetism, electronic structure, preference for ligands, and reactivity. Three-coordinate complexes with a trigonal-planar geometry are accessible using bulky, anionic, bidentate ligands (beta-diketiminates) that steer a monodentate ligand into the plane of their two nitrogen donors. This strategy has led to a variety of three-coordinate iron complexes in which iron is in the +1, +2, and +3 oxidation states. Systematic studies on the electronic structures of these complexes have been useful in interpreting their properties. The iron ions are generally high spin, with singly occupied orbitals available for pi interactions with ligands. Trends in sigma-bonding show that iron(II) complexes favor electronegative ligands (O, N donors) over electropositive ligands (hydride). The combination of electrostatic sigma-bonding and the availability of pi-interactions stabilizes iron(II) fluoride and oxo complexes. The same factors destabilize iron(II) hydride complexes, which are reactive enough to add the hydrogen atom to unsaturated organic molecules and to take part in radical reactions. Iron(I) complexes use strong pi-backbonding to transfer charge from iron into coordinated alkynes and N 2, whereas iron(III) accepts charge from a pi-donating imido ligand. Though the imidoiron(III) complex is stabilized by pi-bonding in the trigonal-planar geometry, addition of pyridine as a fourth donor weakens the pi-bonding, which enables abstraction of H atoms from hydrocarbons. The unusual bonding and reactivity patterns of three-coordinate iron compounds may lead to new catalysts for oxidation and reduction reactions and may be used by nature in transient intermediates of nitrogenase enzymes.

New Kinematical Constraints on Cosmic Acceleration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rapetti, David; Allen, Steve W.; Amin, Mustafa A.

2007-05-25

We present and employ a new kinematical approach to ''dark energy'' studies. We construct models in terms of the dimensionless second and third derivatives of the scale factor a(t) with respect to cosmic time t, namely the present-day value of the deceleration parameter q{sub 0} and the cosmic jerk parameter, j(t). An elegant feature of this parameterization is that all {Lambda}CDM models have j(t)=1 (constant), which facilitates simple tests for departures from the {Lambda}CDM paradigm. Applying our model to redshift-independent distance measurements, from type Ia supernovae and X-ray cluster gas mass fraction measurements, we obtain clear statistical evidence for amore » late time transition from a decelerating to an accelerating phase. For a flat model with constant jerk, j(t)=j, we measure q{sub 0}=-0.81 {+-} 0.14 and j=2.16 +0.81 -0.75, results that are consistent with {Lambda}CDM at about the 1{sigma} confidence level. In comparison to dynamical analyses, the kinematical approach uses a different model set and employs a minimum of prior information, being independent of any particular gravity theory. The results obtained with this new approach therefore provide important additional information and we argue that both kinematical and dynamical techniques should be employed in future dark energy studies, where possible.« less

Observation of Upsilon(2S)-->etaUpsilon(1S) and search for related transitions.

PubMed

He, Q; Insler, J; Muramatsu, H; Park, C S; Thorndike, E H; Yang, F; Artuso, M; Blusk, S; Khalil, S; Li, J; Mountain, R; Nisar, S; Randrianarivony, K; Sultana, N; Skwarnicki, T; Stone, S; Wang, J C; Zhang, L M; Bonvicini, G; Cinabro, D; Dubrovin, M; Lincoln, A; Naik, P; Rademacker, J; Asner, D M; Edwards, K W; Reed, J; Briere, R A; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Alexander, J P; Cassel, D G; Duboscq, J E; Ehrlich, R; Fields, L; Galik, R S; Gibbons, L; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Hunt, J M; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Ledoux, J; Mahlke-Krüger, H; Mohapatra, D; Onyisi, P U E; Patterson, J R; Peterson, D; Riley, D; Ryd, A; Sadoff, A J; Shi, X; Stroiney, S; Sun, W M; Wilksen, T; Athar, S B; Patel, R; Yelton, J; Rubin, P; Eisenstein, B I; Karliner, I; Mehrabyan, S; Lowrey, N; Selen, M; White, E J; Wiss, J; Mitchell, R E; Shepherd, M R; Besson, D; Pedlar, T K; Xavier, J V; Cronin-Hennessy, D; Gao, K Y; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Poling, R; Scott, A W; Zweber, P; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Libby, J; Martin, L; Powell, A; Wilkinson, G; Ecklund, K M; Love, W; Savinov, V; Mendez, H; Ge, J Y; Miller, D H; Shipsey, I P J; Xin, B; Adams, G S; Anderson, M; Cummings, J P; Danko, I; Hu, D; Moziak, B; Napolitano, J

2008-11-07

We report the first observation of Upsilon(2S)-->etaUpsilon(1S), with a branching fraction B=(2.1(-0.6)+0.7(stat)+/-0.3(syst)) x 10(-4) and a statistical significance 5.3sigma. Data were acquired with the CLEO III detector at the CESR e+e(-) symmetric collider. This is the first process observed involving a b-quark spin flip. For related transitions, 90% confidence limits in units of 10(-4) are B(Upsilon(2S)-->pi0Upsilon(1S)) < 1.8, B(Upsilon(3S)-->etaUpsilon(1S)) < 1.8, B(Upsilon(3S)-->pi0Upsilon(1S)) < 0.7, and B(Upsilon(3S)-->pi0Upsilon(2S)) < 5.1.

Inequalities between Kappa and Kappa-Like Statistics for "k x k" Tables

ERIC Educational Resources Information Center

Warrens, Matthijs J.

2010-01-01

The paper presents inequalities between four descriptive statistics that can be expressed in the form [P-E(P)]/[1-E(P)], where P is the observed proportion of agreement of a "kappa x kappa" table with identical categories, and E(P) is a function of the marginal probabilities. Scott's "pi" is an upper bound of Goodman and Kruskal's "lambda" and a…

Pi Lambda Theta Summer 1988 Orient Study Tour, University of Hawaii at Manoa Campus. Course Title: International Education and East Asia. Research Report.

ERIC Educational Resources Information Center

Buzzelli, Charlotte Grace

This study compares the educational history, present educational systems, and current educational practices of Japan and Korea for the purpose of applying the study's results to improving elementary, secondary, and higher education liberal arts curricula in the United States. Framing the report is the notion of international educational exchange…

Reference scales for the characterization of cationic electrophiles and neutral nucleophiles.

PubMed

Mayr, H; Bug, T; Gotta, M F; Hering, N; Irrgang, B; Janker, B; Kempf, B; Loos, R; Ofial, A R; Remennikov, G; Schimmel, H

2001-10-03

Twenty-three diarylcarbenium ions and 38 pi-systems (arenes, alkenes, allyl silanes and stannanes, silyl enol ethers, silyl ketene acetals, and enamines) have been defined as basis sets for establishing general reactivity scales for electrophiles and nucleophiles. The rate constants of 209 combinations of these benzhydrylium ions and pi-nucleophiles, 85 of which are first presented in this article, have been subjected to a correlation analysis to determine the electrophilicity parameters E and the nucleophilicity parameters N and s as defined by the equation log k(20 degrees C) = s(N + E) (Mayr, H.; Patz, M. Angew. Chem., Int. Ed. Engl. 1994, 33, 938-957). Though the reactivity scales thus obtained cover more than 16 orders of magnitude, the individual rate constants are reproduced with a standard deviation of a factor of 1.19 (Table 1). It is shown that the reactivity parameters thus derived from the reactions of diarylcarbenium ions with pi-nucleophiles (Figure 3) are also suitable for characterizing the nucleophilic reactivities of alkynes, metal-pi-complexes, and hydride donors (Table 2) and for characterizing the electrophilic reactivities of heterosubstituted and metal-coordinated carbenium ions (Table 3). The reactivity parameters in Figure 3 are, therefore, recommended for the characterization of any new electrophiles and nucleophiles in the reactivity range covered. The linear correlation between the electrophilicity parameters E of benzhydryl cations and the corresponding substituent constants sigma(+) provides Hammett sigma(+) constants for 10 substituents from -1.19 to -2.11, i.e., in a range with only very few previous entries.

Cosmology with EMSS Clusters of Galaxies

NASA Technical Reports Server (NTRS)

Donahue, Megan; Voit, G. Mark

1999-01-01

We use ASCA observations of the Extended Medium Sensitivity Survey sample of clusters of galaxies to construct the first z = 0.5 - 0.8 cluster temperature function. This distant cluster temperature function, when compared to local z approximately 0 and to a similar moderate redshift (z = 0.3 - 0.4) temperature function strongly constrains the matter density of the universe. Best fits to the distributions of temperatures and redshifts of these cluster samples results in Omega(sub M) = 0.45 +/- 0.1 if Lambda = 0 and Omega = 0.27 +/- 0.1 if Lambda + Omega(sub M) = 1. The uncertainties are 1sigma statistical. We examine the systematics of our approach and find that systematics, stemming mainly from model assumptions and not measurement errors, are about the same size as the statistical uncertainty +/- 0.1. In this poster proceedings, we clarify the issue of a8 as reported in our paper Donahue & Voit (1999), since this was a matter of discussion at the meeting.

Stable and 'bounded excursion' gravastars, and black holes in Einstein's theory of gravity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rocha, P; Da Silva, M F A; Wang, Anzhong

2008-11-15

Dynamical models of prototype gravastars are constructed and studied. The models are the Visser-Wiltshire three-layer gravastars, in which an infinitely thin spherical shell of a perfect fluid with the equation of state p = (1-{gamma}){sigma} divides the whole spacetime into two regions, where the internal region is de Sitter, and the external one is Schwarzschild. When {gamma}<1 and {Lambda}{ne}0, it is found that in some cases the models represent stable gravastars, and in some cases they represent 'bounded excursion' stable gravastars, where the thin shell is oscillating between two finite radii, while in some other cases they collapse until themore » formation of black holes occurs. However, when {gamma}{>=}1, even with {Lambda}{ne}0, only black holes are found. In the phase space, the region for both stable gravastars and 'bounded excursion' gravastars is very small in comparison to that for black holes, although it is not completely empty.« less

Observation of a resonancelike structure in the pi +- psi' mass distribution in exclusive B-->Kpi +- psi' decays.

PubMed

Choi, S-K; Olsen, S L; Adachi, I; Aihara, H; Aulchenko, V; Aushev, T; Aziz, T; Bakich, A M; Balagura, V; Bedny, I; Bitenc, U; Bondar, A; Bozek, A; Bracko, M; Brodzicka, J; Browder, T E; Chang, P; Chao, Y; Chen, A; Chen, K-F; Chen, W T; Cheon, B G; Chistov, R; Choi, Y; Dalseno, J; Danilov, M; Dash, M; Eidelman, S; Gabyshev, N; Golob, B; Haba, J; Hara, T; Hayasaka, K; Hayashii, H; Hazumi, M; Heffernan, D; Hoshi, Y; Hou, W-S; Hyun, H J; Iijima, T; Inami, K; Ishikawa, A; Ishino, H; Itoh, R; Iwasaki, M; Iwasaki, Y; Kah, D H; Kang, J H; Katayama, N; Kawai, H; Kawasaki, T; Kichimi, H; Kim, H O; Kim, S K; Kim, Y J; Kinoshita, K; Krizan, P; Krokovny, P; Kumar, R; Kuo, C C; Kuzmin, A; Kwon, Y-J; Lange, J S; Lee, J S; Lee, M J; Lee, S E; Lesiak, T; Limosani, A; Lin, S-W; Liu, Y; Liventsev, D; Mandl, F; Matyja, A; McOnie, S; Medvedeva, T; Mitaroff, W; Miyabayashi, K; Miyake, H; Miyata, H; Miyazaki, Y; Mizuk, R; Moloney, G R; Nakano, E; Nakao, M; Nishida, S; Nitoh, O; Nozaki, T; Ogawa, S; Ohshima, T; Okuno, S; Ozaki, H; Pakhlov, P; Pakhlova, G; Park, C W; Park, H; Peak, L S; Pestotnik, R; Piilonen, L E; Sahoo, H; Sakai, Y; Schneider, O; Schwartz, A J; Senyo, K; Shapkin, M; Shen, C P; Shibuya, H; Shwartz, B; Singh, J B; Somov, A; Stanic, S; Staric, M; Sumiyoshi, T; Suzuki, S Y; Takasaki, F; Tamai, K; Tanaka, M; Teramoto, Y; Tikhomirov, I; Uehara, S; Uglov, T; Unno, Y; Uno, S; Urquijo, P; Varner, G; Vervink, K; Villa, S; Wang, C H; Wang, M-Z; Wang, P; Wang, X L; Watanabe, Y; Wedd, R; Won, E; Yabsley, B D; Yamashita, Y; Yuan, C Z; Zhang, Z P; Zhulanov, V; Zupanc, A; Zyukova, O

2008-04-11

A distinct peak is observed in the pi +/- psi' invariant mass distribution near 4.43 GeV in B-->K pi +/- psi' decays. A fit using a Breit-Wigner resonance shape yields a peak mass and width of M=4433+/-4(stat)+/-2(syst) MeV and Gamma=45-13+18(stat)-13+30(syst) MeV. The product branching fraction is determined to be B(B 0-->K -/+Z+/-(4430)) x B(Z+/-(4430)-->pi+/-psi')=(4.1+/-1.0(stat)+/-1.4(syst)) x 10(-5), where Z+/-(4430) is used to denote the observed structure. The statistical significance of the observed peak is 6.5 sigma. These results are obtained from a 605 fb(-1) data sample that contains 657 x 10(6) BB pairs collected near the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric energy e+ e- collider.

Cosmological constraints from Galaxy Clusters in 2500 square-degree SPT-SZ survey

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haan, T. de; Benson, B. A.; Bleem, L. E.

We present cosmological parameter constraints obtained from galaxy clusters identified by their SunyaevZel'dovich effect signature in the 2500 square-degree South Pole Telescope Sunyaev Zel'dovich (SPT-SZ) survey. We consider the 377 cluster candidates identified at z > 0.25 with a detection significance greater than five, corresponding to the 95% purity threshold for the survey. We compute constraints on cosmological models using the measured cluster abundance as a function of mass and redshift. We include additional constraints from multi-wavelength observations, including Chandra X-ray data for 82 clusters and a weak lensing-based prior on the normalization of the mass-observable scaling relations. Assuming amore » spatially flat Lambda CDM cosmology, we combine the cluster data with a prior on H-0 and find sigma(8)= 0.784. +/- 0.039 and Omega(m) = 0.289. +/- 0.042, with the parameter combination sigma(8) (Omega(m)/0.27)(0.3) = 0.797 +/- 0.031. These results are in good agreement with constraints from the cosmic microwave background (CMB) from SPT, WMAP, and Planck, as well as with constraints from other cluster data sets. We also consider several extensions to Lambda CDM, including models in which the equation of state of dark energy w, the species-summed neutrino mass, and/or the effective number of relativistic species (N-eff) are free parameters. When combined with constraints from the Planck CMB, H-0, baryon acoustic oscillation, and SNe, adding the SPT cluster data improves the w constraint by 14%, to w = -1.023 +/- 0.042.« less

Imprint of DES superstructures on the cosmic microwave background

DOE PAGES

Kovács, A.; Sánchez, C.; García-Bellido, J.; ...

2016-11-17

Here, small temperature anisotropies in the Cosmic Microwave Background can be sourced by density perturbations via the late-time integrated Sachs-Wolfe effect. Large voids and superclusters are excellent environments to make a localized measurement of this tiny imprint. In some cases excess signals have been reported. We probed these claims with an independent data set, using the first year data of the Dark Energy Survey in a different footprint, and using a different super-structure finding strategy. We identified 52 large voids and 102 superclusters at redshiftsmore » $0.2 < z < 0.65$. We used the Jubilee simulation to a priori evaluate the optimal ISW measurement configuration for our compensated top-hat filtering technique, and then performed a stacking measurement of the CMB temperature field based on the DES data. For optimal configurations, we detected a cumulative cold imprint of voids with $$\\Delta T_{f} \\approx -5.0\\pm3.7~\\mu K$$ and a hot imprint of superclusters $$\\Delta T_{f} \\approx 5.1\\pm3.2~\\mu K$$ ; this is $$\\sim1.2\\sigma$$ higher than the expected $$|\\Delta T_{f}| \\approx 0.6~\\mu K$$ imprint of such super-structures in $$\\Lambda$$CDM. If we instead use an a posteriori selected filter size ($$R/R_{v}=0.6$$), we can find a temperature decrement as large as $$\\Delta T_{f} \\approx -9.8\\pm4.7~\\mu K$$ for voids, which is $$\\sim2\\sigma$$ above $$\\Lambda$$CDM expectations and is comparable to previous measurements made using SDSS super-structure data.« less

Imprint of DES superstructures on the cosmic microwave background

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kovács, A.; Sánchez, C.; García-Bellido, J.

Here, small temperature anisotropies in the Cosmic Microwave Background can be sourced by density perturbations via the late-time integrated Sachs-Wolfe effect. Large voids and superclusters are excellent environments to make a localized measurement of this tiny imprint. In some cases excess signals have been reported. We probed these claims with an independent data set, using the first year data of the Dark Energy Survey in a different footprint, and using a different super-structure finding strategy. We identified 52 large voids and 102 superclusters at redshiftsmore » $0.2 < z < 0.65$. We used the Jubilee simulation to a priori evaluate the optimal ISW measurement configuration for our compensated top-hat filtering technique, and then performed a stacking measurement of the CMB temperature field based on the DES data. For optimal configurations, we detected a cumulative cold imprint of voids with $$\\Delta T_{f} \\approx -5.0\\pm3.7~\\mu K$$ and a hot imprint of superclusters $$\\Delta T_{f} \\approx 5.1\\pm3.2~\\mu K$$ ; this is $$\\sim1.2\\sigma$$ higher than the expected $$|\\Delta T_{f}| \\approx 0.6~\\mu K$$ imprint of such super-structures in $$\\Lambda$$CDM. If we instead use an a posteriori selected filter size ($$R/R_{v}=0.6$$), we can find a temperature decrement as large as $$\\Delta T_{f} \\approx -9.8\\pm4.7~\\mu K$$ for voids, which is $$\\sim2\\sigma$$ above $$\\Lambda$$CDM expectations and is comparable to previous measurements made using SDSS super-structure data.« less

BAT AGN Spectroscopic Survey - III. An Observed Link Between AGN Eddington Ratio and Narrow-Emission-Line Ratios

NASA Technical Reports Server (NTRS)

Oh, Kyuseok; Schawinski, Kevin; Koss, Michael; Trakhtenbrot, Benny; Lamperti, Isabella; Ricci, Claudio; Mushotzky, Richard; Veilleux, Sylvain; Berney, Simon; Crenshaw, D. Michael;

X-ray clusters in a cold dark matter + lambda universe: A direct, large-scale, high-resolution, hydrodynamic simulation

NASA Technical Reports Server (NTRS)

Cen, Renyue; Ostriker, Jeremiah P.

1994-01-01

A new, three-dimensional, shock-capturing, hydrodynamic code is utilized to determine the distribution of hot gas in a cold dark matter (CDM) + lambda model universe. Periodic boundary conditions are assumed: a box with size 85/h Mpc, having cell size 0.31/h Mpc, is followed in a simulation with 270(exp 3) = 10(exp 7.3) cells. We adopt omega = 0.45, lambda = 0.55, h identically equal to H/100 km/s/Mpc = 0.6, and then, from the cosmic background explorer (COBE) and light element nucleosynthesis, sigma(sub 8) = 0.77, omega(sub b) = 0.043. We identify the X-ray emitting clusters in the simulation box, compute the luminosity function at several wavelength bands, the temperature function and estimated sizes, as well as the evolution of these quantities with redshift. This open model succeeds in matching local observations of clusters in contrast to the standard omega = 1, CDM model, which fails. It predicts an order of magnitude decline in the number density of bright (h nu = 2-10 keV) clusters from z = 0 to z = 2 in contrast to a slight increase in the number density for standard omega = 1, CDM model. This COBE-normalized CDM + lambda model produces approximately the same number of X-ray clusters having L(sub x) greater than 10(exp 43) erg/s as observed. The background radiation field at 1 keV due to clusters is approximately the observed background which, after correction for numerical effects, again indicates that the model is consistent with observations.

About some Regge-like relations for (stable) black holes

NASA Astrophysics Data System (ADS)

Recami, E.; Tonin-Zanchin, Vilson

1991-08-01

Within a purely classical formulation of 'strong gravity', we associated hadron constituents (and even hadrons themselves) with suitable stationary, axisymmetric solutions of certain new Einstein-type equations supposed to describe the strong field inside hadrons. Such equations are nothing but Einstein equations - with cosmological term - suitably scaled down. As a consequence, the cosmological constant (lambda) and the masses M result in our theory to be scaled up and transformed into a 'hadronic constant' and into 'strong masses', respectively. Due to the unusual range of lambda and M values considered, we met a series of solutions of the Kerr-Newman-de Sitter (KNdS) type with such interesting properties that it is worth studying them - from our particular point of view - also in the case of ordinary gravity. This is the aim of the present work. The requirement that those solutions be stable, i.e., that their temperature (or surface gravity) be vanishingly small, implies the coincidence of at least two of their (in general, three) horizons. Imposing the stability condition of a certain horizon does yield (once chosen the values of J, q, and lambda) mass and radius of the associated black-hole. In the case of ordinary Einstein equations and for stable black-holes of the KNdS type, we get in particular Regge-like relations among mass M, angular momentum J, charge q, and cosmological constant (lambda). For instance, with the standard definitions Q2 is identical to Gq2 /(4(pi)(epsilon)0c4); a is identical to J/(Mc); m is identical to GM/c2, in the case lambda = 0 in which m2 = a2 + Q2 and if q is negligible we find m2 = J. When considering, for simplicity, lambda greater than 0 and J = 0 (and q still negligible), then we obtain m2 = 1/(9(lambda)).

A Simulation Study of Rater Agreement Measures with 2x2 Contingency Tables

ERIC Educational Resources Information Center

Ato, Manuel; Lopez, Juan Jose; Benavente, Ana

2011-01-01

A comparison between six rater agreement measures obtained using three different approaches was achieved by means of a simulation study. Rater coefficients suggested by Bennet's [sigma] (1954), Scott's [pi] (1955), Cohen's [kappa] (1960) and Gwet's [gamma] (2008) were selected to represent the classical, descriptive approach, [alpha] agreement…

78 FR 77711 - National Register of Historic Places; Notification of Pending Nominations and Related Actions

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-24

... Cook County Bush Temple of Music, 100 W. Chicago Ave., 800 N. Clark St., Chicago, 13001001 Stony Island Trust and Savings Bank Building, 6760 S. Stony Island Ave., Chicago, 13001002 Lake County Waukegan... Johnson County Sigma Pi Fraternity House, 108 McLean St., Iowa City, 13001019 Maryland Baltimore...

Ring-breaking electron attachment to uracil: following bond dissociations via evolving resonances.

PubMed

Gianturco, Franco A; Sebastianelli, F; Lucchese, R R; Baccarelli, I; Sanna, N

2008-05-07

Calculations are carried out at various distinct energies to obtain both elastic cross sections and S-matrix resonance indicators (poles) from a quantum treatment of the electron scattering from gas-phase uracil. The low-energy region confirms the presence of pi(*) resonances as revealed by earlier calculations and experiments which are compared with the present findings. They turn out to be little affected by bond deformation, while the transient negative ions (TNIs) associated with sigma(*) resonances in the higher energy region ( approximately 8 eV) indeed show that ring deformations which allow vibrational redistribution of the excess electron energy into the molecular target strongly affect these shape resonances: They therefore evolve along different dissociative pathways and stabilize different fragment anions. The calculations further show that the occurrence of conical intersections between sigma(*) and pi(*)-type potential energy surfaces (real parts) is a very likely mechanism responsible for energy transfers between different TNIs. The excess electron wavefunctions for such scattering states, once mapped over the molecular space, provide nanoscopic reasons for the selective breaking of different bonds in the ring region.

Superfluid-ferromagnet-superfluid junction and the {pi} phase in a superfluid Fermi gas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kashimura, Takashi; Tsuchiya, Shunji; CREST

2010-09-15

We investigate the possibility of a superfluid-ferromagnet-superfluid (SFS) junction in a superfluid Fermi gas. To examine this possibility in a simple manner, we consider an attractive Hubbard model at T=0 within the mean-field theory. When a potential barrier is embedded in a superfluid Fermi gas with population imbalance (N{sub {up_arrow}}>N{sub {down_arrow}}, where N{sub {sigma}} is the number of atoms with pseudospin {sigma}= {up_arrow}, {down_arrow}), this barrier is shown to be magnetized in the sense that excess {up_arrow}-spin atoms are localized around it. The resulting superfluid Fermi gas is spatially divided into two by this ferromagnet, so that one obtains amore » junction similar to the superconductor-ferromagnet-superconductor junction discussed in superconductivity. Indeed, we show that the so-called {pi} phase, which is a typical phenomenon in the SFS junction, is realized, where the superfluid order parameter changes its sign across the junction. Our results would be useful for the study of magnetic effects on fermion superfluidity using an ultracold Fermi gas.« less

A Study of Multiplicities in Hadronic Interactions (in Spanish)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Estrada Tristan, Nora Patricia; /San Luis Potosi U.

Using data from the SELEX (Fermilab E781) experiment obtained with a minimum-bias trigger, we study multiplicity and angular distributions of secondary particles produced in interactions in the experimental targets. We observe interactions of {Sigma}{sup -}, proton, {pi}{sup -}, and {pi}{sup +}, at beam momenta between 250 GeV/c and 650 GeV/c, in copper, polyethylene, graphite, and beryllium targets. We show that the multiplicity and angular distributions for meson and baryon beams at the same momentum are identical. We also show that the mean multiplicity increases with beam momentum, and presents only small variations with the target material.

Power spectrum, correlation function, and tests for luminosity bias in the CfA redshift survey

NASA Astrophysics Data System (ADS)

Park, Changbom; Vogeley, Michael S.; Geller, Margaret J.; Huchra, John P.

1994-08-01

We describe and apply a method for directly computing the power spectrum for the galaxy distribution in the extension of the Center for Astrophysics Redshift Survey. Tests show that our technique accurately reproduces the true power spectrum for k greater than 0.03 h Mpc-1. The dense sampling and large spatial coverage of this survey allow accurate measurement of the redshift-space power spectrum on scales from 5 to approximately 200 h-1 Mpc. The power spectrum has slope n approximately equal -2.1 on small scales (lambda less than or equal 25 h-1 Mpc) and n approximately -1.1 on scales 30 less than lambda less than 120 h-1 Mpc. On larger scales the power spectrum flattens somewhat, but we do not detect a turnover. Comparison with N-body simulations of cosmological models shows that an unbiased, open universe CDM model (OMEGA h = 0.2) and a nonzero cosmological constant (CDM) model (OMEGA h = 0.24, lambdazero = 0.6, b = 1.3) match the CfA power spectrum over the wavelength range we explore. The standard biased CDM model (OMEGA h = 0.5, b = 1.5) fails (99% significance level) because it has insufficient power on scales lambda greater than 30 h-1 Mpc. Biased CDM with a normalization that matches the Cosmic Microwave Background (CMB) anisotropy (OMEGA h = 0.5, b = 1.4, sigma8 (mass) = 1) has too much power on small scales to match the observed galaxy power spectrum. This model with b = 1 matches both Cosmic Background Explorer Satellite (COBE) and the small-scale power spect rum but has insufficient power on scales lambda approximately 100 h-1 Mpc. We derive a formula for the effect of small-scale peculiar velocities on the power spectrum and combine this formula with the linear-regime amplification described by Kaiser to compute an estimate of the real-space power spectrum. Two tests reveal luminosity bias in the galaxy distribution: First, the amplitude of the power spectrum is approximately 40% larger for the brightest 50% of galaxies in volume-limited samples that have Mlim greater than M*. This bias in the power spectrum is independent of scale, consistent with the peaks-bias paradigm for galaxy formation. Second, the distribution of local density around galaxies shows that regions of moderate and high density contain both very bright (M less than M* = -19.2 + 5 log h) and fainter galaxies, but that voids preferentially harbor fainter galaxies (approximately 2 sigma significance level).

Monitoring of environmental conditions in taiga forests using ERS-1 SAR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rignot, E.; Way, J.B.; McDonald, K.

1994-08-01

Synthetic-aperture radar images of forest site near Manley Hot Springs (64[degree]N, 151[degree]W), Alaska, were collected between August 1991 and December 1991, day and night, every 3 days, at C-band frequency ([lambda] = 5.7 cm), vertical receive and transmit polarization, by the European Space Agency First Remote Sensing Satellite, ERS-1. During the same period, air and soil temperatures and dielectric and gravimetric moisture properties of the forest canopy and forest floor were monitored in three forest stands dominated, respectively, by black spruce (Picea mariana), white spruce (Picea glauca), and balsam poplar (Populus balsamifera). The calibrated ERS-1 radar backscatter values, [sigma][degree], ofmore » the forest stands are shown to exhibit a pronounced temporal pattern, with little separability between tree species. The largest change in [sigma][degree], a 3-dB decrease almost independent of tree species, is observed in early winter when the soil and vegetation freeze. In the summer, temporal fluctuations in [sigma][degree] are about 1--2 dB in magnitude, depending on tree species. Diurnal variations in [sigma][degree] are as large as 2 dB during fall freeze-up, and less than 1 dB in summer and winter. These temporal variations in radar backscatter from the forest are interpreted using the MIMICS radar backscatter model and the in situ surface observations as due to changes in the dielectric properties of the forest floor and forest canopy induced by precipitation (summer), drought (fall), and freezing (fall-winter) events. In winter, [sigma][degree] increases across the entire landscape, probably because of volume scattering from large depth hoar ice crystals forming in the snow pack.« less

Engagement of Arginine Finger to ATP Triggers Large Conformational Changes in NtrC1 AAA+ ATPase for Remodeling Bacterial RNA Polymerase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Baoyu; Sysoeva, Tatyana A.; Chowdhury, Saikat

The NtrC-like AAA+ ATPases control virulence and other important bacterial activities through delivering mechanical work to {sigma}54-RNA polymerase to activate transcription from {sigma}54-dependent genes. We report the first crystal structure for such an ATPase, NtrC1 of Aquifex aeolicus, in which the catalytic arginine engages the {gamma}-phosphate of ATP. Comparing the new structure with those previously known for apo and ADP-bound states supports a rigid-body displacement model that is consistent with large-scale conformational changes observed by low-resolution methods. First, the arginine finger induces rigid-body roll, extending surface loops above the plane of the ATPase ring to bind {sigma}54. Second, ATP hydrolysismore » permits Pi release and retraction of the arginine with a reversed roll, remodeling {sigma}54-RNAP. This model provides a fresh perspective on how ATPase subunits interact within the ring-ensemble to promote transcription, directing attention to structural changes on the arginine-finger side of an ATP-bound interface.« less

Current distribution and ac susceptibility response of a thin superconducting disc in an axial field: a theoretical approach

NASA Astrophysics Data System (ADS)

Aruna, S. A.; Zhang, P.; Lin, F. Y.; Ding, S. Y.; Yao, X. X.

2000-04-01

Within the framework of the thermally activated process of the flux line or flux line bundles, and by time integration of the 1D equation of motion of the circulating current density icons/Journals/Common/vecJ" ALT="vecJ" ALIGN="TOP"/> (icons/Journals/Common/rho" ALT="rho" ALIGN="TOP"/> ,t ), which is suitable for thin superconducting films (R >>d ,icons/Journals/Common/le" ALT="le" ALIGN="TOP"/> icons/Journals/Common/lambda" ALT="lambda" ALIGN="TOP"/> ), we present numerical calculations of the current profiles, magnetization hysteresis loops and ac susceptibility icons/Journals/Common/chi" ALT="chi" ALIGN="TOP"/> n = icons/Journals/Common/chi" ALT="chi" ALIGN="TOP"/> ´n +iicons/Journals/Common/chi" ALT="chi" ALIGN="TOP"/> ´´n for n = 1, 3 and 5 of a thin disc immersed in an axial time-dependent external magnetic field Ba (t ) = Bdc +Bac cos(2icons/Journals/Common/pi" ALT="pi" ALIGN="TOP"/> icons/Journals/Common/nu" ALT="nu" ALIGN="TOP"/> t ). Our calculated results are compared with those of the critical state model (CSM) and found to prove the approximate validity of the CSM below the irreversibility field. The differences between our computed results and those of the CSM are also discussed.

Search for resonances decaying to etac pi pi- in two-photon interactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lees, J.P.; Poireau, V.; Tisserand, V.

2012-06-18

We report a study of the process {gamma}{gamma} {yields} X {yields} {eta}{sub c}{pi}{sup +}{pi}{sup -}, where X stands for one of the resonances {chi}{sub c2}(1P), {eta}{sub c}(2S), X(3872), X(3915), or {chi}{sub c2}(2P). The analysis is performed with a data sample of 473.9 fb{sup -1} collected with the BABAR detector at the PEP-II asymmetric-energy electron-positron collider. We do not observe a significant signal for any channel, and calculate 90% confidence-level upper limits on the products of branching fractions and two-photon widths {Lambda}{sub X{yields}{gamma}{gamma}} {Beta}(X {yields} {eta}{sub c}{pi}{sup +}{pi}{sup -}): 15.7 eV for {chi}{sub c2}(1P), 133 eV for {eta}{sub c}(2S), 11.1 eVmore » for X(3872) (assuming it to be a spin-2 state), 16 eV for X(3915) (assuming it to be a spin-2 state), and 19 eV for {chi}{sub c2}(2P). We also report upper limits on the ratios of branching fractions {Beta}({eta}{sub c}(2S) {yields} {eta}{sub c}{pi}{sup +}{pi}{sup -})/{Beta}({eta}{sub c}(2S) {yields} K{sub S}{sup 0}K{sup +}{pi}{sup -}) < 10.0 and {Beta}({chi}{sub c2}(1P) {yields} {eta}{sub c}{pi}{sup +}{pi}{sup -})/{Beta}({chi}{sub c2}(1P) {yields} K{sub S}{sup 0}K{sup +}{pi}{sup -}) < 32.9 at the 90% confidence level.« less

Millimeter wave coherent synchrotron radiation in a compact electron storage ring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murphy, J.B.; Blum, E.; Heese, R.

1998-01-01

Installation of a 2,856 MHz RF system into the XLS compact electron storage ring would allow the generation of millimeter wave coherent synchrotron radiation. Operating at 150 MeV, one could produce bunches containing on the order of 2 {times} 10{sup 7} electrons with a bunch length {sigma}{sub L0} = 0.3 mm, resulting in coherent emission at wavelengths above 0.8 mm. The characteristics of the source and the emitted radiation are discussed. In the case of 100 mrad horizontal collection angle, the average power radiated in the wavelength band 1 mm {le} {lambda} {le} 2 mm is 0.3 mW for singlemore » bunch operation and 24 mW for 80 bunch operation. The peak power in a single pulse of a few picosecond duration is on the order of one watt. By reducing the momentum compaction, the bunch length could be reduced to {sigma}{sub L0} = 0.15 mm, resulting in coherent synchrotron radiation down to 500 {micro}m.« less

Is Self-Interacting Dark Matter Undergoing Dark Fusion?

DOE Office of Scientific and Technical Information (OSTI.GOV)

McDermott, Samuel D.

2017-11-02

We suggest that two-to-two dark matter fusion may be the relaxation process that resolves the small-scale structure problems of the cold collisionless dark matter paradigm. In order for the fusion cross section to scale correctly across many decades of astrophysical masses from dwarf galaxies to galaxy clusters, we require the fractional binding energy released to be greater than v^n ~ [10^{-(2-3)}]^n, where n=1,2 depends on local dark sector chemistry. The size of the dark-sector interaction cross sections must be sigma ~ 0.1-1 barn, moderately larger than for Standard Model deuteron fusion, indicating a dark nuclear scale Lambda ~ O(100 MeV).more » Dark fusion firmly predicts constant sigma v below the characteristic velocities of galaxy clusters. Observations of the inner structure of galaxy groups with velocity dispersion of several hundred kilometer per second, of which a handful have been identified, could differentiate dark fusion from a dark photon model.« less

Deep Exclusive Pseudoscalar Meson Production at Jefferson Lab Hall C

DOE Office of Scientific and Technical Information (OSTI.GOV)

Basnet, Samip

2017-09-01

Measurements of exclusive meson production are a useful tool in the study of hadronic structure. In particular, one can discern the relevant degrees of freedom at different distance scales through these studies. In the transition region between low momentum transfer (where a description of hadronic degrees of freedom in terms of effective hadronic Lagrangians is valid) and high momentum transfer (where the degrees of freedom are quarks and gluons), the predictive power of Quantum Chromodynamics (QCD), the theory of the strong interaction, is limited due to the absence of a complete solution. Thus, one has to rely upon experimental datamore » from the non-perturbative intermediate-energy regime to thoroughly understand the onset of perturbative QCD (pQCD) as the momentum transfer is increased. This work involves two deep exclusive meson electroproduction experiments at Jefferson Lab (JLab). The p(e,e'pi+)n reaction is studied at fixed Q^2 and W of 2.5 GeV2 and 2.0 GeV, respectively, while varying the four momentum transfer to the nucleon -t from 0.2 to 2.1 GeV2 . As -t is increased, the hadronic interaction scale is reduced independently of the observation scale of the virtual photon, providing valuable information about the hard- scattering process in general. The data was taken at JLab Hall C in 2003, as a part of the experiment E01-004, Fpi-2, using the High Momentum Spectrometer (HMS) and Short Orbit Spectrometer (SOS), and in this work, the results of the differential cross section analysis are presented and compared to prior data, as well as two theoretical models. Using these results over a wide -t range, the transition from hard to soft QCD is also studied. In addition, the p(e,e'K+)Lambda(Sigma0) reactions are also studied. Despite their importance in elucidating the reaction mechanism underlying strangeness production, we still do not have complete understanding of these reactions above the resonance region. The experiment, E12- 09-011, intends to perform, for the first time, a full Rosenbluth (L/T/LT/TT) separation of p(e,e'K+)Lambda(Sigma0) cross sections above the resonance region using the newly upgraded standard equipment, Super High Momentum Spectrometer (SHMS) at JLab Hall C. The separated data will allow us to better understand the Kaon production reaction mechanism and the hard-soft QCD transition in exclusive processes. The kinematic settings being studied in the experiment ranges from Q^2 of 0.4 to 5.5 GeV2, W of 2.3 to 3.1 GeV, and -t of 0.06 to 0.53 GeV2. Here, the results from some pre-experimental studies with regards to estimations of singles rates as well as real and accidental coincidence rates are presented, using two different models. The implications of these projections on the runplan for the experiment are also discussed.« less

Molecular Beam Studies of the Dynamics of Reactions Involving the Azide Radical and Hydrazoic Acid

NASA Astrophysics Data System (ADS)

Chen, Jing

1992-01-01

Several elementary reactions of atoms with N _3, HN_3, or halogens have been studied by laser fluorescence detection in a molecular beam-gas scattering arrangement approaching single -collision conditions. In the H + N_3, NCO to NH(X^3Sigma^ {-}, a^1Delta, b^1Sigma^{+}) + N_2, CO reactions, the NH product was detected. It was found in the N_3 reaction that product NH(a^1Delta ) carries considerable amount of vibrational energy (35% of the total available energy) while the NH(X ^3Sigma^{-}) product was vibrationally cold. An electronic state branching ratio of 3.2 +/- 1.3 was obtained for the X^3Sigma^{-} to a^1Delta electronic states. Comparison was made to the HN_3 (X ^1rm A^' ) photodissociation experiments and to our expectations based on our fragmentary knowledge of HN_3 potential energy surfaces. The corresponding NCO reaction was found to produce almost exclusively NH(X ^3Sigma^{-}) product due to the slight endothermicity of the NH(a^1 Delta) + CO channel. The total reaction cross section for H + NCO vs that for H + N_3 was estimated to be 1.2 +/- 0.3: 1. In the system of Ca, Sr + HN_3 , emission from electronically excited M( ^1P, ^3P), the MH(A ^2Pi, B^2Sigma ^{+}), and MOH(A^2 Pi, B^2Sigma^ {+}) was observed. The formation of MOH* was found due to a secondary reaction involving O _2 impurity in the HN_3 samples. Ground state MOH and MN_3 were detected but the search for CaNH was unsuccessful. All of the observed emissions can be explained as arising from secondary reactions of the metal imide (MNH) forced in the M + HN_3 primary reaction. A kinetic model shows that the M + HN_3 reaction proceeds mainly by formation of MNH, rather than MN_3. In the reactions of Pb + F_2 and Cl_2, the PbX products were detected. The PbCl product was observed in 18 vibrational levels of the ground electronic state with an average vibrational excitation of 21% of the total available energy. The PbF product was found to be characterized by a 300 K Boltzmann distribution for all the detected rovibrational states and proven to be an artifact. The radiative lifetimes of the PbF(A,B) and PbCl(A) states were also measured.

Instantaneous temperature field measurements using planar laser-induced fluorescence.

PubMed

Seitzman, J M; Kychakoff, G; Hanson, R K

1985-09-01

A single-pulse, laser-induced-fluorescence diagnostic for the measurement of two-dimensional temperature fields in combustion flows is described. The method uses sheet illumination from a tunable laser to excite planar laserinduced fluorescence in a stable tracer molecule, seeded at constant mole fraction into the flow field. The temporal resolution of this technique is determined by the laser pulse length. Experimental results are presented for a rodstabilized, premixed methane-air flame, using the Q(1) (22) line of the nitric oxide A(2) Sigma(+) (v = 0) ? X(2)II((1/2))(v = 0) transition (lambda approximately 225.6 nm).

Tuning metal-to-metal charge transfer of mixed-valence complexes containing ferrocenylpyridine and rutheniumammines via solvent donicity and substituent effects.

PubMed

Chen, Y J; Kao, C H; Lin, S J; Tai, C C; Kwan, K S

2000-01-24

A homogeneous series of heterobimetallic complexes of [R-Fc(4-py)Ru(NH3)5](PF6)2 (R = H, Et, Br, acetyl; Fc(4-py) = 4-ferrocenylpyridine) have been prepared and characterized. The mixed-valence species generated in situ using ferrocenium hexafluorophosphate as the oxidant show class II behavior, and the oxidized sites are ruthenium centered. deltaE(1/2), E(1/2)(Fe(III)/Fe(II)) - E(1/2)(Ru(III)/Ru(II)), an upper limit for deltaGo that is an energetic difference between the donor and acceptor sites, changes sharply and linearly with Gutmann solvent donor number (DN) and Hammett substituent constants (sigma). The solvent-dependent and substituent-dependent intervalence transfer bands were found to vary almost exclusively with deltaE(1/2). The activation energy for the optical electron transfer versus deltaE(1/2) plot yields a common nuclear reorganization energy (lambda) of 0.74 +/- 0.04 eV for this series. The equation that allows one to incorporate the effect of both solvent donicity and substituents on optical electron transfer is Eop = lambda + deltaGo, where deltaGo = (deltaGo)intrinsic + (deltaGo)solvent donicity + (deltaGo)substituent effect (deltaGo )intinnsic with a numerical value of 0.083 +/- 0.045 eV was obtained from the intercept of the deltaE(1/2) of [H-Fc(4-py)Ru(NH3)5]2+,3+,4+ versus DN plot. (deltaGo)solvent donicity was obtained from the average slopes of the deltaE(1/2) of [R-Fc-(4-py)Ru(NH3)5]2+,3+,4+ versus DN plot, and (deltaGo)substituent effect was obtained from the average slopes of the corresponding deltaE(1/2) versus sigma plot. The empirical equation allows one to finely tune Eop of this series to Eop = 0.82 + 0.019(DN) + 0.44sigma eV at 298 K, and the discrepancy between the calculated and experimental data is less than 6%.

Search for diphoton events with large missing transverse momentum in 1 fb(-1) of 7 TeV proton-proton collision data with the ATLAS detector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aad G.; Abbott B.; Abdallah J.

2012-04-20

A search for diphoton events with large missing transverse momentum has been performed using 1.07 fb{sup -1} of proton-proton collision data at {radical}s = 7 TeV recorded with the ATLAS detector. No excess of events was observed above the Standard Model prediction and 95% Confidence Level (CL) upper limits are set on the production cross section for new physics. The limits depend on each model parameter space and vary as follows: {sigma} < (22-129) fb in the context of a generalized model of gauge-mediated supersymmetry breaking (GGM) with a bino-like lightest neutralino, {sigma} < (27-91) fb in the context ofmore » a minimal model of gauge-mediated supersymmetry breaking (SPS8), and {sigma} < (15-27) fb in the context of a specific model with one universal extra dimension (UED). A 95% CL lower limit of 805 GeV, for bino masses above 50 GeV, is set on the GGM gluino mass. Lower limits of 145 TeV and 1.23 TeV are set on the SPS8 breaking scale {Lambda} and on the UED compactification scale 1/R, respectively. These limits provide the most stringent tests of these models to date.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Conley, A.; Goldhaber, G.; Wang, L.

We present measurements of {Omega}{sub m} and {Omega}{sub {Lambda}} from a blind analysis of 21 high redshift supernovae using a new technique (CMAGIC) for fitting the multicolor lightcurves of Type Ia supernovae, first introduced in Wang et al. (2003). CMAGIC takes advantage of the remarkably simple behavior of Type Ia supernovae on color-magnitude diagrams, and has several advantages over current techniques based on maximum magnitudes. Among these are a reduced sensitivity to host galaxy dust extinction, a shallower luminosity-width relation, and the relative simplicity of the fitting procedure. This allows us to provide a cross check of previous supernova cosmologymore » results, despite the fact that current data sets were not observed in a manner optimized for CMAGIC. We describe the details of our novel blindness procedure, which is designed to prevent experimenter bias. The data are broadly consistent with the picture of an accelerating Universe, and agree with a at Universe within 1.7{sigma}, including systematics. We also compare the CMAGIC results directly with those of a maximum magnitude fit to the same SNe, finding that CMAGIC favors more acceleration at the 1.6{sigma} level, including systematics and the correlation between the two measurements. A fit for w assuming a at Universe yields a value which is consistent with a cosmological constant within 1.2{sigma}.« less

Photochemistry and reactivity of the phenyl radical-water system: a matrix isolation and computational study.

PubMed

Mardyukov, Artur; Crespo-Otero, Rachel; Sanchez-Garcia, Elsa; Sander, Wolfram

2010-08-02

The reaction of the phenyl radical 1 with water has been investigated by using matrix isolation spectroscopy and quantum chemical calculations. The primary thermal product of the reaction between 1 and water is a weakly bound complex stabilized by an OH...pi interaction. This complex is photolabile, and visible-light irradiation (lambda>420 nm) results in hydrogen atom transfer from water to radical 1 and the formation of a highly labile complex between benzene and the OH radical. This complex is stable under the conditions of matrix isolation, however, continuous irradiation with lambda>420 nm light results in the complete destruction of the aromatic system and formation of an acylic unsaturated ketene. The mechanisms of all reaction steps are discussed in the light of ab initio and DFT calculations.

Optical fiber sensor having an active core

NASA Technical Reports Server (NTRS)

Egalon, Claudio Oliveira (Inventor); Rogowski, Robert S. (Inventor)

1993-01-01

An optical fiber is provided. The fiber is comprised of an active fiber core which produces waves of light upon excitation. A factor ka is identified and increased until a desired improvement in power efficiency is obtained. The variable a is the radius of the active fiber core and k is defined as 2 pi/lambda wherein lambda is the wavelength of the light produced by the active fiber core. In one embodiment, the factor ka is increased until the power efficiency stabilizes. In addition to a bare fiber core embodiment, a two-stage fluorescent fiber is provided wherein an active cladding surrounds a portion of the active fiber core having an improved ka factor. The power efficiency of the embodiment is further improved by increasing a difference between the respective indices of refraction of the active cladding and the active fiber core.

Spectroscopic Investigation of p-Shell Lambda Hypernuclei by the (e,e'K +) Reaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Chunhua

2014-08-01

Hypernuclear spectroscopy is a powerful tool to investigate Lambda-N interaction. Compared with other Lambda hypernuclei productions, electroproduction via the (e,e'K+) reaction has the advantage of exciting states deeply inside of the hypernucleus and achieving sub-MeV energy resolution. The E05-115 experiment, which was successfully performed in 2009, is the third generation hypernuclear experiment in JLab Hall C. A new splitter magnet and electron spectrometer were installed, and beam energy of 2.344 GeV was selected in this experiment. These new features gave better field uniformity, optics quality and made the tilt method more effective in improving yield-to-background ratio. The magnetic optics ofmore » the spectrometers were carefully studied with GEANT simulation, and corrections were applied to compensate for the fringe field cross talk between the compact spectrometer magnets. The non-linear least chi-squared method was used to further calibrate the spectrometer with the events from Lambda, Sigma0 and B12Lambda and uniform magnetic optics as well as precise kinematics were achieved. Several p-shell Lambda hypernuclear spectra, including B 12 Λ, Be 10 Λ, He 7 Λ, were obtained with high energy resolution and good accuracy. For B 12 Λ, eight peaks were recognized with the resolution of ~540keV (FWHM), and the ground state binding energy was obtained as 11.529 ± 0.012(stat.) ± 0.110(syst.) MeV. Be 10 Λ, twelve peaks were recognized with the resolution of ~520keV (FWHM), and the binding energy of the ground state was determined as 8.710 ± 0.059(stat.) ± 0.114(syst.) MeV. For He 7 Λ, three peaks were recognized with the resolution of ~730keV, and the ground state binding energy was obtained as 5.510 ± 0.050(stat.) ± 0.120(syst.) MeV. Compared with the published data of B 12 Λ from the JLab Hall A experiment, four extra peaks were fitted and interpreted thanks to the highest ever energy resolution and sufficient statistics. The determined binding energy of Be 10 Λ provides new information on charge symmetry breaking effect in the Lambda-N interaction. Compared with the results of He7Lambda from the E01-011 experiment, the ground state position is consistent with 4 times more statistics, and two extra peaks corresponding to excited states were recognized.« less

Conceptual Integration of Hybridization by Algerian Students Intending to Teach Physical Sciences

ERIC Educational Resources Information Center

Salah, Hazzi; Dumon, Alain

2011-01-01

This work aims to assess the difficulties encountered by students of the Ecole Normale Superieure of Kouba (Algeria) intending to teach physical science in the integration of the hybridization of atomic orbitals. It is a concept that they should use in describing the formation of molecular orbitals ([sigma] and [pi]) in organic chemistry and gaps…

VIEW OF PIEDMONT AVENUE TRAFFIC CIRCLE AT INTERSECTION OF CHANNING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW OF PIEDMONT AVENUE TRAFFIC CIRCLE AT INTERSECTION OF CHANNING WAY. SEEN FROM SW CORNER TOWARDS 2395 PIEDMONT, SIGMA PI HOUSE BY FREDERICK H. REIMERS, 1928. LOOKING NORTH. Photograph by Brian Grogan, July 8, 2007 - Piedmont Way & the Berkeley Property Tract, East of College Avenue between Dwight Way & U.C. Memorial Stadium, Berkeley, Alameda County, CA

The PI3K p110delta is required for down-regulation of RAG expression in immature B cells.

PubMed

Llorian, Miriam; Stamataki, Zania; Hill, Susan; Turner, Martin; Mårtensson, Inga-Lill

2007-02-15

At the immature B cell stage the BCR signals the down-regulation of the RAG genes and Ig L chain (LC) allelic and isotype exclusion. The signaling pathway that regulates these events is poorly characterized. We demonstrate that immature B cells from mice deficient in the PI3K catalytic subunit p110delta fail to suppress RAG expression and inappropriately recombine kappa and lambda LC loci. In addition, in the presence of the autoantigen, clonal deletion and receptor editing still takes place, demonstrating that these processes are independent of p110delta. These results demonstrate a role for p110delta in the regulation of RAG gene expression and thereby LC allelic/isotype exclusion.

The permanent electric dipole moment of CaOH

NASA Technical Reports Server (NTRS)

Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Steimle, Timothy; Shirley, Jeffrey E.

1990-01-01

The X 2 Sigma(+), A 2Pi, and B 2Sigma(+) states of CaOH are characterized theoretically and experimentally, with a focus on the value of the permanent electric dipole moment (mu). Calculations based on SCF and SDCI studies of CaOH (Bauschlicher et al., 1984 and 1986) give mu values of 0.98, 0.49, and 0.11 D for the X, A, and B states, respectively, in good agreement with experiments in which the pure rotational spectra of these states were not detected. Modified Rittner (1951) and ligand-field models of these states are explored in detail, and the applicability of these results to observational searches for CaOH in circumstellar envelopes is indicated.

The Hubble Constant to 1%: Physics beyond LambdaCDM

NASA Astrophysics Data System (ADS)

Riess, Adam

2017-08-01

By steadily advancing the precision and accuracy of the Hubble constant, we now see 3.4-sigma evidence for a deviation from the standard LambdaCDM model and thus the exciting chance of discovering new fundamental physics such as exotic dark energy, a new relativistic particle, dark matter interactions, or a small curvature, to name a few possibilities. We propose a coordinated program to accomplish three goals with one set of observations: (1) improve the precision of the best route to H_0 with HST observations of Cepheids in the hosts of 11 SNe Ia, lowering the uncertainty to 1.3% to reach the discovery threshold of 5-sigma and begin resolving the underlying source of the deviation; (2) continue testing the quality of Cepheid distances, so far the most accurate and reliable indicators in the near Universe, using the tip of the red giant branch (TRGB); and (3) use oxygen-rich Miras to confirm the present tension with the CMB and establish a future route available to JWST. We can achieve all three goals with one dataset and take the penultimate step to reach 1% precision in H_0 after Gaia. With its long-pass filter and NIR capability, we can collect these data with WFC3 many times faster than previously possible while overcoming the extinction and metallicity effects that challenged the first generation of H_0 measurements. Our results will complement the leverage available at high redshift from other cosmological tools such as BAO, the CMB, and SNe Ia, and will provide a 40% improvement on the WFIRST measurements of dark energy. Reaching this precision will be a fitting legacy for the telescope charged to resolve decades of uncertainty regarding the Hubble constant.

Why CO bonds side-on at low coverage and both side-on and upright at high coverage on the Cr(110) surface

NASA Technical Reports Server (NTRS)

Mehandru, S. P.; Anderson, A. B.

1985-01-01

An atom superposition and electron delocalization molecular orbital study of CO adsorption on the Cr(110) surface shows a high coordinate lying down orientation is favored. This is a result of the large number of empty d-band energy levels in chromium, which allows the antibonding counterparts to sigma and pi donation bonds to the surface to be empty. When lying down, backbonding to CO pi sup * orbitals is enhanced. Repulsive interactions cause additional CO to stand upright at 1/4 monolyer coverage. The results confirm the recent experimental study of Shinn and Madey.

Laser-saturated fluorescence of nitric oxide and chemiluminescence measurements in premixed ethanol flames

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marques, Carla S.T.; Barreta, Luiz G.; Sbampato, Maria E.

In this study, nitric oxide laser-saturated fluorescence (LSF) measurements were acquired from premixed ethanol flames at atmospheric pressure in a burner. NO-LSF experimental profiles for fuel-rich premixed ethanol flames ({phi} = 1.34 and {phi} = 1.66) were determined through the excitation/detection scheme of the Q{sub 2}(26.5) rotational line in the A{sup 2}{sigma}{sup +} - X{sup 2}{pi} (0,0) vibronic band and {gamma}(0,1) emission band. A calibration procedure by NO doping into the flame was applied to establish the NO concentration profiles in these flames. Chemiluminescent emission measurements in the (0, 0) vibronic emission bands of the OH{sup *} (A{sup 2}{sigma}{sup +}more » - X{sup 2}{pi}) and CH{sup *}(A{sup 2}{delta} - X{sup 2}{pi}) radicals were also obtained with high spatial and spectral resolution for fuel-rich premixed ethanol flames to correlate them with NO concentrations. Experimental chemiluminescence profiles and the ratios of the integrated areas under emission spectra (A{sub CH*}/A{sub CH*}(max.) and A{sub CH*}/A{sub OH*}) were determined. The relationships between chemiluminescence and NO concentrations were established along the premixed ethanol flames. There was a strong connection between CH{sup *} radical chemiluminescence and NO formation and the prompt-NO was identified as the governing mechanism for NO production. The results suggest the optimum ratio of the chemiluminescence of two radicals (A{sub CH*}/A{sub OH*}) for NO diagnostic purposes. (author)« less

Fur-dependent detoxification of organic acids by rpoS mutants during prolonged incubation under aerobic, phosphate starvation conditions.

PubMed

Guillemet, Mélanie L; Moreau, Patrice L

2008-08-01

The activity of amino acid-dependent acid resistance systems allows Escherichia coli to survive during prolonged incubation under phosphate (P(i)) starvation conditions. We show in this work that rpoS-null mutants incubated in the absence of any amino acid survived during prolonged incubation under aerobic, P(i) starvation conditions. Whereas rpoS(+) cells incubated with glutamate excreted high levels of acetate, rpoS mutants grew on acetic acid. The characteristic metabolism of rpoS mutants required the activity of Fur (ferric uptake regulator) in order to decrease the synthesis of the small RNA RyhB that might otherwise inhibit the synthesis of iron-rich proteins. We propose that RpoS (sigma(S)) and the small RNA RyhB contribute to decrease the synthesis of iron-rich proteins required for the activity of the tricarboxylic acid (TCA) cycle, which redirects the metabolic flux toward the production of acetic acid at the onset of stationary phase in rpoS(+) cells. In contrast, Fur activity, which represses ryhB, and the lack of RpoS activity allow a substantial activity of the TCA cycle to continue in stationary phase in rpoS mutants, which decreases the production of acetic acid and, eventually, allows growth on acetic acid and P(i) excreted into the medium. These data may help explain the fact that a high frequency of E. coli rpoS mutants is found in nature.

Scalar formalism for non-Abelian gauge theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hostler, L.C.

1986-09-01

The gauge field theory of an N-italic-dimensional multiplet of spin- 1/2 particles is investigated using the Klein--Gordon-type wave equation )Pi x (1+i-italicsigma) x Pi+m-italic/sup 2/)Phi = 0, Pi/sub ..mu../equivalentpartial/partiali-italicx-italic/sub ..mu../-e-italicA-italic/sub ..mu../, investigated before by a number of authors, to describe the fermions. Here Phi is a 2 x 1 Pauli spinor, and sigma repesents a Lorentz spin tensor whose components sigma/sub ..mu..//sub ..nu../ are ordinary 2 x 2 Pauli spin matrices. Feynman rules for the scalar formalism for non-Abelian gauge theory are derived starting from the conventional field theory of the multiplet and converting it to the new description. Themore » equivalence of the new and the old formalism for arbitrary radiative processes is thereby established. The conversion to the scalar formalism is accomplished in a novel way by working in terms of the path integral representation of the generating functional of the vacuum tau-functions, tau(2,1, xxx 3 xxx)equivalent<0-chemically bondT-italic(Psi/sub in/(2) Psi-bar/sub in/(1) xxx A-italic/sub ..mu../(3)/sub in/ xxx S-italic)chemically bond0->, where Psi/sub in/ is a Heisenberg operator belonging to a 4N-italic x 1 Dirac wave function of the multiplet. The Feynman rules obtained generalize earlier results for the Abelian case of quantum electrodynamics.« less

Time dependent density functional theory study of the near-edge x-ray absorption fine structure of benzene in gas phase and on metal surfaces.

PubMed

Asmuruf, Frans A; Besley, Nicholas A

2008-08-14

The near-edge x-ray absorption fine structure of benzene in the gas phase and adsorbed on the Au(111) and Pt(111) surfaces is studied with time dependent density functional theory. Excitation energies computed with hybrid exchange-correlation functionals are too low compared to experiment. However, after applying a constant shift the spectra are in good agreement with experiment. For benzene on the Au(111) surface, two bands arising from excitation to the e(2u)(pi(*)) and b(2g)(pi(*)) orbitals of benzene are observed for photon incidence parallel to the surface. On Pt(111) surface, a broader band arises from excitation to benzene orbitals that are mixed with the surface and have both sigma(*)(Pt-C) and pi(*) characters.

First observation of B(s)(0) --> D(s)(+/-)K(-/+) and measurement of the ratio of branching fractions B(B(s)(0) --> D(s)(+/-)K(-/+)/B(B(s)(0) --> D(s)(+)pi(-)).

PubMed

Aaltonen, T; Adelman, J; Akimoto, T; Albrow, M G; Alvarez González, B; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Apresyan, A; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Azzurri, P; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Bartsch, V; Bauer, G; Beauchemin, P-H; Bedeschi, F; Bednar, P; Beecher, D; Behari, S; Bellettini, G; Bellinger, J; Benjamin, D; Beretvas, A; Beringer, J; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Bridgeman, A; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Calancha, C; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carlsmith, D; Carosi, R; Carrillo, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavaliere, V; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Compostella, G; Convery, M E; Conway, J; Copic, K; Cordelli, M; Cortiana, G; Cox, D J; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Cully, J C; Dagenhart, D; Datta, M; Davies, T; de Barbaro, P; De Cecco, S; Deisher, A; De Lorenzo, G; Dell'Orso, M; Deluca, C; Demortier, L; Deng, J; Deninno, M; Derwent, P F; di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Elagin, A; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Ferrazza, C; Field, R; Flanagan, G; Forrest, R; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garberson, F; Garcia, J E; Garfinkel, A F; Genser, K; Gerberich, H; Gerdes, D; Gessler, A; Giagu, S; Giakoumopoulou, V; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C M; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Group, R C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Hays, C; Heck, M; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hewamanage, S; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; James, E; Jayatilaka, B; Jeon, E J; Jha, M K; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Kar, D; Karchin, P E; Kato, Y; Kephart, R; Keung, J; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Knuteson, B; Ko, B R; Koay, S A; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kreps, M; Kroll, J; Krop, D; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhr, T; Kulkarni, N P; Kurata, M; Kusakabe, Y; Kwang, S; Laasanen, A T; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; LeCompte, T; Lee, E; Lee, H S; Lee, S W; Leone, S; Lewis, J D; Lin, C S; Linacre, J; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, C; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Lovas, L; Lu, R-S; Lucchesi, D; Lueck, J; Luci, C; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; MacQueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis-Katsikakis, A; Margaroli, F; Marino, C; Marino, C P; Martin, A; Martin, V; Martínez, M; Martínez-Ballarín, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Mattson, M E; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzione, A; Merkel, P; Mesropian, C; Miao, T; Miladinovic, N; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyake, H; Moggi, N; Moon, C S; Moore, R; Morello, M J; Morlok, J; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nodulman, L; Norman, M; Norniella, O; Nurse, E; Oakes, L; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Osterberg, K; Pagan Griso, S; Pagliarone, C; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Pianori, E; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Pueschel, E; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Reisert, B; Rekovic, V; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rodriguez, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Safonov, A; Sakumoto, W K; Saltó, O; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, A; Schmidt, E E; Schmidt, M A; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sfyrla, A; Shalhout, S Z; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shiraishi, S; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spreitzer, T; Squillacioti, P; Stanitzki, M; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Suslov, I; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thompson, G A; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Totaro, P; Tourneur, S; Tu, Y; Turini, N; Ukegawa, F; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Vellidis, C; Veszpremi, V; Vidal, M; Vidal, R; Vila, I; Vilar, R; Vine, T; Vogel, M; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner-Kuhr, J; Wagner, W; Wakisaka, T; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Xie, S; Yagil, A; Yamamoto, K; Yamaoka, J; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zhang, X; Zheng, Y; Zucchelli, S

2009-11-06

A combined mass and particle identification fit is used to make the first observation of the decay B(s)(0) --> D(s)(+/-)K(-/+) and measure the branching fraction of B(s)(0) --> D(s)(+/-)K(-/+) relative to B(s)(0) --> D(s)(+)pi(-). This analysis uses 1.2 fb(-1) integrated luminosity of pp collisions at square root(s) = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron collider. We observe a B(s)(0) --> D(s)(+/-)K(-/+) signal with a statistical significance of 8.1 sigma and measure B(B(s)(0) --> D(s)(+/-)K(-/+) /B(B(s)(0) --> D(s)(+)pi(-) 0.097+/-0.018(stat) +/- 0.009(syst).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morrill, J.S.; Benesch, W.M.

Previous model results have shown that the N{sub 2} triplet vibrational level populations in the aurora are strongly affected by cascade and quenching by atomic and molecular oxygen. As the aurora penetrates to lower altitudes (less than 100 km) the role of quenching by atomic oxygen becomes less important and processes involving N{sub 2} collisions begin to play a more prominent part. The authors are developing a model which will yield steady state vibrational level populations for both the singlet and triplet valence states of N{sub 2}. The model currently provides results for the seven low-lying N{sub 2} triplet statesmore » (A {sup 3}{Sigma}{sub u}{sup +}, B {sup 3}{Pi}{sub g}, W {sup 3}{Delta}{sub u}, B{prime}{sup 3}{Sigma}{sub u}, C{sup 3}{Pi}{sub u}, D{sup 3}{Sigma}{sub u}{sup +}, and E{sup 3}{Sigma}{sub g}{sup +}). These states are responsible for auroral emissions from the UV (Vegard-Kaplan (VK), second positive (2PG)) through the visible to the infrared (first positive (1PG), infrared afterglow (IRA), Wu-Benesch (WB)). The authors have included two additional collisional processes in the current model which were not treated previously. These are the intersystem collisional transfer of excitation (ICT) between the B state and the A, W, and B{prime} states and vibrational redistribution within the A state vibrational manifold, both due to collisions with ground state N{sub 2}. The present work compares the current model results with those of a previous model as well as ground, airborne, and rocket observations. The comparison between N{sub 2}(A) (VK) and N{sub 2}(B) (1PG) vibrational level populations predicted by this model and a number of auroral observations indicate that the current model achieves a significant improvement in the fit between calculation and observation. 81 refs., 12 figs., 2 tabs.« less

Polynomial time blackbox identity testers for depth-3 circuits : the field doesn't matter.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seshadhri, Comandur; Saxena, Nitin

Let C be a depth-3 circuit with n variables, degree d and top fanin k (called {Sigma}{Pi}{Sigma}(k, d, n) circuits) over base field F. It is a major open problem to design a deterministic polynomial time blackbox algorithm that tests if C is identically zero. Klivans & Spielman (STOC 2001) observed that the problem is open even when k is a constant. This case has been subjected to a serious study over the past few years, starting from the work of Dvir & Shpilka (STOC 2005). We give the first polynomial time blackbox algorithm for this problem. Our algorithm runsmore » in time poly(n)d{sup k}, regardless of the base field. The only field for which polynomial time algorithms were previously known is F = Q (Kayal & Saraf, FOCS 2009, and Saxena & Seshadhri, FOCS 2010). This is the first blackbox algorithm for depth-3 circuits that does not use the rank based approaches of Karnin & Shpilka (CCC 2008). We prove an important tool for the study of depth-3 identities. We design a blackbox polynomial time transformation that reduces the number of variables in a {Sigma}{Pi}{Sigma}(k, d, n) circuit to k variables, but preserves the identity structure. Polynomial identity testing (PIT) is a major open problem in theoretical computer science. The input is an arithmetic circuit that computes a polynomial p(x{sub 1}, x{sub 2},..., x{sub n}) over a base field F. We wish to check if p is the zero polynomial, or in other words, is identically zero. We may be provided with an explicit circuit, or may only have blackbox access. In the latter case, we can only evaluate the polynomial p at various domain points. The main goal is to devise a deterministic blackbox polynomial time algorithm for PIT.« less

Strong transverse fields in delta-spots

NASA Technical Reports Server (NTRS)

Zirin, Harold; Wang, Haimin

1993-01-01

Spectroscopic measurements of the strength and direction of transverse magnetic fields in six delta-spots are presented. The field direction is determined by the relative strength of the pi- and sigma-components at different polarizer orientations, and is, with one exception, parallel to the neutral line and as strong as the umbral field. Field strengths determined by line splitting are as high as 3980 G.

Light Weight Portable Plasma Medical Device - Plasma Engineering Research Laboratory

DTIC Science & Technology

2011-10-01

Millennial Student. 15. Thiyagarajan, M. (2011). Portable Plasma Biomedical Device for Cancer Treatment. Irvine, California: ASME Emerging...American Society of Mechanical Engineers Sigma Xi Toastmasters International Club MIT Entrepreneur Club Eta Kappa Nu Tau Beta Pi Institute of...Learning Environment. Corpus Christi, TX: TAMUCC 1st Faculty Symposium: Course Design for the Millennial Student. Thiyagarajan, M. (2011). Portable

DETAIL VIEW OF SIDEWALKS AND TREES ON CHANNING WAY AT ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

DETAIL VIEW OF SIDEWALKS AND TREES ON CHANNING WAY AT INTERSECTION OF PIEDMONT AVENUE WITH 2395 PIEDMONT, SIGMA PI HOUSE BY FREDERICK H. REIMERS, 1928, LOOKING NW. Photograph by Fredrica Drotos and Michael Kelly, July 9, 2006 - Piedmont Way & the Berkeley Property Tract, East of College Avenue between Dwight Way & U.C. Memorial Stadium, Berkeley, Alameda County, CA

DETAIL VIEW OF PIEDMONT AVENUE TRAFFIC CIRCLE AT INTERSECTION OF ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

DETAIL VIEW OF PIEDMONT AVENUE TRAFFIC CIRCLE AT INTERSECTION OF CHANNING WAY. SEEN FROM EAST SIDE OF CIRCLE LOOKING NORTH AT 2395 PIEDMONT, SIGMA PI HOUSE BY FREDERICK H. REIMERS, 1928. Photograph by Brian Grogan, July 8, 2007 - Piedmont Way & the Berkeley Property Tract, East of College Avenue between Dwight Way & U.C. Memorial Stadium, Berkeley, Alameda County, CA

Rotational and translational effects in collisions of electronically excited diatomic hydrides

NASA Technical Reports Server (NTRS)

Crosley, David R.

1988-01-01

Collisional quenching and vibrational energy proceed competitively with rotational energy transfer for several excited states of the diatomic radicals OH, NH, and CH. This occurs for a wide variety of molecular collision partners. This phenomenon permits the examination of the influence of rotational motion on the collision dynamics of these theoretically tractable species. Measurements can also be made as a function of temperature, i.e., collision velocity. In OH (sup 2 sigma +), both vibrational transfer and quenching are found to decrease with an increase in rotational level, while quenching decreases with increasing temperature. This behavior indicates that for OH, anisotropic attractive forces govern the entrance channel dynamics for these collisions. The quenching of NH (sup 3 pi sub i) by many (although not all) collision partners also decreases with increasing rotational and translational energy, and NH (sup 1 pi) behaves much like OH (sup 2 sigma +). However, the quenching of CH (sup 2 delta) appears to decrease with increasing rotation but increases with increasing temperature, suggesting in this case anisotropic forces involving a barrier or repulsive wall. Such similarities and differences should furnish useful comparisons with both simple and detailed theoretical pictures of the appropriate collision dynamics.

Electronic excitation of H{sub 2} by electron impact using soft norm-conserving pseudopotentials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Natalense, A.P.; Sartori, C.S.; Ferreira, L.G.

1996-12-01

We calculate electronic excitation cross sections for the {ital b}{sup 3}{Sigma}{sup +}{sub {ital u}} {ital a}{sup 3}{Sigma}{sup +}{sub {ital g}} {ital c}{sup 3}{Pi}{sub {ital u}}, and {ital d}{sup 3}{Pi}{sub {ital u}} states of H{sub 2} by electron impact. Our results were obtained with the Schwinger multichannel method with pseudopotentials and real potentials at the two-channel level of approximation. Pseudo-H atoms are used to generate H{sub 2} molecules with almost the same low-energy spectrum as the real molecules. We show that the dynamics of the electronic excitation process of the pseudomolecules by electron impact is very similar to the real case.more » Our results support the idea that pseudopotentials can be used to obtain reliable molecular electronic excitation cross sections by low-energy electron impact, confirming the expectations of previous studies with CH{sub 2}O [Bettega {ital et} {ital al}., Phys. Rev. A {bold 25}, 1111 (1993)] and HBr [Rescigno, J. Chem. Phys. {bold 104}, 125 (1996)]. {copyright} {ital 1996 The American Physical Society.}« less

Papain hydrolysis of X-phenyl-N-methanesulfonyl glycinates: a quantitative structure-activity relationship and molecular graphics analysis.

PubMed

Carotti, A; Smith, R N; Wong, S; Hansch, C; Blaney, J M; Langridge, R

1984-02-15

The hydrolysis of 32 X-phenyl-N-methanesulfonyl glycinates by papain was investigated. It was found that the variation in the Michaelis constants could be rationalized by the following correlation equation: log 1/Km = 0.61 pi '3 + 0.46 MR4 + 0.55 sigma + 2.00 with a correlation coefficient of 0.945. In this expression, pi '3 is the hydrophobic constant for the more lipophilic of the two possible meta substituents, MR4 is the molar refractivity of 4-substituents, and sigma is the Hammett constant summed for all substituents. Using this equation, we designed, synthesized, and successfully predicted Km for a new congener intended to maximize binding (1/Km). The interactions involved in enzyme-substrate binding, as characterized by the correlation equation, are interpreted using a computer-constructed color three-dimensional-graphics molecular model of the enzyme active site. The nonenzymatic hydrolysis (both acid and basic) of phenyl hippurates yield rate constants which are well correlated by Hammett equations; however, log k for both acid and alkaline hydrolysis are not linearly related to log 1/Km or log kcat/Km.

Line Mixing in Parallel and Perpendicular Bands of CO2: A Further Test of the Refined Robert-Bonamy Formalism

NASA Technical Reports Server (NTRS)

Boulet, C.; Ma, Qiancheng; Tipping, R. H.

2015-01-01

Starting from the refined Robert-Bonamy formalism [Q. Ma, C. Boulet, and R. H. Tipping, J. Chem. Phys. 139, 034305 (2013)], we propose here an extension of line mixing studies to infrared absorptions of linear polyatomic molecules having stretching and bending modes. The present formalism does not neglect the internal degrees of freedom of the perturbing molecules, contrary to the energy corrected sudden (ECS) modeling, and enables one to calculate the whole relaxation matrix starting from the potential energy surface. Meanwhile, similar to the ECS modeling, the present formalism properly accounts for roles played by all the internal angular momenta in the coupling process, including the vibrational angular momentum. The formalism has been applied to the important case of CO2 broadened by N2. Applications to two kinds of vibrational bands (sigma yields sigma and sigma yields pi) have shown that the present results are in good agreement with both experimental data and results derived from the ECS model.

Radiative lifetimes and quenching rate coefficients for directly excited rotational levels of OH/A 2Sigma +, v-prime = 0/

NASA Technical Reports Server (NTRS)

Mcdermid, I. S.; Laudenslager, J. B.

1982-01-01

A narrow-bandwidth pulsed dye laser was used to excite OH X 2Pi i radicals to the A 2Sigma(+) state by pumping in the (0, 0) vibrational band around 308 nm. The radiative lifetimes of specific (K-prime, J-prime) rotational levels in v-prime = 0 were measured at low pressures (not greater than 1 mtorr), which yielded a mean lifetime of 0.71 + or - 0.009 microsec (2 sigma). Electronic quenching rate constants for N2, O2, H2O, and H2 were measured for a range of initially excited rotational levels. A strong dependence of this rate constant on the initially excited rotational level was found for N2, and less markedly for O2, with the rate constant tending to increase for the lowest rotational levels K-prime not greater than 3. The implications of these results for the laser-induced fluorescence detection of atmospheric OH are discussed.

Search with COPERNICUS for interstellar N/sub 2/ in diffuse clouds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lutz, B.L.; Owen, T.; Snow, T.P. Jr.

1979-01-01

Multiple Copernicus scans of the rho'/sup 1/..sigma../sub u//sup +/--X/sup 1/..sigma../sub g//sup +/(0--0) and l/sup 1/Pi/sub u/--X/sup 1/..sigma../sub g//sup +/(0--0) band regions of N/sub 2/ in the spectra of delta Sco and epsilon Per result in upper limits of N (N/sub 2/) < or =1.0--3.8 x 10/sup 12/ cm/sup -2/ and N (N/sub 2/) < or =1.2--4.4 x 10/sup 12/ cm/sup -2/, respectively, depending upon the cloud temperature. These limits are consistent with the column densities expected from current chemical models for diffuse interstellar clouds, representing relative abundances with respect to hydrogen nuclei of N (N/sub 2/)/2N (H/sub 2/)+N (H I)more » < or =0.69--2.6 x 10/sup -9/ for delta Sco and < or =0.31--1.1 x 10/sup -8/ for epsilon Per.« less

Regioselectivity of pyridine deprotonation in the gas phase.

PubMed

Schafman, Bonnie S; Wenthold, Paul G

2007-03-02

The regioselective deprotonation of pyridine in the gas phase has been investigated by using chemical reactivity studies. The mixture of regioisomers, trapped as carboxylates, formed in an equilibrium mixture is determined to result from 70-80% deprotonation in the 4-position, and 20-30% deprotonation at the 3-position. The ion formed by deprotonation in the 2-position is not measurably deprotonated at equilibrium because the ion is destabilized by lone-pair repulsion. From the composition of the mixture, the gas-phase acidities (DeltaH degrees acid) at the 4-, 3-, and 2-positions are determined to be 389.9 +/- 2.0, 391.2-391.5, and >391.5 kcal/mol, respectively. The relative acidities of the 4- and 3-positions are explained by using Hammett-Taft parameters, derived by using the measured gas-phase acidities of pyridine carboxylic acids. The values of sigmaF and sigmaR are -0.18 and 0.74, respectively, showing the infused nitrogen in pyridine to have a strong pi electron-withdrawing effect, but with little sigma-inductive effect.

Free electron laser designs for laser amplification

DOEpatents

Prosnitz, Donald; Szoke, Abraham

1985-01-01

Method for laser beam amplification by means of free electron laser techniques. With wiggler magnetic field strength B.sub.w and wavelength .lambda..sub.w =2.pi./k.sub.w regarded as variable parameters, the method(s) impose conditions such as substantial constancy of B.sub.w /k.sub.w or k.sub.w or B.sub.w and k.sub.w (alternating), coupled with a choice of either constant resonant phase angle or programmed phase space "bucket" area.

ROSAT survey of emission from Be stars

NASA Technical Reports Server (NTRS)

Grady, Carol

1993-01-01

ROSAT pointed observations of bright, classical Be stars have demonstrated that detection of soft x-rays at a level expected for normal B stars of comparable T(sub eff) and luminosity is anti-correlated with the presence of episodes of enhanced mass ejection and formation of a dense, moderately ionized equatorial circumstellar disk. At epochs of lower than average disk column density, x-ray flaring has been detected in 2 Be stars, lambda Eri and pi Aqr.

Microspectrophotometric demonstration of four classes of photoreceptor in an old world primate, Macaca fascicularis.

PubMed Central

Bowmaker, J K; Dartnall, H J; Mollon, J D

1980-01-01

1. Microspectrophotometric measurements reveal four classes of photoreceptor in the retina of the cynomolgus monkey, Macaca fascicularis, which is known to possess colour vision similar to that of a normal human trichromat. 2. Although the eyes were removed in bright illumination, the densities of pigment were comparable to those we have measured in dark-adapted rhesus retinae. 3. The mean wave-lengths of peak sensitivity (lambda max) for the four classes of photoreceptor were 415, 500, 535 and 567 nm. 4. The band widths of the absorbance spectra decreased linearly as the wave-number of peak sensitivity decreased. 5. If, by assuming a reasonable value for the axial density of the rod outer segment and correcting for lens absorption, a spectral sensitivity for human vision is reconstructed from the P500 pigment, it is found to be systematically broader than the CIE scotopic sensitivity function. 6. Given explicit assumptions, it is possible from the P535 and P567 pigments to reconstruct human psychophysical sensitivities that resemble the pi 4 and pi 5 mechanisms of W. S. Stiles. 7. Although the P415 pigment has a lambda max much shorter than that of the psychophysically measured blue mechanisms, the two spectral-sensitivity functions are brought into proximity when the microspectrophotometric data are corrected for absorption by the optic media. Images Fig. 1 PMID:6767023

Harmonic surface acoustic waves on gallium nitride thin films.

PubMed

Justice, Joshua; Lee, Kyoungnae; Korakakis, D

2012-08-01

SAW devices operating at the fundamental frequency and the 5th, 7th, 9th, and 11th harmonics have been designed, fabricated, and measured. Devices were fabricated on GaN thin films on sapphire substrates, which were grown via metal organic vapor phase epitaxy (MOVPE). Operating frequencies of 230, 962, 1338, 1720, and 2100 MHz were achieved with devices that had a fundamental wavelength, lambda0 = 20 μm. Gigahertz operation is realized with relatively large interdigital transducers that do not require complicated submicrometer fabrication techniques. SAW devices fabricated on the GaN/sapphire bilayer have an anisotropic propagation when the wavelength is longer than the GaN film thickness. It is shown that for GaN thin films, where kh(GaN) > 10 (k = 2pi/lambda and h(GaN) = GaN film thickness), effects of the substrate on the SAW propagation are eliminated. Bulk mode suppression at harmonic operation is also demonstrated.

Production asymmetry of $$\\Lambda^0$$ and $${\\overline{\\Lambda}}^0$$ in $$\\pi^{\\pm}$$, $$K^{\\pm}$$, p - nucleon collisions at 250 GeV/c (in Portuguese)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nicola, Marcello Santo

Using data from Fermilab xed-target experiment E769, we have measured particleantiparticle production asymmetries for Λ 0 hyperons in π ± - nucleon interactions, K ± - nucleon interactions and p - nucleon interactions at 250 GeV/c. The asymmetries are measured as functions of Feynman-x (x f ) and p T 2 over the ranges 0 ≤ p T 2 ≤ 4(GeV/c) 2 and -0.12 ≤ x F ≤ 0.12 (for positive beam) and 0 ≤ p T 2 ≤ 10(GeV/c) 2 and -0.16 ≤ x F ≤ 0:.0 for the negative beam. We find substantial asymmetries, even at x Fmore » = 0. We also observe leading-particle-type asymmetries which qualitatively agree with theoretical predictions.« less

Optical and mechanical design of a "zipper" photonic crystal optomechanical cavity.

PubMed

Chan, Jasper; Eichenfield, Matt; Camacho, Ryan; Painter, Oskar

2009-03-02

Design of a doubly-clamped beam structure capable of localizing mechanical and optical energy at the nanoscale is presented. The optical design is based upon photonic crystal concepts in which patterning of a nanoscale-cross-section beam can result in strong optical localization to an effective optical mode volume of 0.2 cubic wavelengths ( (lambdac)(3)). By placing two identical nanobeams within the near field of each other, strong optomechanical coupling can be realized for differential motion between the beams. Current designs for thin film silicon nitride beams at a wavelength of lambda?= 1.5 microm indicate that such structures can simultaneously realize an optical Q-factor of 7x10(6), motional mass m(u) approximately 40 picograms, mechanical mode frequency Omega(M)/2pi approximately 170 MHz, and an optomechanical coupling factor (g(OM) identical with domega(c)/dx = omega(c)/L(OM)) with effective length L(OM) approximately lambda= 1.5 microm.

Strange baryon resonance production in sqrt s NN=200 GeV p+p and Au+Au collisions.

PubMed

Abelev, B I; Aggarwal, M M; Ahammed, Z; Amonett, J; Anderson, B D; Anderson, M; Arkhipkin, D; Averichev, G S; Bai, Y; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellingeri-Laurikainen, A; Bellwied, R; Benedosso, F; Bhardwaj, S; Bhasin, A; Bhati, A K; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Blyth, S-L; Bonner, B E; Botje, M; Bouchet, J; Brandin, A V; Bravar, A; Burton, T P; Bystersky, M; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Castillo, J; Catu, O; Cebra, D; Chajecki, Z; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, J H; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Coffin, J P; Cormier, T M; Cosentino, M R; Cramer, J G; Crawford, H J; Das, D; Das, S; Dash, S; Daugherity, M; de Moura, M M; Dedovich, T G; DePhillips, M; Derevschikov, A A; Didenko, L; Dietel, T; Djawotho, P; Dogra, S M; Dong, W J; Dong, X; Draper, J E; Du, F; Dunin, V B; Dunlop, J C; Dutta Mazumdar, M R; Eckardt, V; Edwards, W R; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Fatemi, R; Fedorisin, J; Filimonov, K; Filip, P; Finch, E; Fine, V; Fisyak, Y; Fu, J; Gagliardi, C A; Gaillard, L; Ganti, M S; Gaudichet, L; Ghazikhanian, V; Ghosh, P; Gonzalez, J E; Gorbunov, Y G; Gos, H; Grebenyuk, O; Grosnick, D; Guertin, S M; Guimaraes, K S F F; Gupta, N; Gutierrez, T D; Haag, B; Hallman, T J; Hamed, A; Harris, J W; He, W; Heinz, M; Henry, T W; Hepplemann, S; Hippolyte, B; Hirsch, A; Hjort, E; Hoffman, A M; Hoffmann, G W; Horner, M J; Huang, H Z; Huang, S L; Hughes, E W; Humanic, T J; Igo, G; Jacobs, P; Jacobs, W W; Jakl, P; Jia, F; Jiang, H; Jones, P G; Judd, E G; Kabana, S; Kang, K; Kapitan, J; Kaplan, M; Keane, D; Kechechyan, A; Khodyrev, V Yu; Kim, B C; Kiryluk, J; Kisiel, A; Kislov, E M; Klein, S R; Kocoloski, A; Koetke, D D; Kollegger, T; Kopytine, M; Kotchenda, L; Kouchpil, V; Kowalik, K L; Kramer, M; Kravtsov, P; Kravtsov, V I; Krueger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; LaPointe, S; Laue, F; Lauret, J; Lebedev, A; Lednicky, R; Lee, C-H; Lehocka, S; LeVine, M J; Li, C; Li, Q; Li, Y; Lin, G; Lin, X; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, H; Liu, J; Liu, L; Liu, Z; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; Love, W A; Lu, Y; Ludlam, T; Lynn, D; Ma, G L; Ma, J G; Ma, Y G; Magestro, D; Mahapatra, D P; Majka, R; Mangotra, L K; Manweiler, R; Margetis, S; Markert, C; Martin, L; Matis, H S; Matulenko, Yu A; McClain, C J; McShane, T S; Melnick, Yu; Meschanin, A; Millane, J; Miller, M L; Minaev, N G; Mioduszewski, S; Mironov, C; Mischke, A; Mishra, D K; Mitchell, J; Mohanty, B; Molnar, L; Moore, C F; Morozov, D A; Munhoz, M G; Nandi, B K; Nattrass, C; Nayak, T K; Nelson, J M; Netrakanti, P K; Nogach, L V; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Pachr, M; Pal, S K; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Peitzmann, T; Perevoztchikov, V; Perkins, C; Peryt, W; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Poljak, N; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M; Potrebenikova, E; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Rakness, G; Raniwala, R; Raniwala, S; Ray, R L; Razin, S V; Reinnarth, J; Relyea, D; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Rose, A; Roy, C; Ruan, L; Russcher, M J; Sahoo, R; Sakuma, T; Salur, S; Sandweiss, J; Sarsour, M; Sazhin, P S; Schambach, J; Scharenberg, R P; Schmitz, N; Schweda, K; Seger, J; Selyuzhenkov, I; Seyboth, P; Shabetai, A; Shahaliev, E; Shao, M; Sharma, M; Shen, W Q; Shimanskiy, S S; Sichtermann, E; Simon, F; Singaraju, R N; Smirnov, N; Snellings, R; Sood, G; Sorensen, P; Sowinski, J; Speltz, J; Spinka, H M; Srivastava, B; Stadnik, A; Stanislaus, T D S; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Suaide, A A P; Sugarbaker, E; Sumbera, M; Sun, Z; Surrow, B; Swanger, M; Symons, T J M; Szanto de Toledo, A; Tai, A; Takahashi, J; Tang, A H; Tarnowsky, T; Thein, D; Thomas, J H; Timmins, A R; Timoshenko, S; Tokarev, M; Trainor, T A; Trentalange, S; Tribble, R E; Tsai, O D; Ulery, J; Ullrich, T; Underwood, D G; Buren, G Van; van der Kolk, N; van Leeuwen, M; Molen, A M Vander; Varma, R; Vasilevski, I M; Vasiliev, A N; Vernet, R; Vigdor, S E; Viyogi, Y P; Vokal, S; Voloshin, S A; Waggoner, W T; Wang, F; Wang, G; Wang, J S; Wang, X L; Wang, Y; Watson, J W; Webb, J C; Westfall, G D; Wetzler, A; Whitten, C; Wieman, H; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Q H; Xu, Z; Yepes, P; Yoo, I-K; Yurevich, V I; Zhan, W; Zhang, H; Zhang, W M; Zhang, Y; Zhang, Z P; Zhao, Y; Zhong, C; Zoulkarneev, R; Zoulkarneeva, Y; Zubarev, A N; Zuo, J X

2006-09-29

We report the measurements of Sigma(1385) and Lambda(1520) production in p+p and Au+Au collisions at sqrt[s{NN}]=200 GeV from the STAR Collaboration. The yields and the p(T) spectra are presented and discussed in terms of chemical and thermal freeze-out conditions and compared to model predictions. Thermal and microscopic models do not adequately describe the yields of all the resonances produced in central Au+Au collisions. Our results indicate that there may be a time span between chemical and thermal freeze-out during which elastic hadronic interactions occur.

Efficient production of high-energy nonthermal particles during magnetic reconnection in a magnetically dominated ion-electron plasma

DOE PAGES

Guo, Fan; Li, Xiaocan; Li, Hui; ...

2016-02-03

Magnetic reconnection is a leading mechanism for dissipating magnetic energy and accelerating nonthermal particles in Poynting-flux-dominated flows. We investigate nonthermal particle acceleration during magnetic reconnection in a magnetically dominated ion–electron plasma using fully kinetic simulations. For an ion–electron plasma with a total magnetization ofmore » $${\\sigma }_{0}={B}^{2}/(4\\pi n({m}_{i}+{m}_{e}){c}^{2})$$, the magnetization for each species is $${\\sigma }_{i}\\sim {\\sigma }_{0}$$ and $${\\sigma }_{e}\\sim ({m}_{i}/{m}_{e}){\\sigma }_{0}$$, respectively. We have studied the magnetically dominated regime by varying σe = 103–105 with initial ion and electron temperatures $${T}_{i}={T}_{e}=5-20{m}_{e}{c}^{2}$$ and mass ratio $${m}_{i}/{m}_{e}=1-1836$$. Our results demonstrate that reconnection quickly establishes power-law energy distributions for both electrons and ions within several (2–3) light-crossing times. For the cases with periodic boundary conditions, the power-law index is $$1\\lt s\\lt 2$$ for both electrons and ions. The hard spectra limit the power-law energies for electrons and ions to be $${\\gamma }_{{be}}\\sim {\\sigma }_{e}$$ and $${\\gamma }_{{bi}}\\sim {\\sigma }_{i}$$, respectively. The main acceleration mechanism is a Fermi-like acceleration through the drift motions of charged particles. When comparing the spectra for electrons and ions in momentum space, the spectral indices sp are identical as predicted in Fermi acceleration. We also find that the bulk flow can carry a significant amount of energy during the simulations. Finally, we discuss the implication of this study in the context of Poynting-flux dominated jets and pulsar winds, especially the applications for explaining nonthermal high-energy emissions.« less

Quantum phases of a vortex string.

PubMed

Auzzi, Roberto; Prem Kumar, S

2009-12-04

We argue that the world sheet dynamics of magnetic k strings in the Higgs phase of the mass-deformed N = 4 theory is controlled by a bosonic O(3) sigma model with anisotropy and a topological theta term. The theory interpolates between a massless O(2) symmetric regime, a massive O(3) symmetric phase, and another massive phase with a spontaneously broken Z(2) symmetry. The first two phases are separated by a Kosterlitz-Thouless transition. When theta = pi, the O(3) symmetric phase flows to an interacting fixed point; sigma model kinks and their dyonic partners become degenerate, mirroring the behavior of monopoles in the parent gauge theory. This leads to the identification of the kinks with monopoles confined on the string.

Secret Lives of the Hidden Physicists---from Spandex to Spintronics

NASA Astrophysics Data System (ADS)

White, Gary

2006-10-01

What is a physicist? A case is made for defining a physicist as anyone with a bachelor's degree (or higher) in physics. Under this definition, a large fraction of physicists are hidden, that is, they have left, or never belonged to, the traditional lot of Ph.D. academicians. Data from the Statistical Research Center at the American Institute of Physics and from a survey of members of the national physics honor society, Sigma Pi Sigma, show the vast array of actual career paths taken by physicists. From spandex to blackberries to bioinformatics to flight control to wind energy to spintronics, physicists can be found in nearly every job sector in some of the coolest and most farfetched careers imaginable.

Efficiencies of state and velocity-changing collisions of superthermal CN A(2)Pi with He, Ar, N(2) and O(2).

PubMed

Alagappan, Azhagammai; Ballingall, Iain; Costen, Matthew L; McKendrick, Kenneth G; Paterson, Grant

2007-02-14

Polarized laser photolysis of ICN is combined with saturated optical pumping to prepare state-selected CN Alpha(2)Pi (nu' = 4, J = 0.5, F(2), f) with a well-defined anisotropic superthermal speed distribution. The collisional evolution of the prepared state is observed by Doppler-resolved Frequency Modulated (FM) spectroscopy via stimulated emission on the CN Alpha(2)Pi-Chi(2)Sigma(+) (4,2) band. The phenomenological rate constants for removal of the prepared state in collisions with He, Ar, N(2) and O(2) are reported. The observed collision cross-sections are consistent with attractive forces contributing significantly for all the colliders with the exception of He. The collisional evolution of the prepared velocity distribution demonstrates that no significant back-transfer into the prepared level occurs, and that any elastic scattering is strongly in the forward hemisphere.

Fitting of Hadron Mass Spectra and Contributions to Perturbation Theory of Conformal Quantum Field Theory

NASA Astrophysics Data System (ADS)

Luna Acosta, German Aurelio

The masses of observed hadrons are fitted according to the kinematic predictions of Conformal Relativity. The hypothesis gives a remarkably good fit. The isospin SU(2) gauge invariant Lagrangian L(,(pi)NN)(x,(lamda)) is used in the calculation of d(sigma)/d(OMEGA) to 2nd-order Feynman graphs for simplified models of (pi)N(--->)(pi)N. The resulting infinite mass sums over the nucleon (Conformal) families are done via the Generalized-Sommerfeld-Watson Transform Theorem. Even though the models are too simple to be realistic, they indicate that if (DELTA)-internal lines were to be included, 2nd-order Feynman graphs may reproduce the experimental data qualitatively. The energy -dependence of the propagator and couplings in Conformal QFT is different from that of ordinary QFT. Suggestions for further work are made in the areas of ultra-violet divergences and OPEC calculations.

New probes of Cosmic Microwave Background large-scale anomalies

NASA Astrophysics Data System (ADS)

Aiola, Simone

Fifty years of Cosmic Microwave Background (CMB) data played a crucial role in constraining the parameters of the LambdaCDM model, where Dark Energy, Dark Matter, and Inflation are the three most important pillars not yet understood. Inflation prescribes an isotropic universe on large scales, and it generates spatially-correlated density fluctuations over the whole Hubble volume. CMB temperature fluctuations on scales bigger than a degree in the sky, affected by modes on super-horizon scale at the time of recombination, are a clean snapshot of the universe after inflation. In addition, the accelerated expansion of the universe, driven by Dark Energy, leaves a hardly detectable imprint in the large-scale temperature sky at late times. Such fundamental predictions have been tested with current CMB data and found to be in tension with what we expect from our simple LambdaCDM model. Is this tension just a random fluke or a fundamental issue with the present model? In this thesis, we present a new framework to probe the lack of large-scale correlations in the temperature sky using CMB polarization data. Our analysis shows that if a suppression in the CMB polarization correlations is detected, it will provide compelling evidence for new physics on super-horizon scale. To further analyze the statistical properties of the CMB temperature sky, we constrain the degree of statistical anisotropy of the CMB in the context of the observed large-scale dipole power asymmetry. We find evidence for a scale-dependent dipolar modulation at 2.5sigma. To isolate late-time signals from the primordial ones, we test the anomalously high Integrated Sachs-Wolfe effect signal generated by superstructures in the universe. We find that the detected signal is in tension with the expectations from LambdaCDM at the 2.5sigma level, which is somewhat smaller than what has been previously argued. To conclude, we describe the current status of CMB observations on small scales, highlighting the tensions between Planck, WMAP, and SPT temperature data and how the upcoming data release of the ACTpol experiment will contribute to this matter. We provide a description of the current status of the data-analysis pipeline and discuss its ability to recover large-scale modes.

Measurement of inclusive muon pair production by 225-GeV/c. pi. /sup +/,. pi. /sup -/, and proton beams with a large acceptance spectrometers. [Cross sections, 225 GeV/c, tables

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brason, J G

1977-05-01

Inclusive muon pair production by 225 GeV/c ..pi../sup +/, ..pi../sup -/ and proton beams incident upon carbon and tin targets was measured over a large range of kinematic variables (2m/sub ..mu../ < m/sub ..mu mu.. < 1 GeV/c/sup 2/, 0 < x/sub F/ < 1, P/sub perpendicular to/ < 4 GeV/c and vertical bar cos theta* vertical bar < .3). The value of the invariant cross section E d/sup 4/sigma/dmdx/sub f/dp/sup 2//sub perpendicular to/ is presented as a function of these variables. The vector mesons rho, ..omega.., phi, J and psi' appear in the data along with apparently nonresonant ..mu..-pairs.more » By looking for additional muons accompanying J ..-->.. ..mu../sup +/..mu../sup -/ events, a 1.0% upper limit on production of pairs of charmed particles in association with the J is obtained. Aspects of the continuum muon pair data are compared to Drell-Yan model calculations. The ratio of ..mu..-pairs produced by ..pi../sup +/ beam particles to ..mu..-pairs produced by ..pi../sup -/ beam particles supports electromagnetic production at high mass.« less

Measurements of Surfactant Squeeze-out Using Magnetically-Levitated Liquid Bridges

NASA Technical Reports Server (NTRS)

Rosenblatt, Charles

2004-01-01

Liquid bridges: Columns of liquid supported by two solid surfaces. These are generally opposing right circular cylinders in 0g. For a cylindrical bridge of length L and diameter d, in zero g, the maximum slenderness ratio Lambda [L/d] = pi [Rayleigh]. In the presence of gravity the cylindrical shape of an axisymmetric bridge tends to deform. Fluid has a volumetric magnetic susceptibility X. Magnetic levitation has numerous applications in studies of fluids, "soft" and "hard" condensed matter physics, and biophysics

Photoelectron spectra of carbonyls. Propellenes and propellanones

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dougherty, D.; Bloomfield, J.J.; Newkome, G.R.

1976-09-23

The HeI photoelectron spectra (UPS) of a number of unsaturated (4.4.2)propellanes and (4.4.2)propellane-dione derivatives are presented. The interpretation of the UPS data is based on through-space and through-bond interaction models and on CNDO/s computations. An analysis of the photoelectron spectra of (4.4.2)propella-3,8-diene-11,12-dione (1), (4.4.2)propell-3-ene-11,12-dione (2), (4.4.2)propellane-11,12-dione (3), (4.4.2)propella-3,8-dien-11-one (4), and (4.4.2) propella-3,8-diene (5) involves the assignment of n/sub +/, n/sub -/, ..pi../sub +/, ..pi../sub -/, and sigma/sub square/ (i.e., cyclobutane sigma) ionization events. The analysis of the data for 5, (4.4.2)propella-3,8,11-triene (6), (4.4.2)propella-3,11-diene (7), and (4.4.2)propell-11-ene (8) leads to the conclusion that the photoelectron spectrum of 6 should be reassigned.more » The /sup 1/GAMMA/sub n..pi..*/ reverse arrow /sup 1/GAMMA/sub 1/ absorption spectra of 1,2, and 3 have been investigated as a function of temperature. The low energy of this transition in 1 is attributed to a high degree of CO/CO coplanarity, the high energy of this transition in 3 is attributed to CO/CO noncoplanarity, and the isomerism evident in 2 is attributed to multiple minima of the potential energy along the CO/CO dihedral angle coordinate of the ground state.« less

Purple sweet potato color alleviates D-galactose-induced brain aging in old mice by promoting survival of neurons via PI3K pathway and inhibiting cytochrome C-mediated apoptosis.

PubMed

Lu, Jun; Wu, Dong-mei; Zheng, Yuan-lin; Hu, Bin; Zhang, Zi-feng

2010-05-01

Purple sweet potato color (PSPC), a class of naturally occurring anthocyanins, protects brain function against oxidative stress induced by D-galactose (D-gal) (Sigma-Aldrich, St. Louis, MO, USA). Our data showed that PSPC enhanced open-field activity, decreased step-through latency, and improved spatial learning and memory ability in D-gal-treated old mice by decreasing advanced glycation end-products' (AGEs) formation and the AGE receptor (RAGE) expression, and by elevating Cu,Zn-superoxide dismutase (Cu,Zn-SOD) (Sigma-Aldrich) and catalase (CAT) expression and activity. Cleavage of caspase-3 and increased terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP) nick-end-labeling (TUNEL)-positive cells in D-gal-treated old mice were inhibited by PSPC, which might be attributed to its antioxidant property. PSPC also suppressed the activation of c-Jun NH(2)-terminal kinase (JNK) and the release of cytochrome c from mitochondria that counteracted the onset of neuronal apoptosis in D-gal-treated old mice. Furthermore, it was demonstrated that phosphoinositide 3-kinase (PI3K) activation was required for PSPC to promote the neuronal survival accompanied with phosphorylation and activation of Akt and p44/42 mitogen-activated protein kinase (MAPK) by using PI3K inhibitor LY294002 (Cell Signaling Technology, Inc., Beverly, MA, USA), implicating a neuronal survival mechanism. The present results suggest that neuronal survival promoted by PSPC may be a potentially effective method to enhance resistance of neurons to age-related disease.

The metal-carbonyl bond in Ni(CO)4 and Fe(CO)5 - A clear-cut analysis

NASA Technical Reports Server (NTRS)

Bauschlicher, C. W., Jr.; Bagus, P. S.

1984-01-01

A detailed analysis of the metal-carbonyl bonding in Ni(CO)4 and Fe(CO)5, based on the newly developed contained space orbital variation (CSOV) method, is carried out to investigate various contributing factors to the interaction. Three aspects about the metal-CO interaction are presented: (1) the frozen orbital repulsion between the metal 4s and the CO is large; (2) the metal to CO pi donation is energetically much more important than the CO to the metal sigma donation; and (3) the metal 4s and 4p orbitals make a very small contribution (smaller than 0.4 eV) to the interaction energy; the largest portion of this contribution arises from the CO to metal sigma donation.

PART 2 OF 2 PART PANORAMA WITH NO. CA212 VIEW ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PART 2 OF 2 PART PANORAMA WITH NO. CA-2-12 VIEW OF PIEDMONT AVENUE TRAFFIC CIRCLE AT INTERSECTION OF CHANNING WAY WITH 2395 PIEDMONT, SIGMA PI HOUSE BY FREDERICK H. REIMERS, 1928. SEEN FROM SE CORNER LOOKING NW. Photograph by Brian Grogan, July 8, 2007 - Piedmont Way & the Berkeley Property Tract, East of College Avenue between Dwight Way & U.C. Memorial Stadium, Berkeley, Alameda County, CA

State-to-state dynamics of {\\rm{F}}({}^{2}{\\rm{P}})+{\\rm{HO}}({}^{2}{\\rm{\\Pi }})\\to {\\rm{O}}({}^{3}{\\rm{P}})+{\\rm{HF}}({}^{1}{\\rm{\\Sigma }}^{+}) reaction on {1}^{3}{{\\rm{A}}}^{\\prime\\prime} potential energy surface

NASA Astrophysics Data System (ADS)

Zhao, Juan; Wu, Hui; Sun, Hai-Bo; Wang, Li-Fei

2018-02-01

Not Available Project supported by the National Natural Science Foundation of China (Grant Nos. 11504206 and 11404049), the China Postdoctoral Science Foundation (CPSF) (Grant No. 2014M561259), and the Ph. D. Research Start-up Fund of Shandong Jiaotong University.

A self-adaption compensation control for hysteresis nonlinearity in piezo-actuated stages based on Pi-sigma fuzzy neural network

NASA Astrophysics Data System (ADS)

Xu, Rui; Zhou, Miaolei

2018-04-01

Piezo-actuated stages are widely applied in the high-precision positioning field nowadays. However, the inherent hysteresis nonlinearity in piezo-actuated stages greatly deteriorates the positioning accuracy of piezo-actuated stages. This paper first utilizes a nonlinear autoregressive moving average with exogenous inputs (NARMAX) model based on the Pi-sigma fuzzy neural network (PSFNN) to construct an online rate-dependent hysteresis model for describing the hysteresis nonlinearity in piezo-actuated stages. In order to improve the convergence rate of PSFNN and modeling precision, we adopt the gradient descent algorithm featuring three different learning factors to update the model parameters. The convergence of the NARMAX model based on the PSFNN is analyzed effectively. To ensure that the parameters can converge to the true values, the persistent excitation condition is considered. Then, a self-adaption compensation controller is designed for eliminating the hysteresis nonlinearity in piezo-actuated stages. A merit of the proposed controller is that it can directly eliminate the complex hysteresis nonlinearity in piezo-actuated stages without any inverse dynamic models. To demonstrate the effectiveness of the proposed model and control methods, a set of comparative experiments are performed on piezo-actuated stages. Experimental results show that the proposed modeling and control methods have excellent performance.

Flavor and baryon quantum numbers and their nondiffractive renormalizations of the Pomeron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dash, J.W.; Jones, S.T.; Manesis, E.K.

We present a theoretical review and a detailed phonomenological description of the ''flavoring'' of the bare Pomeron pole at t = 0 (i.e., the nondiffractive renormalization of its multiperipheral unitarity sum by strange quarks, charmed quarks, diquarks,...) from an ''unflavored'' intercept alpha-circumflex = 0.85 to a ''flavored'' intercept ..cap alpha.. approx. = 1.08. Experimentally, flavoring effects seem to converge rapidly; hence this number is probably close to the bare intercept of the Reggeon field theory. We treat NN, ..pi..N, and KN total cross sections and real to imaginary amplitude ratios. We do not observe oscillations. We pay particular attention tomore » 2sigma/sub K/N - sigma/sub piN/ which rises monotonically. We present a closely related combination of inelastic diffraction cross sections which decreases monotonically, indicating that vacuum amplitudes are not simply the sum of a Pomeron pole and an ideally mixed f. In fact we argue that a Pomeron + f structure is neither compatible with flavoring nor with schemes in which flavoring is somehow absorbed away. In contrast, flavoring is required for consistency with experiment by the Chew-Rosenzweig hypothesis of the Pomeron-f identity. We close with a description of flavoring threshold effects on the Reggeon field theory at current energies.« less

Variable thickness double-refracting plate

DOEpatents

Hadeishi, Tetsuo

1976-01-01

This invention provides an A.C., cyclic, current-controlled, phase retardation plate that uses a magnetic clamp to produce stress birefringence. It was developed for an Isotope-Zeeman Atomic Absorption Spectrometer that uses polarization modulation to effect automatic background correction in atomic absorption trace-element measurements. To this end, the phase retardation plate of the invention is a variable thickness, photoelastic, double-refracting plate that is alternately stressed and released by the magnetic clamp selectively to modulate specific components selected from the group consisting of circularly and plane polarized Zeeman components that are produced in a dc magnetic field so that they correspond respectively to Zeeman reference and transmission-probe absorption components. The polarization modulation changes the phase of these polarized Zeeman components, designated as .sigma. reference and .pi. absorption components, so that every half cycle the components change from a transmission mode to a mode in which the .pi. component is blocked and the .sigma. components are transmitted. Thus, the Zeeman absorption component, which corresponds in amplitude to the amount of the trace element to be measured in a sample, is alternately transmitted and blocked by a linear polarizer, while the circularly polarized reference components are continuously transmitted thereby. The result is a sinusoidally varying output light amplitude whose average corresponds to the amount of the trace element present in the sample.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gu, M F; Holcomb, C; Jayakuma, J

We present detailed atomic physics models for motional Stark effects (MSE) diagnostic on magnetic fusion devices. Excitation and ionization cross sections of the hydrogen or deuterium beam traveling in a magnetic field in collisions with electrons, ions, and neutral gas are calculated in the first Born approximation. The density matrices and polarization states of individual Stark-Zeeman components of the Balmer {alpha} line are obtained for both beam into plasma and beam into gas models. A detailed comparison of the model calculations and the MSE polarimetry and spectral intensity measurements obtained at the DIII-D tokamak is carried out. Although our beammore » into gas models provide a qualitative explanation for the larger {pi}/{sigma} intensity ratios and represent significant improvements over the statistical population models, empirical adjustment factors ranging from 1.0-2.0 must still be applied to individual line intensities to bring the calculations into full agreement with the observations. Nevertheless, we demonstrate that beam into gas measurements can be used successfully as calibration procedures for measuring the magnetic pitch angle through {pi}/{sigma} intensity ratios. The analyses of the filter-scan polarization spectra from the DIII-D MSE polarimetry system indicate unknown channel and time dependent light contaminations in the beam into gas measurements. Such contaminations may be the main reason for the failure of beam into gas calibration on MSE polarimetry systems.« less

Induction of the SHARP-2 mRNA level by insulin is mediated by multiple signaling pathways.

PubMed

Kanai, Yukiko; Asano, Kosuke; Komatsu, Yoshiko; Takagi, Katsuhiro; Ono, Moe; Tanaka, Takashi; Tomita, Koji; Haneishi, Ayumi; Tsukada, Akiko; Yamada, Kazuya

2017-02-01

The rat enhancer of split- and hairy-related protein-2 (SHARP-2) is an insulin-inducible transcription factor which represses transcription of the rat phosphoenolpyruvate carboxykinase gene. In this study, a regulatory mechanism of the SHARP-2 mRNA level by insulin was analyzed. Insulin rapidly induced the level of SHARP-2 mRNA. This induction was blocked by inhibitors for phosphoinositide 3-kinase (PI 3-K), protein kinase C (PKC), and mammalian target of rapamycin (mTOR), actinomycin D, and cycloheximide. Whereas an adenovirus infection expressing a dominant negative form of atypical PKC lambda (aPKCλ) blocked the insulin-induction of the SHARP-2 mRNA level, insulin rapidly activated the mTOR. Insulin did not enhance transcriptional activity from a 3.7 kb upstream region of the rat SHARP-2 gene. Thus, we conclude that insulin induces the expression of the rat SHARP-2 gene at the transcription level via both a PI 3-K/aPKCλ- and a PI 3-K/mTOR- pathways and that protein synthesis is required for this induction.

Finite field equation of Yang--Mills theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brandt, R.A.; Wing-Chiu, N.; Yeung, W.

1980-03-01

We consider the finite local field equation -)(1+1/..cap alpha.. (1+f/sub 4/))g/sup munu/D'Alembertian-partial/sup ..mu../partial/sup ..nu../)A/sup nua/ =-(1+f/sub 3/) g/sup 2/N(A/sup c/..nu..A/sup a/..mu..A/sub ..nu..//sup c/) +xxx+(1-s)/sup 2/M/sup 2/A/sup a/..mu.., introduced by Lowenstein to rigorously describe SU(2) Yang--Mills theory, which is written in terms of normal products. We also consider the operator product expansion A/sup c/..nu..(x+xi) A/sup a/..mu..(x) A/sup b/lambda(x-xi) approx...sigma..M/sup c/ab..nu mu..lambda/sub c/'a'b'..nu..'..mu..'lambda' (xi) N(A/sup nuprimec/'A/sup muprimea/'A/sup lambdaprimeb/')(x), and using asymptotic freedom, we compute the leading behavior of the Wilson coefficients M/sup ...//sub .../(xi) with the help of a computer, and express the normal products in the field equation in terms ofmore » products of the c-number Wilson coefficients and of operator products like A/sup c/..nu..(x+xi) A/sup a/..mu..(x) A/sup b/lambda(x-xi) at separated points. Our result is -)(1+(1/..cap alpha..)(1+f/sub 4/))g/sup munu/D'Alembertian-partial/sup ..mu../partial/sup ..nu../)A/sup nua/ =-(1+f/sub 3/) g/sup 2/lim/sub xiarrow-right0/) (lnxi)/sup -0.28/2b/(A/sup c/..nu.. (x+xi) A/sup a/..mu..(x) A/sub ..nu..//sup c/(x-xi) +epsilon/sup a/bcA/sup muc/(x+xi) partial/sup ..nu../A/sup b//sub ..nu../(x)+xxx) +xxx)+(1-s)/sup 2/M/sup 2/A/sup a/..mu.., where ..beta.. (g) =-bg/sup 3/, and so (lnxi)/sup -0.28/2b/ is the leading behavior of the c-number coefficient multiplying the operator products in the field equation.« less

Optical emission spectroscopic study of plasma plumes generated by IR CO2 pulsed laser on carbon targets

NASA Astrophysics Data System (ADS)

Camacho, J. J.; Díaz, L.; Santos, M.; Reyman, D.; Poyato, J. M. L.

2008-05-01

Optical emission spectroscopy studies, in the spectral range ultraviolet-visible-near infrared (UV-Vis-NIR), were performed to investigate thermal and dynamical properties of a plume produced by laser ablation of a graphite target. Ablation is carried out using a high-power IR CO2 pulsed laser at λ = 9.621 µm, power density ranging from 0.22 to 5.36 GW cm-2 and air pressures around 4 Pa. The strong emission observed in the plasma region is mainly due to electronic relaxation of excited C, ionic fragments C+, C2+ and C3+ and molecular features of C2(d 3Πg-a 3Πu Swan band system). The medium-weak emission is mainly due to excited atomic N, H, O, ionic fragment C4+ and molecular features of C2( E\\,^1\\Sigma _g^+\\--A\\,^{1}\\Pi _u ; Freymark system), C2( D\\,^1\\Sigma _u^+\\--X\\,^1\\Sigma _g^+ ; Mulliken system), CN(D 2Π-A 2Π), C2(e 3Πg-a 3Πu Fox-Herzberg system), C2(C 1Πg-A 1Πu Deslandres-d'Azambuja system), OH(A 2Σ+-X 2Π), CH(C 2Σ+-X 2Π), NH(A 3Π-X 3Σ-), CN(B 2Σ+-X 2Σ+ violet system), CH(B 2Σ+-X 2Π), CH(A 2Δ-X 2Π), C2( A\\,^{1}\\Pi_u\\--X\\,^{1}\\Sigma ^{+}_g ; Phillips system) and CN(A 2Π-X 2Σ+ red system). An excitation temperature Texc = 23 000 ± 1900 K and electron densities in the range (0.6-5.6) × 1016 cm-3 were estimated by means of C+ ionic lines. The characteristics of the spectral emission intensities from different species have been investigated as functions of the ambient pressure and laser irradiance. Estimates of vibrational temperatures of C2 and CN electronically excited species under various laser irradiance conditions are made.

Study on improving the turbidity measurement of the absolute coagulation rate constant.

PubMed

Sun, Zhiwei; Liu, Jie; Xu, Shenghua

2006-05-23

The existing theories dealing with the evaluation of the absolute coagulation rate constant by turbidity measurement were experimentally tested for different particle-sized (radius = a) suspensions at incident wavelengths (lambda) ranging from near-infrared to ultraviolet light. When the size parameter alpha = 2pi a/lambda > 3, the rate constant data from previous theories for fixed-sized particles show significant inconsistencies at different light wavelengths. We attribute this problem to the imperfection of these theories in describing the light scattering from doublets through their evaluation of the extinction cross section. The evaluations of the rate constants by all previous theories become untenable as the size parameter increases and therefore hampers the applicable range of the turbidity measurement. By using the T-matrix method, we present a robust solution for evaluating the extinction cross section of doublets formed in the aggregation. Our experiments show that this new approach is effective in extending the applicability range of the turbidity methodology and increasing measurement accuracy.

'Direct' Gas-Phase Metallicities, Stellar Properties, and Local Environments of Emission-Line Galaxies at Redshifts Below 0.90

NASA Technical Reports Server (NTRS)

Ly, Chun; Malkan, Matthew A.; Nagao, Tohru; Kashikawa, Nobunari; Shimasaku, Kazuhiro; Hayashi, Masao

2013-01-01

Using deep narrow-band (NB) imaging and optical spectroscopy from the Keck telescope and the Multi Mirror Telescope (MMT), we identify a sample of 20 emission-line galaxies (ELGs) at z = 0.065-0.90 where the weak auroral emission line, [O iii] lambda4363, is detected at >=3sigma. These detections allow us to determine the gas-phase metallicity using the "direct" method. With electron temperature measurements, and dust attenuation corrections from Balmer decrements, we find that 4 of these low-mass galaxies are extremely metal-poor with 12+log(O/H) <= 7.65 or one-tenth solar. Our most metal-deficient galaxy has 12+log(O/H)= 7.24(+0.45 / -0.30) (95% confidence), similar to some of the lowest metallicity galaxies identified in the local universe. We find that our galaxies are all undergoing significant star formation with average specific star formation rate (SFR) of (100 Myra)(exp -1), and that they have high central SFR surface densities (average of 0.5 Solar M / yr/ sq. kpc). In addition, more than two-thirds of our galaxies have between one and four nearby companions within a projected radius of 100 kpc, which we find is an excess among star-forming galaxies at z =0.4 -- 0.85. We also find that the gas-phase metallicities for a given stellar mass and SFR lie systematically lower than the local stellar M-Z-(SFR) relation by approx. = 0.2 dex (2 sigma significance). These results are partly due to selection effects, since galaxies with strong star formation and low metallicity are more likely to yield [O iii] lambda4363 detections. Finally, the observed higher ionization parameter and high electron density suggest that they are lower redshift analogs to typical z approx. > 1 galaxies.

Statistical Measures of Large-Scale Structure

NASA Astrophysics Data System (ADS)

Vogeley, Michael; Geller, Margaret; Huchra, John; Park, Changbom; Gott, J. Richard

1993-12-01

\\inv Mpc} To quantify clustering in the large-scale distribution of galaxies and to test theories for the formation of structure in the universe, we apply statistical measures to the CfA Redshift Survey. This survey is complete to m_{B(0)}=15.5 over two contiguous regions which cover one-quarter of the sky and include ~ 11,000 galaxies. The salient features of these data are voids with diameter 30-50\\hmpc and coherent dense structures with a scale ~ 100\\hmpc. Comparison with N-body simulations rules out the ``standard" CDM model (Omega =1, b=1.5, sigma_8 =1) at the 99% confidence level because this model has insufficient power on scales lambda >30\\hmpc. An unbiased open universe CDM model (Omega h =0.2) and a biased CDM model with non-zero cosmological constant (Omega h =0.24, lambda_0 =0.6) match the observed power spectrum. The amplitude of the power spectrum depends on the luminosity of galaxies in the sample; bright (L>L(*) ) galaxies are more strongly clustered than faint galaxies. The paucity of bright galaxies in low-density regions may explain this dependence. To measure the topology of large-scale structure, we compute the genus of isodensity surfaces of the smoothed density field. On scales in the ``non-linear" regime, <= 10\\hmpc, the high- and low-density regions are multiply-connected over a broad range of density threshold, as in a filamentary net. On smoothing scales >10\\hmpc, the topology is consistent with statistics of a Gaussian random field. Simulations of CDM models fail to produce the observed coherence of structure on non-linear scales (>95% confidence level). The underdensity probability (the frequency of regions with density contrast delta rho //lineρ=-0.8) depends strongly on the luminosity of galaxies; underdense regions are significantly more common (>2sigma ) in bright (L>L(*) ) galaxy samples than in samples which include fainter galaxies.

Core-shell photoabsorption and photoelectron spectra of gas-phase pentacene: experiment and theory.

PubMed

Alagia, Michele; Baldacchini, Chiara; Betti, Maria Grazia; Bussolotti, Fabio; Carravetta, Vincenzo; Ekström, Ulf; Mariani, Carlo; Stranges, Stefano

2005-03-22

The C K-edge photoabsorption and 1s core-level photoemission of pentacene (C22H14) free molecules are experimentally measured, and calculated by self-consistent-field and static-exchange approximation ab initio methods. Six nonequivalent C atoms present in the molecule contribute to the C 1s photoemission spectrum. The complex near-edge structures of the carbon K-edge absorption spectrum present two main groups of discrete transitions between 283 and 288 eV photon energy, due to absorption to pi* virtual orbitals, and broader structures at higher energy, involving sigma* virtual orbitals. The sharp absorption structures to the pi* empty orbitals lay well below the thresholds for the C 1s ionizations, caused by strong excitonic and localization effects. We can definitely explain the C K-edge absorption spectrum as due to both final (virtual) and initial (core) orbital effects, mainly involving excitations to the two lowest-unoccupied molecular orbitals of pi* symmetry, from the six chemically shifted C 1s core orbitals.

Inclusive strange-resonance production in pp,. pi. /sup +/p, and K/sup +/p interactions at 147 GeV/c

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brick, D.; Rudnicka, H.; Shapiro, A.M.

1982-05-01

We have studied the inclusive production of K/sup asteriskplus-or-minus/(890) and Y/sup asteriskplus-or-minus/(1385) in pp, ..pi../sup +/p, and K/sup +/p interactions at 147 GeV/c. The experiment used the Fermilab 30-inch hydrogen bubble chamber with the hybrid spectrometer system. Results are based on a sample of 1916 observed K/sub S/ and 932 observed ..lambda... Inclusive cross sections are given for K/sup asteriskplus-or-minus/ and Y/sup asteriskplus-or-minus/ production from the three beams, and comparisons are made with experiments at other energies. Feynman-x and transverse-momentum-squared distributions are also calculated. The results suggest that the K/sup asterisk-/ is entirely produced in the central region, while themore » K/sup asterisk+/ includes a component from beam fragmentation. Comparisons are made with the additive quark model.« less

Cosmological implications of a large complete quasar sample.

PubMed

Segal, I E; Nicoll, J F

1998-04-28

Objective and reproducible determinations of the probabilistic significance levels of the deviations between theoretical cosmological prediction and direct model-independent observation are made for the Large Bright Quasar Sample [Foltz, C., Chaffee, F. H., Hewett, P. C., MacAlpine, G. M., Turnshek, D. A., et al. (1987) Astron. J. 94, 1423-1460]. The Expanding Universe model as represented by the Friedman-Lemaitre cosmology with parameters qo = 0, Lambda = 0 denoted as C1 and chronometric cosmology (no relevant adjustable parameters) denoted as C2 are the cosmologies considered. The mean and the dispersion of the apparent magnitudes and the slope of the apparent magnitude-redshift relation are the directly observed statistics predicted. The C1 predictions of these cosmology-independent quantities are deviant by as much as 11sigma from direct observation; none of the C2 predictions deviate by >2sigma. The C1 deviations may be reconciled with theory by the hypothesis of quasar "evolution," which, however, appears incapable of being substantiated through direct observation. The excellent quantitative agreement of the C1 deviations with those predicted by C2 without adjustable parameters for the results of analysis predicated on C1 indicates that the evolution hypothesis may well be a theoretical artifact.

Detailed Structure of the Outer Disk Around HD 169142 with Polarized Light in H-band

NASA Technical Reports Server (NTRS)

Momose, Munetake; Morita, Ayaka; Fukagawa, Misato; Muto, Takayuki; Takeuchi, Taku; Hashimoto, Jun; Honda, Mitsuhiko; Kudo, Tomoyuki; Okamoto, Yoshiko K.; Kanagawa, Kazuhiro D.;

Measuring the scatter in the cluster optical richness-mass relation with machine learning

NASA Astrophysics Data System (ADS)

Boada, Steven Alvaro

The distribution of massive clusters of galaxies depends strongly on the total cosmic mass density, the mass variance, and the dark energy equation of state. As such, measures of galaxy clusters can provide constraints on these parameters and even test models of gravity, but only if observations of clusters can lead to accurate estimates of their total masses. Here, we carry out a study to investigate the ability of a blind spectroscopic survey to recover accurate galaxy cluster masses through their line-of- sight velocity dispersions (LOSVD) using probability based and machine learning methods. We focus on the Hobby Eberly Telescope Dark Energy Experiment (HETDEX), which will employ new Visible Integral-Field Replicable Unit Spectrographs (VIRUS), over 420 degree2 on the sky with a 1/4.5 fill factor. VIRUS covers the blue/optical portion of the spectrum (3500 - 5500 A), allowing surveys to measure redshifts for a large sample of galaxies out to z < 0.5 based on their absorption or emission (e.g., [O II], Mg II, Ne V) features. We use a detailed mock galaxy catalog from a semi-analytic model to simulate surveys observed with VIRUS, including: (1) Survey, a blind, HETDEX-like survey with an incomplete but uniform spectroscopic selection function; and (2) Targeted, a survey which targets clusters directly, obtaining spectra of all galaxies in a VIRUS-sized field. For both surveys, we include realistic uncertainties from galaxy magnitude and line-flux limits. We benchmark both surveys against spectroscopic observations with perfect" knowledge of galaxy line-of-sight velocities. With Survey observations, we can recover cluster masses to ˜ 0.1 dex which can be further improved to < 0.1 dex with Targeted observations. This level of cluster mass recovery provides important measurements of the intrinsic scatter in the optical richness-cluster mass relation, and enables constraints on the key cosmological parameter, sigma 8, to < 20%. As a demonstration of the methods developed previously, we present a pilot survey with integral field spectroscopy of ten galaxy clusters optically selected from the Sloan Digital Sky Survey's DR8 at z = 0.2 - 0.3. Eight of the clusters are rich (lambda > 60) systems with total inferred masses (1.58 -17.37) x1014 M (M 200c), and two are poor (lambda < 15) systems with inferred total masses ˜ 0.5 x 1014 M? (M200c ). We use the Mitchell Spectrograph, (formerly the VIRUS-P spectrograph, a prototype of the HETDEX VIRUS instrument) located on the McDonald Observatory 2.7m telescope, to measure spectroscopic redshifts and line-of-sight velocities of the galaxies in and around each cluster, determine cluster membership and derive LOSVDs. We test both a LOSVD-cluster mass scaling relation and a machine learning based approach to infer total cluster mass. After comparing the cluster mass estimates to the literature, we use these independent cluster mass measurements to estimate the absolute cluster mass scale, and intrinsic scatter in the optical richness-mass relationship. We measure the intrinsic scatter in richness at fixed cluster mass to be sigmaM/lambda = 0.27 +/- 0.07 dex in excellent agreement with previous estimates of sigmaM/lambda ˜ 0.2 - 0.3 dex. We discuss the importance of the data used to train the machine learning methods and suggest various strategies to import the accuracy of the bias (offset) and scatter in the optical richness-cluster mass relation. This demonstrates the power of blind spectroscopic surveys such as HETDEX to provide robust cluster mass estimates which can aid in the determination of cosmological parameters and help to calibrate the observable-mass relation for future photometric large area-sky surveys.

Measurements of B --> {pi,eta,eta;{'}}lnu_{l} branching fractions and determination of |V_{ub}| with semileptonically tagged B mesons.

PubMed

Aubert, B; Bona, M; Karyotakis, Y; Lees, J P; Poireau, V; Prencipe, E; Prudent, X; Tisserand, V; Garra Tico, J; Grauges, E; Lopez, L; Palano, A; Pappagallo, M; Eigen, G; Stugu, B; Sun, L; Abrams, G S; Battaglia, M; Brown, D N; Cahn, R N; Jacobsen, R G; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Osipenkov, I L; Ronan, M T; Tackmann, K; Tanabe, T; Hawkes, C M; Soni, N; Watson, A T; Koch, H; Schroeder, T; Walker, D; Asgeirsson, D J; Cuhadar-Donszelmann, T; Fulsom, B G; Hearty, C; Mattison, T S; McKenna, J A; Barrett, M; Khan, A; Teodorescu, L; Blinov, V E; Bukin, A D; Buzykaev, A R; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Bondioli, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M; Martin, E C; Stoker, D P; Abachi, S; Buchanan, C; Gary, J W; Liu, F; Long, O; Shen, B C; Vitug, G M; Yasin, Z; Zhang, L; Sharma, V; Campagnari, C; Hong, T M; Kovalskyi, D; Mazur, M A; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Schalk, T; Schumm, B A; Seiden, A; Wang, L; Wilson, M G; Winstrom, L O; Cheng, C H; Doll, D A; Echenard, B; Fang, F; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Andreassen, R; Mancinelli, G; Meadows, B T; Mishra, K; Sokoloff, M D; Blanc, F; Bloom, P C; Ford, W T; Gaz, A; Hirschauer, J F; Kreisel, A; Nagel, M; Nauenberg, U; Smith, J G; Ulmer, K A; Wagner, S R; Ayad, R; Soffer, A; Toki, W H; Wilson, R J; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Karbach, M; Merkel, J; Petzold, A; Spaan, B; Wacker, K; Kobel, M J; Mader, W F; Nogowski, R; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Latour, E; Thiebaux, Ch; Verderi, M; Clark, P J; Gradl, W; Playfer, S; Watson, J E; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cecchi, A; Cibinetto, G; Franchini, P; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Santoro, V; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Contri, R; Lo Vetere, M; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Chaisanguanthum, K S; Morii, M; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Klose, V; Lacker, H M; De Nardo, G; Lista, L; Monorchio, D; Onorato, G; Sciacca, C; Bard, D J; Dauncey, P D; Nash, J A; Panduro Vazquez, W; Tibbetts, M; Behera, P K; Chai, X; Charles, M J; Mallik, U; Cochran, J; Crawley, H B; Dong, L; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gao, Y Y; Gritsan, A V; Guo, Z J; Lae, C K; Denig, A G; Fritsch, M; Schott, G; Arnaud, N; Béquilleux, J; D'Orazio, A; Davier, M; Firmino da Costa, J; Grosdidier, G; Höcker, A; Lepeltier, V; Le Diberder, F; Lutz, A M; Pruvot, S; Roudeau, P; Schune, M H; Serrano, J; Sordini, V; Stocchi, A; Wormser, G; Lange, D J; Wright, D M; Bingham, I; Burke, J P; Chavez, C A; Fry, J R; Gabathuler, E; Gamet, R; Hutchcroft, D E; Payne, D J; Touramanis, C; Bevan, A J; George, K A; Di Lodovico, F; Sacco, R; Sigamani, M; Cowan, G; Flaecher, H U; Hopkins, D A; Paramesvaran, S; Salvatore, F; Wren, A C; Brown, D N; Davis, C L; Alwyn, K E; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Lafferty, G D; West, T J; Yi, J I; Anderson, J; Chen, C; Jawahery, A; Roberts, D A; Simi, G; Tuggle, J M; Dallapiccola, C; Hertzbach, S S; Li, X; Salvati, E; Saremi, S; Cowan, R; Dujmic, D; Fisher, P H; Koeneke, K; Sciolla, G; Spitznagel, M; Taylor, F; Yamamoto, R K; Zhao, M; McLachlin, S E; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Sanders, D A; Summers, D J; Zhao, H W; Simard, M; Taras, P; Viaud, F B; Nicholson, H; Baak, M A; Raven, G; Snoek, H L; Jessop, C P; Knoepfel, K J; Losecco, J M; Wang, W F; Benelli, G; Corwin, L A; Honscheid, K; Kagan, H; Kass, R; Morris, J P; Rahimi, A M; Regensburger, J J; Sekula, S J; Wong, Q K; Blount, N L; Brau, J; Frey, R; Igonkina, O; Kolb, J A; Lu, M; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Castelli, G; Gagliardi, N; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Del Amo Sanchez, P; Ben-Haim, E; Briand, H; Calderini, G; Chauveau, J; David, P; Del Buono, L; Hamon, O; Leruste, Ph; Ocariz, J; Perez, A; Prendki, J; Gladney, L; Biasini, M; Covarelli, R; Manoni, E; Angelini, C; Batignani, G; Bettarini, S; Carpinelli, M; Cervelli, A; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Morganti, M; Neri, N; Paoloni, E; Rizzo, G; Walsh, J J; Biesiada, J; Lopes Pegna, D; Lu, C; Olsen, J; Smith, A J S; Telnov, A V; Anulli, F; Baracchini, E; Cavoto, G; Del Re, D; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Jackson, P D; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Renga, F; Voena, C; Ebert, M; Hartmann, T; Schröder, H; Waldi, R; Adye, T; Franek, B; Olaiya, E O; Roethel, W; Wilson, F F; Emery, S; Escalier, M; Esteve, L; Gaidot, A; Ganzhur, S F; Hamel de Monchenault, G; Kozanecki, W; Vasseur, G; Yèche, Ch; Zito, M; Chen, X R; Liu, H; Park, W; Purohit, M V; White, R M; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Benitez, J F; Cenci, R; Coleman, J P; Convery, M R; Dingfelder, J C; Dorfan, J; Dubois-Felsmann, G P; Dunwoodie, W; Field, R C; Gabareen, A M; Gowdy, S J; Graham, M T; Grenier, P; Hast, C; Innes, W R; Kaminski, J; Kelsey, M H; Kim, H; Kim, P; Kocian, M L; Leith, D W G S; Li, S; Lindquist, B; Luitz, S; Luth, V; Lynch, H L; Macfarlane, D B; Marsiske, H; Messner, R; Muller, D R; Neal, H; Nelson, S; O'Grady, C P; Ofte, I; Perazzo, A; Perl, M; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Va'vra, J; Wagner, A P; Weaver, M; West, C A; Wisniewski, W J; Wittgen, M; Wright, D H; Wulsin, H W; Yarritu, A K; Yi, K; Young, C C; Ziegler, V; Burchat, P R; Edwards, A J; Majewski, S A; Miyashita, T S; Petersen, B A; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Pan, B; Saeed, M A; Zain, S B; Spanier, S M; Wogsland, B J; Eckmann, R; Ritchie, J L; Ruland, A M; Schilling, C J; Schwitters, R F; Drummond, B W; Izen, J M; Lou, X C; Bianchi, F; Gamba, D; Pelliccioni, M; Bomben, M; Bosisio, L; Cartaro, C; Della Ricca, G; Lanceri, L; Vitale, L; Azzolini, V; Lopez-March, N; Martinez-Vidal, F; Milanes, D A; Oyanguren, A; Albert, J; Banerjee, Sw; Bhuyan, B; Choi, H H F; Hamano, K; Kowalewski, R; Lewczuk, M J; Nugent, I M; Roney, J M; Sobie, R J; Gershon, T J; Harrison, P F; Ilic, J; Latham, T E; Mohanty, G B; Band, H R; Chen, X; Dasu, S; Flood, K T; Pan, Y; Pierini, M; Prepost, R; Vuosalo, C O; Wu, S L

2008-08-22

We report measurements of branching fractions for the decays B-->Plnu_{l}, where P are the pseudoscalar charmless mesons pi;{-}, pi;{0}, eta and eta;{'}, based on 348 fb;{-1} of data collected with the BABAR detector, using B0 and B+ mesons found in the recoil of a second B meson decaying as B-->D;{(*)}lnu_{l}. Assuming isospin symmetry, we combine pionic branching fractions to obtain B(B;{0}-->pi;{-}l;{+}nu_{l})=(1.54+/-0.17_{(stat)}+/-0.09_{(syst)})x10;{-4}; we find 3.2sigma evidence of the decay B;{+}-->etal;{+}nu_{l} and measure its branching fraction to be (0.64+/-0.20_{(stat)}+/-0.03_{(syst)})x10;{-4}, and determine B(B;{+}-->eta;{'}l;{+}nu_{l})<0.47x10;{-4} to 90% confidence level. Using partial branching fractions for the pionic decays in ranges of the momentum transfer and a variety of form factor calculation, we obtain values of the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element |V_{ub}| in ranging from 3.6x10;{-3} to 4.1x10;{-3}.

Resonances in the predissociation of the A{sup 2}{Pi}{sub {Omega}} state of MgBr

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sadygov, R.G.; Rostas, J.; Taieb, G.

1997-03-01

Electronic structure methods and nonperturbative resonance theory are applied to study the radiative and radiationless decay mechanisms of the MgBr (A{sup 2}{Pi}{sub {Omega}}) vibrational levels. The X{sup 2}{Sigma}{sup +} and 1,2{sup 2}{Pi}{sub {Omega}} adiabatic electronic states are characterized using {ital ab initio} state-averaged multiconfigurational self-consistent field/second order configuration interaction wave functions. Interstate derivative couplings between the {sup 2}{Pi} states have been calculated and used to construct a rigorous diabatic basis. The nonrelativistic potential energy curves are modified in the first order of degenerate perturbation theory to take account of the spin{endash}orbit interactions treated within Breit{endash}Pauli approximation. All vibrational levels inmore » the A{sup 2}{Pi}{sub {Omega}} manifold are resonances predissociated by the repulsive 2{sup 2}{Pi} state. A recently developed computational approach [S. Han and D. R. Yarkony, Mol. Phys. {bold 88}, 53 (1996)] based on a Feshbach formalism is employed to determine energies, linewidths, and radiative and radiationless decay rates in a coupled diabatic states basis within a Hund`s case (a) approximation. Large nonadiabatic interactions cause significant energy shifts in the resonances levels. It is shown that a pronounced {Omega}-dependence in the radiationless decay rates results from the large fine structure splitting in the 2{sup 2}{Pi}{sub {Omega}} diabatic state which corresponds to Mg({sup 1}S)Br({sup 2}P). Comparisons with absorption and fluorescence spectra reveal important insights into A{sup 2}{Pi}{sub {Omega}} state decay. The spectroscopic constants of the A{sup 2}{Pi}{sub {Omega}}, {Omega}=3/2 and 1/2 states and the A{sup 2}{Pi}{sub 3/2} state predissociation are well described in a Hund`s case (a) approximation. However it is found that the A{sup 2}{Pi}{sub 1/2} state predissociation is significantly underestimated in this limit. (Abstract Truncated)« less

Coherent and phase-sensitive phenomena of ultrashort laser pulses propagating in three-level {lambda}-type systems studied with the finite-difference time-domain method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loiko, Yurii; Institute of Molecular and Atomic Physics, National Academy of Sciences of Belarus, Nezaleznasty Ave. 70, 220072 Minsk; Serrat, Carles

2006-06-15

Propagation of single- and two-color hyperbolic secant femtosecond laser pulses in a three-level {lambda}-type quantum system is investigated by solving the Maxwell and density matrix equations with the finite-difference time-domain and Runge-Kutta methods. As a first study of our modeling, we simulate pulse self-induced transparency (SIT) in two-level systems and see how this phenomenon can be controlled by manipulating the initial relative phase between the SIT pulse and a second control pulse, provided the ratio between both pulse frequencies obeys the relation {omega}{sub 1}/{omega}{sub 2}=3. We then examine frequency down-conversion processes that are observed with single- and two-color pulses themore » envelope area of which is equal to or a multiple of 2{pi}, for pulse frequencies close to resonance with the transitions of a three-level {lambda} medium. Also, phase-sensitive phenomena are discussed in the case of two-color {omega}-3{omega} pulses propagating resonantly in the three-level system. In particular, possibilities for such coherent control are found for frequency down-conversion processes when the ratio of the frequencies of optical transitions is {omega}{sub 13}/{omega}{sub 12}=3. The conditions for quantum control of four-wave mixing processes are also examined when the pulse frequencies of two-color {omega}-3{omega} pulses are far from any resonance of the three-level system. We demonstrate the possibility to cancel the phase sensitivity of the four-wave coupling in a {lambda}-type system by competition effects between optical transitions.« less

Ab initio calculations on the positive ions of the alkaline-earth oxides, fluorides, and hydroxides

NASA Technical Reports Server (NTRS)

Partridge, H.; Langhoff, S. R.; Bauschlicher, C. W., Jr.

1986-01-01

Theoretical dissociation energies are presented for the alkaline-earth fluoride, hydroxide, and oxide positive ions that are considered to be accurate to 0.1-0.2 eV. The r(e) for the positive ions are found to be consistently shorter than the corresponding neutrals by 0.07 + or -0.02 A. The bonding in the ground states is demonstrated to be of predominantly M + 2 X - character. The a 3 Pi and A 1 Pi are found to lie considerably above the X 1 Sigma + ground states of the alkaline-earth fluoride and hydroxide positive ions. The overall agreement of the theoretical ionization potentials with the available experimental appearance potentials is satisfactory; these values should represent the most accurate and consistent set available.

Measurement of the beam asymmetry Σ for π 0 and η photoproduction on the proton at E γ = 9 GeV

DOE PAGES

Al Ghoul, H.; Anassontzis, E. G.; Austregesilo, A.; ...

2017-04-24

In this paper, we report measurements of the photon beam asymmetrymore » $$\\Sigma$$ for the reactions $$\\vec{\\gamma}p\\to p\\pi^0$$ and $$\\vec{\\gamma}p\\to p\\eta $$ from the GLUEX experiment using a 9 GeV linearly polarized, tagged photon beam incident on a liquid hydrogen target in Jefferson Lab's Hall D. The asymmetries, measured as a function of the proton momentum transfer, possess greater precision than previous $$\\pi^0$$ measurements and are the first $$\\eta$$ measurements in this energy regime. Lastly, the results are compared with theoretical predictions based on $t$-channel, quasi-particle exchange and constrain the axial-vector component of the neutral meson production mechanism in these models.« less

Discovery of a Color-selected Quasar at z = 5.50.

PubMed

Stern; Spinrad; Eisenhardt; Bunker; Dawson; Stanford; Elston

2000-04-20

We present observations of RD J030117+002025, a quasar at z=5.50 discovered from deep, multicolor, ground-based observations covering 74 arcmin2. This is the most distant quasar or active galaxy currently known. The object was targeted as an R-band dropout, with RAB>26.3 (3 sigma limit in a 3&arcsec; diameter region), IAB=23.8, and zAB=23.4. The Keck/Low-Resolution Imaging Spectrometer spectrum shows broad Lyalpha/N v lambda1240 emission and sharp absorption decrements from the highly redshifted hydrogen forests. The fractional continuum depression due to the Lyalpha forest is DA=0.90. RD J030117+002025 is the least luminous high-redshift quasar known (MB approximately -22.7).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matsuta, K.; Fukuda, M.; Tanigaki, M.

The magnetic moment of the proton drip-line nucleus {sup 9}C(I{sup {pi}}=3/2{sup -}, T{sub {1/2}}=126 ms) has been measured for the first time, using the {beta}-NMR detection technique with polarized radioactive beams. The measured value for the magnetic moment is {vert_bar} {mu}({sup 9}C) {vert_bar} = 1.3914{+-}0.0005 {mu}{sub N}. The deduced spin expectation value<{sigma}> of 1.44 is unusually larger than an other ones of even-odd nuclei.

Dissociative and double photoionization cross sections of NO from threshold to 120 A

NASA Technical Reports Server (NTRS)

Samson, J. A. R.; Masuoka, T.; Pareek, P. N.

1985-01-01

The partial photoionization cross sections for producing the NO(+) parent ion and the O(+), N(+), and NO(2+) fragmentations from neutral NO are presented from 120 to 614 A. The results indicate predissociation of the 3 pi (21.72 eV) and B-prime 1Sigma(+) (22.73 eV) electronic states of NO(+). The photoionization threshold for double ionization was found to be 39.4 + or - 0.12 eV.

Magnetic Moment of Proton Drip-Line Nucleus (9)C

NASA Technical Reports Server (NTRS)

Matsuta, K.; Fukuda, M.; Tanigaki, M.; Minamisono, T.; Nojiri, Y.; Mihara, M.; Onishi, T.; Yamaguchi, T.; Harada, A.; Sasaki, M.

1994-01-01

The magnetic moment of the proton drip-line nucleus C-9(I(sup (pi)) = 3/2, T(sub 1/2) = 126 ms) has been measured for the first time, using the beta-NMR detection technique with polarized radioactive beams. The measure value for the magnetic moment is 1mu(C-9)! = 1.3914 +/- 0.0005 (mu)N. The deduced spin expectation value of 1.44 is unusually larger than any other ones of even-odd nuclei.

Experimental search for radiative decays of the pentaquark baryon {Theta}{sup +}(1540)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barmin, V. V.; Asratyan, A. E.; Borisov, V. S.

2010-07-15

The data on the reactions K{sup +}Xe {sup {yields}}K{sup 0{gamma}}X and K{sup +}Xe {sup {yields}}K{sup +{gamma}}X, obtained with the bubble chamber DIANA, have been analyzed for possible radiative decays of the {Theta}{sup +}(1540) baryon: {Theta}{sup +} {sup {yields}}K{sup 0}p{gamma} and {Theta}{sup +} {sup {yields}}K{sup +}n{gamma}. No signals have been observed, and we derive the upper limits {Gamma}({Theta}{sup +} {sup {yields}}K{sup 0}p{gamma})/{Gamma}({Theta}{sup +} {sup {yields}}K{sup 0}p) < 0.032 and {Gamma}({Theta}{sup +} {sup {yields}}K{sup +}n{gamma})/{Gamma}({Theta}{sup +} {sup {yields}}K{sup +}n{gamma}) < 0.041 which, using our previous measurement of {Gamma}({Theta}{sup +} {sup {yields}}KN) = 0.39 {+-} 0.10 MeV, translate to {Gamma}({Theta}{sup +} {sup {yields}}K{supmore » 0}p{gamma}) < 8 keV and {Gamma}({Theta}{sup +} {sup {yields}}K{sup +}n{gamma}) < 11 keV at 90% confidence level. We have also measured the cross sections of K{sup +}-induced reactions involving emission of a neutral pion: {sigma}(K{sup +}n {sup {yields}}K{sup 0}p{pi}{sup 0}) = 68 {+-} 18 {mu}b and {sigma}(K{sup +}N {sup {yields}}K{sup +}N{pi}{sup 0}) = 30 {+-} 8 {mu}b for incident K{sup +} momentum of 640 MeV.« less

K(892)* resonance production in Au+Au and p+p collisions at {radical}s{sub NN} = 200 GeV at RHIC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adams, J.; Aggarwal, M.M.; Ahammed, Z.

2004-12-09

The short-lived K(892)* resonance provides an efficient tool to probe properties of the hot and dense medium produced in relativistic heavy-ion collisions. We report measurements of K* in {radical}s{sub NN} = 200 GeV Au+Au and p+p collisions reconstructed via its hadronic decay channels K(892)*{sup 0} {yields} K{pi} and K(892)*{sup +-} {yields} K{sub S}{sup 0}{pi}{sup +-} using the STAR detector at RHIC. The K*{sup 0} mass has been studied as function of p{sub T} in minimum bias p + p and central Au+Au collisions. The K* p{sub T} spectra for minimum bias p + p interactions and for Au+Au collisions inmore » different centralities are presented. The K*/K ratios for all centralities in Au+Au collisions are found to be significantly lower than the ratio in minimum bias p + p collisions, indicating the importance of hadronic interactions between chemical and kinetic freeze-outs. The nuclear modification factor of K* at intermediate p{sub T} is similar to that of K{sub S}{sup 0}, but different from {Lambda}. This establishes a baryon-meson effect over a mass effect in the particle production at intermediate p{sub T} (2 < p{sub T} {le} 4 GeV/c). A significant non-zero K*{sup 0} elliptic flow (v{sub 2}) is observed in Au+Au collisions and compared to the K{sub S}{sup 0} and {Lambda} v{sub 2}.« less

Nascent Phosphorus Oxide

NASA Astrophysics Data System (ADS)

Sumida, David Shuji

PO(X('2)(PI)) is produced via the collision-free infrared multiple photon dissociation (IRMPD) of volatile organophosphorus molecules, and is detected by 2-frequency 2-photon ionization, using the B('2)(SIGMA)('+) state to provide a spectral signature from which X('2)(PI) populations are obtained. Sequential dissociations occur during the IR laser photolysis, in which nascent fragments continue to undergo IRMPD, and PO(X('2)(PI)) accrues from a series of bond fission reactions. Nascent vibrational, rotational, and translational excitations are in sensible accord with this mechanism, except for a few rotational states near J = 19.5. Unlike the nuclear degrees of freedom, the PO(X('2)(PI)) spin-orbit states are populated quite selectively. The ('2)(PI)(,3/2) state, lying only 224 cm('-1) above the ('2)(PI)(,1/2) ground state, contains only (TURN)11% of the population, compared to 34% for a 300K sample. This result is unambiguous; it persists with all precursors, laser fluences, etc., and is verified by comparisons to spectra obtained using a microwave discharge, a flame, and when thermalizing nascent excitations with an inert diluent. This result underscores the sanctity of the separate potential surfaces which correlate to the product spin -orbit states, and the small amount of ('2)(PI)(,3/2) population can be accounted for by non-adiabatic coupling during dissociation, and/or 'freezing' the amount of S(,1) character in an excited precursor in which S(,0) and S(,1) are coupled non-radiatively. We note that such electronic specificity should be dealt with in the analogous recombination reactions. (Copies available exclusively from Micrographics Department, Doheny Library, USC, Los Angeles, CA 90089.).

Electron transport through rectifying self-assembled monolayer diodes on silicon: Fermi-level pinning at the molecule-metal interface.

PubMed

Lenfant, S; Guerin, D; Tran Van, F; Chevrot, C; Palacin, S; Bourgoin, J P; Bouloussa, O; Rondelez, F; Vuillaume, D

2006-07-20

We report the synthesis and characterization of molecular rectifying diodes on silicon using sequential grafting of self-assembled monolayers of alkyl chains bearing a pi group at their outer end (Si/sigma-pi/metal junctions). We investigate the structure-performance relationships of these molecular devices, and we examine the extent to which the nature of the pi end group (change in the energy position of their molecular orbitals) drives the properties of these molecular diodes. Self-assembled monolayers of alkyl chains (different chain lengths from 6 to 15 methylene groups) functionalized by phenyl, anthracene, pyrene, ethylene dioxythiophene, ethylene dioxyphenyl, thiophene, terthiophene, and quaterthiophene were synthesized and characterized by contact angle measurements, ellipsometry, Fourier transform infrared spectroscopy, and atomic force microscopy. We demonstrate that reasonably well-packed monolayers are obtained in all cases. Their electrical properties were assessed by dc current-voltage characteristics and high-frequency (1-MHz) capacitance measurements. For all of the pi groups investigated here, we observed rectification behavior. These results extend our preliminary work using phenyl and thiophene groups (Lenfant et al., Nano Lett. 2003, 3, 741). The experimental current-voltage curves were analyzed with a simple analytical model, from which we extracted the energy position of the molecular orbital of the pi group in resonance with the Fermi energy of the electrodes. We report experimental studies of the band lineup in these silicon/alkyl pi-conjugated molecule/metal junctions. We conclude that Fermi-level pinning at the pi group/metal interface is mainly responsible for the observed absence of a dependence of the rectification effect on the nature of the pi groups, even though the groups examined were selected to have significant variations in their electronic molecular orbitals.

Matrix elements of the electromagnetic operator between kaon and pion states

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baum, I.; Lubicz, V.; INFN, Sezione di Roma Tre, Via della Vasca Navale 84, I-00146 Roma

2011-10-01

We compute the matrix elements of the electromagnetic operator sF{sub {mu}{nu}}{sigma}{sup {mu}{nu}}d between kaon and pion states, using lattice QCD with maximally twisted-mass fermions and two flavors of dynamical quarks (N{sub f}=2). The operator is renormalized nonperturbatively in the RI'/MOM scheme and our simulations cover pion masses as light as 270 MeV and three values of the lattice spacing from {approx_equal}0.07 up to {approx_equal}0.1 fm. At the physical point our result for the corresponding tensor form factor at zero-momentum transfer is f{sub T}{sup K{pi}}(0)=0.417(14{sub stat})(5{sub syst}), where the systematic error does not include the effect of quenching the strange andmore » charm quarks. Our result differs significantly from the old quenched result f{sub T}{sup K{pi}}(0)=0.78(6) obtained by the SPQ{sub cd}R Collaboration with pion masses above 500 MeV. We investigate the source of this difference and conclude that it is mainly related to the chiral extrapolation. We also study the tensor charge of the pion and obtain the value f{sub T}{sup {pi}{pi}}(0)=0.195(8{sub stat})(6{sub syst}) in good agreement with, but more accurate than the result f{sub T}{sup {pi}{pi}}(0)=0.216(34) obtained by the QCDSF Collaboration using higher pion masses.« less

A Dependence of Charmed Meson Production (in Portuguese)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alves, Gilvan Augusto

One report is presented of a recent direct measurement of the nucleon number (A) dependence of the production cross sections for the charmed mesonsmore » $D^0$ and $D^+$ using $$\\pi^+_{-}$$ and $$K^+_{-}$$ beams incident on a segmented target of Be, Al, Cu and W. The data derive from the experiment E769 - Hadroproductlon of Charm at Fermilab. The experimental apparatus is described together with the following analysis. Starting from a sample of -1500 D mesons in the range of $$O< x_{f} <1$$, the data are found to be well described by the parameterization $$\\sigma_{A}$$ = $$\\sigma_{O}$$ , with $$\\alpha = 0.99 \\pm 0.03$$. The $$x_f$$ dependence of $$\\alpha$$ is examined and the results obtained are compared with those of other .experiments and wl th -theoretical expectations based on perturbatlve QCD and on an EMC like model of nuclear shadowing« less

MCSCF wave functions for excited states of polar molecules - Application to BeO. [Multi-Configuration Self-Consistent Field

NASA Technical Reports Server (NTRS)

Bauschlicher, C. W., Jr.; Yarkony, D. R.

1980-01-01

A previously reported multi-configuration self-consistent field (MCSCF) algorithm based on the generalized Brillouin theorem is extended in order to treat the excited states of polar molecules. In particular, the algorithm takes into account the proper treatment of nonorthogonality in the space of single excitations and invokes, when necessary, a constrained optimization procedure to prevent the variational collapse of excited states. In addition, a configuration selection scheme (suitable for use in conjunction with extended configuration interaction methods) is proposed for the MCSCF procedure. The algorithm is used to study the low-lying singlet states of BeO, a system which has not previously been studied using an MCSCF procedure. MCSCF wave functions are obtained for three 1 Sigma + and two 1 Pi states. The 1 Sigma + results are juxtaposed with comparable results for MgO in order to assess the generality of the description presented here.

Microwave background distortions from domain walls

NASA Technical Reports Server (NTRS)

Goetz, Guenter; Noetzold, Dirk

1990-01-01

Domain walls arising in a cosmic phase transition after decoupling were recently proposed as seeds for the formation of large scale structure. The distortion induced in the microwave background radiation is calculated in dependence of the wall thickness, surface density, scalar field potential, cosmic redshift and the velocity of the wall. It was found that the maximal redshift distortion for both spherical and planar walls is of the order pi G sigma H(sup -1)(sub 0), where sigma is the surface energy density and H(sup -1)(sub 0) the Hubble parameter. It was also found that, for a wall thickness smaller than the horizon, walls can be treated as infinitely thin, i.e., the redshift distortion is independent of the wall thickness and the specific form of the scalar potential. For planar walls moving with a Lorentz-factor gamma the redshift distortion is enhanced by gamma cubed.

FIRST RESULTS FROM Z -FOURGE : DISCOVERY OF A CANDIDATE CLUSTER AT z = 2.2 IN COSMOS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spitler, Lee R.; Glazebrook, Karl; Poole, Gregory B.

2012-04-01

We report the first results from the Z -FOURGE survey: the discovery of a candidate galaxy cluster at z = 2.2 consisting of two compact overdensities with red galaxies detected at {approx}> 20{sigma} above the mean surface density. The discovery was made possible by a new deep (K{sub s} {approx}< 24.8 AB 5{sigma}) Magellan/FOURSTAR near-IR imaging survey with five custom medium-bandwidth filters. The filters pinpoint the location of the Balmer/4000 A break in evolved stellar populations at 1.5 < z < 3.5, yielding significantly more accurate photometric redshifts than possible with broadband imaging alone. The overdensities are within 1' ofmore » each other in the COSMOS field and appear to be embedded in a larger structure that contains at least one additional overdensity ({approx}10{sigma}). Considering the global properties of the overdensities, the z = 2.2 system appears to be the most distant example of a galaxy cluster with a population of red galaxies. A comparison to a large {Lambda}CDM simulation suggests that the system may consist of merging subclusters, with properties in between those of z > 2 protoclusters with more diffuse distributions of blue galaxies and the lower-redshift galaxy clusters with prominent red sequences. The structure is completely absent in public optical catalogs in COSMOS and only weakly visible in a shallower near-IR survey. The discovery showcases the potential of deep near-IR surveys with medium-band filters to advance the understanding of environment and galaxy evolution at z > 1.5.« less

Particle Acceleration in Dissipative Pulsar Magnetospheres

NASA Technical Reports Server (NTRS)

Kazanas, Z.; Kalapotharakos, C.; Harding, A.; Contopoulos, I.

2012-01-01

Pulsar magnetospheres represent unipolar inductor-type electrical circuits at which an EM potential across the polar cap (due to the rotation of their magnetic field) drives currents that run in and out of the polar cap and close at infinity. An estimate ofthe magnitude of this current can be obtained by dividing the potential induced across the polar cap V approx = B(sub O) R(sub O)(Omega R(sub O)/c)(exp 2) by the impedance of free space Z approx eq 4 pi/c; the resulting polar cap current density is close to $n {GJ} c$ where $n_{GJ}$ is the Goldreich-Julian (GJ) charge density. This argument suggests that even at current densities close to the GJ one, pulsar magnetospheres have a significant component of electric field $E_{parallel}$, parallel to the magnetic field, a condition necessary for particle acceleration and the production of radiation. We present the magnetic and electric field structures as well as the currents, charge densities, spin down rates and potential drops along the magnetic field lines of pulsar magnetospheres which do not obey the ideal MHD condition $E cdot B = 0$. By relating the current density along the poloidal field lines to the parallel electric field via a kind of Ohm's law $J = sigma E_{parallel}$ we study the structure of these magnetospheres as a function of the conductivity $sigma$. We find that for $sigma gg OmegaS the solution tends to the (ideal) Force-Free one and to the Vacuum one for $sigma 11 OmegaS. Finally, we present dissipative magnetospheric solutions with spatially variable $sigma$ that supports various microphysical properties and are compatible with the observations.

Far-infrared vibration--rotation-tunneling spectroscopy of Ar--NH sub 3 : Intermolecular vibrations and effective angular potential energy surface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmuttenmaer, C.A.; Cohen, R.C.; Loeser, J.G.

Two new intermolecular vibration--rotation-tunneling (VRT) bands of Ar--NH{sub 3} have been measured using tunable far infrared laser spectroscopy. We have unambiguously assigned these and a previously measured FIR band (Gwo {ital et} {ital al}., Mol. Phys. {bold 71}, 453 (1990)) as {Pi}(1{sub 0}, {ital n}=0){l arrow}{Sigma}(0{sub 0}, {ital n}=0), {Sigma}(1{sub 0}, {ital n}=0){l arrow}{Sigma}(0{sub 0}, {ital n}=0), and {Sigma}(0{sub 0}, {ital n}=1){l arrow}{Sigma}(0{sub 0}, {ital n}=0). The three upper states of these are found to be strongly mixed by anisotropy and Coriolis effects. A simultaneous least squares fit of all transitions has yielded vibrational frequencies, rotational and centrifugal distortion constants,more » and a Coriolis parameter as well as quadrupole hyperfine coupling constants for the upper states. An effective angular potential energy surface for Ar--NH{sub 3} in its lowest stretching state has been determined from these data, after explicitly accounting for the effects of bend stretch interactions. Features of the surface include a global minimum at the near T-shaped configuration ({theta}=90{degree}), a 30 cm{sup {minus}1} to 60 cm{sup {minus}1} barrier to rotation at {theta}=180{degree} (or 0{degree}), and a very low barrier or possibly a secondary minimum at {theta}=0{degree} (or 180{degree}). Both attractive and repulsive interactions are shown to contribute significantly to the anisotropic forces in the complex. Comparison with {ital ab} {ital initio} calculations are presented.« less

Multistrange baryon production in Au-Au collisions at sqrt[s(NN)]=130 GeV.

PubMed

Adams, J; Adler, C; Aggarwal, M M; Ahammed, Z; Amonett, J; Anderson, B D; Arkhipkin, D; Averichev, G S; Bai, Y; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bezverkhny, B I; Bharadwaj, S; Bhatia, V S; Bichsel, H; Bland, L C; Blyth, C O; Bonner, B E; Botje, M; Boucham, A; Brandin, A; Bravar, A; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Carroll, J; Castillo, J; Cebra, D; Chaloupka, P; Chattopdhyay, S; Chen, H F; Chen, Y; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Coffin, J P; Cormier, T M; Cramer, J G; Crawford, H J; Das, D; Das, S; de Moura, M M; Derevschikov, A A; Didenko, L; Dietel, T; Dong, W J; Dong, X; Draper, J E; Du, F; Dubey, A K; Dunin, V B; Dunlop, J C; Dutta Mazumdar, M R; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Faivre, J; Fatemi, R; Fedorisin, J; Filimonov, K; Filip, P; Finch, E; Fine, V; Fisyak, Y; Flierl, D; Foley, K J; Fomenko, K; Fu, J; Gagliardi, C A; Gans, J; Ganti, M S; Gaudichet, L; Geurts, F; Ghazikhanian, V; Ghosh, P; Gonzalez, J E; Grachov, O; Grebenyuk, O; Gronstal, S; Grosnick, D; Guertin, S M; Gupta, A; Gutierrez, T D; Hallman, T J; Hamed, A; Hardtke, D; Harris, J W; Heinz, M; Henry, T W; Hepplemann, S; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Huang, H Z; Huang, S L; Hughes, E; Humanic, T J; Igo, G; Ishihara, A; Jacobs, P; Jacobs, W W; Janik, M; Jiang, H; Jones, P G; Judd, E G; Kabana, S; Kang, K; Kaplan, M; Keane, D; Khodyrev, V Yu; Kiryluk, J; Kisiel, A; Kislov, E M; Klay, J; Klein, S R; Klyachko, A; Koetke, D D; Kollegger, T; Kopytine, M; Kotchenda, L; Kramer, M; Kravtsov, P; Kravtsov, V I; Krueger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kunz, C L; Kutuev, R Kh; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Lansdell, C L; Laue, F; Lauret, J; Lebedev, A; Lednicky, R; Lehocka, S; LeVine, M J; Li, C; Li, Q; Li, Y; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Q J; Liu, Z; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Ludlam, T; Lynn, D; Ma, G L; Ma, J G; Ma, Y G; Magestro, D; Mahajan, S; Mahapatra, D P; Majka, R; Mangotra, L K; Manweiler, R; Margetis, S; Markert, C; Martin, L; Marx, J N; Matis, H S; Matulenko, Yu A; McClain, C J; McShane, T S; Meissner, F; Melnick, Yu; Meschanin, A; Miller, M L; Milosevich, Z; Minaev, N G; Mironov, C; Mischke, A; Mishra, D; Mitchell, J; Mohanty, B; Molnar, L; Moore, C F; Mora-Corral, M J; Morozov, D A; Morozov, V; Munhoz, M G; Nandi, B K; Nayak, T K; Nelson, J M; Netrakanti, P K; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Pal, S K; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Peitzmann, T; Perevoztchikov, V; Perkins, C; Peryt, W; Petrov, V A; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M; Potrebenikova, E; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Rai, G; Rakness, G; Raniwala, R; Raniwala, S; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Renault, G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Rose, A; Ruan, L; Sakrejda, I; Salur, S; Sandweiss, J; Savin, I; Sazhin, P S; Schambach, J; Scharenberg, R P; Schmitz, N; Schroeder, L S; Schweda, K; Seger, J; Seyboth, P; Shahaliev, E; Shao, M; Shao, W; Sharma, M; Shen, W Q; Shestermanov, K E; Shimanskiy, S S; Simon, F; Singaraju, R N; Skoro, G; Smirnov, N; Snellings, R; Sood, G; Sorensen, P; Sowinski, J; Speltz, J; Spinka, H M; Srivastava, B; St Claire, L; Stadnik, A; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Struck, C; Suaide, A A P; Sugarbaker, E; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; Szanto de Toledo, A; Szarwas, P; Tai, A; Takahashi, J; Tang, A H; Thein, D; Thomas, J H; Timoshenko, S; Tokarev, M; Trainor, T A; Trentalange, S; Tribble, R E; Tsai, O; Ullrich, T; Underwood, D G; Urkinbaev, A; Van Buren, G; Vander Molen, A M; Varma, R; Vasilevski, I M; Vasiliev, A N; Vernet, R; Vigdor, S E; Viyogi, V P; Vokal, S; Vznuzdaev, M; Waggoner, B; Wang, F; Wang, G; Wang, G; Wang, X L; Wang, Y; Wang, Y; Wang, Z M; Ward, H; Webb, J C; Wells, R; Westfall, G D; Wetzler, A; Whitten, C; Wieman, H; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Z; Xu, Z; Yamamoto, E; Yepes, P; Yurevich, V I; Zanevsky, Y V; Zhang, H; Zhang, Z P; Zolnierczuk, P A; Zoulkarneev, R; Zoulkarneeva, Y; Zubarev, A N

2004-05-07

The transverse mass spectra and midrapidity yields for Xis and Omegas are presented. For the 10% most central collisions, the (-)Xi(+)/h(-) ratio increases from the Super Proton Synchrotron to the Relativistic Heavy Ion Collider energies while the Xi(-)/h(-) stays approximately constant. A hydrodynamically inspired model fit to the Xi spectra, which assumes a thermalized source, seems to indicate that these multistrange particles experience a significant transverse flow effect, but are emitted when the system is hotter and the flow is smaller than values obtained from a combined fit to pi, K, p, and Lambdas.

Enhanced effect of temporal variation of the fine structure constant and the strong interaction in 229Th.

PubMed

Flambaum, V V

2006-09-01

The relative effects of the variation of the fine structure constant alpha = e2/variant Planck's over 2pi c and the dimensionless strong interaction parameter m(q)/LambdaQCD are enhanced by 5-6 orders of magnitude in a very narrow ultraviolet transition between the ground and the first excited states in the 229Th nucleus. It may be possible to investigate this transition with laser spectroscopy. Such an experiment would have the potential of improving the sensitivity to temporal variation of the fundamental constants by many orders of magnitude.

The Electronic Spectra of CaN2(+) and Ca(N2)2(+)

NASA Technical Reports Server (NTRS)

Rodriguez-Santiago, Luis; Bauschlicher, Charles W., Jr.; Arnold, James (Technical Monitor)

1998-01-01

The ground and low-lying electronic states of CaN2(+) are studied at several levels of theory. The results for the X(sup 2)Sigma(+) state and the excited (2)(sup 2)Pi state, arising from occupying the Ca 4p orbital, are in good agreement with experiment. The analogous states of Ca(N2)2(+) are studied using the same theoretical approaches, and predictions are made as to the changes caused by the addition of the second N2 ligand.

Dissociative and double photoionization cross sections of NO from threshold to 120 A

NASA Technical Reports Server (NTRS)

Samson, J. A. R.; Masuoka, T.; Pareek, P. N.

1985-01-01

The partial photoionization cross sections for producing the NO(+) parent ion and the O(+), N(+), and NO2(+) fragment ions from neutral NO are presented from 120 to 614 A. The results indicate predissociation of the c(sup3) pi (21.72 eV) and B prime (sup 1) sigma (+) (22.73 eV) electronic states of NO(+). The photoionization threshold for double ionization was found to be 39.4 + or 0.12 eV.

Dissociation energy and photochemistry of NO[sub 3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davis, H.F.; Kim, Bongsoo; Johnston, H.S.

1993-03-11

The photodissociation of NO[sub 3] was studied using the method of molecular beam photofragmentation translational spectroscopy. The existence of two photodissociation channels was confirmed under collision-free conditions. At excitation energies below D[sub 0](O-NO[sub 2]) for internally cold NO[sub 3], the authors observe a large quantum yield (0.70 [+-] 0.10 at 588 nm) for a concerted three-center rearrangement resulting in NO([sup 2][Pi]) + O[sub 2]([sup 3][Sigma][sub g][sup [minus

Polarization characteristic of a room-temperature Co:MgF2 laser.

PubMed

Zhang, Zengming M; Cui, Yiben B; Li, Fuli L; Zhang, Guobin B; Pu, Qirong R; Xu, Gaojie J

2002-02-20

A study of the polarization characteristic of a Co:MgF2 laser with a 1320-nm YAG pumping laser at room temperature is reported. The thresholds, output energies, and efficiencies of the laser are given at the various polarization states. The more intensive emission is in the pi-polarization pump laser and sigma-polarization laser operation. Performances of the Co:MgF2 lasers are similar for the polarized and unpolarized laser pumping along the optical axis of the crystal.

Approximating smooth functions using algebraic-trigonometric polynomials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharapudinov, Idris I

2011-01-14

The problem under consideration is that of approximating classes of smooth functions by algebraic-trigonometric polynomials of the form p{sub n}(t)+{tau}{sub m}(t), where p{sub n}(t) is an algebraic polynomial of degree n and {tau}{sub m}(t)=a{sub 0}+{Sigma}{sub k=1}{sup m}a{sub k} cos k{pi}t + b{sub k} sin k{pi}t is a trigonometric polynomial of order m. The precise order of approximation by such polynomials in the classes W{sup r}{sub {infinity}(}M) and an upper bound for similar approximations in the class W{sup r}{sub p}(M) with 4/3

Near resonant bubble acoustic cross-section corrections, including examples from oceanography, volcanology, and biomedical ultrasound.

PubMed

Ainslie, Michael A; Leighton, Timothy G

2009-11-01

The scattering cross-section sigma(s) of a gas bubble of equilibrium radius R(0) in liquid can be written in the form sigma(s)=4piR(0) (2)[(omega(1) (2)omega(2)-1)(2)+delta(2)], where omega is the excitation frequency, omega(1) is the resonance frequency, and delta is a frequency-dependent dimensionless damping coefficient. A persistent discrepancy in the frequency dependence of the contribution to delta from radiation damping, denoted delta(rad), is identified and resolved, as follows. Wildt's [Physics of Sound in the Sea (Washington, DC, 1946), Chap. 28] pioneering derivation predicts a linear dependence of delta(rad) on frequency, a result which Medwin [Ultrasonics 15, 7-13 (1977)] reproduces using a different method. Weston [Underwater Acoustics, NATO Advanced Study Institute Series Vol. II, 55-88 (1967)], using ostensibly the same method as Wildt, predicts the opposite relationship, i.e., that delta(rad) is inversely proportional to frequency. Weston's version of the derivation of the scattering cross-section is shown here to be the correct one, thus resolving the discrepancy. Further, a correction to Weston's model is derived that amounts to a shift in the resonance frequency. A new, corrected, expression for the extinction cross-section is also derived. The magnitudes of the corrections are illustrated using examples from oceanography, volcanology, planetary acoustics, neutron spallation, and biomedical ultrasound. The corrections become significant when the bulk modulus of the gas is not negligible relative to that of the surrounding liquid.

ON THE Q-VALUES OF THE /cap lamba/$sup 0$ AND THE /theta/$sup 0$ AND ON THE ANOMALOUS V$sup 0$-DECAYS

DOE Office of Scientific and Technical Information (OSTI.GOV)

D'Andlau, C.; Armenteros, R.; Astier, A.

1957-11-01

A study of 161 V/sup 0/-decays observed in the momentum chamber of the Ecole Polytechnique at the Pic du Midi has been made. These events correspond to a strict choice based on the measurability of the momenta of both secondaries (better than 10%). The main results are: No direct evidence for anomalous neutral hyperon decays. Upper limits (6 to 8%) can be placed on the existence of various hypothetical modes. The Q-values for the LAMBDA /sup 0/-decay: Q LAMBDA /sup 0/ = (37.9 plus or minus 0.4) Mev. The direct identification of the pi natare of both secondaries of themore » THETA /sup 0/-decay-mode. The Qvalue for THETA /sup0/-decay: Q/sub TT/sup 0/ = (217 plus or minus 4) Mev. A direct proof of the non identity of the particles responsible for the THETA /sup 0/ decay and the anomalous nu /sup 0/-decays based on the significant difference between the number of slow and fast events of each category. (auth)« less

Measurement of the beam asymmetry Σ and the target asymmetry T in the photoproduction of ω mesons off the proton using CLAS at Jefferson Laboratory

DOE PAGES

Roy, P.; Akbar, Z.; Park, S.; ...

2018-05-04

Here, the photoproduction ofmore » $$\\omega$$ mesons off the proton has been studied in the reaction $$\\gamma p\\to p\\,\\omega$$ using the CEBAF Large Acceptance Spectrometer (CLAS) and the frozen-spin target (FROST) in Hall B at the Thomas Jefferson National Accelerator Facility. For the first time, the target asymmetry, $T$, has been measured in photoproduction from the decay $$\\omega\\to\\pi^+\\pi^-\\pi^0$$, using a transversely-polarized target with energies ranging from just above the reaction threshold up to 2.8 GeV. Significant non-zero values are observed for these asymmetries, reaching about 30-40% in the third-resonance region. New measurements for the photon-beam asymmetry, $$\\Sigma$$, are also presented, which agree well with previous CLAS results and extend the world database up to 2.1 GeV. These data and additional $$\\omega$$-photoproduction observables from CLAS were included in a partial-wave analysis within the Bonn-Gatchina framework. Significant contributions from $s$-channel resonance production were found in addition to $t$-channel exchange processes.« less

Measurement of the beam asymmetry Σ and the target asymmetry T in the photoproduction of ω mesons off the proton using CLAS at Jefferson Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roy, P.; Akbar, Z.; Park, S.

Here, the photoproduction ofmore » $$\\omega$$ mesons off the proton has been studied in the reaction $$\\gamma p\\to p\\,\\omega$$ using the CEBAF Large Acceptance Spectrometer (CLAS) and the frozen-spin target (FROST) in Hall B at the Thomas Jefferson National Accelerator Facility. For the first time, the target asymmetry, $T$, has been measured in photoproduction from the decay $$\\omega\\to\\pi^+\\pi^-\\pi^0$$, using a transversely-polarized target with energies ranging from just above the reaction threshold up to 2.8 GeV. Significant non-zero values are observed for these asymmetries, reaching about 30-40% in the third-resonance region. New measurements for the photon-beam asymmetry, $$\\Sigma$$, are also presented, which agree well with previous CLAS results and extend the world database up to 2.1 GeV. These data and additional $$\\omega$$-photoproduction observables from CLAS were included in a partial-wave analysis within the Bonn-Gatchina framework. Significant contributions from $s$-channel resonance production were found in addition to $t$-channel exchange processes.« less

Assessing the superelectrophilic dimension through sigma-complexation, SNAr and Diels-Alder reactivity.

PubMed

Buncel, Erwin; Terrier, François

2010-05-21

In the domain of organic chemistry, S(N)Ar substitutions represent a class of reactions of overwhelming importance, both in synthesis and in the understanding of structure-reactivity relationships, especially the role of sigma-complex intermediates. The primary factor necessary for achievement of S(N)Ar reactions is the presence of a good leaving group, which allows facile rearomatization of the ring undergoing nucleophilic attack. Consistent is the finding that the superelectrophilic chloronitrobenzofuroxans--or furazans--exhibit a very high S(N)Ar reactivity, allowing a number of C-C, C-N, C-O couplings to be achieved that are not accessible with the classical series of nitro-substituted aromatics. Of particular interest is the synthesis of a number of indoles, indolizines, pyrroles and extended pi-excessive aromatic structures like azulene substituted by superelectrophilic moieties. The remarkable driving force for the facile completion of these reactions is the 10 orders of magnitude greater reactivity of 10pi-electron-deficient heteroaromatics such as 4,6-dinitrobenzofuroxan (DNBF) than of the most reactive trinitrobenzene derivatives in sigma-adduct complexation. Among the factors that have been recognized as governing superelectrophilicity, there is the poor aromaticity of 6-membered 10pi-electron structures investigated, with a common origin for sigma-complexation and pericyclic processes. A remarkable capacity of these structures is actually to contribute to a variety of Diels-Alder reactions. As an example, the DNBF molecule formally behaves as a nitroalkene, being susceptible to act as a dienophile as well as a heterodiene. Another remarkable Diels-Alder pathway is the capacity of the 6-membered carbocyclic ring of DNBF to act as a carbodiene. Also noteworthy is the successful Diels-Alder trapping of the dinitroso intermediate associated with 1-oxide/3-oxide tautomerism of the furoxan moiety of 4-aza-6-nitrobenzofuroxan. A point of fundamental importance in taking advantage of the reactivity of superelectrophilic structures at hand has been a successful calibration of their reactivity within the electrophilicity E scale developed by Mayr to describe nucleophile-electrophile combinations in general. It has thus been established that the E parameters measuring the electrophilicity of neutral heteroaromatics lie in the same region of the E scale as a number of highly reactive cationic reagents. Besides a reactivity rather similar to that of the 4-nitrobenzenediazonium cation (vide supra), the most electrophilic neutral molecules (DNBF, DNTP, DNBZ) are as electrophilic as tropylium cations or a number of metal-coordinated carbenium ions. Furthermore, there is a remarkable link between the pK(a)(H(2)O) and E scales, as evidenced by the existence of a unique linear relationship spanning more than 20 orders of reactivity. This relationship appears as being a nice probe to predict the feasibility of S(N)Ar substitutions and related sigma-complexation processes. Also revealing in terms of feasibility of the reactions is the existence of a close correlation between the electrochemical oxidation potential E degrees of sigma-adducts and their positioning on the pK(a)(H(2)O) scale. Our data can also be used to evaluate the potential of a theoretical model recently derived from DFT calculations, namely the global electrophilicity index omega, for the description of nucleophile-electrophile combinations. While showing several significant deviations, a reasonably linear omega vs. pK(a)(H(2)O) relationship is obtained when restricting the correlation to structurally similar electrophilic moieties. On this basis, valuable information could be derived regarding the polar character of some DA reactions. Overall, the global electrophilicity (omega) approach may be a promising avenue in future work of electrophile-nucleophile combinations.

Dynamics of Single Chains of Suspended Ferrofluid Particles

NASA Technical Reports Server (NTRS)

Cutillas, S.; Liu, J.

1999-01-01

We present an experimental study of the dynamics of isolated chains made of super-paramagnetic particles under the influence of a magnetic field. The motivation of this work is to understand if the chain fluctuations exist and, if it does, how does the fluctuation affect chain aggregation. We find that single chains strongly fluctuate and that the characteristic frequency of their fluctuations is inversely proportional to the magnetic field strength. The higher the field the lower the characteristic frequency of the chain fluctuations. In the high magnetic field limit, chains behave like rigid rods without any internal motions. In this work, we used ferrofluid particles suspended in water. These particles do not have any intrinsic magnetization. Once a magnetic field is applied, a dipole moment is induced in each particle, proportional to the magnetic field. A dipolar magnetic interaction then occurs between particles. If dipole-dipole magnetic energy is higher than the thermal energy, the result is a structure change inside the dipolar fluid. The ratio of these two energies is expressed by a coupling constant lambda as: lambda = (pi(a(exp 3))(chi(exp 2))(mu(sub 0))(H(sub 0))(exp 2))/18kT Where a is the particle radius, mu(sub 0) is the vacuum magnetic permeability, H(sub 0) the applied magnetic field, k the Boltzmann constant and T the absolute temperature. If lambda > 1, magnetic particles form chains along the field direction. The lateral coalescence of several chains may form bigger aggregates especially if the particle volume fraction is high. While many studies and applications deal with the rheological properties and the structural changes of these dipolar fluids, this work focuses on the understanding of the chain dynamics. In order to probe the chain dynamics, we used dynamic light scattering (DLS) in self-beating mode as our experimental technique. The experimental geometry is such that the scattering plane is perpendicular to the magnetic field. Therefore, only motions in this plane are probed. A very dilute sample of a ferrofluid emulsion with a particle volume fraction of 10(exp -5) is used in this experiment. We chose such a low volume fraction to avoid multiple light scattering as well as lateral chain-chain aggregation. DLS measures the dynamic structure factor S(q,t) of the sample (q is the scattering wave vector, t is the time). In the absence of the magnetic field, identical particles of ferrofluid droplets are randomly distributed and S(q,t) reduces to exp(-q(exp 2)2D(sub 0)t). D(sub 0)=(kT/(6(pi)(eta)(a)) is the diffusion coefficient of Brownian particles (where Xi = (6(pi)(eta)(a)) is the Stokes frictional coefficient of a spherical particle in a fluid of viscosity eta). If interactions or polydispersity can not be ignored, an effective diffusion coefficient is introduced. Formally, D(sub eff) is defined as: D(sub eff) = - q(exp -2) partial derivative of (ln(S(q,t)) with respect to time, as t goes to 0. D(sub eff) reduces to D(sub 0) if no interactions and only a few particles size are present. Therefore, we can use DLS to measure particle size. The particle radius was found to be a=0.23 mu m with 7% of polydispersity. In this case, if we vary the scattering angle theta (and so q) we do not have any change in the measured diffusion coefficient: it is q-independent. When a magnetic field is applied, particles aggregate into chains if lambda > 1. We first studied the kinetics of the chain formation when lambda = 406. At a fixed scattering angle, we measured diffusion coefficient D(sub eff) as a function of time. Experimentally, we find that D(sub eff) decreases monotonously with time. Physically, this means that chains are becoming longer and longer. Since we are only sensitive to motions in the scattering plane and since chains have their main axis perpendicular to this plane, the measured diffusion coefficient is the trans-verse diffusion coefficient. We can relate D(sub eff) to the mean number of particles per chain N(t) at a given time and to the diffusion coefficient of an isolated particle D(sub 0) as D(sub eff)=f(N(t))D(sub 0). Since f(N) is known from other recent work, N can be expressed as a function of the time. We found a square root dependency: N(t) proportional to the square root of t. As expected for very low volume fraction, this behavior is characteristic of a diffusion-limited aggregation as suggested by several authors and by our previous work. In this study, we focus on the dependence of the effective diffusion coefficient on the scattering angle and the magnetic field strength. After the magnetic field is applied (lambda = 406) for a long time, typically 6 hours, kinetics of chain formation becomes very slow. Chain size does not vary much over the next hour period. Thus, we can perform different interesting experiments. First, at a fixed magnetic field, we measure the effective diffusion coefficient as a function of the scattering angle (from 5 to 130 deg). Our results show that the measured diffusion coefficient increases linearly with the scattering angle: D(sub eff) proportional to q. If we do the same experiment for different lambda values, D(sub eff) depends on lambda as D(sub eff) proportional to lambda(exp -1/2). We also find for different lambda values that the same asymptotic D(sub eff) value is obtained when q approaches zero. The angle dependency of D(sub eff) suggests that an additional motion exists besides chain drifting. Chain size is constant during experiment, which was verified by measuring the same diffusion coefficient at the beginning and at the end of the angle switching. If chains are rigid, D(sub eff) is independent of q. Therefore, we found that D(sub eff) not only measures the motion of the entire chain but also its internal fluctuations. These internal motions are the fluctuations of the particles in the chain. To understand the q dependency of D(sub eff), let us look at the probing length used. In our study, the characteristic length scale probed is l=2pi/q which is in the range of 0.9

Production and Decay of {xi}{sub c}{sup 0} at BABAR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aubert, B.; Barate, R.; Boutigny, D.

Using 116.1 fb{sup -1} of data collected by the BABAR detector, we present an analysis of {xi}{sub c}{sup 0} production in B decays and from the cc continuum, with the {xi}{sub c}{sup 0} decaying into {omega}{sup -}K{sup +} and {xi}{sup -}{pi}{sup +} final states. We measure the ratio of branching fractions B({xi}{sub c}{sup 0}{yields}{omega}{sup -}K{sup +})/B({xi}{sub c}{sup 0}{yields}{xi}{sup -}{pi}{sup +}) to be 0.294{+-}0.018{+-}0.016, where the first uncertainty is statistical and the second is systematic. The {xi}{sub c}{sup 0} momentum spectrum is measured on and 40 MeV below the {upsilon}(4S) resonance. From these spectra the branching fraction product B(B{yields}{xi}{sub c}{sup 0}X)xB({xi}{submore » c}{sup 0}{yields}{xi}{sup -}{pi}{sup +}) is measured to be (2.11{+-}0.19{+-}0.25)x10{sup -4}, and the cross-section product {sigma}(e{sup +}e{sup -}{yields}{xi}{sub c}{sup 0}X)xB({xi}{sub c}{sup 0}{yields}{xi}{sup -}{pi}{sup +}) from the continuum is measured to be (388{+-}39{+-}41) fb at a center-of-mass energy of 10.58 GeV.« less

1984-1995 Evolution of Stratospheric Aerosol Size, Surface Area, and Volume Derived by Combining SAGE II and CLAES Extinction Measurements

NASA Technical Reports Server (NTRS)

Russell, Philip B.; Bauman, Jill J.

2000-01-01

This SAGE II Science Team task focuses on the development of a multi-wavelength, multi- sensor Look-Up-Table (LUT) algorithm for retrieving information about stratospheric aerosols from global satellite-based observations of particulate extinction. The LUT algorithm combines the 4-wavelength SAGE II extinction measurements (0.385 <= lambda <= 1.02 microns) with the 7.96 micron and 12.82 micron extinction measurements from the Cryogenic Limb Array Etalon Spectrometer (CLAES) instrument, thus increasing the information content available from either sensor alone. The algorithm uses the SAGE II/CLAES composite spectra in month-latitude-altitude bins to retrieve values and uncertainties of particle effective radius R(sub eff), surface area S, volume V and size distribution width sigma(sub g).

The Pan-STARRS pipeline and data products

NASA Astrophysics Data System (ADS)

Flewelling, Heather

2018-01-01

I will give a brief overview of the pipeline, database, and dataproducts for Pan-STARRS1 data release 1 (DR1) and data release 2 (DR2). DR1 and DR2 provides access to data from the Pan-STARRS1 3pi survey, a survey which covers ¾ of the sky over 4 years (2010-2014), everything with a declination greater than -30, in 5 filters (g,r,i,z,y), with at least 12 epochs per filter per area of sky. DR1, released in December 2016, and available to the public at http://stsci.panstarrs.edu, consists of two parts: the stacked images with a 5 sigma depth of (23.3,23.2,23.1,22.3,21.3) for (g,r,i,z,y), and the catalog database, which consists of 10 billion distinct objects, their mean properties from single exposures, and stack photometry. DR2, to be released early 2108, will contain the individual exposure images, with a 5 sigma depth of (22.0,21.8,21.5,20.9,19.7) for (g,r,i,z,y), and the time domain catalogs, from the 374k individual exposures taken for the 3pi survey. I will primarily focus on the catalog database, describing a subset of the tables and different use cases for them. Specifically, I will describe the major tables and metadata of DR1 - objects, their mean properties, and stack photometry, when different tables should be used, and basics on how to filter the data.

Self-force calculations with matched expansions and quasinormal mode sums

DOE Office of Scientific and Technical Information (OSTI.GOV)

Casals, Marc; Dolan, Sam; Ottewill, Adrian C.

2009-06-15

Accurate modeling of gravitational wave emission by extreme-mass ratio inspirals is essential for their detection by the LISA mission. A leading perturbative approach involves the calculation of the self-force acting upon the smaller orbital body. In this work, we present the first application of the Poisson-Wiseman-Anderson method of 'matched expansions' to compute the self-force acting on a point particle moving in a curved spacetime. The method employs two expansions for the Green function, which are, respectively, valid in the 'quasilocal' and 'distant past' regimes, and which may be matched together within the normal neighborhood. We perform our calculation in amore » static region of the spherically symmetric Nariai spacetime (dS{sub 2}xS{sup 2}), in which scalar-field perturbations are governed by a radial equation with a Poeschl-Teller potential (frequently used as an approximation to the Schwarzschild radial potential) whose solutions are known in closed form. The key new ingredients in our study are (i) very high order quasilocal expansions and (ii) expansion of the distant past Green function in quasinormal modes. In combination, these tools enable a detailed study of the properties of the scalar-field Green function. We demonstrate that the Green function is singular whenever x and x{sup '} are connected by a null geodesic, and apply asymptotic methods to determine the structure of the Green function near the null wave front. We show that the singular part of the Green function undergoes a transition each time the null wave front passes through a caustic point, following a repeating fourfold sequence {delta}({sigma}), 1/{pi}{sigma}, -{delta}({sigma}), -1/{pi}{sigma}, etc., where {sigma} is Synge's world function. The matched-expansion method provides insight into the nonlocal properties of the self-force. We show that the self-force generated by the segment of the worldline lying outside the normal neighborhood is not negligible. We apply the matched-expansion method to compute the scalar self-force acting on a static particle on the Nariai spacetime, and validate against an alternative method, obtaining agreement to six decimal places. We conclude with a discussion of the implications for wave propagation and self-force calculations. On black hole spacetimes, any expansion of the Green function in quasinormal modes must be augmented by a branch-cut integral. Nevertheless, we expect the Green function in Schwarzschild spacetime to inherit certain key features, such as a fourfold singular structure manifesting itself through the asymptotic behavior of quasinormal modes. In this way, the Nariai spacetime provides a fertile testing ground for developing insight into the nonlocal part of the self-force on black hole spacetimes.« less

Multinucleon pion absorption on {sup 4}He into the pppn final state

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lehmann, A.; Backenstoss, G.; Koehler, J.

1997-10-01

Results from a 4{pi} solid angle measurement of the reaction {pi}{sup +4}He{r_arrow}pppn at incident pion energies of T{sub {pi}{sup +}}= 70, 118, 162, 239, and 330 MeV are presented. Integrated cross sections are given for the reactions where three nucleons participate, leading to energetic (ppp) or (ppn) final states, and for states where four nucleons are involved (pppn). The two three-nucleon absorption modes were investigated in particular, and an energy dependent isospin ratio of the cross sections of {sigma}{sub ppn}/ {sigma}{sub ppp}=3.6{plus_minus}1.3, 2.6 {plus_minus}0.5, 1.8{plus_minus}0.3, 1.4{plus_minus} 0.2, and 1.8{plus_minus}0.6 was determined from 70 to 330 MeV. The differential cross sectionsmore » were described by a complete set of eight independent variables and compared to simple cascade and phase space models. From this analysis the contributions from initial state interactions to the multinucleon absorption cross sections were found to be more important at higher pion energies, while those from final state interactions are stronger at lower energies. However, both mechanisms combined were found to account for not more than one-third of the total pppn multinucleon yield. The remaining strength is reasonably well reproduced by phase space models, but shows a dependence on the incident pion{close_quote}s orbital angular momentum. The isospin structure of the (ppp) and (ppn) final states is not understood, nor are some structures in their distributions. The four-nucleon yield (pppn) was found to be weak (1{endash}8{percent} of the total absorption cross section) and shows no evidence for a {open_quotes}double- {Delta}{close_quotes} excitation. {copyright} {ital 1997} {ital The American Physical Society}« less

Measurement of the B0 ---> Psi (2S) Lambda0 Branching Fraction on BaBar at the Stanford Linear Accelerator Center (Abstract Only)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olivas, Alexander Raymond, Jr.; /Colorado U.

2005-11-16

The decays of B{sup 0} mesons to hadronic final states remains a rich area of physics on BaBar. Not only do the c{bar c}-K final states (e.g. B{sup 0} {yields} {psi}(2S)K{sup 0}) allow for the measurement of CP Violation, but the branching fractions provide a sensitive test of the theoretical methods used to account for low energy non-perturbative QCD effects. They present the measurement of the branching fraction for the decay B{sup 0} {yields} {psi}(2S)K{sub s}. The data set consists of 88.8 {+-} 1.0 x 10{sup 6} B{bar b} pairs collected on the e{sup +}e{sup -} {yields} {Upsilon}(4S) resonance onmore » BaBar/PEP-II at the Stanford Linear Accelerator Center (SLAC). This analysis features a modification of present cuts, with respect to those published so far on BaBar, on the K{sub S} {yields} {pi}{sup +}{pi}{sup -} and {psi}(2S) {yields} J/{psi}{pi}{sup +}{pi}{sup -} which aim at reducing the background while keeping the signal intact. Various data selection criteria are studied for the lepton modes (e{sup +}e{sup -} and {mu}{sup +}{mu}{sup -}) of the J/{psi} and {psi}(2S) to improve signal purity as well as study the stability of the resultant branching fractions.« less

Fourier transform spectroscopy of the Swan (d(sup 3)pi(sub g) - a(sup 3)pi(sub u)) system of the jet-cooled C2 molecule

NASA Technical Reports Server (NTRS)

Prasad, C. V. V.; Bernath, P. F.

1994-01-01

The Swan (d(sup 3)pi(sub g) - a(sup 3)pi(sub u)) system of the C2 molecule was produced in a jet-cooled corona excited supersonic expansion of helium using diazoacetonitrile as a percursor molecule. This spectrum was recorded using the McMath Fourier transform spectrometer of the National Solar Observatory at Kitt Peak. A total of nine bands with v prime = 0 to 3 and v prime prime = 0 to 4 in the range 16,570-22,760/cm were observed and rotationally analyzed. The C2 molecules in this source had a rotational temperature of only 90 K so that only the low-J lines were present in the spectrum. In some sense the low temperatures in the jet source simulate conditions in the interstellar medium. The Swan system of C2 was also produced in a composite wall hollow cathode made Al4C3/Cu, and the rotational structure of the 1-0, 2-1, 3-2, 0-0, and 1-1 bands were analyzed. The data obtained from both these spectra were fitted together along with some recently published line positions. The rotational constants, lambda doubling parameters and the vibrational constants were estimated from this global fit. Our work on jet-cooled C2 follows similar work on the violet and red systems of CN. A summary of this CN work is also presented. also presented.

Measurement of the spin of the {xi}(1530) resonance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aubert, B.; Bona, M.; Karyotakis, Y.

The properties of the {xi}(1530) resonance are investigated in the {lambda}{sub c}{sup +}{yields}{xi}{sup -}{pi}{sup +}K{sup +} decay process. The data sample was collected with the BABAR detector at the SLAC PEP-II asymmetric-energy e{sup +}e{sup -} collider operating at center-of-mass energies 10.58 and 10.54 GeV. The corresponding integrated luminosity is approximately 230 fb{sup -1}. The spin of the {xi}(1530) is established to be 3/2. The existence of an S-wave amplitude in the {xi}{sup -}{pi}{sup +} system is inferred, and its interference with the {xi}(1530){sup 0} amplitude provides the first clear demonstration of the Breit-Wigner phase motion expected for the {xi}(1530). Themore » P{sub 1}(cos{theta}{sub {xi}}{sub {sup -}}) Legendre polynomial moment indicates the presence of a significant S-wave amplitude for {xi}{sup -}{pi}{sup +} mass values above 1.6 GeV/c{sup 2}, and a dip in the mass distribution at approximately 1.7 GeV/c{sup 2} is interpreted as due to the coherent addition of a {xi}(1690){sup 0} contribution to this amplitude. This would imply J{sup P}=1/2{sup -} for the {xi}(1690). Attempts at fitting the {xi}(1530){sup 0} line shape yield unsatisfactory results, and this failure is attributed to interference effects associated with the amplitudes describing the K{sup +}{pi}{sup +} and/or {xi}{sup -}K{sup +} systems.« less

Measurement of the Spin of the $$\\Xi(1530)$$ Resonance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aubert, B.; Bona, M.; Karyotakis, Y.

The properties of the {Xi}(1530) resonance are investigated in the {Lambda}{sub c}{sup +} {yields} {Xi}{sup -}{pi}{sup +}K{sup +} decay process. The data sample was collected with the BABAR detector at the SLAC PEP-II asymmetric-energy e{sup +}e{sup -} collider operating at center of mass energies 10.58 and 10.54 GeV. The corresponding integrated luminosity is approximately 230 fb{sup -1}. The spin of the {Xi}(1530) is established to be 3/2. The existence of an S-wave amplitude in the {Xi}{sup -}{pi}{sup +} system is inferred, and its interference with the {Xi}(1530)0 amplitude provides the first clear demonstration of the Breit-Wigner phase motion expected formore » the {Xi}(1530). The P{sub 1}(cos {theta}{sub {Xi}{sup -}}) Legendre polynomial moment indicates the presence of a significant S-wave amplitude for {Xi}{sup -}{pi}{sup +} mass values above 1.6 GeV/c{sup 2}, and a dip in the mass distribution at approximately 1.7 GeV/c{sup 2} is interpreted as due to coherent addition of a {Xi}(1690){sup 0} contribution to this amplitude. This would imply J{sup P} = 1/2{sup -} for the {Xi}(1690). Attempts at fitting the {Xi}(1530){sup 0} lineshape yield unsatisfactory results, and this failure is attributed to interference effects associated with the amplitudes describing the K{sup +}{pi}{sup +} and/or {Xi}{sup -}K{sup +} systems.« less

Microplastic bases for constitutive characterization of aluminum alloys and their correlation to sheet formability

NASA Astrophysics Data System (ADS)

Diak, Bradley James

Forming limit predictions that incorporate crystal plasticity models still cannot adequately predict the deformation performance of polycrystalline materials. The reason for the limitation in predictive power is that the constitutive equations used to connect to the atomic scale assume an affine deformation which do not have a physical basis, but give general trends. This study was undertaken to better elucidate the microplastic process and how it manifests itself phenomenologically. In this endeavour, the strain rate sensitivity of the flow stress was identified as one parameter that greatly affects the forming limit. Hence, an attempt was made to properly define and measure the strain rate sensitivity according to the dictates of thermodynamics. The thermodynamics of systems can delineate the evolution of the state of a material if the state variables can be characterized and measured. Inevitably, these variables must be determined at constant structure. Using the theory of thermally activated flow, where the movement of dislocations past obstacles is the rate controlling step, the mechanical testing techniques have been designed to statistically assess the dynamic evolution of the microstructure by controlling the temperature, T, and strain rate, dotvarepsilon, and measuring the stress, sigma, mean slip distance, lambda, and mean slip velocity, dotlambda, to define sigma=f(lambda,dotlambda, T). The apparent activation volume, which characterizes the obstacle resistance of strain centres, is determined at constant structure by applying the strain rate change technique. Strain rate sensitivity data are compared to the Cottrell-Stokes relation, and the Haasen plot is used to separate the different contributions to the flow stress. Using these precise measurements at interrupted segments of strain, the evolution of a microstructure during plastic flow can be monitored. By this examination of different rate controlling obstacles, the microstructural parameters which correlate to formability were assessed. Detailed experimental evidence is given for different aluminum alloys containing mainly fast or slow diffusing solute species, transition precipitates, dispersed particles, and/or dislocation debris. These systems of Al-Fe, Al-Cr, Al-Cu, Al-Mg, and Al-Mg-Si, all displayed unique dislocation-defect interactions which could be elucidated by the current theory of thermally activated flow.

A New Z Score Curve of the Coronary Arterial Internal Diameter Using the Lambda-Mu-Sigma Method in a Pediatric Population.

PubMed

Kobayashi, Tohru; Fuse, Shigeto; Sakamoto, Naoko; Mikami, Masashi; Ogawa, Shunichi; Hamaoka, Kenji; Arakaki, Yoshio; Nakamura, Tsuneyuki; Nagasawa, Hiroyuki; Kato, Taichi; Jibiki, Toshiaki; Iwashima, Satoru; Yamakawa, Masaru; Ohkubo, Takashi; Shimoyama, Shinya; Aso, Kentaro; Sato, Seiichi; Saji, Tsutomu

2016-08-01

Several coronary artery Z score models have been developed. However, a Z score model derived by the lambda-mu-sigma (LMS) method has not been established. Echocardiographic measurements of the proximal right coronary artery, left main coronary artery, proximal left anterior descending coronary artery, and proximal left circumflex artery were prospectively collected in 3,851 healthy children ≤18 years of age and divided into developmental and validation data sets. In the developmental data set, smooth curves were fitted for each coronary artery using linear, logarithmic, square-root, and LMS methods for both sexes. The relative goodness of fit of these models was compared using the Bayesian information criterion. The best-fitting model was tested for reproducibility using the validation data set. The goodness of fit of the selected model was visually compared with that of the previously reported regression models using a Q-Q plot. Because the internal diameter of each coronary artery was not similar between sexes, sex-specific Z score models were developed. The LMS model with body surface area as the independent variable showed the best goodness of fit; therefore, the internal diameter of each coronary artery was transformed into a sex-specific Z score on the basis of body surface area using the LMS method. In the validation data set, a Q-Q plot of each model indicated that the distribution of Z scores in the LMS models was closer to the normal distribution compared with previously reported regression models. Finally, the final models for each coronary artery in both sexes were developed using the developmental and validation data sets. A Microsoft Excel-based Z score calculator was also created, which is freely available online (http://raise.umin.jp/zsp/calculator/). Novel LMS models with which to estimate the sex-specific Z score of each internal coronary artery diameter were generated and validated using a large pediatric population. Copyright © 2016 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

Is interstellar detection of higher members of the linear radicals CnCH and CnN feasible?

NASA Technical Reports Server (NTRS)

Pauzat, F.; Ellinger, Y.; Mclean, A. D.

1991-01-01

Rotational constants and dipole moments for linear-chain radicals CnCH and CnN are estimated using a combinatiaon of ab initio molecular orbital calculations and observed data on the starting members of the series. CnCH with n = 0-5 have been observed by radioastronomy in carbon-rich interstellar clouds; higher members of the series have 2Pi ground states with large dipole moments and are strong candidates for observation. CN and C3N have also been observed by radioastronomy; higher members of the series, with the possible exception of C5N, have 2Pi ground states with near-zero dipole moments making their interstellar detection hopeless under present observational conditions. C5N can be a strong candidate only if it has a 2Sigma ground state, and best computations so far indicate that this is not the case.

Is interstellar detection of higher members of the linear radicals CnCH and CnN feasible?

PubMed

Pauzat, F; Ellinger, Y; McLean, A D

1991-03-01

Rotational constants and dipole moments for linear-chain radicals CnCH and CnN are estimated using a combination of ab initio molecular orbital calculations and observed data on the starting members of the series. CnCH with n = 0-5 have been observed by radioastronomy in carbon-rich interstellar clouds; higher members of the series have 2 pi ground states with large dipole moments and are strong candidates for observation. CN and C3N have also been observed by radioastronomy; higher members of the series, with the possible exception of C5N, have 2 pi ground states with near-zero dipole moments making their interstellar detection hopeless under present observational conditions. C5N can be a strong candidate only if it has a 2 sigma ground state, and our best computations so far indicate that this is not the case.

Is interstellar detection of higher members of the linear radicals CnCH and CnN feasible

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pauzat, F.; Ellinger, Y.; Mclean, A.D.

1991-03-01

Rotational constants and dipole moments for linear-chain radicals CnCH and CnN are estimated using a combinatiaon of ab initio molecular orbital calculations and observed data on the starting members of the series. CnCH with n = 0-5 have been observed by radioastronomy in carbon-rich interstellar clouds; higher members of the series have 2Pi ground states with large dipole moments and are strong candidates for observation. CN and C3N have also been observed by radioastronomy; higher members of the series, with the possible exception of C5N, have 2Pi ground states with near-zero dipole moments making their interstellar detection hopeless under presentmore » observational conditions. C5N can be a strong candidate only if it has a 2Sigma ground state, and best computations so far indicate that this is not the case. 20 refs.« less

A photoionization study of OH and OD from 680A to 950A: An analysis of the Rydberg series

NASA Technical Reports Server (NTRS)

Cutler, J. N.; He, Z. X.; Samson, J. A. R.

1994-01-01

The photoionization spectra of OH(+) and OD(+) have been reported from 680 to 950 A (18.23 to 13.05 eV) at a wavelength resolution of 0.07 A. Through interpretation of both spectra, the Rydberg series and their higher vibrational members have been reported for three of the excited ionic states, a(sup 1)Delta, A(sup 3)Pi(i), and b(sup 1) Sigma(sup +). A vibrational progression has also been observed in both OH(+) and OD(+) which is apparently related to a fourth excited ionic state, c(sup 1)Pi. Finally, the dissociative ionization limits, corrected to 0 K,for H2O AND D2O have been measured to be 18.11+/-0.01 and 18.21+/-0.01 eV, respectively, and shown to be in good agreement with previously reported results.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baird, K.; SLD Collaboration

The authors have measured production fractions and spectra for {pi}{sup {+-}}, K{sup {+-}} and p, and production spectra for K{sup 0} and {Lambda}{sup 0} in both hadronic Z{sup 0} decays and a Z{sup 0} {yields} light quark (uds) subset at SLD. The SLD Cherenkov Ring Imaging Detector was used to identify charged hadrons. The CCD vertex detector was used to select the enriched uds sample. For the global sample, the results are consistent with previous experiments. The authors observe a clear flavor dependence in production spectra, but only a small effect in hadron fractions and {xi} = ln(1/x{sub p}) peakmore » positions.« less

The photodissociation lifetimes of the OH and OD radicals in comets

NASA Technical Reports Server (NTRS)

Singh, P. D.; Van Dishoeck, E. F.; Dalgarno, A.

1983-01-01

The photodissociation rates of OH and OD molecules due to absorption of solar radiation in the X(2)Pi-A(2)Sigma(+) electronic transition are calculated to lie between 3.5 and 6.7 x 10 to the -6th/sec for OH for heliocentric velocities between -60 and +60 km/sec and at about 4.7 x 10 to the -7th/sec for OD at 1 AU from the sun. The corresponding lifetimes, which are upper bounds to the actual lifetimes, are generally consistent with the observational cometary data.

Trisphenalenyl-based neutral radical molecular conductor.

PubMed

Pal, Sushanta K; Itkis, Mikhail E; Tham, Fook S; Reed, Robert W; Oakley, Richard T; Haddon, Robert C

2008-03-26

We report the preparation, crystallization, and solid-state characterization of the first member of a new family of tris(1,9-disubstituted phenalenyl)silicon neutral radicals. In the solid state, the radical packs as weak partial pi-dimers with intermolecular carbon...carbon contacts that fall at the van der Waals atomic separation. Magnetic susceptibility measurements indicate approximately 0.7 Curie spins per molecule from room temperature down to 50 K, below which antiferromagnetic coupling becomes apparent; the compound has a room-temperature single-crystal conductivity of sigmaRT = 2.4 x 10(-6) S cm(-1).

Analysis of solar spectra in the middle ultraviolet and visible for atmospheric trace constituents measurements. [hydroxyl radicals

NASA Technical Reports Server (NTRS)

Goldman, A.

1980-01-01

Individual spectral line parameters including line positions, strengths, and intensities were generated for the sq Alpha Sigma - sq Chi Pi (0,0) band of OH, applicable to atmospheric and high temperatures. Energy levels and transition frequencies are calculated by numerically diagonalizing the Hamiltonian. Line strengths are calculated using the dipole matrix and eigenvectors derived from energy matrix diagonalization. The line strengths are compared to those calculated from previously published algebraic line strength formulas. Tables of line parameters are presented for 240 K and 4600 K.

An orbital localization criterion based on the theory of "fuzzy" atoms.

PubMed

Alcoba, Diego R; Lain, Luis; Torre, Alicia; Bochicchio, Roberto C

2006-04-15

This work proposes a new procedure for localizing molecular and natural orbitals. The localization criterion presented here is based on the partitioning of the overlap matrix into atomic contributions within the theory of "fuzzy" atoms. Our approach has several advantages over other schemes: it is computationally inexpensive, preserves the sigma/pi-separability in planar systems and provides a straightforward interpretation of the resulting orbitals in terms of their localization indices and atomic occupancies. The corresponding algorithm has been implemented and its efficiency tested on selected molecular systems. (c) 2006 Wiley Periodicals, Inc.

Far-Ultraviolet Observations of Comet C 2012 S1 (ISON) From Fortis

NASA Technical Reports Server (NTRS)

Mccandiss, Stephan R.; Feldman, Paul D.; Weaver, Harold; Fleming, Brian; Redwine, Keith; Li, Mary J.; Kutyrev, Alexander; Moseley, S. Harvey

2016-01-01

We have used the unique far-UV imaging capability offered by a sounding-rocket-borne instrument to acquire observations of C/2012 S1 (ISON) when its angular separation with respect to the Sun was 26 deg.3 on 2013 November 20.49. At the time of observation, the comet's heliocentric distance and velocity relative to the Sun were r h = 0.43 au and r (sub h) = 62.7 km s)exp. -1). Images dominated by C Iota Lambda 1657 and H Iota Lambda 1216 were acquired over a 10(exp. 6) x 10(exp. 6) km(exp. 2) region. The water production rate implied by the Ly Alpha observations is constrained to be Q H2O is much greater than 8 x 10(exp. 29) s(exp. -1) while the neutral carbon production rate was Q(sub c) is much greater than 4 x 10(exp. 28) s(exp. -1). The radial profile of C I was consistent with it being a dissociation product of a parent molecule with a lifetime T is approx. 5 x 10(exp. 4) s, favoring a parent other than CO. We constrain the Q(sub co) production rate to 5(+1.5)(-7.5), 10(exp. 28) s(exp. -1) with 1 sigma errors derived from photon statistics. The upper limit on the Q (sub CO)/Q(sub H2O) is 6%.

Chemiluminescence of nitric oxide

NASA Technical Reports Server (NTRS)

Sharp, W. E.; Rusch, D. W.

1981-01-01

Measurements of the intensities of the delta and gamma bands of nitric oxide in the nighttime terrestrial thermosphere are presented and used to infer the rate coefficient for the transition from the C 2 Pi to the A 2 Sigma + states. The nightglow spectrum was observed between 1900 and 2300 A at a resolution of 15 A by a rocket-borne scanning 1/4-m spectrometer pointing north at an apogee of 150 km. Progressions of the delta, gamma and epsilon bands are identified on the spectra by the construction of synthetic spectra, and the contributions of resonance fluorescence to the total band intensities are calculated. Finally, the ratio of the sum of the gamma bands for v-prime = 0 to the sum of the delta bands for v-prime = 0 is used to derive a branching ratio of 0.21 + or - 0.04 to the A 2 Sigma + state, which yields a probability for the C-A transition of 5.6 + or - 1.5 x to the 6th/sec.

Spectrocopic measurements of water vapor plasmas at high resolution: The optical transition probabilities for OH (A 2 Sigma - X 2 Pi)

NASA Technical Reports Server (NTRS)

Klein, L.

1972-01-01

Emission and absorption spectra of water vapor plasmas generated in a wall-stabilized arc at atmospheric pressure and 4 current, and at 0.03 atm and 15 to 50 A, were measured at high spatial and spectral resolution. The gas temperature was determined from the shape of Doppler-broadened rotational lines of OH. The observed nonequilibrium population distributions over the energy levels of atoms are interpreted in terms of a theoretical state model for diffusion-controlled arc plasmas. Excellent correlation is achieved between measured and predicted occupation of hydrogen energy levels. It is shown that the population distribution over the nonpredissociating rotational-vibrational levels of the A 2 Sigma state of OH is close to an equilibrium distribution at the gas temperature, although the total density of this state is much higher than its equilibrium density. The reduced intensities of the rotational lines originating in these levels yielded Boltzmann plots that were strictly linear.

Paramagnetic Liquid Bridge in a Gravity-Compensating Magnetic Field

NASA Technical Reports Server (NTRS)

Mahajan, Milind P.; Tsige, Mesfin; Taylor, P. L.; Rosenblatt, Charles

1999-01-01

Magnetic levitation was used to stabilize cylindrical columns of a paramagnetic liquid in air between two solid supports. The maximum achievable length to diameter ratio R(sub max) was approx. (3.10 +/- 0.07), very close to the Rayleigh-Plateau limit of pi. For smaller R, the stability of the column was measured as a function of the Bond number, which could be continuously varied by adjusting the strength of the magnetic field. Liquid bridges supported by two solid surfaces have been attracting scientific attention since the time of Rayleigh and Plateau. For a cylindrical bridge of length L and diameter d, it was shown theoretically that in zero gravity the maximum slenderness ratio R (identically = L/d) is pi. The stability and ultimate collapse of such bridges is of interest because of their importance in a number of industrial processes and their potential for low gravity applications. In the presence of gravity, however, the cylindrical shape of an axisymmetric bridge tends to deform, limiting its stability and decreasing the maximum achievable value of R. Theoretical studies have discussed the stability and possible shapes of axisymmetric bridges. Experiments typically are performed in either a Plateau tank, in which the bridge is surrounded by a density-matched immiscible fluid, or in a space-borne microgravity environment. It has been shown, for example, that the stability limit R can be pushed beyond pi by using flow stabilization, by acoustic radiation pressure, or by forming columns in the presence of an axial electric field. In this work, magnetic levitation was used to simulate a low gravity environment and create quasi-cylindrical liquid columns in air. Use of a magnetic field permits us to continuously vary the Bond number B identically equal to (g)(rho)d(exp 2)/4(sigma), where g is the gravitational acceleration, rho is the density of the liquid, and sigma is the surface tension of the liquid in air. The dimensionless Bond number represents the relative importance of external forces acting on the liquid column to those due to surface tension. Our central result is that in a large magnetic field gradient we could create and stabilize columns of mixtures of water and paramagnetic manganese chloride tetrahydrate (MnCl2.4H2O), achieving a length to diameter ratio very close to pi.

{{\\rm{H}}}_{2}\\,X{}^{1}{{\\rm{\\Sigma }}}_{g}^{+}-c{}^{3}{{\\rm{\\Pi }}}_{u} Excitation by Electron Impact: Energies, Spectra, Emission Yields, Cross-sections, and H(1s) Kinetic Energy Distributions

NASA Astrophysics Data System (ADS)

Liu, Xianming; Shemansky, Donald E.; Yoshii, Jean; Liu, Melinda J.; Johnson, Paul V.; Malone, Charles P.; Khakoo, Murtadha A.

2017-10-01

The c{}3{{{\\Pi }}}u state of the hydrogen molecule has the second largest triplet-state excitation cross-section, and plays an important role in the heating of the upper thermospheres of outer planets by electron excitation. Precise energies of the H2, D2, and HD c{}3{{{\\Pi }}}u-(v,N) levels are calculated from highly accurate ab initio potential energy curves that include relativistic, radiative, and empirical non-adiabatic corrections. The emission yields are determined from predissociation rates and refined radiative transition probabilities. The excitation function and excitation cross-section of the c{}3{{{\\Pi }}}u state are extracted from previous theoretical calculations and experimental measurements. The emission cross-section is determined from the calculated emission yield and the extracted excitation cross-section. The kinetic energy (E k ) distributions of H atoms produced via the predissociation of the c{}3{{{\\Pi }}}u state, the c{}3{{{\\Pi }}}u- - b{}3{{{Σ }}}u+ dissociative emission by the magnetic dipole and electric quadrupole, and the c{}3{{{\\Pi }}}u - a{}3{{{Σ }}}g+ - b{}3{{{Σ }}}u+ cascade dissociative emission by the electric dipole are obtained. The predissociation of the c{}3{{{\\Pi }}}u+ and c{}3{{{\\Pi }}}u- states both produce H(1s) atoms with an average E k of ˜4.1 eV/atom, while the c{}3{{{\\Pi }}}u- - b{}3{{{Σ }}}u+ dissociative emissions by the magnetic dipole and electric quadrupole give an average E k of ˜1.0 and ˜0.8 eV/atom, respectively. The c{}3{{{\\Pi }}}u - a{}3{{{Σ }}}g+ - b{}3{{{Σ }}}u+ cascade and dissociative emission gives an average E k of ˜1.3 eV/atom. On average, each H2 excited to the c{}3{{{\\Pi }}}u state in an H2-dominated atmosphere deposits ˜7.1 eV into the atmosphere while each H2 directly excited to the a{}3{{{Σ }}}g+ and d{}3{{{\\Pi }}}u states contribute ˜2.3 and ˜3.3 eV, respectively, to the atmosphere. The spectral distribution of the calculated continuum emission arising from the X{}1{{{Σ }}}g+ - c{}3{{{\\Pi }}}u excitation is significantly different from that of direct a{}3{{{Σ }}}g+ or d{}3{{{\\Pi }}}u excitations.

SPT-CL J2040–4451: An SZ-selected galaxy cluster at x=1.478 with significant ongoing star formation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bayliss, M. B.; Ashby, M. L. N.; Ruel, J.

2014-09-18

SPT-CL J2040-4451-spectroscopically confirmed at z = 1.478-is the highest-redshift galaxy cluster yet discovered via the Sunyaev-Zel'dovich effect. SPT-CL J2040-4451 was a candidate galaxy cluster identified in the first 720 deg(2) of the South Pole Telescope Sunyaev-Zel'dovich (SPT-SZ) survey, and has been confirmed in follow-up imaging and spectroscopy. From multi-object spectroscopy with Magellan-I/Baade+ IMACS we measure spectroscopic redshifts for 15 cluster member galaxies, all of which have strong [O Pi]lambda lambda 3727 emission. SPT-CL J2040-4451 has an SZ-measured mass of M-500,(SZ) = 3.2 ± 0.8 x 10 14M(circle dot) h(-1) 70, corresponding to M-200,M- (SZ) = 5.8 ± 1.4 x 10more » 14M(circle dot) h(70-)(1.) The velocity dispersion measured entirely from blue star-forming members is sv = 1500 ± 520 km s -1. The prevalence of star-forming cluster members (galaxies with > 1.5M(circle dot) yr -1 implies that this massive, high-redshift cluster is experiencing a phase of active star formation, and supports recent results showing a marked increase in star formation occurring in galaxy clusters at z greater than or similar to 1.4. We also compute the probability of finding a cluster as rare as this in the SPT-SZ survey to be > 99%, indicating that its discovery is not in tension with the concordance Lambda CDM cosmological model.« less

Structures Of Magnetically-Supported Filaments And Their Appearance In The Linear Polarization

NASA Astrophysics Data System (ADS)

Tomisaka, Kohji

2017-10-01

Dust thermal emissions observed with Herschel have revealed that interstellar molecular clouds consist of many filaments. Polarization observation of interstellar extinctions in the optical and near IR wavelengths shows that the dense filaments are extending perpendicular to the interstellar magnetic field. Magnetohydrostatic structures of such filaments are studied. It is well known that a hydrostatic filament without magnetic field has a maximum line mass of ¥lambda_max=2c_s^2/G (c_s:the isothermal sound speed and G: the gravitational constant). On the other hand, the magnetically-supported maximum line mass increases in proportion to the magnetic flux per unit length threading the filament (¥phi), as ¥lambda_max 2c_s^2/G + ¥phi/(2¥pi G^1/2). Comparison is made with 3D clouds. Stability of these magnetized filaments is studied using time-dependent 3D MHD simulations to discuss star formation in the filaments. Polarization pattern expected for the magnetically subcritical filaments is calculated. The distribution function of the angle between B-field and the axis of the filament, which is obtained with Planck Satellite, is compared with this mock observation.

The Composition of Comet C/2009 PI (Garradd) from Infrared Spectroscopy: Evidence for an Oxygen-Rich Heritage?

NASA Technical Reports Server (NTRS)

DiSanti, M. A.; Bonev, B. P.; Villanueva, G. L.; Paganini, L.; Mumma, M. J.; Charnley, S. B.; Keane, J. V.; Meech, K. J.; Blake, G. A.; Boehnhardt, H.;

Electronic structure of monodentate-coordinated diphosphine complexes. Photoelectron spectra of Mo(CO)[sub 5](P(CH[sub 3])[sub 2]CH[sub 2]P(CH[sub 3])[sub 2]) and Mo(CO)[sub 5](P(CH[sub 3])[sub 2]CH[sub 2]CH[sub 2]P(CH[sub 3])[sub 2])

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lichtenberger, D.L.; Jatcko, M.E.

1992-02-05

Photoelectron spectroscopy is used to study the electronic structure of molybdenum carbonyl complexes that contain diphosphine ligands bound to the metal through only one of the two phosphorus atoms. Photoelectron spectra are reported for Mo(CO)[sub 5]DMPE and Mo(CO)[sub 5]DMPM and compared to the spectra of Mo(CO)[sub 5]PMe[sub 3] and the corresponding free phosphine and diphosphine ligands (PMe[sub 3] is trimethylphosphine, DMPE is 1,2-bis(dimethylphosphino)ethane, and DMPM is bis(dimethylphosphino)methane). The energy splittings between the d[sup 6] metal-based ionizations of these complexes indicate that the [pi]-back-bonding ability is the same for each of these phosphine ligands and is relatively small, about 25% thatmore » of carbon monoxide. The metal-based ionizations shift only slightly to lower binding energy from the PMe[sub 3] to the DMPE to the DMPM complex due to a slightly increasing negative charge potential at the metal along this series. This would normally be interpreted as slightly increasing [sigma]-donor strength in the order PMe[sub 3] < DMPE < DMPM. However, the difference between the ionization energy of the coordinated lone pair (CLP) of the phosphine and the ionization energy of the lone pair of the free ligand indicates an opposite trend in [sigma]-donor strength with PMe[sub 3] (1.28 eV) > DMPE (1.27 eV) > DMPM (1.23 eV). The shift of the uncoordinated phosphine lone-pair ionization (ULP) of the monocoordinated diphosphine complexes, which is affected primarily by charge potential effects, reveals that the important factor is a transfer of negative charge from the uncoordinated end of the phosphine through the alkyl linkage to the coordinated phosphine. Aside from these subtle details of charge distribution, the primary conclusion is that the diphosphine ligands, DMPE and DMPM, have [sigma]-donor and [pi]-acceptor strengths extremely similar to those of PMe[sub 3].« less

The Physical Meaning Of The Titius - Bode Formula

NASA Astrophysics Data System (ADS)

Smirnov, Vladimir

The process of evolution of the solar system means the development of the structure of gas-dust cloud after the initial impulse by way of the impact of a supernova explosion. Thus the wave motions are practically excluded from consideration. As the experience shows at the time of the formation of standing waves with the observed acoustic resonance the wave motions at the nodal points can accumulate clumps of matter that make up the primary cloud. (A similar pattern is observed in the experiments of Chladni E.). J. Kepler's plan of the solar system, which took into account the distribution of the planets according to their distance from the Sun, was built as a series of inscribed and circumscribed Platonic figures (J. Kepler ;1939): Welt-Harmonik, Verlag R.Oldenbourg, Munchen-Berlin,p. 403). According to his scheme the average distances of the planets from the Sun could be obtained in the form of the radiuses of the circumscribed spheres. This fact indicates the existence of a common measure of the Platonic figures constructed in such a way. In the time of Kepler the concepts of the wavelength were not yet used. That’s why Kepler could come to the conclusion that the length of a standing wave lambda, emitted by the central formation of the Solar system that forms waves of energy into space, which are shaping with the reflected waves from the interface of more dense environmental conditions of the gaseous nebula and less dense environmental conditions of the surrounding space, could serve as a common measure for measuring distances of the planets from the sun. If the standing wave in the one-dimensional case is formed in the Y axis direction with the displacement X, the wave equation can be written as : X=acos(2pi\\char92lambda)Ycos(2pi\\char92T)t The planets are being formed in the nodes generated in the wave where the oscillation amplitude is zero. In astronomical units the distances from the sun are determined at the points along the axisY=((2n+1)\\char924)lambda, wherein n=0,1,2... The comparison of the observed and calculated distances from the planets to the Sun and the distances from the satellites to the planets according to the proposed wave principle one can find in the author's work: 'The Wave Principle of Material Distribution within the Solar System’, published in Proceedings of the International Meteor Conference, Cerkno, Slovenia, 20 - 23 September 2001 Pp 64 - 71 The above formula for the distances from the planets to the Sun, the distances from the planets to their satellites, reveals the physical meaning of the well-known formula, composed empirically by Bode - Titius: Y=0,4+0,3*2 (n) , wherein n=1,2,4,5... Note that in some cases the standing waves are responsible for the formation of symmetrical shapes of galaxies by cosmic objects that resemble the inscribed and circumscribed Platonic figures and the vortex formation in the form of hexagon on Saturn recently shown on the Internet. According to the observations the elementary calculation shows that the hexagon vortex is formed by a standing wave with a wavelength lambda=6250km According to the reports of the Hubble telescope’s (Hubble EP) observations in outer space the energy waves are observed in the substance of the outer space while the evolution of galaxies and other objects, and the length of these energy waves reaches lambda hundreds of light years.

Biased immunoglobulin light chain gene usage in the shark1

PubMed Central

Iacoangeli, Anna; Lui, Anita; Naik, Ushma; Ohta, Yuko; Flajnik, Martin; Hsu, Ellen

2015-01-01

This study of a large family of kappa light (L) chain clusters in nurse shark completes the characterization of its classical immunoglobulin (Ig) gene content (two heavy chain classes, mu and omega, and four L chain isotopes, kappa, lambda, sigma, and sigma-2). The shark kappa clusters are minigenes consisting of a simple VL-JL-CL array, where V to J recombination occurs over a ~500 bp interval, and functional clusters are widely separated by at least 100 kb. Six out of ca. 39 kappa clusters are pre-rearranged in the germline (GL-joined). Unlike the complex gene organization and multistep assembly process of Ig in mammals, each shark Ig rearrangement, somatic or in the germline, appears to be an independent event localized to the minigene. This study examined the expression of functional, non-productive, and sterile transcripts of the kappa clusters compared to the other three L chain isotypes. Kappa cluster usage was investigated in young sharks, and a skewed pattern of split gene expression was observed, one similar in functional and non-productive rearrangements. These results show that the individual activation of the spatially distant kappa clusters is non-random. Although both split and GL-joined kappa genes are expressed, the latter are prominent in young animals and wane with age. We speculate that, in the shark, the differential activation of the multiple isotypes can be advantageously used in receptor editing. PMID:26342033

A search for an excited muon decaying to a muon and two jets in pp collisions at $$\\sqrt{s}\\;=\\;8\\;{\\rm{TeV}}$$ with the ATLAS detector

DOE PAGES

Aad, G.; Abbott, B.; Abdallah, J.; ...

2016-07-11

In this study, a new search signature for excited leptons is explored. Excited muons are sought in the channelmore » $${pp}\\to \\mu {\\mu }^{* }\\to \\mu \\mu \\ {\\rm{jet}}\\;{\\rm{jet}}$$, assuming both the production and decay occur via a contact interaction. The analysis is based on 20.3 fb –1 of pp collision data at a centre-of-mass energy of $$\\sqrt{s}\\;=\\;8\\;{\\rm{TeV}}$$ taken with the ATLAS detector at the large hadron collider. No evidence of excited muons is found, and limits are set at the 95% confidence level on the cross section times branching ratio as a function of the excited-muon mass $${m}_{{\\mu }^{* }}$$. For $${m}_{{\\mu }^{* }}$$ between 1.3 and 3.0 TeV, the upper limit on $$\\sigma B({\\mu }^{* }\\to \\mu q\\bar{q}$$) is between 0.6 and 1 fb. Limits on $$\\sigma B$$ are converted to lower bounds on the compositeness scale Λ. In the limiting case $${\\rm{\\Lambda }}={m}_{{\\mu }^{* }}$$, excited muons with a mass below 2.8 TeV are excluded. With the same model assumptions, these limits at larger $${\\mu }^{* }$$ masses improve upon previous limits from traditional searches based on the gauge-mediated decay $${\\mu }^{* }\\to \\mu \\gamma $$.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yagi, Kent; Tanaka, Takahiro; Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502

We calculate how strongly one can put constraints on alternative theories of gravity such as Brans-Dicke and massive graviton theories with LISA. We consider inspiral gravitational waves from a compact binary composed of a neutron star and an intermediate mass black hole in Brans-Dicke (BD) theory and that composed of a super massive black hole in massive graviton theories. We use the restricted second post-Newtonian waveforms including the effects of spins. We also take both precession and eccentricity of the orbit into account. For simplicity, we set the fiducial value for the spin of one of the binary constituents tomore » zero so that we can apply the approximation called simple precession. We perform the Monte Carlo simulations of 10{sup 4} binaries, estimating the determination accuracy of binary parameters including the BD parameter {omega}{sub BD} and the Compton wavelength of graviton {lambda}{sub g} for each binary using the Fisher matrix method. We find that including both the spin-spin coupling {sigma} and the eccentricity e into the binary parameters reduces the determination accuracy by an order of magnitude for the Brans-Dicke case, while it has less influence on massive graviton theories. On the other hand, including precession enhances the constraint on {omega}{sub BD} only 20% but it increases the constraint on {lambda}{sub g} by several factors. Using a (1.4+1000)M{sub {center_dot}}neutron star/black hole binary of SNR={radical}(200), one can put a constraint {omega}{sub BD}>6944, while using a (10{sup 7}+10{sup 6})M{sub {center_dot}}black hole/black hole binary at 3 Gpc, one can put {lambda}{sub g}>3.10x10{sup 21} cm, on average. The latter is 4 orders of magnitude stronger than the one obtained from the solar system experiment. These results are consistent with previous results within uncontrolled errors and indicate that the effects of precession and eccentricity must be taken carefully in the parameter estimation analysis.« less

Constraints on cosmological models and reconstructing the acceleration history of the Universe with gamma-ray burst distance indicators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liang Nan; Wu Puxun; Zhang Shuangnan

2010-04-15

Gamma-ray bursts (GRBs) have been regarded as standard candles at very high redshift for cosmology research. We have proposed a new method to calibrate GRB distance indicators with Type Ia supernova (SNe Ia) data in a completely cosmology-independent way to avoid the circularity problem that had limited the direct use of GRBs to probe cosmology [N. Liang, W. K. Xiao, Y. Liu, and S. N. Zhang, Astrophys. J. 685, 354 (2008).]. In this paper, a simple method is provided to combine GRB data into the joint observational data analysis to constrain cosmological models; in this method those SNe Ia datamore » points used for calibrating the GRB data are not used to avoid any correlation between them. We find that the {Lambda}CDM model is consistent with the joint data in the 1-{sigma} confidence region, using the GRB data at high redshift calibrated with the interpolating method, the Constitution set of SNe Ia, the cosmic microwave background radiation from Wilkinson Microwave Anisotropy Probe five year observation, the baryonic acoustic oscillation from the spectroscopic Sloan Digital Sky Survey Data Release 7 galaxy sample, the x-ray baryon mass fraction in clusters of galaxies, and the observational Hubble parameter versus redshift data. Comparing to the joint constraints with GRBs and without GRBs, we find that the contribution of GRBs to the joint cosmological constraints is a slight shift in the confidence regions of cosmological parameters to better enclose the {Lambda}CDM model. Finally, we reconstruct the acceleration history of the Universe up to z>6 with the distance moduli of SNe Ia and GRBs and find some features that deviate from the {Lambda}CDM model and seem to favor oscillatory cosmology models; however, further investigations are needed to better understand the situation.« less

Dark Energy Survey Year 1 Results: Cosmological Constraints from Galaxy Clustering and Weak Lensing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abbott, T.M.C.; et al.

We present cosmological results from a combined analysis of galaxy clustering and weak gravitational lensing, using 1321 degmore » $^2$ of $griz$ imaging data from the first year of the Dark Energy Survey (DES Y1). We combine three two-point functions: (i) the cosmic shear correlation function of 26 million source galaxies in four redshift bins, (ii) the galaxy angular autocorrelation function of 650,000 luminous red galaxies in five redshift bins, and (iii) the galaxy-shear cross-correlation of luminous red galaxy positions and source galaxy shears. To demonstrate the robustness of these results, we use independent pairs of galaxy shape, photometric redshift estimation and validation, and likelihood analysis pipelines. To prevent confirmation bias, the bulk of the analysis was carried out while blind to the true results; we describe an extensive suite of systematics checks performed and passed during this blinded phase. The data are modeled in flat $$\\Lambda$$CDM and $w$CDM cosmologies, marginalizing over 20 nuisance parameters, varying 6 (for $$\\Lambda$$CDM) or 7 (for $w$CDM) cosmological parameters including the neutrino mass density and including the 457 $$\\times$$ 457 element analytic covariance matrix. We find consistent cosmological results from these three two-point functions, and from their combination obtain $$S_8 \\equiv \\sigma_8 (\\Omega_m/0.3)^{0.5} = 0.783^{+0.021}_{-0.025}$$ and $$\\Omega_m = 0.264^{+0.032}_{-0.019}$$ for $$\\Lambda$$CDM for $w$CDM, we find $$S_8 = 0.794^{+0.029}_{-0.027}$$, $$\\Omega_m = 0.279^{+0.043}_{-0.022}$$, and $$w=-0.80^{+0.20}_{-0.22}$$ at 68% CL. The precision of these DES Y1 results rivals that from the Planck cosmic microwave background measurements, allowing a comparison of structure in the very early and late Universe on equal terms. Although the DES Y1 best-fit values for $$S_8$$ and $$\\Omega_m$$ are lower than the central values from Planck ...« less

Optical emission spectroscopic diagnostics of a non-thermal atmospheric pressure helium-oxygen plasma jet for biomedical applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thiyagarajan, Magesh; Sarani, Abdollah; Nicula, Cosmina

In this work, we have applied optical emission spectroscopy diagnostics to investigate the characteristics of a non-thermal atmospheric pressure helium plasma jet. The discharge characteristics in the active and afterglow region of the plasma jet, that are critical for biomedical applications, have been investigated. The voltage-current characteristics of the plasma discharge were analyzed and the average plasma power was measured to be around 18 W. The effect of addition of small fractions of oxygen at 0.1%-0.5% on the plasma jet characteristics was studied. The addition of oxygen resulted in a decrease in plasma plume length due to the electronegativity propertymore » of oxygen. Atomic and molecular lines of selected reactive plasma species that are considered to be useful to induce biochemical reactions such as OH transitions A{sup 2}{Sigma}{sup +}({nu}=0,1){yields}X{sup 2}{Pi}({Delta}{nu}=0) at 308 nm and A{sup 2}{Sigma}{sup +}({nu}=0,1){yields}X{sup 2}{Pi}({Delta}{nu}=1) at 287 nm, O I transitions 3p{sup 5}P{yields}3s{sup 5}S{sup 0} at 777.41 nm, and 3p{sup 3}P{yields}3s{sup 3}S{sup 0} at 844.6 nm, N{sub 2}(C-B) second positive system with electronic transition C{sup 3}{Pi}{sub u}{sup {yields}}B{sup 3}{Pi}{sub g}'' in the range of 300-450 nm and N{sub 2}{sup +}(B-X) first negative system with electronic transition B{sup 2}{Sigma}{sub u}{sup +}{yields}X{sup 2}{Sigma}{sub g}{sup +}({Delta}{nu}=0) at 391.4 nm have been studied. The atomic emission lines of helium were identified, including the He I transitions 3p{sup 3}P{sup 0}{yields}2s{sup 3}S at 388.8 nm, 3p{sup 1}P{sup 0}{yields} 2s{sup 1}S at 501.6 nm, 3d{sup 3}D{yields}2p{sup 3}P{sup 0} at 587.6 nm, 3d{sup 1}D{yields}2p{sup 1}P{sup 0} at 667.8 nm, 3s{sup 3}S{sup 1}{yields}2p{sup 3}P{sup 0} at 706.5 nm, 3s{sup 1}S{sup 0}{yields}2p{sup 1}P{sup 0} at 728.1 nm, and H{sub {alpha}} transition 2p-3d at 656.3 nm. Using a spectral fitting method, the OH radicals at 306-312 nm, the rotational and vibrational temperatures equivalent to gas temperatures of the discharge was measured and the effective non-equilibrium nature of the plasma jet was demonstrated. Our results show that, in the entire active plasma region, the gas temperature remains at 310 {+-} 25 K and 340 {+-} 25 K and it increases to 320 {+-} 25 K and 360 {+-} 25 K in the afterglow region of the plasma jet for pure helium and helium/oxygen (0.1%) mixture, respectively. Additionally, the vibrational temperatures range from 2200 {+-} 100 K and 2500 {+-} 100 K for pure helium and helium/oxygen (0.1%) mixture, respectively. The plasma jet was tested on heat sensitive polymer films used in biomedical applications such as polyethylene terephthalate and poly-L-lactide samples continuously for several minutes without causing any physical or thermal damage to the films. The plasma jet produces significant reactive species of interest while the gas temperatures remain very low demonstrating its potential for a range of biomedical applications.« less

Photodissociation of PbI2 in the ultraviolet: analysis of the A rightarrow X band of PbI

NASA Astrophysics Data System (ADS)

Rodriguez, G.; Herring, C. M.; Fraser, R. D.; Eden, J. G.

1996-07-01

Emission and absorption studies of lead moniodide (PbI) have been carried out by photodissociation of PbI2 vapor at one of several wavelengths (193, 248, 266, 308, and 351 nm) in the ultraviolet. Strong emission on the A \\rightarrow X2 Pi 1/2 band (14400-22800 cm -1 ; 440 \\similar-or-less lambda \\similar-or-less 695 nm) occurs when PbI2 is photodissociated at 248 or 266 nm. Also, absorption bands attributed to the B \\leftarrow X2 Pi 1/2,3/2 , D \\leftarrow X2 Pi 1/2,3/2 , and E \\leftarrow X2 Pi 1/2,3/2 transitions of the diatomic molecule have been observed at 290 and 380, 225 and 265, and 203 and 240 nm, respectively, as have emission bands peaking at 397.6, 531.6, 582.0, 595.1, 639.7, 685.9, and 707.9 nm that appear to arise from PbI2 itself. Analysis and computer simulations of the A \\rightarrow X2 Pi 1/2 emission spectra have resulted in identifications for virtually all (>120) of the observed vibrational bandheads. Several spectroscopic constants for the A and the X2 Pi 1/2 states of PbI have been determined to be Te(A)=20659+/-130 cm-1 , omega e\\prime =132.2+/-1.0cm -1 , omega e\\prime xe\\prime =1.91+/-0.06cm -1 , omega e\\prime \\prime=160.3+/-0.6cm-1 , and omega e\\prime \\primexe \\prime\\prime=0.24+/-0.03cm -1 . Also, the difference between the equilibrium internuclear separations for the X2 Pi 1/2 and the A states has been determined to be Delta Re=0.45+/-0.05 . The spontaneous-emission lifetime for the PbI(A) state and the rate constant for quenching of this state by PbI2 (in two-body collisions) have been measured to be (94.3+/-8.8) ns and (4.3+/-0.4) \\times 10-10 cm3s -1 , respectively.

Review: Hamiltonian Linearization of the Rest-Frame Instant Form of Tetrad Gravity in a Completely Fixed 3-Orthogonal Gauge: A Radiation Gauge for Background-Independent Gravitational Waves in a Post-Minkowskian Einstein Spacetime

NASA Astrophysics Data System (ADS)

Agresti, Juri; De Pietri, Roberto; Lusanna, Luca; Martucci, Luca

2004-05-01

In the framework of the rest-frame instant form of tetrad gravity, where the Hamiltonian is the weak ADM energy {\\hat E}ADM, we define a special completely fixed 3-orthogonal Hamiltonian gauge, corresponding to a choice of non-harmonic 4-coordinates, in which the independent degrees of freedom of the gravitational field are described by two pairs of canonically conjugate Dirac observables (DO) r_{\\bar a}(\\tau ,\\vec \\sigma ), \\pi_{\\bar a}(\\tau ,\\vec \\sigma ), \\bar a = 1,2. We define a Hamiltonian linearization of the theory, i.e. gravitational waves, without introducing any background 4-metric, by retaining only the linear terms in the DO's in the super-hamiltonian constraint (the Lichnerowicz equation for the conformal factor of the 3-metric) and the quadratic terms in the DO's in {\\hat E}ADM. We solve all the constraints of the linearized theory: this amounts to work in a well defined post-Minkowskian Christodoulou-Klainermann space-time. The Hamilton equations imply the wave equation for the DO's r_{\\bar a}(\\tau ,\\vec \\sigma ), which replace the two polarizations of the TT harmonic gauge, and that linearized Einstein's equations are satisfied. Finally we study the geodesic equation, both for time-like and null geodesics, and the geodesic deviation equation.

Five-Body Cluster Structure of the Double-{Lambda} Hypernucleus {sub {Lambda}{Lambda}}{sup 11}Be

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hiyama, E.; Kamimura, M.; Yamamoto, Y.

2010-05-28

Energy levels of the double {Lambda} hypernucleus, {sub {Lambda}{Lambda}}{sup 11}Be are calculated within the framework of a {alpha}{alpha}n{Lambda}{Lambda} five-body model. Interactions between constituent particles are determined so as to reproduce reasonably the observed low-energy properties of the {alpha}{alpha}, {alpha}{alpha}n nuclei and the existing data for {Lambda}-binding energies of the {alpha}{Lambda}, {alpha}{alpha}{Lambda}, {alpha}n{Lambda}, and {alpha}{alpha}n{Lambda} systems. An effective {Lambda}{Lambda} interaction is constructed so as to reproduce, within the {alpha}{Lambda}{Lambda} three-body model, the B{sub {Lambda}{Lambda}}of {sub {Lambda}{Lambda}}{sup 6}He, which was extracted from the emulsion experiment, the NAGARA event. With no adjustable parameters for the {alpha}{alpha}n{Lambda}{Lambda} system, B{sub {Lambda}{Lambda}}of the ground and boundmore » excited states of {sub {Lambda}{Lambda}}{sup 11}Be are calculated with the Gaussian expansion method. The Hida event, recently observed at KEK-E373 experiment, is interpreted as an observation of the ground state of the {sub {Lambda}{Lambda}}{sup 11}Be.« less

A Numerical Model for the Computation of Radiance Distributions in Natural Waters with Wind-Roughened Surfaces, Part 2: User’s Guide and Code Listing

DTIC Science & Technology

1988-07-01

8217) END IF C..... SOLUTION STEP 9 C COMPUTE THE AMPLITUDE A(A.’) C CALL AMPAP c WERKY1) NOW COtJ1AINS ACCA ,’). THE kF.,ELTED DIRECT BEAM C C END OF...FUNCTID IN IS USED;’//, SIGMA(V.COS(PSI)) = )’Y)I(44PI) wHERE/fl 2’ IV V S(V) ALPHA(Y) S,/ALPH-A!) 102 FORMAT ( H 14, F8 .IF8 .3,FI10.3, FlI1.3 END 95 §5

Energy-switching potential energy surface for the water molecule revisited: A highly accurate singled-sheeted form.

PubMed

Galvão, B R L; Rodrigues, S P J; Varandas, A J C

2008-07-28

A global ab initio potential energy surface is proposed for the water molecule by energy-switching/merging a highly accurate isotope-dependent local potential function reported by Polyansky et al. [Science 299, 539 (2003)] with a global form of the many-body expansion type suitably adapted to account explicitly for the dynamical correlation and parametrized from extensive accurate multireference configuration interaction energies extrapolated to the complete basis set limit. The new function mimics also the complicated Sigma/Pi crossing that arises at linear geometries of the water molecule.

Bond order potential module for LAMMPS

DOE Office of Scientific and Technical Information (OSTI.GOV)

2012-09-11

pair_bop is a module for performing energy calculations using the Bond Order Potential (BOP) for use in the parallel molecular dynamics code LAMMPS. The bop pair style computes BOP based upon quantum mechanical incorporating both sigma and pi bondings. By analytically deriving the BOP pair bop from quantum mechanical theory its transferability to different phases can approach that of quantum mechanical methods. This potential is extremely effective at modeling 111-V and II-VI compounds such as GaAs and CdTe. This potential is similar to the original BOP developed by Pettifor and later updated by Murdock et al. and Ward et al.

The Scalar Resonances a0/f0(980) at COSY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buescher, M.

2006-02-11

Fundamental properties of the scalar resonances a0/f0(980), like their masses, widths and couplings to KK-bar, are poorly known. In particular, precise knowledge of the latter quantity would be of great importance since it can be related to the KK-bar content of these resonances.An experimental program is under way at COSY-Juelich aiming at the extraction of the isospin violating a0/f0 mixing amplitude {lambda} which is in leading order proportional to the product of the coupling constants of the a0 and f0 to kaons. a0/f0 production is studied in pp, pn and dd interactions, both for the KK-bar and the {pi}{eta}/{pi}{pi} decays,more » using the ANKE and WASA spectrometers. The latter will be available for measurements at COSY in 2007.As a first step, isovector KK-bar production has been measured in the reaction pp {yields} dK+K-bar0. The data reveal dominance of the a{sub 0}{sup +} channel, thus demonstrating the feasibility of scalar meson studies at COSY. Analyses of KK-bar- and K-bard-FSI effects yield the corresponding scattering lengths, a(KK-bar)I=1 = -(0.02 {+-} 0.03) - i(0.61 {+-} 0.05) fm and vertical bar Re a(K-bard) vertical bar {<=}1.3 fm, Im a(K-bard){<=}1.3 fm.« less

Cosmic microwave background snapshots: pre-WMAP and post-WMAP.

PubMed

Bond, J Richard; Contaldi, Carlo; Pogosyan, Dmitry

2003-11-15

We highlight the remarkable evolution in the cosmic microwave background (CMB) power spectrum C(l) as a function of multipole l over the past few years, and in the cosmological parameters for minimal inflation models derived from it: from anisotropy results before 2000; in 2000 and 2001 from Boomerang, Maxima and the Degree Angular Scale Interferometer (DASI), extending l to approximately 1000; and in 2002 from the Cosmic Background Imager (CBI), Very Small Array (VSA), ARCHEOPS and Arcminute Cosmology Bolometer Array Receiver (ACBAR), extending l to approximately 3000, with more from Boomerang and DASI as well. Pre-WMAP (pre-Wilkinson Microwave Anisotropy Probe) optimal band powers are in good agreement with each other and with the exquisite one-year WMAP results, unveiled in February 2003, which now dominate the l less, similar 600 bands. These CMB experiments significantly increased the case for accelerated expansion in the early Universe (the inflationary paradigm) and at the current epoch (dark energy dominance) when they were combined with "prior" probabilities on the parameters. The minimal inflation parameter set, [omega(b), omega(cdm), Omega(tot), Omega(Lambda), n(s), tau(C), sigma(8)], is applied in the same way to the evolving data. C(l) database and Monte Carlo Markov Chain (MCMC) methods are shown to give similar values, which are highly stable over time and for different prior choices, with the increasing precision best characterized by decreasing errors on uncorrelated "parameter eigenmodes". Priors applied range from weak ones to stronger constraints from the expansion rate (HST-h), from cosmic acceleration from supernovae (SN1) and from galaxy clustering, gravitational lensing and local cluster abundance (LSS). After marginalizing over the other cosmic and experimental variables for the weak + LSS prior, the pre-WMAP data of January 2003 compared with the post-WMAP data of March 2003 give Omega(tot) = 1.03(-0.04)(+0.05) compared with 1.02(-0.03)(+0.04), consistent with (non-Baroque) inflation theory. Adding the flat Omega(tot) = 1 prior, we find a nearly scale-invariant spectrum, n(s) = 0.95(-0.04)(+0.07) compared with 0.97(-0.02)(+0.02). The evidence for a logarithmic variation of the spectral tilt is less than or approximately 2sigma. The densities are for: baryons, omega(b) identical with Omega(b)h(2) = 0.0217(-0.002)(+0.002) (compared with 0.0228(-0.001)(+0.001)), near the Big Bang nucleosynthesis (BBN) estimate of 0.0214 +/- 0.002; CDM, omega(cdm) = Omega(cdm)h(2) = 0.126(-0.012)(+0.012) (compared with 0.121(-0.010)(+0.010)); the substantial dark (unclustered) energy, Omega(Lambda) approximately 0.66(-0.09)(+0.07) (compared with 0.70(-0.05)(+0.05)). The dark energy pressure-to-density ratio w(Q) is not well constrained by our weak + LSS prior, but adding SN1 gives w(Q) less than or approximately -0.7 for January 2003 and March 2003, consistent with the w(Q) = -1 cosmological constant case. We find sigma(8) = 0.89(-0.07)(+0.06) (compared with 0.86(-0.04)(+0.04)), implying a sizable Sunyaev-Zel'dovich (SZ) effect from clusters and groups; the high-l power found in the January 2003 data suggest sigma(8) approximately 0.94(-0.16)(+0.08) is needed to be SZ-compatible.

A Search for r-Modes from 1825 to the Present

NASA Technical Reports Server (NTRS)

Wolff, Charles L.

1998-01-01

Global oscillations (r-modes) of the Sun's outer convective envelope with periods approximately 1 month and longer have been detected in several short data strings of several years duration. To test whether r-modes might persist beyond one 11 year cycle, the daily sunspot numbers from 1825 to the present were analyzed. Good evidence, but confidence level less than 3sigma, was found for most of the 14 r-modes with spherical harmonic index lambda less than or equal to 5 that can exist in the presence of solar differential rotation. The characteristic rotation rate of almost every such r-mode was detected, displaced systematically from its expected value by only 0.15%. If this probable detection is real, then most low harmonic r-modes have lifetimes exceeding one century and the rotation of the Sun's outer layers varies by less than 0.05%, except possibly at solar minimum.