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Sample records for radiative decay

  1. Radiative decays at LHCb

    NASA Astrophysics Data System (ADS)

    Giubega, L. E.

    2016-12-01

    Precise measurements on rare radiative B decays are performed with the LHCb experiment at LHC. The LHCb results regarding the ratio of branching fractions for two radiative decays, B 0 → K *0 γ and B s → ϕ γ, the direct CP asymmetry in B 0 → K *0 γ decay channel and the observation of the photon polarization in the B ± → K ±π∓π± γ decay, are included. The first two measurements were performed in 1 fb-1 of pp collisions data and the third one in 3 fb-1 of data, respectively.

  2. Radiative B Decays

    SciTech Connect

    Bard, D.; /Imperial Coll., London

    2011-11-23

    I discuss recent results in radiative B decays from the Belle and BaBar collaborations. I report new measurements of the decay rate and CP asymmetries in b {yields} s{gamma} and b {yields} d{gamma} decays, and measurements of the photon spectrum in b {yields} s{gamma}. Radiative penguin decays are flavour changing neutral currents which do not occur at tree level in the standard model (SM), but must proceed via one loop or higher order diagrams. These transitions are therefore suppressed in the SM, but offer access to poorlyknown SM parameters and are also a sensitive probe of new physics. In the SM, the rate is dominated by the top quark contribution to the loop, but non-SM particles could also contribute with a size comparable to leading SM contributions. The new physics effects are potentially large which makes them theoretically very interesting, but due to their small branching fractions they are typically experimentally challenging.

  3. RADIATIVE PENGUIN DECAYS FROM BABAR

    SciTech Connect

    Eigen, Gerald

    2003-08-28

    Electroweak penguin decays provide a promising hunting ground for Physics beyond the Standard Model (SM). The decay B {yields} X{sub s}{gamma}, which proceeds through an electromagnetic penguin loop, already provides stringent constraints on the supersymmetric (SUSY) parameter space. The present data samples of {approx}1 x 10{sup 8} B{bar B} events allow to explore radiative penguin decays with branching fractions of the order of 10{sup -6} or less. In this brief report they discuss a study of B {yields} K*{ell}{sup +}{ell}{sup -} decay modes and a search for B {yields} {rho}({omega}){gamma} decays.

  4. Radiative Leptonic B Decays

    SciTech Connect

    Chen, Edward Tann

    2007-01-01

    We present the results of a search for B+ meson decays into γℓ+v, where ℓ = e,μ. We use a sample of 232 million B$\\bar{B}$ meson pairs recorded at the Υ(4S) resonance with the BABAR detector at the PEP-II B factory. We measure a partial branching fraction Δβ in a restricted region of phase space that reduces the effect of theoretical uncertainties, requiring the lepton energy to be in the range 1.875 and 2.850 GeV, the photon energy to be in the range 0.45 and 2.35 GeV, and the cosine of the angle between the lepton and photon momenta to be less than -0.36, with all quantities computed in the Υ(4S) center-of-mass frame. We find Δβ(B+ → γℓ+v) = (-0.31.5+1.3(statistical) -0.6+0.6(systematic) ± 0.1(theoretical)) x 10-6, under the assumption of lepton universality. Interpreted as a 90% confidence-level Bayesian upper limit, the result corresponds to 1.7 x 10-6 for a prior at in amplitude, and 2.3 x 10-6 for a prior at in branching fraction.

  5. Rare and radiative kaon decays

    NASA Astrophysics Data System (ADS)

    D’Ambrosio, Giancarlo

    2017-01-01

    We discuss theoretical issues in radiative rare kaon decays. The interest is twofold: to extract useful short-distance information and understand the underlying dynamics. We emphasize channels where either we can understand non-perturbative aspects of QCD or there is a chance to test the Standard Model. An interesting channel, K + → π + π 0 e + e ‑, is studied also in connection with the recent experimental NA48 results. Motivated by LHCB results on KS → μ + μ ‑ we discuss other channels like KS,L → l + l ‑ l + l ‑. Motivated by recent theoretical work by Buras and collaborators we study also the K ± → π±l + l ‑ form factor.

  6. Weak radiative baryonic decays of B mesons

    SciTech Connect

    Kohara, Yoji

    2004-11-01

    Weak radiative baryonic B decays B{yields}B{sub 1}B{sub 2}-bar{gamma} are studied under the assumption of the short-distance b{yields}s{gamma} electromagnetic penguin transition dominance. The relations among the decay rates of various decay modes are derived.

  7. Radiative Penguin Decays at the B Factories

    SciTech Connect

    Koneke, Karsten; /MIT, LNS

    2007-11-16

    In this article, I review the most recent results in radiative penguin decays from the B factories Belle and BABAR. Most notably, I will talk about the recent new observations in the decays B {yields} ({rho}/{omega}) {gamma}, a new analysis technique in b {yields} s{gamma}, and first measurements of radiative penguin decays in the B{sup 0}{sub s} meson system. Finally, I will summarize the current status and future prospects of radiative penguin B physics at the B factories.

  8. Electrical Analogs of Atomic Radiative Decay Processes

    ERIC Educational Resources Information Center

    Fontana, Peter R.; Srivastava, Rajendra P.

    1977-01-01

    Analyzes simple electrical circuits, showing that for high frequencies they have frequency and time responses identical to the spontaneous radiative decay of atoms. Compares a two-circuit electrical system with a two-level atom. (MLH)

  9. Competition between radiative and strong force decay

    NASA Astrophysics Data System (ADS)

    Tabor, Samuel

    2017-01-01

    For nuclear states unbound to neutron decay, radiative emission is often assumed to not dominate over neutron decay mediated by the far stronger strong interaction, except for very low neutron energies and high angular momentum barriers. Recent experimental investigations of 19O and 27 Mg populated in heavy-ion fusion-evaporation reactions have revealed predominantly gamma decays from a number of states unbound to neutron decay by up to 2 MeV. In most cases the angular momentum barrier is not sufficient to inhibit neutron decay enough to allow E-M decay with widths of up to an eV or so to win. Other inhibitions to particle decay, including low spectroscopic factors, will be discussed. Supported in part by NSF Grant No. 1401574.

  10. Radiative β decay of the free neutron

    NASA Astrophysics Data System (ADS)

    Cooper, R. L.; Chupp, T. E.; Dewey, M. S.; Gentile, T. R.; Mumm, H. P.; Nico, J. S.; Thompson, A. K.; Fisher, B. M.; Kremsky, I.; Wietfeldt, F. E.; Beise, E. J.; Kiriluk, K. G.; Byrne, J.; Coakley, K. J.; Fu, C.

    2010-03-01

    The theory of quantum electrodynamics predicts that the β decay of the neutron into a proton, electron, and antineutrino is accompanied by a continuous spectrum of emitted photons described as inner bremsstrahlung. While this phenomenon has been observed in nuclear β decay and electron-capture decay for many years, it has only been recently observed in free-neutron decay. We present a detailed discussion of an experiment in which the radiative decay mode of the free neutron was observed. In this experiment, the branching ratio for this rare decay was determined by recording photons that were correlated with both the electron and proton emitted in neutron decay. We determined the branching ratio for photons with energy between 15 and 340 keV to be (3.09±0.32)×10-3 (68% level of confidence), where the uncertainty is dominated by systematic effects. This value for the branching ratio is consistent with theoretical predictions. The characteristic energy spectrum of the radiated photons, which differs from the uncorrelated background spectrum, is also consistent with the theoretical spectrum.

  11. Radiative And Electroweak Penguin Decays of B

    SciTech Connect

    Richman, Jeffrey D.; /UC, Santa Barbara

    2007-11-09

    Radiative and electroweak penguin decays of B mesons are flavor-changing-neutral-current processes that provide powerful ways to test the Standard Model at the one-loop level, to search for the effects of new physics, and to extract Standard Model parameters such as CKM matrix elements and quark masses. The large data samples obtained by the B-factory experiments BaBar and Belle, together with an intensive theoretical effort, have led to significant progress towards understanding these rare decays. Recent experimental results include the measurements of the b {yields} d{gamma} decays B {yields} {rho}({omega}){gamma}, the observation of B {yields} K(*){ell}{sup +}{ell}{sup -} decays (together with studies of the associated kinematic distributions), and improved measurements of the inclusive B {yields} Xs{gamma} rate and photon energy spectrum.

  12. STUDIES OF RADIATIVE PENGUIN DECAYS AT BABAR

    SciTech Connect

    Jessop, C

    2003-10-27

    The electromagnetic radiative ''penguin'' decays b {yields} s{gamma}, b {yields} d{gamma} are sensitive to physics beyond the Standard Model. The authors present recent studies made with the BABAR detector at the PEP-II asymmetric e{sup +}e{sup -} storage ring.

  13. Penguin diagram dominance in radiative weak decays of bottom baryons

    SciTech Connect

    Kohara, Yoji

    2005-05-01

    Radiative weak decays of antitriplet bottom baryons are studied under the assumption of penguin diagram dominance and flavor-SU(3) (or SU(2)) symmetry. Relations among decay rates of various decay modes are derived.

  14. Biomedical applications of radiative decay engineering

    NASA Astrophysics Data System (ADS)

    Lakowicz, Joseph R.; Gryczynski, Ignacy; Malicka, Joanna; Shen, Yibing; Gryczynski, Zygmunt

    2002-06-01

    Fluorescence spectroscopy is a widely used research tool in biochemistry and has also become the dominant method enabling the revolution in medical diagnostics, DNA sequencing and genomics. In this forward-looking article we describe a new opportunity in fluorescence, radiative decay engineering (RDE). By RDE we mean modifying the emission of fluorophores or chromophores by a nearby metallic surface, the most important effect being an increase in the radiative decay rate. We describe the usual effects expected form increase in the radiative rates with reference to the biomedical applications of immunoassay and DNA hybridization. We also present experiments which show that metallic particles can increase the quantum yield of low quantum yield fluorophores, increase fluorophore photostability and increase the distance for resonance energy transfer. And finally we show that proximity to silver particles can increase the intensity of the intrinsic fluorescence from DNA.

  15. Study of the radiative pion decay

    SciTech Connect

    Chen, Chuan-Hung; Geng, Chao-Qiang; Lih, Chong-Chung

    2011-04-01

    We study the radiative pion decay of {pi}{sup +}{yields}e{sup +}{nu}{sub e}{gamma} in the light-front quark model. We also summarize the result in the chiral perturbation theory. The vector and axial-vector hadronic form factors (F{sub V,A}) for the {pi}{yields}{gamma} transition are evaluated in the whole allowed momentum transfer. In terms of these momentum dependent form factors, we calculate the decay branching ratio and compare our results with the experimental data and other theoretical predictions in the literature. We also constrain the possible size of the tensor interaction in the light-front quark model.

  16. Form factors in the radiative pion decay

    NASA Astrophysics Data System (ADS)

    Mateu, V.; Portolés, J.

    2007-10-01

    We perform an analysis of the form factors that rule the structure-dependent amplitude in radiative pion decay. The resonance contributions to π→eνeγ decays are computed through the proper construction of the vector and axial-vector form factors by setting the QCD driven asymptotic properties of the three-point Green functions and , and by demanding the smoothening of the form factors at high transfer of momentum. A comparison between theoretical and experimental determination of the form factors is also carried out. We also consider and evaluate the role played by a non-standard tensor form factor. We conclude that, at present and due to the hadronic uncertainties, the search for new physics in this process is not feasible.

  17. Radiative decays of the neutral Zc(3900 )

    NASA Astrophysics Data System (ADS)

    Chen, Dian-Yong; Dong, Yu-Bing

    2016-01-01

    We study the radiative decays of the Zc(3900 )0 in a hadronic molecule picture, where the Zc(3900 ) is treated as a D D¯ *+c .c hadronic molecule. The partial widths of Γ (Zc(3900 )0→γ ηc(2 S )) and Γ (Zc(3900 )0→γ χc 0) are predicted to be of order 10 keV, and the cross sections for σ (e+e-→π0Zc(3900 )→π0γ ηc(2 S )) and σ (e+e-→π0Zc(3900 )→π0γ χc 0) are of order 0.1 pb at 4.23 GeV, which may be accessible for the BESIII and forthcoming Belle II.

  18. Radiative corrections to top-quark decay

    NASA Astrophysics Data System (ADS)

    Eilam, G.; Mendel, R. R.; Migneron, R.; Soni, A.

    1991-06-01

    We calculate all radiative corrections to one-loop order for the main decay of the top quark, t-->b+W, in the standard model, retaining exact dependence on all masses. For mt=150 GeV and MH=100 GeV we find a -2.9% (-6.9%) correction with a very weak dependence on the Higgs-boson mass, in renormalization schemes that use α, GF, and MZ (GF, MW, and MZ) as input parameters. Out of the above results, -8.5% is due to QCD. The mt and MH dependence is given up to 300 and 1000 GeV, respectively. The inadequacy of a leading mt calculation is pointed out.

  19. Inclusive radiative J/{psi} decays

    SciTech Connect

    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.

    2008-08-01

    Using data taken with the CLEO-c detector at the Cornell Electron Storage Ring, we have investigated the direct-photon momentum spectrum in the decay J/{psi}(1S){yields}{gamma}gg, via the ''tagged'' process: e{sup +}e{sup -}{yields}{psi}(2S); {psi}(2S){yields}J/{psi}{pi}{sup +}{pi}{sup -}; J/{psi}{yields}{gamma}+X. Including contributions from two-body radiative decay processes, we find the ratio of the inclusive direct-photon branching fraction to that of the dominant three-gluon branching fraction [R{sub {gamma}}=B(gg{gamma})/B(ggg)] to be R{sub {gamma}}=0.137{+-}0.001{+-}0.016{+-}0.004, where the errors shown are statistical, systematic, and the model-dependent uncertainty related to the extrapolation to zero photon energy. The shape of the scaled photon energy spectrum in J/{psi}{yields}gg{gamma} is observed to be very similar to that of {upsilon}{yields}gg{gamma}. The R{sub {gamma}} value obtained is roughly consistent with that expected by a simple quark-charge scaling [R{sub {gamma}}{approx}(q{sub c}/q{sub b}){sup 2}] of the value determined at the {upsilon}(1S), but somewhat higher than the value expected from the running of the strong coupling constant.

  20. J/psi and UPSILON radiative and hadronic decays

    SciTech Connect

    Bloom, E.D.

    1987-07-01

    The search for gluonium at the J/psi and UPSILON is discussed, as well as the search for exotics at the UPSILON. Reactions discussed include radiative and hadronic decays of the J/psi and the search for radiative decays of the UPSILON. Future perspectives are also briefly considered. 45 refs., 27 figs. (LEW)

  1. Radiative decay of massious neutrinos: Implications for physics and astrophysics

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1981-01-01

    The radiative lifetime tau for the decay of massious neutrinos is calculated using various physical models for neutrino decay. The results are related to the astrophysical problem of the detectability of the decay photons from cosmic neutrinos. Conversely, the astrophysical data are used to place lower limits on tau. However, an observed feature at approximately 1700 A in the ultraviolet background radiation at high galactic latitudes may be from the decay of neutrinos with mass approximately 14 eV. This would require a decay rate much larger than the predictions of standard models but could be indicative of a decay rate possible in composite models. It is considered that this may be an important test for substructure in leptons and quarks.

  2. Studies of Radiative Penguin B Decays at BABAR

    SciTech Connect

    Hamel de Monchenault, Gautier

    2003-05-14

    We summarize results on a number of observations of penguin dominated radiative decays of the B meson. Such decays are forbidden at tree level and proceed via electroweak loops. As such they may be sensitive to physics beyond the standard model. The observations have been made at the BaBar experiment at PEPII, the asymmetric B factory at SLAC.

  3. An electroweak enigma: Hyperon radiative decays

    SciTech Connect

    Vorobyov, A.,; Jastrzembski, E.; Lach, J.; Marriner, J.; Golovtsov, V.; Krivshich, A.; Schegelsky, V.; Smirnov, N.; Terentiev, N.K.; Uvarov, L.; McCliment, E.; Newsom, C.; Norbeck, E.; Cooper, P.S.; /Yale U.

    1985-04-03

    The main thrust of this experiment will be to measure the asymmetry parameter for the electroweak decay {Sigma}{sup +} {yields} p{gamma} and verify its branching ratio. As a secondary goal they will measure, or set new upper limits for, the branching ratio of the electroweak decay {Xi}{sup -} {yields} {Sigma}{sup -}{gamma}. Since the {Xi}{sup -} are expected to be polarized, information on the asymmetry parameter may also be available.

  4. Dark radiation from particle decay: cosmological constraints and opportunities

    SciTech Connect

    Hasenkamp, Jasper; Kersten, Jörn E-mail: Joern.Kersten@desy.de

    2013-08-01

    We study particle decay as the origin of dark radiation. After elaborating general properties and useful parametrisations we provide model-independent and easy-to-use constraints from nucleosynthesis, the cosmic microwave background and structure formation. Bounds on branching ratios and mass hierarchies depend in a unique way on the time of decay. We demonstrate their power to exclude well-motivated scenarios taking the example of the lightest ordinary sparticle decaying into the gravitino. We point out signatures and opportunities in cosmological observations and structure formation. For example, if there are two dark decay modes, dark radiation and the observed dark matter with adjustable free-streaming can originate from the same decaying particle, solving small-scale problems of structure formation. Hot dark matter mimicking a neutrino mass scale as deduced from cosmological observations can arise and possibly be distinguished after a discovery. Our results can be used as a guideline for model building.

  5. Dark radiation from particle decays during big bang nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Menestrina, Justin L.; Scherrer, Robert J.

    2012-02-01

    CMB observations suggest the possibility of an extra dark radiation component, while the current evidence from big bang nucleosynthesis (BBN) is more ambiguous. Dark radiation from a decaying particle can affect these two processes differently. Early decays add an additional radiation component to both the CMB and BBN, while late decays can alter the radiation content seen in the CMB while having a negligible effect on BBN. Here, we quantify this difference and explore the intermediate regime by examining particles decaying during BBN, i.e., particle lifetimes τX satisfying 0.1sec<τX<1000sec. We calculate the change in the effective number of neutrino species, Neff, as measured by the CMB, ΔNCMB, and the change in the effective number of neutrino species as measured by BBN, ΔNBBN, as a function of the decaying particle initial energy density and lifetime, where ΔNBBN is defined in terms of the number of additional two-component neutrinos needed to produce the same change in the primordial He4 abundance as our decaying particle. As expected, for short lifetimes (τX≲0.1sec), the particles decay before the onset of BBN, and ΔNCMB=ΔNBBN, while for long lifetimes (τX≳1000sec), ΔNBBN is dominated by the energy density of the nonrelativistic particles before they decay, so that ΔNBBN remains nonzero and becomes independent of the particle lifetime. By varying both the particle energy density and lifetime, one can obtain any desired combination of ΔNBBN and ΔNCMB, subject to the constraint that ΔNCMB≥ΔNBBN. We present limits on the decaying particle parameters derived from observational constraints on ΔNCMB and ΔNBBN.

  6. Radiative Corrections to One-Photon Decays of Hydrogenic Ions

    SciTech Connect

    Sapirstein, J; Pachucki, K; Cheng, K T

    2003-11-11

    Radiative corrections to the decay rate of n = 2 states of hydrogenic ions are calculated. The transitions considered are the M1 decay of the 2s state to the ground state and the E1(M2) decays of the 2p{sub 1/2} and 2p{sub 3/2} states to the ground state. The radiative corrections start in order {alpha}(Z{alpha}){sup 2}, but the method used sums all orders of Z{alpha}. The leading {alpha}(Z{alpha}){sup 2} correction for the E1 decays is calculated and compared with the exact result. The extension of the calculational method to parity nonconserving transitions in neutral atoms is discussed.

  7. Radiative decays of resonances on the lattice

    SciTech Connect

    Agadjanov, Andria; Bernard, Véronique; Rusetsky, Akaki

    2016-01-22

    We discuss a generalization of the Lüscher approach to the calculation of the matrix elements of the unstable states. A theoretical framework for the lattice extraction of the ΔNγ* transition form factors is formulated. The procedure to measure the form factors at the resonance pole is given. The current theoretical progress on the B → K*γ* decays is briefly summarized.

  8. Time reversal violation in radiative beta decay: experimental plans

    NASA Astrophysics Data System (ADS)

    Behr, J. A.; McNeil, J.; Anholm, M.; Gorelov, A.; Melconian, D.; Ashery, D.

    2017-01-01

    Some explanations for the excess of matter over antimatter in the universe involve sources of time reversal violation (TRV) in addition to the one known in the standard model of particle physics. We plan to search for TRV in a correlation between the momenta of the beta, neutrino, and the radiative gamma sometimes emitted in nuclear beta decay. Correlations involving three (out of four) momenta are sensitive at lowest order to different TRV physics than observables involving spin, such as electric dipole moments and spin-polarized beta decay correlations. Such experiments have been done in radiative kaon decay, but not in systems involving the lightest generation of quarks. An explicit low-energy physics model being tested produces TRV effects in the Fermi beta decay of the neutron, tritium, or some positron-decaying isotopes. We will present plans to measure the TRV asymmetry in radiative beta decay of laser-trapped 38mK at better than 0.01 sensitivity, including suppression of background from positron annihilation. Supported by NSERC, D.O.E., Israel Science Foundation. TRIUMF receives federal funding via a contribution agreement with the National Research Council of Canada.

  9. Decay processes and radiative cooling of small anionic copper clusters

    NASA Astrophysics Data System (ADS)

    Breitenfeldt, Christian; Blaum, Klaus; Froese, Michael W.; George, Sebastian; Guzmán-Ramírez, Gregorio; Lange, Michael; Menk, Sebastian; Schweikhard, Lutz; Wolf, Andreas

    2016-09-01

    The decay of copper clusters Cun- with size n =4 -7 , produced in a metal ion sputter source, was studied in an electrostatic ion-beam trap. The neutral products after electron emission and fragmentation were monitored for ion storage times of up to a second. The observations indicated the presence of radiative cooling. The energy distributions of the remaining clusters were probed by laser irradiation up to several further seconds of storage time. This defined excitation lead to photoinduced decay signals which, again, showed signs of radiative cooling for Cu6,7 -, not, however, for Cu4,5 -.

  10. Ultraviolet background radiation and the search for decaying neutrinos

    NASA Technical Reports Server (NTRS)

    Henry, R. C.

    1981-01-01

    The spectrum of the observed far-ultraviolet background at high galactic latitudes is studied in order to find evidence of radiation from neutrino decay. It is concluded that at latitudes above about 20 degrees, the limit on any light scattered from interstellar dust or the limit on light from any source other than stars is of order 300 photons/sq cm sec ster A. Superficial evidence for radiation from decaying neutrinos is provided by an examination of the spectrum of the observed background at the highest galactic latitudes, although the spectrum is so uncertain that conclusions are not possible.

  11. Comparison of two experiments on radiative neutron decay

    SciTech Connect

    Khafizov, R. U.; Tolokonnikov, S. V.; Solovei, V. A.; Kolhidashvili, M. R.

    2009-12-15

    Over 10 years ago we proposed an experiment on measuring the characteristics of radiative neutron decay in papers [1, 2]. At the same time we had published the theoretical spectrum of radiative gamma quanta, calculated within the framework of the electroweak interactions, on the basis of which we proposed the methodology for the future experiment [3, 4]. However, because we were denied beam time on the intensive cold neutron beam at ILL (Grenoble, France) for a number of years, we could only conduct the experiment in 2005 on the newly opened FRMII reactor of Technical University of Muenchen. The main result of this experiment was the discovery of radiative neutron decay and the measurement of its relative intensity B.R. = (3.2 {+-} 1.6) x 10{sup -3} with C.L. = 99.7% for radiative gamma quanta with energy over 35 kev [5, 6]. Over a year after our first announcement about the results of the conducted experiment, 'Nature' [7] published a letter asserting that its authors have also measured the branching ratio of radiative neutron decay B.R. = (3.13 {+-} 0.34) x 10{sup -3} with c.l. = 68% and gamma quanta energy from 15 to 340 kev. This article aims to compare these two experiments. It is shown that the use of strong magnetic fields in the NIST (Washington, USA) experiment methodology not only prevents any exact measurement of the branching ratio and identification of radiative neutron decay events, but also makes registration of ordinary neutron decay events impossible.

  12. Precision theoretical analysis of neutron radiative beta decay

    NASA Astrophysics Data System (ADS)

    Ivanov, A. N.; Höllwieser, R.; Troitskaya, N. I.; Wellenzohn, M.; Berdnikov, Ya. A.

    2017-02-01

    In the Standard Model of electroweak interactions and in the tree approximation we calculate the rate and branching ratio of the neutron radiative β- decay with one real photon emission by taking into account the contributions of the weak magnetism and proton recoil to order 1 /mp of the large proton mass mp expansion. We find that the obtained contributions of the weak magnetism and proton recoil increase the rate and branching ratio of the neutron radiative β- decay by about 0.70%. This is large compared with the contribution of the weak magnetism and proton recoil of about 0.16% to the rate of the neutron β- decay, calculated in Phys. Rev. D 88, 073002 (2013), 10.1103/PhysRevD.88.073002.

  13. Decay rate of the second radiation belt.

    PubMed

    Badhwar, G D; Robbins, D E

    1996-01-01

    Variations in the Earth's trapped (Van Allen) belts produced by solar flare particle events are not well understood. Few observations of increases in particle populations have been reported. This is particularly true for effects in low Earth orbit, where manned spaceflights are conducted. This paper reports the existence of a second proton belt and it's subsequent decay as measured by a tissue-equivalent proportional counter and a particle spectrometer on five Space Shuttle flights covering an eighteen-month period. The creation of this second belt is attributed to the injection of particles from a solar particle event which occurred at 2246 UT, March 22, 1991. Comparisons with observations onboard the Russian Mir space station and other unmanned satellites are made. Shuttle measurements and data from other spacecraft are used to determine that the e-folding time of the peak of the second proton belt. It was ten months. Proton populations in the second belt returned to values of quiescent times within eighteen months. The increase in absorbed dose attributed to protons in the second belt was approximately 20%. Passive dosimeter measurements were in good agreement with this value.

  14. Decay rate of the second radiation belt

    NASA Technical Reports Server (NTRS)

    Badhwar, G. D.; Robbins, D. E.

    1996-01-01

    Variations in the Earth's trapped (Van Allen) belts produced by solar flare particle events are not well understood. Few observations of increases in particle populations have been reported. This is particularly true for effects in low Earth orbit, where manned spaceflights are conducted. This paper reports the existence of a second proton belt and it's subsequent decay as measured by a tissue-equivalent proportional counter and a particle spectrometer on five Space Shuttle flights covering an eighteen-month period. The creation of this second belt is attributed to the injection of particles from a solar particle event which occurred at 2246 UT, March 22, 1991. Comparisons with observations onboard the Russian Mir space station and other unmanned satellites are made. Shuttle measurements and data from other spacecraft are used to determine that the e-folding time of the peak of the second proton belt. It was ten months. Proton populations in the second belt returned to values of quiescent times within eighteen months. The increase in absorbed dose attributed to protons in the second belt was approximately 20%. Passive dosimeter measurements were in good agreement with this value.

  15. Radiative decay rates of impurity states in semiconductor nanocrystals

    NASA Astrophysics Data System (ADS)

    Turkov, Vadim K.; Baranov, Alexander V.; Fedorov, Anatoly V.; Rukhlenko, Ivan D.

    2015-10-01

    Doped semiconductor nanocrystals is a versatile material base for contemporary photonics and optoelectronics devices. Here, for the first time to the best of our knowledge, we theoretically calculate the radiative decay rates of the lowest-energy states of donor impurity in spherical nanocrystals made of four widely used semiconductors: ZnS, CdSe, Ge, and GaAs. The decay rates were shown to vary significantly with the nanocrystal radius, increasing by almost three orders of magnitude when the radius is reduced from 15 to 5 nm. Our results suggest that spontaneous emission may dominate the decay of impurity states at low temperatures, and should be taken into account in the design of advanced materials and devices based on doped semiconductor nanocrystals.

  16. Radiative decay rates of impurity states in semiconductor nanocrystals

    SciTech Connect

    Turkov, Vadim K.; Baranov, Alexander V.; Fedorov, Anatoly V.; Rukhlenko, Ivan D.

    2015-10-15

    Doped semiconductor nanocrystals is a versatile material base for contemporary photonics and optoelectronics devices. Here, for the first time to the best of our knowledge, we theoretically calculate the radiative decay rates of the lowest-energy states of donor impurity in spherical nanocrystals made of four widely used semiconductors: ZnS, CdSe, Ge, and GaAs. The decay rates were shown to vary significantly with the nanocrystal radius, increasing by almost three orders of magnitude when the radius is reduced from 15 to 5 nm. Our results suggest that spontaneous emission may dominate the decay of impurity states at low temperatures, and should be taken into account in the design of advanced materials and devices based on doped semiconductor nanocrystals.

  17. Quasiclassical description of bremsstrahlung accompanying {alpha} decay including quadrupole radiation

    SciTech Connect

    Jentschura, U. D.; Milstein, A. I.; Terekhov, I. S.; Boie, H.; Scheit, H.; Schwalm, D.

    2008-01-15

    We present a quasiclassical theory of {alpha} decay accompanied by bremsstrahlung with a special emphasis on the case of {sup 210}Po, with the aim of finding a unified description that incorporates both the radiation during the tunneling through the Coulomb wall and the finite energy E{sub {gamma}} of the radiated photon up to E{sub {gamma}}{approx}Q{sub {alpha}}/{radical}({eta}), where Q{sub {alpha}} is the {alpha}-decay Q-value and {eta} is the Sommerfeld parameter. The corrections with respect to previous quasiclassical investigations are found to be substantial, and excellent agreement with a full quantum mechanical treatment is achieved. Furthermore, we find that a dipole-quadrupole interference significantly changes the {alpha}-{gamma} angular correlation. We obtain good agreement between our theoretical predictions and experimental results.

  18. Limits to the radiative decay of the axion

    NASA Technical Reports Server (NTRS)

    Ressell, M. Ted

    1991-01-01

    An axion with a mass greater than 1 eV should be detectable through its decay into two photons. The astrophysical and cosmological limits which define a small window of allowed axion mass above 3 eV are discussed. A firm upper bound to the axion's mass of M(sub a) less than or equal to 8 eV is derived by considering the effect of decaying axions upon the diffuse extragalactic background radiation and the brightness of the night sky due to axions in the halo of the Milky Way galaxy. The intergalactic light of clusters of galaxies is shown to be an ideal place to search for an emission line arising from the radiative decay of axions. An unsuccessful search for this emission line in three clusters of galaxies is then detailed. Limits to the presence of any intracluster line emission are derived with the result that axions with masses between 3 and 8 eV are excluded by the data, effectively closing this window of axion mass, unless a severe cancellation of axionic decay amplitudes occurs. The intracluster flux limits are then used to constrain the amplitude of any such model dependence.

  19. A search for radiative neutrino decay from supernovae

    NASA Technical Reports Server (NTRS)

    Miller, Richard S.; Svoboda, Robert C.

    1993-01-01

    This document presents the data analysis procedures proposed for use with the COMPTEL instrument aboard the Compton Gamma Ray Observatory (GRO) in the search for radiative neutrino decay from supernovae. The proposed analysis methodology is an extension of a standard procedure used by the COMPTEL team in searching for a variety of source types. We have applied the procedures to a set of simulated data to demonstrate the feasibility of the method to this project.

  20. Limits on neutrino radiative decay from SN1987A

    NASA Technical Reports Server (NTRS)

    Jaffe, Andrew H.; Fenimore, ED; Turner, Michael S.

    1993-01-01

    We calculate limits on the properties of neutrinos using data from gamma ray detectors on the Pioneer Venus Orbiter and Solar Max Mission satellites. A massive neutrino decaying in flight from the supernova would produce gamma rays detectable by these instruments. The lack of such a signal allows us to constrain the mass, radiative lifetime, and branching ratio to photons of a massive neutrino species produced in the supernova.

  1. Radiative hc /b decays to η or η '

    NASA Astrophysics Data System (ADS)

    Zhu, Ruilin; Dai, Jian-Ping

    2016-11-01

    Motivated by recent measurements of the radiative decay rates of the P -wave spin singlet charmonium hc to the light meson η or η' by the BESIII Collaboration, we investigate the decay rates of these channels at order α αs4. The photon is radiated mainly from charm quark pairs in the lowest-order Feynman diagrams, because the diagrams where a photon radiated from light quarks are suppressed by αs or the relative charm quark velocity v , due to charge-parity conservation. The form factors of two gluons to η or η', which are the major mechanism for η and η' production, are employed. η (η') is treated as a light-cone object when we consider that the parent charmonium mass is much heavier than that of the final light meson. We obtain the branching ratio B (hc→γ η')=(1.9 4-0.51+0.70)×10-3 in the nonrelativistic QCD approach, which is in agreement with the BESIII measurement. The prediction of the branching ratio of hc→γ η is also within the range of experimental error after including the larger uncertainty of the total decay width Γh c. The applications of these formulas to the radiative decays to η (η') of the P -wave spin singlet bottomonium hb(n P ) are presented. These studies will shed some light on the η -η' mixing effects, the flavor SU(3) symmetry breaking, and the nonperturbative dynamics of charmonium and bottomonium.

  2. Radiative Decays of Low-Lying Excited-State Hyperons

    SciTech Connect

    Taylor, Simon

    2000-05-01

    The quark wave-functions of the lower-lying excited-state hyperons Lambda(1405), Sigma(1385), and Lambda(1520) are not well understood. For example, the Lambda(1405) may not be a regular three-quark state but a $\\bar{K}$N molecule. Several competing models have been proposed, but none have been convincingly eliminated. Measuring radiative decays provides a means of discriminating between the models. The radiative branching of ratios are predicted to be small (~1%), but the radiative widths vary by factors of 2-10 from model to model. The existing experimental data is sparse and inconsistent; moreover, the radiative decay of the Sigma(1385) has never been observed before (except for one event). These lower-lying excited state hypersons were produced in a tagged photon-beam experiment in the CLAS detector at TJNAF in the reaction gamma p → K+ Y* for photon energies from threshold to 2.4 GeV. The radiative branching ration for the Sigma0(1385) relative to the Sigma0(1385) → Lambda pi0 channel was measured to be 0.021 ± 0.008$+0.004\\atop{-0.007}$, corresponding to a partial width of 640 ± 270$+130\\atop{-220}$ keV.

  3. Decay constants and radiative decays of heavy mesons in light-front quark model

    SciTech Connect

    Choi, Ho-Meoyng

    2007-04-01

    We investigate the magnetic dipole decays V{yields}P{gamma} of various heavy-flavored mesons such as (D,D*,D{sub s},D{sub s}*,{eta}{sub c},J/{psi}) and (B,B*,B{sub s},B{sub s}*,{eta}{sub b},{upsilon}) using the light-front quark model constrained by the variational principle for the QCD-motivated effective Hamiltonian. The momentum dependent form factors F{sub VP}(q{sup 2}) for V{yields}P{gamma}* decays are obtained in the q{sup +}=0 frame and then analytically continued to the timelike region by changing q{sub perpendicular} to iq{sub perpendicular} in the form factors. The coupling constant g{sub VP{gamma}} for real photon case is then obtained in the limit as q{sup 2}{yields}0, i.e. g{sub VP{gamma}}=F{sub VP}(q{sup 2}=0). The weak decay constants of heavy pseudoscalar and vector mesons are also calculated. Our numerical results for the decay constants and radiative decay widths for the heavy-flavored mesons are overall in good agreement with the available experimental data as well as other theoretical model calculations.

  4. QED corrections to radiative recombination and radiative decay of heavy hydrogenlike ions

    NASA Astrophysics Data System (ADS)

    Holmberg, J.; Artemyev, A. N.; Surzhykov, A.; Yerokhin, V. A.; Stöhlker, Th.

    2015-10-01

    One-loop quantum electrodynamic (QED) corrections are studied for two basic atomic processes, radiative recombination of an electron with a bare nucleus and radiative decay of a hydrogenlike ion. The perturbations of the bound-state wave function and the binding energy due to the electron self-energy and the vacuum polarization are computed in the Feynman and Coulomb gauges. QED corrections induced by these perturbations are calculated for the differential cross section and the polarization of the emitted radiation in the radiative recombination of an electron and a bare uranium nuclei, as well as the corresponding corrections to the ratio of the E 1 (electric dipole) and M 2 (magnetic quadrupole) transition amplitudes in the 2 p3 /2→1 s radiative decay of hydrogenlike uranium. The results obtained indicate the expected magnitude of the QED effects in these processes on a subpercent level.

  5. Factorization for radiative heavy quarkonium decays into scalar Glueball

    NASA Astrophysics Data System (ADS)

    Zhu, Ruilin

    2015-09-01

    We establish the factorization formula for scalar Glueball production through radiative decays of vector states of heavy quarkonia, e.g. J/ ψ, ψ(2 S) and Υ( nS), where the Glueball mass is much less than the parent heavy quarkonium mass. The factorization is demonstrated explicitly at one-loop level through the next-to-leading order (NLO) corrections to the hard kernel, the non-relativistic QCD (NRQCD) long-distance matrix elements (LDMEs) of the heavy quarkonium, and the light-cone distribution amplitude (LCDA) of scalar Glueball. The factorization provides a comprehensive theoretical approach to investigate Glueball production in the radiative decays of vector states of heavy quarkonia and determine the physic nature of Glueball. We discuss the scale evolution equation of LCDA for scalar Glueball. In the end, we extract the value of the decay constant of Scalar Glueball from Lattice QCD calculation and analyze the mixing effect among f 0(1370), f 0(1500) and f 0(1710).

  6. The Radiative Decay of Plasma Oscillations on Nonplanar Metal Surfaces

    NASA Astrophysics Data System (ADS)

    Little, John William, Jr.

    We have studied the radiation resulting from electron bombardment of extremely small silver particles and of silver films containing closely-spaced, periodic surface structure. Thin silver films which were heated to a temperature slightly below the bulk-silver melting point were found to break into collections of particles with approximately ellipsoidal cross sections. Electron microscopy and shadow -casting techniques were used to characterize the samples as to the distributions of particle sizes and particle shapes. The wavelength, polarization, and angular intensity characteristics of the radiation emitted by these samples were compared with the predictions of a theoretical model for the radiative decay of surface plasmons on nonspherical particles. The results indicated that two distinct modes of charge density oscillation contributed to the radiation. Very closely-spaced periodic surface modulations were produced in silver films by using the technique of electron beam lithography. Radiation resulting from the electron bombardment of these films showed evidence of structure that has been predicted theoretically. However, this structure was not well resolved. We have made suggestions which should be useful in future studies of the origin of this radiation.

  7. Radiative Leptonic Decay of Ds and D Mesons

    NASA Astrophysics Data System (ADS)

    Barik, N.; Naimuddin, Sk.; Dash, P. C.

    The radiative leptonic decays Ds → μνμγ and D → μνμγ are investigated at the tree level within the relativistic independent quark model based on the confining potential in the scalar-vector harmonic form. The branching ratios for these decays in the vanishing lepton mass limit are obtained as ℬr(Ds → μνμγ) = 4.94×10-4 and ℬr(D → μνμγ) = 3.34×10-5, which includes the contributions of the internal bremsstrahlung and structure dependent diagrams at the level of the quark constituents. Finally, the photon energy spectra as predicted here is found to be symmetric about the peak value of the photon energy at Eγ = MD_(s)/4.

  8. Radiative leptonic Bc decay in the relativistic independent quark model

    NASA Astrophysics Data System (ADS)

    Barik, N.; Naimuddin, Sk.; Dash, P. C.; Kar, Susmita

    2008-12-01

    The radiative leptonic decay Bc-→μ-ν¯μγ is analyzed in its leading order in a relativistic independent quark model based on a confining potential in an equally mixed scalar-vector harmonic form. The branching ratio for this decay in the vanishing lepton mass limit is obtained as Br(Bc→μνμγ)=6.83×10-5, which includes the contributions of the internal bremsstrahlung and structure-dependent diagrams at the level of the quark constituents. The contributions of the bremsstrahlung and the structure-dependent diagrams, as well as their additive interference parts, are compared and found to be of the same order of magnitude. Finally, the predicted photon energy spectrum is observed here to be almost symmetrical about the peak value of the photon energy at Ẽγ≃(MBc)/(4), which may be quite accessible experimentally at LHC in near future.

  9. Hybrid structure of X(3872) and its radiative decays

    NASA Astrophysics Data System (ADS)

    Takizawa, Makoto; Shimizu, Kiyotaka; Takeuchi, Sachiko

    2014-09-01

    We study the radiative decays of the X (3872) using a charmonium-two-meson hybrid model with the two-meson states consisting of the D0 D *0 , D+D*- , J / Φρ , and J / Φω . We can reproduce the observed mass of the X(3872) in this framework. The obtained structure of the X (3872) explains many of the observed properties, such as the isospin symmetry breaking, the production rate in the p p collision, a lack of the existence of the χc 1 (2 P) peak predicted by the quark model and the absence of the charged partner of the X (3872) . We shall report the results of the X (3872) --> J / Φ γ and X (3872) -->Φ' γ decay rates in our approach.

  10. A search for radiative neutrino decay from supernovae

    NASA Technical Reports Server (NTRS)

    Svoboda, Robert C.

    1993-01-01

    Two supernovae have been identified in the COMPTEL data base as being the best sources to investigate for evidence of gamma-ray emission caused by radiative neutrino decay. These are SN1987a and SN1993J. A detailed simulation has shown us that we can expect a gain in sensitivity 1-3 orders of magnitude (depending on neutrino mass) over previous results. Instrument response is now being modeled using a SPARC10 computer acquired for this study. A library of simulated gamma-ray lines is being produced for COMPTEL as a by-product of this effort.

  11. Lageos orbit decay due to infrared radiation from earth

    NASA Technical Reports Server (NTRS)

    Rubincam, David Parry

    1987-01-01

    Infrared radiation from the earth may be the principal reason for the decay of Lageos' orbit. The radiation heats up the laser retroreflectors embedded in Lageos' aluminum surface. This creates a north-south temperature gradient on the satellite. The gradient in turn causes a force to be exerted on Lageos because of recoil from photons leaving its surface. The delayed heating of the retroreflectors due to their thermal inertia gives the force a net along-track component which always acts like drag. A simple thermal model for the retroreflectors indicates that this thermal drag accounts for about half the observed average along-track acceleration of -3.3 x 10 to the -10th power m/sec squared. The contribution from the aluminum surface to this effect is negligible. The infrared effect cannot explain the large observed fluctuations in drag which occur mainly when the orbit intersects the earth's shadow.

  12. Lageos orbit decay due to infrared radiation from Earth

    NASA Technical Reports Server (NTRS)

    Rubincam, David Parry

    1987-01-01

    Infrared radiation from the Earth may be the principal reason for the decay of Lageos' orbit. The radiation heats up the laser retroreflectors embedded in Lageos' aluminum surface. This creates a north-south temperature gradient on the satellite. The gradient in turn causes a force to be exerted on Lageos because of recoil from photons leaving its surface. The delayed heating of the retroreflectors due to their thermal inertia gives the force a net along-track component which always acts like drag. A simple thermal model for the retroreflectors indicates that this thermal drag accounts for about half the observed average along-track acceleration of -3.3 x 10 to the -10 power m/sec squared. The contribution from the aluminum surface to this effect is negligible. The infrared effect cannot explain the large observed fluctuations in drag which occur mainly when the orbit intersects the Earth's shadow.

  13. Interpretation of black body radiation as a decay process

    NASA Astrophysics Data System (ADS)

    Gall, Clarence A.

    2007-06-01

    The treatment of black body radiation as a decay process with the wavelength ( λ) as the time marker, leads to an apportioning function ( Dλ) that distributes the total thermodynamic Stefan-Boltzmann emitted intensity ( I) over the entire wavelength range (Clarence A Gall, BAPS, March Meeting 2007, Denver, CO). The resulting distribution function ( Iλ=IDλ=σT^6b^2λe^-Tbλ) gives the Stefan-Boltzmann law on integration over the same interval. Differentiation of Iλ produces Wien's displacement law as the condition for the wavelength at maximum emitted intensity ( λm) . Substitution of λm in Iλ yields the maximum emitted intensity ( Iλm) as being proportional to T,5. Hence Iλ satisfies exactly the three known empirical laws of black body radiation and fulfils Einstein's hope for a solution of the radiation problem without the use of light quanta. Finally the replacement of Tb with a single constant G simplifies the distribution function so that Iλ=σGG^6λe^-Gλ where σG=b^4σ. Consequently G defines a new temperature scale with units of reciprocal wavelength that unifies the thermodynamic and colour scales.

  14. Reexamination of evidence for a radiatively decaying neutrino

    NASA Technical Reports Server (NTRS)

    Murthy, J.; Henry, R. C.

    1987-01-01

    Large-aperture low-dispersion exposures obtained with the IUE short-wavelength camera have been reanalyzed to examine the possibility of using nonstandard electroweak models to explain the steplike signal of 5-sigma significance in the cosmic background claimed by Auriemma et al. (1985). The present results show that no evidence yet exists for the postulated cosmic UV radiation from neutrino decay. Error bars of the order of 20,000 photons/sq cm per s per A per sr are found for the brightnesses of Auriemma et al., and it is suggested that their steps may be due to fixed pattern noise in the detector rather than to a cosmic signal.

  15. Radiative decay modes of the D{sup 0} meson

    SciTech Connect

    Asner, D.M.; Gronberg, J.; Hill, T.S.; Lange, D.J.; Morrison, R.J.; Nelson, H.N.; Nelson, T.K.; Roberts, D.; Ryd, A.; Balest, R.; Behrens, B.H.; Ford, W.T.; Gritsan, A.; Park, H.; Roy, J.; Smith, J.G.; Alexander, J.P.; Baker, R.; Bebek, C.; Berger, B.E.; Berkelman, K.; Bloom, K.; Boisvert, V.; Cassel, D.G.; Crowcroft, D.S.; Dickson, M.; von Dombrowski, S.; Drell, P.S.; Ecklund, K.M.; Ehrlich, R.; Foland, A.D.; Gaidarev, P.; Gibbons, L.; Gittelman, B.; Gray, S.W.; Hartill, D.L.; Heltsley, B.K.; Hopman, P.I.; Kandaswamy, J.; Kim, P.C.; Kreinick, D.L.; Lee, T.; Liu, Y.; Mistry, N.B.; Ng, C.R.; Nordberg, E.; Ogg, M.; Patterson, J.R.; Peterson, D.; Riley, D.; Soffer, A.; Valant-Spaight, B.; Ward, C.; Athanas, M.; Avery, P.; Jones, C.D.; Lohner, M.; Patton, S.; Prescott, C.; Yelton, J.; Zheng, J.; Brandenburg, G.; Briere, R.A.; Ershov, A.; Gao, Y.S.; Kim, D.Y.; Wilson, R.; Yamamoto, H.; Browder, T.E.; Li, Y.; Rodriguez, J.L.; Bergfeld, T.; Eisenstein, B.I.; Ernst, J.; Gladding, G.E.; Gollin, G.D.; Hans, R.M.; Johnson, E.; Karliner, I.; Marsh, M.A.; Palmer, M.; Selen, M.; Thaler, J.J.; Edwards, K.W.; Bellerive, A.; Janicek, R.; MacFarlane, D.B.; Patel, P.M.; Sadoff, A.J.; Ammar, R.; Baringer, P.; Bean, A.; Besson, D.; and others

    1998-11-01

    In this paper we describe a search for four radiative decay modes of the D{sup 0} meson: D{sup 0}{r_arrow}{phi}{gamma}, D{sup 0}{r_arrow}{omega}{gamma}, D{sup 0}{r_arrow}{bar K}{sup {asterisk}}{gamma}, and D{sup 0}{r_arrow}{rho}{sup 0}{gamma}. We obtain 90{percent} C.L. upper limits on the branching ratios of these modes of 1.9{times}10{sup {minus}4}, 2.4{times}10{sup {minus}4}, 7.6{times}10{sup {minus}4}, and 2.4{times}10{sup {minus}4}, respectively. {copyright} {ital 1998} {ital The American Physical Society}

  16. Search for fj(2220) in radiative J/psi decays

    SciTech Connect

    del Amo Sanchez, P.; Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Battaglia, M.; Brown, D.N.; Hooberman, B.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; Tanabe, T.; /LBL, Berkeley /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /Frascati /INFN, Genoa /Genoa U. /Indian Inst. Tech., Guwahati /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /Paris U., VI-VII /INFN, Perugia /Perugia U. /INFN, Pisa /Princeton U. /Frascati /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Southern Methodist U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison

    2010-07-30

    We present a search for f{sub J}(2220) production in radiative J/{psi} {yields} {gamma}f{sub J}(2220) decays using 460 fb{sup -1} of data collected with the BABAR detector at the SLAC PEP-II e{sup +}e{sup -} collider. The f{sub J}(2220) is searched for in the decays to K{sup +}K{sup -} and K{sub S}{sup 0}K{sub S}{sup 0}. No evidence of this resonance is observed, and 90% confidence level upper limits on the product of the branching fractions for J/{psi} {yields} {gamma}f{sub J}(2220) and f{sub J}(2220) {yields} K{sup +}K{sup -}(K{sub S}{sup 0}K{sub S}{sup 0}) as a function of spin and helicity are set at the level of 10{sup -5}, below the central values reported by the Mark III experiment.

  17. Radiative Beta Decay for Studies of CP Violation

    NASA Astrophysics Data System (ADS)

    Gardner, Susan; He, Daheng

    2013-10-01

    A triple-product correlation in the radiative β decay rate of neutrons or of nuclei, characterized by the kinematical variable, where, e.g., n (p) --> p (p') +e- (le) + νe (lν) + γ (k) , can be generated by the pseudo-Chern-Simons term found by Harvey, Hill, and Hill as a consequence of the baryon vector current anomaly and SU(2)L ×U(1)Y gauge invariance at low energies. The correlation probes the imaginary part of its coupling constant, so that its observation at anticipated levels of sensitivity would reflect the presence of sources of CP violation beyond the standard model. We compute the size of the asymmetry in n --> pe-νe γ decay in chiral effective theory, compare it with the computed background from standard-model final-state interactions, and consider the new physics scenarios which would be limited by its experimental study. Work supported in part by the U.S. Department of Energy Office of Nuclear Physics under contract no. DE-FG02-96ER40989.

  18. Search for Hadronic Decays of a Light Higgs Boson in the Radiative Decay

    SciTech Connect

    Lees, J.P.; Poireau, V.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Milanes, D.A.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Koch, H.; Schroeder, T.; Asgeirsson, D.J.; Hearty, C.; Mattison, T.S.; McKenna, J.A.

    2012-02-16

    The authors search for hadronic decays of a light Higgs boson (A{sup 0}) produced in radiative decays of an {Upsilon}(2S) or {Upsilon}(3S) meson, {Upsilon} {yields} {gamma}A{sup 0}. The data have been recorded by the BABAR experiment at the {Upsilon}(3S) and {Upsilon}(2S) center of mass energies, and include (121.3 {+-} 1.2) x 10{sup 6} {Upsilon}(3S) and (98.3 {+-} 0.9) x 10{sup 6} {Upsilon}(2S) mesons. No significant signal is observed. We set 90% confidence level upper limits on the product branching fractions {beta}({Upsilon}(nS) {yields} {gamma}A{sup 0}) {center_dot} {beta}(A{sup 0} {yields} hadrons) (n = 2 or 3) that range from 1 x 10{sup -6} for an A{sup 0} mass of 0.3 GeV/c{sup 2} to 8 x 10{sup -5} at 7 GeV/c{sup 2}.

  19. Radiative B decays in supersymmetry without R parity

    SciTech Connect

    Kong, Otto C.W.; Vaidya, Rishikesh D.

    2005-03-01

    We present a systematic analysis of all the contributions at the leading log order to the branching ratio of the inclusive radiative decay B{yields}X{sub s}+{gamma} in the framework of supersymmetry without R parity. The relevant set of four-quark operators involved in QCD running are extended from six (within the standard model and the minimal supersymmetric standard model) to 24, with also many new contributions to the Wilson coefficients of (chromo)magnetic penguins for either chiral structure. We present complete analytical results here without any a priori assumptions on the form of R-parity violation. Mass-eigenstate expressions are given; hence the results are free from the commonly adopted mass-insertion approximation. In the numerical analysis, we focus here only on the influence of the trilinear {lambda}{sub ijk}{sup '} couplings and report on the possibility of a few orders of magnitude improvement for the bounds on a few combinations of the {lambda}{sup '} couplings. Our study shows that the Wilson coefficients of the current-current operators due to R-parity violation dominate over the direct contributions to the penguins. However, the interplay of various contributions is complicated due to the QCD corrections which we elaborate here.

  20. Astrophysical tests for radiative decay of neutrinos and fundamental physics implications

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.; Brown, R. W.

    1981-01-01

    The radiative lifetime tau for the decay of massious neutrinos was calculated using various physical models for neutrino decay. The results were then related to the astrophysical problem of the detectability of the decay photons from cosmic neutrinos. Conversely, the astrophysical data were used to place lower limits on tau. These limits are all well below predicted values. However, an observed feature at approximately 1700 A in the ultraviolet background radiation at high galactic latitudes may be from the decay of neutrinos with mass approximately 14 eV. This would require a decay rate much larger than the predictions of standard models but could be indicative of a decay rate possible in composite models or other new physics. Thus an important test for substructure in leptons and quarks or other physics beyond the standard electroweak model may have been found.

  1. Nuclear Decay Data in the MIRD (Medical Internal Radiation Dose) Format

    DOE Data Explorer

    MIRD is a database of evaluated nuclear decay data for over 2,100 radioactive nuclei. Data are extracted from ENSDF, processed by the program RadList, and used for medical internal radiation dose calculations. When using the MIRD interface, tables of nuclear and atomic radiations from nuclear decay and decay scheme drawings will be produced in the MIRD format from the Evaluated Nuclear Structure Data File (ENSDF) for the specified nuclide. Output may be either HTML-formatted tables and JPEG drawings, PostScript tables and drawings, or PDF tables and drawings.

  2. Radiation issues in a radioactive ion decay ring.

    PubMed

    Magistris, M; Silari, M

    2005-01-01

    In a beta-beam facility, a pure beam of electron neutrinos, or their antiparticles, are produced by the decay of fully stripped radioactive ions (6He and 18Ne) circulating in a storage ring. Since the beam is not extracted from the ring, all the particles will eventually be lost somewhere in the machine and thus activate the accelerator components and the surrounding concrete and rock. In particular, as nuclei change their charge in beta-decay, a large part of the particles will be lost in the arcs of the decay ring and mainly irradiate the magnets. The density of inelastic interactions of hadrons in the magnets, concrete and rock and the track-length distribution of secondary hadrons were calculated by means of the FLUKA Monte Carlo code. These values were used to estimate the induced radioactivity in the facility, the dose rates expected in the decay ring and the consequences for the environment.

  3. Activated barrier crossing dynamics in the non-radiative decay of NADH and NADPH

    NASA Astrophysics Data System (ADS)

    Blacker, Thomas S.; Marsh, Richard J.; Duchen, Michael R.; Bain, Angus J.

    2013-08-01

    In live tissue, alterations in metabolism induce changes in the fluorescence decay of the biological coenzyme NAD(P)H, the mechanism of which is not well understood. In this work, the fluorescence and anisotropy decay dynamics of NADH and NADPH were investigated as a function of viscosity in a range of water-glycerol solutions. The viscosity dependence of the non-radiative decay is well described by Kramers and Kramers-Hubbard models of activated barrier crossing over a wide viscosity range. Our combined lifetime and anisotropy analysis indicates common mechanisms of non-radiative relaxation in the two emitting states (conformations) of both molecules. The low frequencies associated with barrier crossing suggest that non-radiative decay is mediated by small scale motion (e.g. puckering) of the nicotinamide ring. Variations in the fluorescence lifetimes of NADH and NADPH when bound to different enzymes may therefore be attributed to differing levels of conformational restriction upon binding.

  4. Radiative Corrections to Asymmetry Parameter in the {Omega}{sup -{yields}{Lambda}}+K{sup -} Decay

    SciTech Connect

    Queijeiro, A.

    2010-07-29

    We compute the radiative corrections, to first order in the fine structure constant {alpha}, to the asymmetry parameter {alpha}{sub {Omega}}of the {Omega}{sup -{yields}{Lambda}}+K{sup -} decay. We use previous results where Sirlin's procedure is used to separate the radiative corrections into two parts, one independent model contribution and a model dependent one.

  5. First Results in Inclusive Radiative Penguin Decays at BABAR

    SciTech Connect

    Jessop, Colin P

    2000-11-17

    We present a preliminary measurement of the branching fraction of the exclusive penguin decay B{sup 0} {yields} K*{sub {gamma}}{sup 0} using (8.6 {+-} 0.3) x 10{sup 6} B{bar B} decays B(B{sup 0} {yields} K*{sub {gamma}}{sup 0}) = (5.42 {+-} 0.82(stat.) {+-} 0.47(sys.)) x 10{sup -5}. In addition they search for the related penguin decays with a lepton pair in the final state, B{sup +} {yields} K{sup +}{ell}{sup +}{ell}{sup -}, B{sup 0} {yields} K*{sup 0} {ell}{sup +}{ell}{sup -}.

  6. Radiative decay of neutron-unbound intruder states in 19O

    NASA Astrophysics Data System (ADS)

    Dungan, R.; Tabor, S. L.; Tripathi, Vandana; Volya, A.; Kravvaris, K.; Abromeit, B.; Caussyn, D. D.; Morrow, S.; Parker, J. J.; Tai, P.-L.; VonMoss, J. M.

    2016-02-01

    The 9Be(14C, α γ ) reaction at EL a b=30 and 35 MeV was used to study excited states of 19O. The Florida State University (FSU) γ detector array was used to detect γ radiation in coincidence with charged particles detected and identified with a silicon Δ E -E particle telescope. γ decays have been observed for the first time from six states ranging from 368 to 2147 keV above the neutron separation energy (Sn=3962 keV) in 19O. The γ -decaying states are interspersed among states previously observed to decay by neutron emission. The ability of electromagnetic decay to compete successfully with neutron decay is explained in terms of neutron angular momentum barriers and small spectroscopic factors implying higher spin and complex structure for these intruder states. These results illustrate the need for complementary experimental approaches to best illuminate the complete nuclear structure.

  7. A New Measurement of the Pi0 Radiative Decay Width

    SciTech Connect

    Larin, I; Clinton, E; Ambrozewicz, P; Lawrence, D; Nakagawa, I; Prok, Y; Teymurazyan, A; Ahmidouch, A; Baker, K; Benton, L; Bernstein, A M; Burkert, V; Cole, P; Collins, P; Dale, D; Danagoulian, S; Davidenko, G; Demirchyan, R; Deur, A; Dolgolenko, A; Dzyubenko, Georgiy; Ent, R; Evdokimov, A; Feng, J; Gabrielyan, M; Gan, L; Gasparian, A; Gevorkyan, S; Glamazdin, A; Goryachev, V; Gyurjyan, V; Hardy, K; He, J; Ito, M; Jiang, L; Kashy, D; Khandaker, M; Kingsberry, P; Kolarkar, A; Konchatnyi, M; Korsch, W; Kowalski, S; Kubantsev, M; Kubarovsky, V; Li, X; Martel, P; Mecking, B; Milbrath, B; Minehart, R; Miskimen, R; Mochalov, V; Mtingwa, S; Overby, S; Pasyuk, E; Payen, M; Pedroni, R; Ritchie, B; Rodrigues, T E; Salgado, C; Shahinyan, A; Sitnikov, A; Sober, D; Stepanyan, S; Stephens, W; Underwood, J; Vishnyakov, V; Wood, M

    2011-04-01

    High precision measurements of the differential cross sections for $\\pi^0$ photoproduction at forward angles for two nuclei, $^{12}$C and $^{208}$Pb, have been performed for incident photon energies of 4.9 - 5.5 GeV to extract the ${\\pi^0 \\to \\gamma\\gamma}$ decay width. The experiment was done at Jefferson Lab using the Hall~B photon tagger and a high-resolution multichannel calorimeter. The ${\\pi^0 \\to \\gamma\\gamma}$ decay width was extracted by fitting the measured cross sections using recently updated theoretical models for the process. The resulting value for the decay width is $\\Gamma{(\\pi^0 \\to \\gamma\\gamma)} = 7.82 \\pm 0.14 ~({\\rm stat.}) \\pm 0.17 ~({\\rm syst.}) ~{\\rm eV}$. With the 2.8\\% total uncertainty, this result is a factor of 2.5 more precise than the current PDG average of this fundamental quantity and it is consistent with current theoretical predictions.

  8. Radiative and Leptonic B-meson Decays from the B-factories

    SciTech Connect

    Walsh, John; /INFN, Pisa

    2011-11-14

    Radiative and leptonic decays of B-mesons represent an excellent laboratory for the search for New Physics. I present here recent results on radiative and leptonic decays from the Belle and BABAR collaborations. Radiative penguin and leptonic B-meson decays are excellent probes for investigating the effects of New Physics. Although current measurements are in agreement with the Standard Model expectations, they are still quite useful for setting bounds on possible NP models. The B {yields} X{sub s}{gamma} and B {yields} {tau}{nu} measurements, for example, put strong constraints on the mass of charged Higgs bosons in Type II two-Higgs double models. The B {yields} X{sub s}{gamma} branching fraction measurements also constrain models with universal extra dimensions.

  9. Search for very light CP-odd Higgs Boson in radiative decays of Upsilon(1S).

    PubMed

    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; 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; 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

    2008-10-10

    We search for a non-SM-like CP-odd Higgs boson (a(1)(0)) decaying to tau(+)tau(-) or mu(+)mu(-) in radiative decays of the Upsilon(1S). No significant signal is found, and upper limits on the product branching ratios are set. Our tau(+)tau(-) results are almost 2 orders of magnitude more stringent than previous upper limits. Our data provide no evidence for a Higgs state with a mass of 214 MeV decaying to mu(+)mu(-), previously proposed as an explanation for 3 Sigma(+)-->pmu(+)mu(-) events observed by the HyperCP experiment. Our results constrain NMSSM models.

  10. Radiative And Electroweak Penguin Processes in Exclusive B Decays

    SciTech Connect

    Kovalskyi, Dmytro; /UC, Santa Barbara

    2011-06-14

    A review of recent BABAR results on exclusive B {yields} ({rho}/{Omega}){gamma}, B {yields} {pi}l{sup +}l{sup -} and B {yields} K(*) l{sup +}l{sup -} decays is presented. It was found that {bar {Beta}}[B {yields} ({rho}/{omega}){gamma}] = (1.01 {+-} 0.21 {+-} 0.08) x 10{sup -6}, {bar {Beta}}[B{sup +} {yields} {pi}l{sup +}l{sup -}] < 7.9 x 10{sup -8} at 90% C.L., {bar {Beta}}[B {yields} Kl{sup +}l{sup -}] = (0.84 {+-} 0.07 {+-} 0.02) x 10{sup -6} and {bar {Beta}}[B {yields} K*l{sup +}l{sup -}] = (0.78{sub -0.17}{sup +0.19} {+-} 0.11) x 10{sup -6}. it was also found that different asymmetry measurements are consistent with Standard Model expectations. Based on these results an independent estimate of the |V{sub td}/V{sub ts}| matrix element of the CKM matrix is derived to be |V{sub td}/V{sub ts}| = 0.171{sub -0.021-0.014}{sup +0.018+0.017}. A first evidence of B{sup +} {yields} {rho}{sup +}{gamma} decays was found and last year's observation of B{sup 0} {yields} {rho}{sup 0}{gamma} was confirmed.

  11. A VMD Based, Nonet and SU(3) Symmetry Broken Model for Radiative Decays of Light Mesons

    SciTech Connect

    Benayoun, M.

    2005-04-06

    We present a VMD based model aiming to describe all radiative decays of light mesons. We show that the SU(3) breaking mechanism proposed by Bando, Kugo and Yamawaki (BKY), supplemented by nonet symmetry breaking in the pseudoscalar sector are sufficient to provide a nice description of all data, except the K*{sup {+-}} radiative width. It is also shown that nonet symmetry breaking has effects which cannot be disentangled from those produced by coupling of glue to the {eta}{prime} meson. Coupling of glue to {eta} is not found to be required by the data. Assuming the K*{sup {+-}} radiative width is indeed at its presently accepted value necessitates to supplement the BKY breaking in a way which finally preserves an equivalence statement between the VMD approach to radiative decays and the Wess-Zumino-Witten Lagrangian.

  12. Spin-flip processes and radiative decay of dark intravalley excitons in transition metal dichalcogenide monolayers

    NASA Astrophysics Data System (ADS)

    Slobodeniuk, A. O.; Basko, D. M.

    2016-09-01

    We perform a theoretical study of radiative decay of dark intravalley excitons in transition metal dichalcogenide monolayers. This decay necessarily involves an electronic spin flip. The intrinsic decay mechanism due to interband spin-flip dipole moment perpendicular to the monolayer plane, gives a rate about 100-1000 times smaller than that of bright excitons. However, we find that this mechanism also introduces an energy splitting due to a local field effect, and the whole oscillator strength is contained in the higher-energy component, while the lowest-energy state remains dark and needs an extrinsic spin-flip mechanism for the decay. Rashba effect due to a perpendicular electric field or a dielectric substrate, gives a negligible radiative decay rate (about 107 times slower than that of bright excitons). Spin flip due to Zeeman effect in a sufficiently strong in-plane magnetic field can give a decay rate comparable to that due to the intrinsic interband spin-flip dipole.

  13. Radiative decays of the Sigma0(1385) and Lambda(1520) hyperons

    SciTech Connect

    Simon Taylor; Gordon Mutchler; CLAS Collaboration

    2005-03-01

    The electromagnetic decays of the {Sigma}{sup 0}(1385) and {Lambda}(1520) hyperons were studied in photon-induced reactions {gamma} p {yields} K{sup +} {Lambda}(1116){gamma} in the CLAS detector at the Thomas Jefferson National Accelerator Facility. We report the first observation of the radiative decay of the {Sigma}{sup 0}(1385) and a measurement of the {Lambda}(1520) radiative decay width. For the {Sigma}{sup 0}(1385) {yields} {Lambda}(1116){gamma} transition, we measured a partial width of 479 {+-} 120(stat){sub -100}{sup +81}(sys) keV, larger than all of the existing model predictions. For the {Lambda}(1520) {yields} {Lambda}(1116){gamma} transition, we obtained a partial width of 167 {+-} 43(stat){sub -12}{sup +26}(sys) keV.

  14. Precision measurement of the radiative beta decay of the free neutron

    NASA Astrophysics Data System (ADS)

    Gentile, Thomas; RDK Collaboration, II

    2017-01-01

    A continuous spectrum of photons is emitted in the decay of the free neutron. We present the results of the RDK II experiment, in which radiative photons were detected in coincidence with the electrons and protons from neutron decay. The experiment was performed on the NG-6 fundamental physics neutron beam line at the National Institute of Standards and Technology Center for Neutron Research using two different photon detector arrays. An annular array of bismuth germanium oxide scintillators detected photons with energies between 14 keV and 782 keV and an array of large area avalanche photodiodes directly detected photons with energies between 0.4 keV and 14 keV . This experiment represents the first precision test of the shape of the photon energy spectrum from neutron radiative decay and a substantially improved determination of the branching ratio over a broad range of photon energies.

  15. Precision measurement of the radiative β decay of the free neutron

    NASA Astrophysics Data System (ADS)

    Bales, Matthew; RDK Collaboration, II

    2016-09-01

    A continuous spectrum of photons is emitted in the decay of the free neutron. We present the results of the RDK II experiment, in which radiative photons were detected in coincidence with the electrons and protons from neutron decay. The experiment was performed on the NG-6 fundamental physics neutron beam line at the NIST Center for Neutron Research using two different photon detector arrays. An annular array of bismuth germanium oxide scintillators detected photons with energies between 14 keV and 782 keV and an array of large area avalanche photodiodes directly detected photons with energies between 0.4 keV and 14 keV . This experiment represents the first precision test of the shape of the photon energy spectrum from neutron radiative decay and a substantially improved determination of the branching ratio over a broad range of photon energies.

  16. Radiative corrections in baryon semileptonic decays with the emission of a polarized baryon

    SciTech Connect

    Juarez-Leon, C.; Martinez, A.; Neri, M.; Torres, J. J.; Flores-Mendieta, R.

    2010-07-29

    We present an overview of the calculation of radiative corrections to the Dalitz plot of baryon semileptonic decays with angular correlation between polarized emitted baryons and charged leptons. We discuss both charged and neutral decaying baryons, restricted to the three-body region of the Dalitz plot. Our analysis is specialized to cover two possible scenarios: The center-of-mass frames of the emitted and the decaying baryons. We have accounted for terms up to order ({alpha}/{pi})(q/M{sub 1}){sup 0}, where q is the momentum-transfer and M{sup 1} is the mass of the decaying baryon, and neglected terms of order ({alpha}/{pi})(q/M{sub 1}){sup n} for n{>=}1. The expressions displayed are ready to obtain numerical results, suitable for model-independent experimental analyses.

  17. Radiative τ leptonic decays and the possibility to determine the τ dipole moments

    NASA Astrophysics Data System (ADS)

    Fael, Matteo

    2016-04-01

    Precise data on radiative leptonic τ decays offer the opportunity to probe the electromagnetic properties of the τ and may allow to determine its anomalous magnetic moment which, in spite of its precise Standard Model prediction, has never been measured. Recently, the branching fractions of the radiative leptonic τ decays (τ to lν bar ν γ, with l = e, μ) were measured by the Babar collaboration. These precise measurements, with a relative error of about 3%, must be compared with the branching ratios at the next-to-leading order in QED. Indeed the radiative corrections are expected to be of order 10%, for l = e, and 3%, for l = μ. Here, we present the prediction of the differential decay rates and branching ratios of the radiative leptonic τ decays in the Standard Model at the next-to-leading order and we compare them with the recent Babar measurements. Moreover, we report on a dedicated feasibility study for the measurements of the τ anomalous magnetic moment at Belle and Belle II.

  18. Rare Hadronic and Radiative Penguin B Decays at BaBar

    SciTech Connect

    Willocq, Stephane

    2002-02-07

    We report recent results in the study of rare hadronic and radiative penguin decays of B mesons. These results are based on a sample of 23 million BB pairs collected by the BaBar Collaboration at the SLAC PEP-II e+e- B Factory.

  19. Connecting radiative neutrino mass, neutron-antineutron oscillation, proton decay, and leptogenesis through dark matter

    NASA Astrophysics Data System (ADS)

    Gu, Pei-Hong; Ma, Ernest; Sarkar, Utpal

    2016-12-01

    The scotogenic mechanism for radiative neutrino mass is generalized to include neutron-antineutron oscillation as well as proton decay. Dark matter is stabilized by extending the notion of lepton parity to matter parity. Leptogenesis is also a possible byproduct. This framework unifies the description of all these important topics in physics beyond the standard model of particle interactions.

  20. Radiative decays of negative parity heavy baryons in the framework of the light cone QCD sum rules

    NASA Astrophysics Data System (ADS)

    Agamaliev, A. K.; Aliev, T. M.; Savcı, M.

    2017-02-01

    The transition form factors responsible for the radiative ΣQ →ΛQ γ and ΞQ‧ →ΞQ γ decays of the negative parity baryons are examined within light cone QCD sum rules. The decay widths of the radiative transitions are calculated using the obtained results of the form factors. A comparison of our predictions on decay widths with the corresponding widths of positive parity baryons is given.

  1. Improved Measurement of Inclusive Radiative B-meson decays

    NASA Astrophysics Data System (ADS)

    Schümann, J.; Limosani, A.

    2008-11-01

    We report a fully inclusive measurement of the flavor changing neutral current decay B→Xsγ in the energy range 1.7 GeV⩽Eγc.m.s⩽2.8 GeV, covering 97% of the total spectrum, where c.m.s is the center of mass system. Using 605 fb-1 of data, we obtain in the rest frame of the B-meson B(B→Xsγ:EγB>1.7 GeV) = (3.31±0.19±0.37±0.01)×10-4, where the errors are statistical, systematic and from the boost correction needed to transform from the rest frame of the Υ(4S) (c.m.s) to that of the B-meson, respectively. We also measure the first and second moments of the photon energy spectrum as functions of various energy thresholds, which extend down to 1.7 GeV. The results are preliminary.

  2. Coincident excitation and radiative decay in electron-nucleus collisions

    NASA Astrophysics Data System (ADS)

    Jakubassa-Amundsen, D. H.; Ponomarev, V. Yu.

    2017-02-01

    The distorted-wave Born approximation formalism for the description of the (e ,e'γ ) reaction, in which emitted photons and scattered electrons are simultaneously detected, is outlined. Both the Coulomb and the magnetic scattering are fully taken into account. The influence of electron bremsstrahlung is estimated within the plane-wave Born approximation. Recoil effects are also discussed. The formalism is applied for the low-energy (e ,e'γ )92Zr reaction with excitation of the first collective (21+) and mixed-symmetry (22+) states. The corresponding transition charge and current densities are taken from a random-phase approximation (RPA) calculation within the quasiparticle phonon model. It is shown, by this example, in which way the magnetic subshell population of the excited state influences the angular distribution of the decay photon. For these quadrupole excitations the influence of magnetic scattering is only prominent at the backmost scattering angles, where a clear distinction of the photon pattern pertaining to the two states is predicted.

  3. Rare radiative decays of the B c meson

    NASA Astrophysics Data System (ADS)

    Ju, Wan-Li; Wang, Tianhong; Jiang, Yue; Yuan, Han; Wang, Guo-Li

    2016-08-01

    In this paper, we study the rare radiative processes {B}c\\to {D}{sJ}(*)γ within the Standard Model, where {D}{sJ}(*) stands for the meson {D}s*, {D}s1(2460,2536) or {D}s2*(2573). During the investigations, we consider the contributions from the penguin, annihilation, color-suppressed and color-favored cascade diagrams. Our results show that: (1) the penguin and annihilation contributions are dominant in the branching fractions; (2) for the processes {B}c\\to {D}s*γ and {B}c\\to {D}s1(2460,2536)γ , the effects from the color-suppressed and color-favored cascade diagrams are un-negligible.

  4. Electromagnetic transition form factor and radiative corrections in decays of neutral pions

    NASA Astrophysics Data System (ADS)

    Husek, Tomáš

    2016-11-01

    We briefly summarize experimental and theoretical results on the rare decay π0 → e+e-. The notorious 3.3σ discrepancy between the SM prediction and the experimental value provided by KTeV collaboration is discussed in the view of a complete set of NLO QED radiative corrections. We also present the Two-Hadron Saturation (THS) scenario for the PVV correlator and apply it to the decay under discussion. The discrepancy then reduces down to 1.8σ.

  5. Evaluation of spent fuel isotopics, radiation spectra and decay heat using the scale computational system

    SciTech Connect

    Parks, C.V.; Hermann, O.W.; Ryman, J.C.

    1986-01-01

    In order to be a self-sufficient system for transport/storage cask shielding and heat transfer analysis, the SCALE system developers included modules to evaluate spent fuel radiation spectra and decay heat. The primary module developed for these analyses is ORIGEN-S which is an updated verision of the original ORIGEN code. The COUPLE module was also developed to enable ORIGEN-S to easily utilize multigroup cross sections and neutron flux data during a depletion analysis. Finally, the SAS2 control module was developed for automating the depletion and decay via ORIGEN-S while using burnup-dependent neutronic data based on a user-specified fuel assembly and reactor history. The ORIGEN-S data libraries available for depletion and decay have also been significantly updated from that developed with the original ORIGEN code.

  6. Observation of tree-level B decays with ss production from gluon radiation.

    PubMed

    Aubert, B; Bona, M; Boutigny, D; Karyotakis, Y; Lees, J P; Poireau, V; Prudent, X; Tisserand, V; Zghiche, A; Garra Tico, J; Grauges, E; Lopez, L; Palano, A; Eigen, G; Stugu, B; Sun, L; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lopes Pegna, D; Lynch, G; Mir, L M; Orimoto, T J; Ronan, M T; Tackmann, K; Wenzel, W A; Del Amo Sanchez, P; Hawkes, C M; Watson, A T; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Schroeder, T; Steinke, M; Walker, D; Asgeirsson, D J; Cuhadar-Donszelmann, T; Fulsom, B G; Hearty, C; Mattison, T S; McKenna, J A; Khan, A; Saleem, M; Teodorescu, L; Blinov, V E; Bukin, A D; 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; Foulkes, S D; Gary, J W; Liu, F; Long, O; Shen, B C; Zhang, L; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; 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; Williams, D C; Wilson, M G; Winstrom, L O; Chen, E; Cheng, C H; 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; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nagel, M; Nauenberg, U; Olivas, A; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Gabareen, A M; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Zeng, Q; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Merkel, J; Petzold, A; Spaan, B; Wacker, K; Brandt, T; Klose, V; Kobel, M J; Lacker, H M; Mader, W F; Nogowski, R; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Latour, E; Lombardo, V; Thiebaux, Ch; Verderi, M; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cecchi, A; Cibinetto, G; Franchini, P; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Santoro, V; Anulli, F; 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; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bard, D J; Dauncey, P D; Flack, R L; Nash, J A; Nikolich, M B; Panduro Vazquez, W; Tibbetts, M; Behera, P K; Chai, X; Charles, M J; Mallik, U; Meyer, N T; Ziegler, V; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gritsan, A V; Guo, Z J; Lae, C K; Denig, A G; Fritsch, M; Schott, G; Arnaud, N; Béquilleux, J; Davier, M; Grosdidier, G; Höcker, A; Lepeltier, V; Le Diberder, F; Lutz, A M; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Serrano, J; Sordini, V; Stocchi, A; Wang, W F; Wormser, G; Lange, D J; Wright, D M; Bingham, I; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; George, K A; Di Lodovico, F; Menges, W; Sacco, R; Cowan, G; Flaecher, H U; Hopkins, D A; Paramesvaran, S; Salvatore, F; Wren, A C; Brown, D N; Davis, C L; Allison, J; 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; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Salvati, E; Saremi, S; Cowan, R; Dujmic, D; Fisher, P H; Koeneke, K; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; Zhao, M; Zheng, Y; McLachlin, S E; Patel, P M; Robertson, S H; Lazzaro, A; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Simard, M; Taras, P; Viaud, F B; Nicholson, H; De Nardo, G; Fabozzi, F; Lista, L; Monorchio, D; Sciacca, C; Baak, M A; Raven, G; Snoek, H L; Jessop, C P; Losecco, J M; Benelli, G; Corwin, L A; Honscheid, K; Kagan, H; Kass, R; Morris, J P; Rahimi, A M; Regensburger, J 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; Gagliardi, N; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Ben-Haim, E; Briand, H; Calderini, G; Chauveau, J; David, P; Del Buono, L; de la Vaissière, Ch; Hamon, O; Leruste, Ph; Malclès, J; Ocariz, J; Perez, A; Gladney, L; Biasini, M; Covarelli, R; Manoni, E; Angelini, C; Batignani, G; Bettarini, S; Carpinelli, M; Cenci, R; Cervelli, A; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Mazur, M A; Morganti, M; Neri, N; Paoloni, E; Rizzo, G; Walsh, J J; Haire, M; Biesiada, J; Elmer, P; Lau, Y P; Lu, C; Olsen, J; Smith, A J S; Telnov, A V; Baracchini, E; Bellini, F; Cavoto, G; D'Orazio, A; 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; Castelli, G; Franek, B; Olaiya, E O; Ricciardi, S; Roethel, W; Wilson, F F; Aleksan, R; Emery, S; Escalier, M; 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; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Berger, N; Claus, R; Coleman, J P; Convery, M R; Dingfelder, J C; Dorfan, J; Dubois-Felsmann, G P; Dunwoodie, W; Field, R C; Glanzman, T; Gowdy, S J; Graham, M T; Grenier, P; Hast, C; Hryn'ova, T; Innes, W R; Kaminski, J; Kelsey, M H; Kim, H; Kim, P; Kocian, M L; Leith, D W G S; Li, S; Luitz, S; Luth, V; Lynch, H L; Macfarlane, D B; Marsiske, H; Messner, R; Muller, D R; O'Grady, C P; Ofte, I; Perazzo, A; Perl, M; Pulliam, T; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Stelzer, J; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Va'vra, J; van Bakel, N; Wagner, A P; Weaver, M; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Yi, K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Jain, V; Pan, B; Saeed, M A; Wappler, F R; Zain, S B; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Ruland, A M; Schilling, C J; Schwitters, R F; Izen, J M; Lou, X C; Ye, S; Bianchi, F; Gallo, F; Gamba, D; Pelliccioni, M; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; 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; Hamano, K; Kowalewski, R; Nugent, I M; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Ilic, J; Latham, T E; Mohanty, G B; Pappagallo, M; Band, H R; Chen, X; Dasu, S; Flood, K T; Hollar, J J; Kutter, P E; Pan, Y; Pierini, M; Prepost, R; Wu, S L; Neal, H

    2008-05-02

    We report on our search for decays proceeding via a tree-level b-->c quark transition in which a gluon radiates into an ss[over ] pair. We present observations of the decays B;{-}-->D_{s};{+}K;{-}pi;{-} and B[over ];{0}-->D_{s};{+}K_{S};{0}pi;{-} and evidence for B;{-}-->D_{s};{+}K;{-}K;{-} and set upper limits on the branching fractions for B[over ];{0}-->D_{s};{+}K_{S};{0}pi;{-} and B;{-}-->D_{s};{+}K;{-}K;{-} using 383x10;{6} Upsilon(4S)-->BB[over ] events collected by the BABAR detector at SLAC. We present evidence that the invariant mass distributions of D_{s};{+}K;{-} pairs from B;{-}-->D_{s};{+}K;{-}pi;{-} decays are inconsistent with the phase-space model, suggesting the presence of charm resonances lying below the D_{s};{+}K;{-} threshold.

  7. Experimental limits for heavy neutrino admixture deduced from 177Lu β decay and constraints on the life time of a radiative neutrino decay mode

    NASA Astrophysics Data System (ADS)

    Schönert, S.; Oberauer, L.; Hagner, C.; Feilitzsch, F. v.; Schreckenbach, K.; Declais, Y.; Mayerhofer, U.

    1996-05-01

    From cosmological constraints, the requirement for stable neutrinos is to have masses less than 30 eV. In the case that neutrino masses exceed this bound, neutrinos must decay sufficiently fast in order to satisfy the presently observed energy density of the universe. The experiments presented in this contribution consist of the complementary search for heavy neutrino admixture in nuclear beta decay of 177Lu and of the search for a radiative neutrino decay mode at the nuclear power station in Bugey, France. The data obtained from the 177Lu beta decay restrict the mixing probability of a heavy neutrino to the electron | U eh| 2 < 0.2 - 0.3% (90% Cl) for neutrino masses between 10 and 95 keV. The radiative lifetime is constrained to exceed t/ m > 180 × | U eh| 2 sec/eV which is one order of magnitude more restrictive than previous laboratory limits.

  8. Nonperturbative charming penguin contributions to isospin asymmetries in radiative B decays

    SciTech Connect

    Kim, Chul; Mehen, Thomas; Leibovich, Adam K.

    2008-09-01

    Recent experimental data on the radiative decays B{yields}V{gamma}, where V is a light vector meson, find small isospin violation in B{yields}K*{gamma} while isospin asymmetries in B{yields}{rho}{gamma} are of order 20%, with large uncertainties. Using soft-collinear effective theory, we calculate isospin asymmetries in these radiative B decays up to O(1/m{sub b}), also including O(v{alpha}{sub s}) contributions from nonperturbative charming penguins (NPCP). In the absence of NPCP contributions, the theoretical predictions for the asymmetries are a few percent or less. Including the NPCP can significantly increase the isospin asymmetries for both B{yields}V{gamma} modes. We also consider the effect of the NPCP on the branching ratio and CP asymmetries in B{sup {+-}}{yields}V{sup {+-}}{gamma}.

  9. Precision Measurement of the Radiative Decay Mode of the Free Neutron

    NASA Astrophysics Data System (ADS)

    O'Neill, Benjamin

    The theory of quantum electrodynamics predicts that beta decay of the neutron into a proton, electron, and anti-neutrino should be accompanied by a continuous spectrum of photons. A recent experiment, RDK I, reported the first detection of radiative decay photons from neutron beta decay with a branching ratio of (3.09 ± 0.32) × 10-3 in the energy range of 15 keV to 340 keV. This was achieved by prompt coincident detection of an electron and photon, in delayed coincidence with a proton. The photons were detected by using a single bar of bismuth germanate scintillating crystal coupled to an avalanche photodiode. This thesis deals with the follow-up experiment, RDK II, to measure the branching ratio at the level of approximately 1% and the energy spectrum at the level of a few percent. The most significant improvement of RDK II is the use of a photon detector with about an order of magnitude greater solid angle coverage than RDK I. In addition, the detectable energy range has been extended down to approximately 250 eV and up to the endpoint energy of 782 keV. This dissertation presents an overview of the apparatus, development of a new data analysis technique for radiative decay, and results for the ratio of electron-proton-photon coincident Repg to electron-proton coincident Rep events.

  10. Simulation of decay processes and radiation transport times in radioactivity measurements

    NASA Astrophysics Data System (ADS)

    García-Toraño, E.; Peyres, V.; Bé, M.-M.; Dulieu, C.; Lépy, M.-C.; Salvat, F.

    2017-04-01

    The Fortran subroutine package PENNUC, which simulates random decay pathways of radioactive nuclides, is described. The decay scheme of the active nuclide is obtained from the NUCLEIDE database, whose web application has been complemented with the option of exporting nuclear decay data (possible nuclear transitions, branching ratios, type and energy of emitted particles) in a format that is readable by the simulation subroutines. In the case of beta emitters, the initial energy of the electron or positron is sampled from the theoretical Fermi spectrum. De-excitation of the atomic electron cloud following electron capture and internal conversion is described using transition probabilities from the LLNL Evaluated Atomic Data Library and empirical or calculated energies of released X rays and Auger electrons. The time evolution of radiation showers is determined by considering the lifetimes of nuclear and atomic levels, as well as radiation propagation times. Although PENNUC is designed to operate independently, here it is used in conjunction with the electron-photon transport code PENELOPE, and both together allow the simulation of experiments with radioactive sources in complex material structures consisting of homogeneous bodies limited by quadric surfaces. The reliability of these simulation tools is demonstrated through comparisons of simulated and measured energy spectra from radionuclides with complex multi-gamma spectra, nuclides with metastable levels in their decay pathways, nuclides with two daughters, and beta plus emitters.

  11. Green's function method for handling radiative effects on false vacuum decay

    NASA Astrophysics Data System (ADS)

    Garbrecht, Björn; Millington, Peter

    2015-05-01

    We introduce a Green's function method for handling radiative effects on false vacuum decay. In addition to the usual thin-wall approximation, we achieve further simplification by treating the bubble wall in the planar limit. As an application, we take the λ Φ4 theory, extended with N additional heavier scalars, wherein we calculate analytically both the functional determinant of the quadratic fluctuations about the classical soliton configuration and the first correction to the soliton configuration itself.

  12. Decays of neutral pions: Electromagnetic transition form factor and radiative corrections

    NASA Astrophysics Data System (ADS)

    Husek, Tomáš

    2017-03-01

    We briefly summarize experimental and theoretical results on the rare decay π0 → e+e-. The notorious 3.3σ discrepancy between the Standard Model prediction and the experimental value provided by KTeV collaboration is discussed in the view of a complete set of next-to-leading-order QED radiative corrections. We also present the Two-Hadron Saturation (THS) scenario for the PVV correlator and apply it to the decay under discussion. The discrepancy under discussion then reduces down to 1.8σ. Finally, we turn our attention the the Dalitz decay π0 → e+e-γ. We have recalculated the Mikaelian and Smith radiative corrections beyond the soft-photon approximation, i.e. over the whole range of the Dalitz plot and with no restrictions on the radiative photon. In contrast to the previous calculations, we also included the one-photon irreducible contribution at one-loop level. Our results can be also used for a further treatment of the processes with heavier particles in the final state.

  13. Radiative decays of double heavy baryons in a relativistic constituent three-quark model including hyperfine mixing effects

    SciTech Connect

    Branz, Tanja; Faessler, Amand; Gutsche, Thomas; Lyubovitskij, Valery E.; Oexl, Bettina; Ivanov, Mikhail A.; Koerner, Juergen G.

    2010-06-01

    We study flavor-conserving radiative decays of double-heavy baryons using a manifestly Lorentz covariant constituent three-quark model. Decay rates are calculated and compared to each other in the full theory, keeping masses finite, and also in the heavy quark limit. We discuss in some detail hyperfine mixing effects.

  14. Radiative corrections to the Dalitz plot of Kl3 0 decays

    NASA Astrophysics Data System (ADS)

    Neri, M.; Martínez, A.; Juárez-León, C.; Torres, J. J.; Flores-Mendieta, Rubén

    2015-10-01

    A model-independent expression for the Dalitz plot of semileptonic decays of neutral kaons, Kl3 0, including radiative corrections to order (α /π )(q /M1), where q is the momentum transfer and M1 is the mass of the kaon, is presented. The model dependence of radiative corrections is kept in a general form within this approximation, which is suitable for model-independent experimental analyses. Expressions for bremsstrahlung radiative corrections are presented in two forms: one with the triple integral over the kinematical variables of the photon ready to be performed numerically and the other one in a fully analytical form. The final result is restricted to the so-called three-body region of the Dalitz plot and it is not compromised to fixing the values of the form factors at predetermined values.

  15. Radiative decays of the {upsilon}(1S) to a pair of charged hadrons

    SciTech Connect

    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.

    2006-02-01

    Using data obtained with the CLEO III detector, running at the Cornell Electron Storage Ring (CESR), we report on a new study of exclusive radiative {upsilon}(1S) decays into the final states {gamma}{pi}{sup +}{pi}{sup -}, {gamma}K{sup +}K{sup -}, and {gamma}pp. We present branching ratio measurements for the decay modes {upsilon}(1S){yields}{gamma}f{sub 2}(1270), {upsilon}(1S){yields}{gamma}f{sub 2}{sup '}(1525), and {upsilon}(1S){yields}{gamma}K{sup +}K{sup -}; helicity production ratios for f{sub 2}(1270) and f{sub 2}{sup '}(1525); upper limits for the decay {upsilon}(1S){yields}{gamma}f{sub J}(2200), with f{sub J}(2220){yields}{pi}{sup +}{pi}{sup -}, K{sup +}K{sup -}, pp; and an upper limit for the decay {upsilon}(1S){yields}{gamma}X(1860), with X(1860){yields}{gamma}pp.

  16. Limits to the radiative decays of neutrinos and axions from gamma-ray observations of SN 1987A

    NASA Technical Reports Server (NTRS)

    Kolb, Edward W.; Turner, Michael S.

    1989-01-01

    Gamma-ray observations obtained by the SMM gamma-ray spectrometer in the energy range 4.1-6.4 MeV are used to provide limits on the possible radiative decay of neutrinos and axions emitted by SN 1987A. For branching ratio values for the radiative decay modes of less than about 0.0001, the present limits are more stringent than those based upon the photon flux from decaying relic neutrinos. The data are also used to set an axion mass limit.

  17. Contribution of Neutron Beta Decay to Radiation Belt Pumping from High Altitude Nuclear Explosion

    SciTech Connect

    Marrs, R

    2002-11-13

    In 1962, several satellites were lost following high altitude nuclear tests by the United States and the Soviet Union. These satellite failures were caused by energetic electrons injected into the earth's radiation belts from the beta decay of bomb produced fission fragments and neutrons. It has been 40 years since the last high altitude nuclear test; there are now many more satellites in orbit, and it is important to understand their vulnerability to radiation belt pumping from nuclear explosions at high altitude or in space. This report presents the results of a calculation of the contribution of neutron beta decay to artificial belt pumping. For most high altitude nuclear explosions, neutrons are expected to make a smaller contribution than fission products to the total trapped electron inventory, and their contribution is usually neglected. However, the neutron contribution may dominate in cases where the fission product contribution is suppressed due to the altitude or geomagnetic latitude of the nuclear explosion, and for regions of the radiation belts with field lines far from the detonation point. In any case, an accurate model of belt pumping from high altitude nuclear explosions, and a self-consistent explanation of the 1962 data, require inclusion of the neutron contribution. One recent analysis of satellite measurements of electron flux from the 1962 tests found that a better fit to the data is obtained if the neutron contribution to the trapped electron inventory was larger than that of the fission products [l]. Belt pumping from high altitude nuclear explosions is a complicated process. Fission fragments are dispersed as part of the ionized bomb debris, which is constrained and guided by the earth's magnetic field. Those fission products that beta decay before being lost to the earth's atmosphere can contribute trapped energetic electrons to the earth's radiation belts. There has been a large effort to develop computer models for the contribution of

  18. First Experimental Study of Photon Polarization in Radiative B_{s}^{0} Decays.

    PubMed

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Idzik, M; Ilten, P; Jacobsson, R; Jaeger, A; Jalocha, J; Jans, E; Jawahery, A; Jiang, F; John, M; Johnson, D; Jones, C R; Joram, C; Jost, B; Jurik, N; Kandybei, S; Kanso, W; Karacson, M; Kariuki, J M; Karodia, S; Kecke, M; Kelsey, M; Kenyon, I R; Kenzie, M; Ketel, T; Khairullin, E; Khanji, B; Khurewathanakul, C; Kirn, T; Klaver, S; Klimaszewski, K; Koliiev, S; Kolpin, M; Komarov, I; Koopman, R F; Koppenburg, P; Kosmyntseva, A; Kozachuk, A; Kozeiha, M; Kravchuk, L; Kreplin, K; Kreps, M; Krokovny, P; Kruse, F; Krzemien, W; Kucewicz, W; Kucharczyk, M; Kudryavtsev, V; Kuonen, A K; Kurek, K; Kvaratskheliya, T; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lanfranchi, G; Langenbruch, C; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J-P; Leflat, A; Lefrançois, J; Lefèvre, R; Lemaitre, F; Lemos Cid, E; Leroy, O; Lesiak, T; Leverington, B; Li, Y; Likhomanenko, T; Lindner, R; Linn, C; Lionetto, F; Liu, B; Liu, X; Loh, D; Longstaff, I; Lopes, J H; Lucchesi, D; Lucio Martinez, M; Luo, H; Lupato, A; Luppi, E; Lupton, O; Lusiani, A; Lyu, X; Machefert, F; Maciuc, F; Maev, O; Maguire, K; Malde, S; Malinin, A; Maltsev, T; Manca, G; Mancinelli, G; Manning, P; Maratas, J; Marchand, J F; Marconi, U; Marin Benito, C; Marino, P; Marks, J; Martellotti, G; Martin, M; Martinelli, M; Martinez Santos, D; Martinez Vidal, F; Martins Tostes, D; Massacrier, L M; Massafferri, A; Matev, R; Mathad, A; Mathe, Z; Matteuzzi, C; Mauri, A; Maurin, B; Mazurov, A; McCann, M; McCarthy, J; McNab, A; McNulty, R; Meadows, B; Meier, F; Meissner, M; Melnychuk, D; Merk, M; Merli, A; Michielin, E; Milanes, D A; Minard, M-N; Mitzel, D S; Mogini, A; Molina Rodriguez, J; Monroy, I A; Monteil, S; Morandin, M; Morawski, P; Mordà, A; Morello, M J; Moron, J; Morris, A B; Mountain, R; Muheim, F; Mulder, M; Mussini, M; Müller, D; Müller, J; Müller, K; Müller, V; Naik, P; Nakada, T; Nandakumar, R; Nandi, A; Nasteva, I; Needham, M; Neri, N; Neubert, S; Neufeld, N; Neuner, M; Nguyen, A D; Nguyen-Mau, C; Nieswand, S; Niet, R; Nikitin, N; Nikodem, T; Novoselov, A; O'Hanlon, D P; Oblakowska-Mucha, A; Obraztsov, V; Ogilvy, S; Oldeman, R; Onderwater, C J G; Otalora Goicochea, J M; Otto, A; Owen, P; Oyanguren, A; Pais, P R; Palano, A; Palombo, F; Palutan, M; Panman, J; Papanestis, A; Pappagallo, M; Pappalardo, L L; Parker, W; Parkes, C; Passaleva, G; Pastore, A; Patel, G D; Patel, M; Patrignani, C; Pearce, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perret, P; Pescatore, L; Petridis, K; Petrolini, A; Petrov, A; Petruzzo, M; Picatoste Olloqui, E; Pietrzyk, B; Pikies, M; Pinci, D; Pistone, A; Piucci, A; Playfer, S; Plo Casasus, M; Poikela, T; Polci, F; Poluektov, A; Polyakov, I; Polycarpo, E; Pomery, G J; Popov, A; Popov, D; Popovici, B; Poslavskii, S; Potterat, C; Price, E; Price, J D; Prisciandaro, J; Pritchard, A; Prouve, C; Pugatch, V; Puig Navarro, A; Punzi, G; Qian, W; Quagliani, R; Rachwal, B; Rademacker, J H; Rama, M; Ramos Pernas, M; Rangel, M S; Raniuk, I; Raven, G; Redi, F; Reichert, S; Dos Reis, A C; Remon Alepuz, C; Renaudin, V; Ricciardi, S; Richards, S; Rihl, M; Rinnert, K; Rives Molina, V; Robbe, P; Rodrigues, A B; Rodrigues, E; Rodriguez Lopez, J A; Rodriguez Perez, P; Rogozhnikov, A; Roiser, S; Rollings, A; Romanovskiy, V; Romero Vidal, A; Ronayne, J W; Rotondo, M; Rudolph, M S; Ruf, T; Ruiz Valls, P; Saborido Silva, J J; Sadykhov, E; Sagidova, N; Saitta, B; Salustino Guimaraes, V; Sanchez Mayordomo, C; Sanmartin Sedes, B; Santacesaria, R; Santamarina Rios, C; Santimaria, M; Santovetti, E; Sarti, A; Satriano, C; Satta, A; Saunders, D M; Savrina, D; Schael, S; Schellenberg, M; Schiller, M; Schindler, H; Schlupp, M; Schmelling, M; Schmelzer, T; Schmidt, B; Schneider, O; Schopper, A; Schubert, K; Schubiger, M; Schune, M-H; Schwemmer, R; Sciascia, B; Sciubba, A; Semennikov, A; Sergi, A; Serra, N; Serrano, J; Sestini, L; Seyfert, P; Shapkin, M; Shapoval, I; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, V; Shires, A; Siddi, B G; Silva Coutinho, R; Silva de Oliveira, L; Simi, G; Simone, S; Sirendi, M; Skidmore, N; Skwarnicki, T; Smith, E; Smith, I T; Smith, J; Smith, M; Snoek, H; Sokoloff, M D; Soler, F J P; Souza De Paula, B; Spaan, B; Spradlin, P; Sridharan, S; Stagni, F; Stahl, M; Stahl, S; Stefko, P; Stefkova, S; Steinkamp, O; Stemmle, S; Stenyakin, O; Stevenson, S; Stoica, S; Stone, S; Storaci, B; Stracka, S; Straticiuc, M; Straumann, U; Sun, L; Sutcliffe, W; Swientek, K; Syropoulos, V; Szczekowski, M; Szumlak, T; T'Jampens, S; Tayduganov, A; Tekampe, T; Tellarini, G; Teubert, F; Thomas, E; van Tilburg, J; Tilley, M J; Tisserand, V; Tobin, M; Tolk, S; Tomassetti, L; Tonelli, D; Topp-Joergensen, S; Toriello, F; Tournefier, E; Tourneur, S; Trabelsi, K; Traill, M; Tran, M T; Tresch, M; Trisovic, A; Tsaregorodtsev, A; Tsopelas, P; Tully, A; Tuning, N; Ukleja, A; Ustyuzhanin, A; Uwer, U; Vacca, C; Vagnoni, V; Valassi, A; Valat, S; Valenti, G; Vallier, A; Vazquez Gomez, R; Vazquez Regueiro, P; Vecchi, S; van Veghel, M; Velthuis, J J; Veltri, M; Veneziano, G; Venkateswaran, A; Vernet, M; Vesterinen, M; Viaud, B; Vieira, D; Vieites Diaz, M; Vilasis-Cardona, X; Volkov, V; Vollhardt, A; Voneki, B; Vorobyev, A; Vorobyev, V; Voß, C; de Vries, J A; Vázquez Sierra, C; Waldi, R; Wallace, C; Wallace, R; Walsh, J; Wang, J; Ward, D R; Wark, H M; Watson, N K; Websdale, D; Weiden, A; Whitehead, M; Wicht, J; Wilkinson, G; Wilkinson, M; Williams, M; Williams, M P; Williams, M; Williams, T; Wilson, F F; Wimberley, J; Wishahi, J; Wislicki, W; Witek, M; Wormser, G; Wotton, S A; Wraight, K; Wright, S; Wyllie, K; Xie, Y; Xing, Z; Xu, Z; Yang, Z; Yin, H; Yu, J; Yuan, X; Yushchenko, O; Zarebski, K A; Zavertyaev, M; Zhang, L; Zhang, Y; Zhang, Y; Zhelezov, A; Zheng, Y; Zhokhov, A; Zhu, X; Zhukov, V; Zucchelli, S

    2017-01-13

    The polarization of photons produced in radiative B_{s}^{0} decays is studied for the first time. The data are recorded by the LHCb experiment in pp collisions corresponding to an integrated luminosity of 3  fb^{-1} at center-of-mass energies of 7 and 8 TeV. A time-dependent analysis of the B_{s}^{0}→ϕγ decay rate is conducted to determine the parameter A^{Δ}, which is related to the ratio of right- over left-handed photon polarization amplitudes in b→sγ transitions. A value of A^{Δ}=-0.98_{-0.52}^{+0.46}_{-0.20}^{+0.23} is measured. This result is consistent with the standard model prediction within 2 standard deviations.

  19. First Experimental Study of Photon Polarization in Radiative Bs0 Decays

    NASA Astrophysics Data System (ADS)

    Aaij, R.; Adeva, B.; Adinolfi, M.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Andreassi, G.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Archilli, F.; d'Argent, P.; Arnau Romeu, J.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Babuschkin, I.; Bachmann, S.; Back, J. J.; Badalov, A.; Baesso, C.; Baker, S.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Baszczyk, M.; Batozskaya, V.; Batsukh, B.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Bel, L. J.; Bellee, V.; Belloli, N.; Belous, K.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Benton, J.; Berezhnoy, A.; Bernet, R.; Bertolin, A.; Betti, F.; Bettler, M.-O.; van Beuzekom, M.; Bezshyiko, I.; Bifani, S.; Billoir, P.; Bird, T.; Birnkraut, A.; Bitadze, A.; Bizzeti, A.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Boettcher, T.; Bondar, A.; Bondar, N.; Bonivento, W.; Borgheresi, A.; Borghi, S.; Borisyak, M.; Borsato, M.; Bossu, F.; Boubdir, M.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Braun, S.; Britsch, M.; Britton, T.; Brodzicka, J.; Buchanan, E.; Burr, C.; Bursche, A.; Buytaert, J.; Cadeddu, S.; Calabrese, R.; Calvi, M.; Calvo Gomez, M.; Camboni, A.; Campana, P.; Campora Perez, D.; Campora Perez, D. H.; Capriotti, L.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carniti, P.; Carson, L.; Carvalho Akiba, K.; Casse, G.; Cassina, L.; Castillo Garcia, L.; Cattaneo, M.; Cauet, Ch.; Cavallero, G.; Cenci, R.; Charles, M.; Charpentier, Ph.; Chatzikonstantinidis, G.; Chefdeville, M.; Chen, S.; Cheung, S.-F.; Chobanova, V.; Chrzaszcz, M.; Cid Vidal, X.; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coco, V.; Cogan, J.; Cogneras, E.; Cogoni, V.; Cojocariu, L.; Collazuol, G.; Collins, P.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coombs, G.; Coquereau, S.; Corti, G.; Corvo, M.; Costa Sobral, C. M.; Couturier, B.; Cowan, G. A.; Craik, D. C.; Crocombe, A.; Cruz Torres, M.; Cunliffe, S.; Currie, R.; D'Ambrosio, C.; Da Cunha Marinho, F.; Dall'Occo, E.; Dalseno, J.; David, P. N. Y.; Davis, A.; De Aguiar Francisco, O.; De Bruyn, K.; De Capua, S.; De Cian, M.; De Miranda, J. M.; De Paula, L.; De Serio, M.; De Simone, P.; Dean, C.-T.; Decamp, D.; Deckenhoff, M.; Del Buono, L.; Demmer, M.; Derkach, D.; Deschamps, O.; Dettori, F.; Dey, B.; Di Canto, A.; Dijkstra, H.; Dordei, F.; Dorigo, M.; Dosil Suárez, A.; Dovbnya, A.; Dreimanis, K.; Dufour, L.; Dujany, G.; Dungs, K.; Durante, P.; Dzhelyadin, R.; Dziurda, A.; Dzyuba, A.; Déléage, N.; Easo, S.; Ebert, M.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; Elsasser, Ch.; Ely, S.; Esen, S.; Evans, H. M.; Evans, T.; Falabella, A.; Farley, N.; Farry, S.; Fay, R.; Fazzini, D.; Ferguson, D.; Fernandez Albor, V.; Fernandez Prieto, A.; Ferrari, F.; Ferreira Rodrigues, F.; Ferro-Luzzi, M.; Filippov, S.; Fini, R. A.; Fiore, M.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fleuret, F.; Fohl, K.; Fontana, M.; Fontanelli, F.; Forshaw, D. C.; Forty, R.; Franco Lima, V.; Frank, M.; Frei, C.; Fu, J.; Furfaro, E.; Färber, C.; Gallas Torreira, A.; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; Garcia Martin, L. M.; García Pardiñas, J.; Garra Tico, J.; Garrido, L.; Garsed, P. J.; Gascon, D.; Gaspar, C.; Gavardi, L.; Gazzoni, G.; Gerick, D.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gianı, S.; Gibson, V.; Girard, O. G.; Giubega, L.; Gizdov, K.; Gligorov, V. V.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gorelov, I. V.; Gotti, C.; Grabalosa Gándara, M.; Graciani Diaz, R.; Granado Cardoso, L. A.; Graugés, E.; Graverini, E.; Graziani, G.; Grecu, A.; Griffith, P.; Grillo, L.; Gruberg Cazon, B. R.; Grünberg, O.; Gushchin, E.; Guz, Yu.; Gys, T.; Göbel, C.; Hadavizadeh, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hall, S.; Hamilton, B.; Han, X.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Harrison, J.; Hatch, M.; He, J.; Head, T.; Heister, A.; Hennessy, K.; Henrard, P.; Henry, L.; Hernando Morata, J. A.; van Herwijnen, E.; Heß, M.; Hicheur, A.; Hill, D.; Hombach, C.; Hopchev, H.; Hulsbergen, W.; Humair, T.; Hushchyn, M.; Hussain, N.; Hutchcroft, D.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jaeger, A.; Jalocha, J.; Jans, E.; Jawahery, A.; Jiang, F.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Jurik, N.; Kandybei, S.; Kanso, W.; Karacson, M.; Kariuki, J. M.; Karodia, S.; Kecke, M.; Kelsey, M.; Kenyon, I. R.; Kenzie, M.; Ketel, T.; Khairullin, E.; Khanji, B.; Khurewathanakul, C.; Kirn, T.; Klaver, S.; Klimaszewski, K.; Koliiev, S.; Kolpin, M.; Komarov, I.; Koopman, R. F.; Koppenburg, P.; Kosmyntseva, A.; Kozachuk, A.; Kozeiha, M.; Kravchuk, L.; Kreplin, K.; Kreps, M.; Krokovny, P.; Kruse, F.; Krzemien, W.; Kucewicz, W.; Kucharczyk, M.; Kudryavtsev, V.; Kuonen, A. K.; Kurek, K.; Kvaratskheliya, T.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lambert, D.; Lanfranchi, G.; Langenbruch, C.; Latham, T.; Lazzeroni, C.; Le Gac, R.; van Leerdam, J.; Lees, J.-P.; Leflat, A.; Lefrançois, J.; Lefèvre, R.; Lemaitre, F.; Lemos Cid, E.; Leroy, O.; Lesiak, T.; Leverington, B.; Li, Y.; Likhomanenko, T.; Lindner, R.; Linn, C.; Lionetto, F.; Liu, B.; Liu, X.; Loh, D.; Longstaff, I.; Lopes, J. H.; Lucchesi, D.; Lucio Martinez, M.; Luo, H.; Lupato, A.; Luppi, E.; Lupton, O.; Lusiani, A.; Lyu, X.; Machefert, F.; Maciuc, F.; Maev, O.; Maguire, K.; Malde, S.; Malinin, A.; Maltsev, T.; Manca, G.; Mancinelli, G.; Manning, P.; Maratas, J.; Marchand, J. F.; Marconi, U.; Marin Benito, C.; Marino, P.; Marks, J.; Martellotti, G.; Martin, M.; Martinelli, M.; Martinez Santos, D.; Martinez Vidal, F.; Martins Tostes, D.; Massacrier, L. M.; Massafferri, A.; Matev, R.; Mathad, A.; Mathe, Z.; Matteuzzi, C.; Mauri, A.; Maurin, B.; Mazurov, A.; McCann, M.; McCarthy, J.; McNab, A.; McNulty, R.; Meadows, B.; Meier, F.; Meissner, M.; Melnychuk, D.; Merk, M.; Merli, A.; Michielin, E.; Milanes, D. A.; Minard, M.-N.; Mitzel, D. S.; Mogini, A.; Molina Rodriguez, J.; Monroy, I. A.; Monteil, S.; Morandin, M.; Morawski, P.; Mordà, A.; Morello, M. J.; Moron, J.; Morris, A. B.; Mountain, R.; Muheim, F.; Mulder, M.; Mussini, M.; Müller, D.; Müller, J.; Müller, K.; Müller, V.; Naik, P.; Nakada, T.; Nandakumar, R.; Nandi, A.; Nasteva, I.; Needham, M.; Neri, N.; Neubert, S.; Neufeld, N.; Neuner, M.; Nguyen, A. D.; Nguyen-Mau, C.; Nieswand, S.; Niet, R.; Nikitin, N.; Nikodem, T.; Novoselov, A.; O'Hanlon, D. P.; Oblakowska-Mucha, A.; Obraztsov, V.; Ogilvy, S.; Oldeman, R.; Onderwater, C. J. G.; Otalora Goicochea, J. M.; Otto, A.; Owen, P.; Oyanguren, A.; Pais, P. R.; Palano, A.; Palombo, F.; Palutan, M.; Panman, J.; Papanestis, A.; Pappagallo, M.; Pappalardo, L. L.; Parker, W.; Parkes, C.; Passaleva, G.; Pastore, A.; Patel, G. D.; Patel, M.; Patrignani, C.; Pearce, A.; Pellegrino, A.; Penso, G.; Pepe Altarelli, M.; Perazzini, S.; Perret, P.; Pescatore, L.; Petridis, K.; Petrolini, A.; Petrov, A.; Petruzzo, M.; Picatoste Olloqui, E.; Pietrzyk, B.; Pikies, M.; Pinci, D.; Pistone, A.; Piucci, A.; Playfer, S.; Plo Casasus, M.; Poikela, T.; Polci, F.; Poluektov, A.; Polyakov, I.; Polycarpo, E.; Pomery, G. J.; Popov, A.; Popov, D.; Popovici, B.; Poslavskii, S.; Potterat, C.; Price, E.; Price, J. D.; Prisciandaro, J.; Pritchard, A.; Prouve, C.; Pugatch, V.; Puig Navarro, A.; Punzi, G.; Qian, W.; Quagliani, R.; Rachwal, B.; Rademacker, J. H.; Rama, M.; Ramos Pernas, M.; Rangel, M. S.; Raniuk, I.; Raven, G.; Redi, F.; Reichert, S.; dos Reis, A. C.; Remon Alepuz, C.; Renaudin, V.; Ricciardi, S.; Richards, S.; Rihl, M.; Rinnert, K.; Rives Molina, V.; Robbe, P.; Rodrigues, A. B.; Rodrigues, E.; Rodriguez Lopez, J. A.; Rodriguez Perez, P.; Rogozhnikov, A.; Roiser, S.; Rollings, A.; Romanovskiy, V.; Romero Vidal, A.; Ronayne, J. W.; Rotondo, M.; Rudolph, M. S.; Ruf, T.; Ruiz Valls, P.; Saborido Silva, J. J.; Sadykhov, E.; Sagidova, N.; Saitta, B.; Salustino Guimaraes, V.; Sanchez Mayordomo, C.; Sanmartin Sedes, B.; Santacesaria, R.; Santamarina Rios, C.; Santimaria, M.; Santovetti, E.; Sarti, A.; Satriano, C.; Satta, A.; Saunders, D. M.; Savrina, D.; Schael, S.; Schellenberg, M.; Schiller, M.; Schindler, H.; Schlupp, M.; Schmelling, M.; Schmelzer, T.; Schmidt, B.; Schneider, O.; Schopper, A.; Schubert, K.; Schubiger, M.; Schune, M.-H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Semennikov, A.; Sergi, A.; Serra, N.; Serrano, J.; Sestini, L.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Shevchenko, V.; Shires, A.; Siddi, B. G.; Silva Coutinho, R.; Silva de Oliveira, L.; Simi, G.; Simone, S.; Sirendi, M.; Skidmore, N.; Skwarnicki, T.; Smith, E.; Smith, I. T.; Smith, J.; Smith, M.; Snoek, H.; Sokoloff, M. D.; Soler, F. J. P.; Souza De Paula, B.; Spaan, B.; Spradlin, P.; Sridharan, S.; Stagni, F.; Stahl, M.; Stahl, S.; Stefko, P.; Stefkova, S.; Steinkamp, O.; Stemmle, S.; Stenyakin, O.; Stevenson, S.; Stoica, S.; Stone, S.; Storaci, B.; Stracka, S.; Straticiuc, M.; Straumann, U.; Sun, L.; Sutcliffe, W.; Swientek, K.; Syropoulos, V.; Szczekowski, M.; Szumlak, T.; T'Jampens, S.; Tayduganov, A.; Tekampe, T.; Tellarini, G.; Teubert, F.; Thomas, E.; van Tilburg, J.; Tilley, M. J.; Tisserand, V.; Tobin, M.; Tolk, S.; Tomassetti, L.; Tonelli, D.; Topp-Joergensen, S.; Toriello, F.; Tournefier, E.; Tourneur, S.; Trabelsi, K.; Traill, M.; Tran, M. T.; Tresch, M.; Trisovic, A.; Tsaregorodtsev, A.; Tsopelas, P.; Tully, A.; Tuning, N.; Ukleja, A.; Ustyuzhanin, A.; Uwer, U.; Vacca, C.; Vagnoni, V.; Valassi, A.; Valat, S.; Valenti, G.; Vallier, A.; Vazquez Gomez, R.; Vazquez Regueiro, P.; Vecchi, S.; van Veghel, M.; Velthuis, J. J.; Veltri, M.; Veneziano, G.; Venkateswaran, A.; Vernet, M.; Vesterinen, M.; Viaud, B.; Vieira, D.; Vieites Diaz, M.; Vilasis-Cardona, X.; Volkov, V.; Vollhardt, A.; Voneki, B.; Vorobyev, A.; Vorobyev, V.; Voß, C.; de Vries, J. A.; Vázquez Sierra, C.; Waldi, R.; Wallace, C.; Wallace, R.; Walsh, J.; Wang, J.; Ward, D. R.; Wark, H. M.; Watson, N. K.; Websdale, D.; Weiden, A.; Whitehead, M.; Wicht, J.; Wilkinson, G.; Wilkinson, M.; Williams, M.; Williams, M. P.; Williams, M.; Williams, T.; Wilson, F. F.; Wimberley, J.; Wishahi, J.; Wislicki, W.; Witek, M.; Wormser, G.; Wotton, S. A.; Wraight, K.; Wright, S.; Wyllie, K.; Xie, Y.; Xing, Z.; Xu, Z.; Yang, Z.; Yin, H.; Yu, J.; Yuan, X.; Yushchenko, O.; Zarebski, K. A.; Zavertyaev, M.; Zhang, L.; Zhang, Y.; Zhang, Y.; Zhelezov, A.; Zheng, Y.; Zhokhov, A.; Zhu, X.; Zhukov, V.; Zucchelli, S.; LHCb Collaboration

    2017-01-01

    The polarization of photons produced in radiative Bs0 decays is studied for the first time. The data are recorded by the LHCb experiment in p p collisions corresponding to an integrated luminosity of 3 fb-1 at center-of-mass energies of 7 and 8 TeV. A time-dependent analysis of the Bs0→ϕ γ decay rate is conducted to determine the parameter AΔ, which is related to the ratio of right- over left-handed photon polarization amplitudes in b →s γ transitions. A value of AΔ=-0.98-0.52-0.20+0.46+0.23

  20. Limits on Higgs bosons, scalar-quarkonia, and ηb's from radiative upsilon decays

    NASA Astrophysics Data System (ADS)

    Franzini, P.; Son, D.; Tuts, P. M.; Youssef, S.; Zhao, T.; Lee-Franzini, J.; Horstkotte, J.; Klopfenstein, C.; Kaarsberg, T.; Lovelock, D. M. J.; Schamberger, R. D.; Sontz, S. B.; Yanagisawa, C.

    1987-05-01

    We have searched for monochromatic photon signals in the reaction Υ(9460)-->X+γ in a sample of 420 000 Υ decays observed in the CUSB detector. From the absence of signal we obtain upper limits for Higgs-boson production in Υ decay which approach the minimal-standard-model expectations, including QCD radiative corrections, for low Higgs-boson masses. For two Higgs-boson models we obtain bounds on the ratio of the vacuum expectation values of the two neutral Higgs fields as a function of the Higgs-boson mass. We do not confirm the ζ(8.3) and find no evidence for a nearby bound scalar-quark-anti-scalar-quark state. We obtain a lower bound for the ηb mass using potential-model predictions.

  1. Radiative decay of excitons in model aggregates of {pi}-conjugated oligomers

    SciTech Connect

    Manas, E.S.; Spano, F.C.

    1998-07-01

    Spontaneous emission from exciton states in an aggregate of {pi}-conjugated oligomers is studied theoretically. Each oligomer is taken as a ring of N carbon atoms and is treated using a PPP Hamiltonian. Coulombic interactions between rings are treated to first order. The radiative decay rate {gamma} from an exciton state in an aggregate of M aligned oligomers is superradiant, being M times faster than the decay rate of an isolated oligomer exciton. Inter-oligomer interactions have little effect on the exciton size and energy when the oligomer size N is large compared to the interoligomer spacing. However, when N is small, both the exciton size and energy are strongly affected by these interactions, leading to a markedly different N dependence for {gamma}.

  2. Established theory of radiation-induced decay is not generalizable to Bolton-Hunter labeled peptides.

    PubMed

    Doran, Amanda C; Wan, Yieh-Ping; Kopin, Alan S; Beinborn, Martin

    2003-05-01

    Peptide hormones radiolabeled with 125I are widely used for the pharmacological characterization of cognate receptors. As a prerequisite for calculating ligand affinities from competition binding assays, and for estimating receptor densities from such studies, it is necessary to know the concentration of bioactive radioligand that is used in respective experiments. It has been demonstrated previously that radioiodinated peptides undergo decay catastrophe, i.e. disintegration of the radioactive label leads to the concomitant destruction of the carrier peptide. Here, we demonstrate that decay catastrophe does not apply to two peptide hormones that are iodinated by Bolton-Hunter conjugation: cholecystokinin octapeptide and glucagon-like peptide 2. The function of aged samples of these radioligands at corresponding recombinantly expressed receptors was assessed by measuring ligand-induced inositol phosphate production or generation of cyclic AMP, respectively. Both of the tested compounds, although predicted by decay catastrophe to contain little or subthreshold remaining bioactivity, stimulated an unexpectedly high level of receptor-mediated second messenger signaling. Quantitative comparison of observed functions with those of corresponding unlabeled peptides suggested that the bioactivity of each radioligand had been largely conserved despite the radioactive decay of the iodine label. Consistent with an apparent absence of decay catastrophe, we noted that the specific radioactivity, when determined immediately following peptide iodination, was close to the theoretical maximum but exponentially decreased over time. These findings raise the possibility that attachment of a Bolton-Hunter conjugate may shield labeled peptides from radiation-induced damage, a scenario that should be considered when performing radioligand binding experiments.

  3. Exclusive radiative B-meson decays within minimal flavor-violating two-Higgs-doublet models

    NASA Astrophysics Data System (ADS)

    Li, Xin-Qiang; Yang, Ya-Dong; Yuan, Xing-Bo

    2014-03-01

    In the "Higgs basis" for a generic two-Higgs-doublet model, only one doublet gets a nonzero vacuum expectation value and, under the criterion of minimal flavor violation, the other one is fixed to be either color-singlet or color-octet, referred to, respectively, as the type-III and type-C models. Both of them can naturally avoid large FCNC transitions and provide very interesting phenomena in some low-energy processes. In this paper, we study their effects on exclusive radiative B-meson decays due to the exchange of colorless or colored charged Higgs. It is found that while constraints from the branching ratios are slightly weaker than the ones from the inclusive B→Xsγ decay, the isospin asymmetries in exclusive decays provide very complementary bounds on the model parameters. As the two models predict similar corrections to the dipole coefficient C7eff, but similar magnitudes with opposite signs to C8eff, the branching ratios cannot discriminate the two models, and we have to resort to the direct CP and isospin asymmetries of b→s processes, which are more sensitive to C8eff. Due to the CKM factors |λu(d)|˜|λt(d)|, the terms proportional to λu(d) make the observables of b→d processes exhibit a different dependence on the possible new physics phase. In addition, correlations between the various observables in the exclusive B→Vγ and the inclusive B→Xs ,dγ decays are investigated, which could provide further insights into the models with more precise experimental measurements and theoretical predictions for these decays.

  4. Evidence against the Sciama Model of Radiative Decay of Massive Neutrinos

    NASA Astrophysics Data System (ADS)

    Bowyer, Stuart; Korpela, Eric J.; Edelstein, Jerry; Lampton, Michael; Morales, Carmen; Pérez-Mercader, Juan; Gómez, José F.; Trapero, Joaquín

    1999-11-01

    We report on spectral observations of the night sky in the band around 900 Å where the emission line in the Sciama model of radiatively decaying massive neutrinos would be present. The data were obtained with a high-resolution, high-sensitivity spectrometer flown on the Spanish satellite MINISAT. The observed emission is far less intense than that expected in the Sciama model. Based on the development and utilization of the Espectrógrafo Ultravioleta de Radiación Difusa, a collaboration of the Spanish Instituto Nacional de Tecnica Aeroespacial and the Center for EUV Astrophysics, University of California, Berkeley.

  5. Experimental limits on the radiative decay of SN 1987A neutrinos

    NASA Technical Reports Server (NTRS)

    Chupp, Edward L.; Vestrand, W. Thomas; Reppin, Claus

    1989-01-01

    SMM gamma-ray spectrometer data are examined to look for gamma-ray emission coincident with the about-10-s neutrino burst from SN 1987A. The absence of a detectable signal suggests that the energy radiated into MeV gamma rays by neutrino decay (or any other process) is less than 10 to the -10th of that in supernova neutrinos above 9 MeV. The results are used to set a direct limit on the lifetime of any massive neutrino type generated in the core collapse leading to SN 1987A.

  6. Radioactive Decay

    EPA Pesticide Factsheets

    Radioactive decay is the emission of energy in the form of ionizing radiation. Example decay chains illustrate how radioactive atoms can go through many transformations as they become stable and no longer radioactive.

  7. A New Decay Path in the {sup 12}C+{sup 16}O Radiative Capture Reaction

    SciTech Connect

    Courtin, S.; Lebhertz, D.; Haas, F.; Beck, C.; Michalon, A.; Salsac, M.-D.; Jenkins, D. G.; Marley, P.; Lister, C. J.

    2009-03-04

    The {sup 12}C({sup 16}O,{gamma}){sup 28}Si radiative capture reaction has been studied at energies close to the Coulomb barrier at Triumf (Vancouver) using the Dragon spectrometer and its associated BGO array. It has been observed that the {gamma} decay flux proceeds mainly via states around 10-11 MeV and via the direct feeding of the {sup 28}Si 3{sub 1}{sup -}(6879 keV) and 4{sub 2}{sup +}(6888 keV) deformed states. A discussion is presented about this selective feeding as well as perspectives for the use of novel detection systems for the study of light heavy-ion radiative capture reactions.

  8. BaBar: sin(2beta) with Charmless and Radiative Decays

    SciTech Connect

    Dujmic, Denis; /SLAC

    2006-02-27

    We present new measurements of time-dependent CP-violation parameters in hadronic penguin decays: B{sup 0} {yields} K{sup +}K{sup -}K{sub L}{sup 0}, K{sub S}{sup 0}{pi}{sup 0}{pi}{sup 0}, K{sub S}{sup 0}K{sub S}{sup 0}K{sub S}{sup 0}, {omega}K{sub L}{sup 0}, and a radiative penguin decay B{sup 0} {yields} K{sub S}{sup 0}{pi}{sup 0}{gamma} in a dataset of around 230 {center_dot} 10{sup 6} B{bar B} pairs collected by the BABAR detector at the asymmetric B Factory at SLAC. These CP asymmetry measurements probe for amplitudes beyond the Standard Model in loop-dominated decays of neutral B mesons. While we find a puzzling deviation of CP-asymmetry parameters from predicted values, a full confirmation still awaits more data.

  9. Decay strength distributions in {sup 12}C({sup 12}C,{gamma}) radiative capture

    SciTech Connect

    Jenkins, D. G.; Fulton, B. R.; Marley, P.; Fox, S. P.; Glover, R.; Wadsworth, R.; Watson, D. L.; Courtin, S.; Haas, F.; Lebhertz, D.; Beck, C.; Papka, P.; Rousseau, M.; Sanchez i Zafra, A.; Hutcheon, D. A.; Davis, C.; Ottewell, D.; Pavan, M. M.; Pearson, J.; Ruiz, C.

    2007-10-15

    The heavy-ion radiative capture reaction, {sup 12}C({sup 12}C,{gamma}), has been investigated at energies both on- and off-resonance, with a particular focus on known resonances at E{sub c.m.}=6.0, 6.8, 7.5, and 8.0 MeV. Gamma rays detected in a BGO scintillator array were recorded in coincidence with {sup 24}Mg residues at the focal plane of the DRAGON recoil separator at TRIUMF. In this manner, the relative strength of all decay pathways through excited states up to the particle threshold could be examined for the first time. Isovector M1 transitions are found to be a important component of the radiative capture from the E{sub c.m.}=6.0 and 6.8 MeV resonances. Comparison with Monte Carlo simulations suggests that these resonances may have either J=0 or 2, with a preference for J=2. The higher energy resonances at E{sub c.m.}=7.5 and 8.0 MeV have a rather different decay pattern. The former is a clear candidate for a J=4 resonance, whereas the latter has a dominant J=4 character superposed on a J=2 resonant component underneath. The relationship between these resonances and the well-known quasimolecular resonances as well as resonances in breakup and electrofission of {sup 24}Mg into two {sup 12}C nuclei are discussed.

  10. Measurement of Inclusive Radiative B -Meson Decay B -> X_s gamma

    SciTech Connect

    Ozcan, V.E.; /SLAC /Stanford U., Appl. Phys. Dept.

    2006-01-06

    Radiative decays of the B meson, B {yields} X{sub s}{gamma}, proceed via virtual flavor changing neutral current processes that are sensitive to contributions from high mass scales, either within the Standard Model of electroweak interactions or beyond. In the Standard Model, these transitions are sensitive to the weak interactions of the top quark, and relatively robust predictions of the inclusive decay rate exist. Significant deviation from these predictions could be interpreted as indications for processes not included in the minimal Standard Model, like interactions of charged Higgs or SUSY particles. The analysis of the inclusive photon spectrum from B {yields} X{sub s}{gamma} decays is rather challenging due to high backgrounds from photons emitted in the decay of mesons in B decays as well as e{sup +}e{sup -} annihilation to low mass quark and lepton pairs. Based on 88.5 million B{bar B} events collected by the BABAR detector, the photon spectrum above 1.9 GeV is presented. By comparison of the first and second moments of the photon spectrum with QCD predictions (calculated in the kinetic scheme), QCD parameters describing the bound state of the b quark in the B meson are extracted: m{sub b} = (4.45 {+-} 0.16) GeV/c{sup 2}; {mu}{sub {pi}}{sup 2} = (0.65 {+-} 0.29) GeV{sup 2}. These parameters are useful input to non-perturbative QCD corrections to the semileptonic B decay rate and the determination of the CKM parameter |V{sub ub}|. Based on these parameters and heavy quark expansion, the full branching fraction is obtained as: {Beta}(B {yields} X{sub s}{gamma}){sup E{sub {gamma}}>1.6 GeV} = (4.05 {+-} 0.32(stat) {+-} 0.38(syst) {+-} 0.29(model)) x 10{sup -4}. This result is in good agreement with previous measurements, the statistical and systematic errors are comparable. It is also in good agreement with the theoretical Standard Model predictions, and thus within the present errors there is no indication of any interactions not accounted for in the

  11. Addendum to Radiative corrections to the Dalitz plot of semileptonic decays of neutral baryons with light or charm quarks''

    SciTech Connect

    Martinez, A.; Tun, D.M.; Garcia, A.; Sanchez-Colon, G. Coordinacion de Dinamica Orbital, Telecomunicaciones de Mexico, Av. de las Telecomunicaciones s/n, C.P. 09300, Mexico, Distrito Federal Departamento de Fisica, Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional, Apartado Postal 14-740, C.P. 07000, Mexico, Distrito Federal )

    1994-08-01

    We show that the radiative corrections containing terms up to order [alpha][ital q]/[pi][ital M][sub 1] for unpolarized semileptonic decays of baryons with positron emission can be obtained by simply reversing the sign of the axial-vector form factors in the corresponding final expressions of such decays with electron emission. This rule is valid regardless of the final kinematical variables chosen and of the particular Lorentz frame in which the final results are required.

  12. Fluorescence quenching and photobleaching in Au/Rh6G nanoassemblies: impact of competition between radiative and non-radiative decay

    NASA Astrophysics Data System (ADS)

    Dong, L.; Ye, F.; Hu, J.; Popov, S.; Friberg, A. T.; Muhammed, M.

    2011-04-01

    Fluorescence quenching from nanoassemblies formed by Rhodamine 6G and gold nanoparticles (Au NPs) of 2.6 nm radius has been investigated. The presence of Au NPs also induces long-term degradation of the photostability (photobleaching) of Rhodamine 6G used as gain medium in a Fabry-Perot laser cavity. We found that the degradation gets profound when the Au NPs concentration is significantly increased. Calculation of the radiative rate and direct time-resolved measurement of the fluorescence decay indicates that both the decrease of radiative decay rate and increase of non-radiative decay rate are responsible for the fluorescence quenching and photostability degradation. An energy transfer from the dye molecules to gold nanoparticles is dominating within the small distance between them and suppresses the quantum efficiency of Rhodamine 6G drastically. In long time scale, the photobleaching rate was slowing down, and laser output intensity reached a stabilized level which depends on the gold nanoparticles concentration.

  13. Spectral and Non Radiative Decay Studies of Lead Di Bromide Single Crystals by Mode Matched Thermal Lens Technique.

    PubMed

    Rejeena, I; Lillibai, B; Thomas, V; Nampoori, V P N; Radhakrishnan, P

    2016-07-01

    In the present paper, the investigations on the non radiative decay mechanism, optical band gap determination from absorption spectroscopic studies and fluorescence emission by photo luminescence techniques using different excitation wavelengths on gel derived lead di bromide single crystals are reported. Non radiative decay of the sample is studied using high sensitive dual beam mode matched thermal lens technique. For the thermal lensing experiment the crystal in solution phase is incorporated with rhodamine 6G dye for enhancing the absorption of the crystal sample. The thermal diffusivity of lead di bromide is determined using the probe beam intensity v/s time measurements.

  14. Search for radiative decays of {upsilon}(1S) into {eta} and {eta}'

    SciTech Connect

    Athar, S. B.; 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.

    2007-10-01

    We report on a search for the radiative decay of {upsilon}(1S) to the pseudoscalar mesons {eta} and {eta}{sup '} in (21.2{+-}0.2)x10{sup 6} {upsilon}(1S) decays collected with the CLEO III detector at the Cornell Electron Storage Ring. The {eta} meson was reconstructed in the three modes {eta}{yields}{gamma}{gamma}, {eta}{yields}{pi}{sup +}{pi}{sup -}{pi}{sup 0}, or {eta}{yields}{pi}{sup 0}{pi}{sup 0}{pi}{sup 0}. The {eta}{sup '} meson was reconstructed in the mode {eta}{sup '}{yields}{pi}{sup +}{pi}{sup -}{eta} with {eta} decaying through any of the above three modes, and also {eta}{sup '}{yields}{gamma}{rho}{sup 0}, where {rho}{sup 0}{yields}{pi}{sup +}{pi}{sup -}. Five out of the seven submodes are found to have very low backgrounds. In four of them we find no signal candidates and in one [{upsilon}(1S){yields}{gamma}{eta}{sup '}, {eta}{sup '}{yields}{pi}{sup +}{pi}{sup -}{eta}, {eta}{yields}{pi}{sup +}{pi}{sup -}{pi}{sup 0}] there are two good signal candidates, which is insufficient evidence to claim a signal. The other two submodes ({eta}{yields}{gamma}{gamma} and {eta}{sup '}{yields}{gamma}{rho}) are background limited, and show no excess of events in their signal regions. We combine the results from different channels and obtain upper limits at the 90% C.L. which are B({upsilon}(1S){yields}{gamma}{eta})<1.0x10{sup -6} and B({upsilon}(1S){yields}{gamma}{eta}{sup '})<1.9x10{sup -6}. Our limits are an order of magnitude tighter than the previous ones and below the predictions made by some theoretical models.

  15. Observation of hc Radiative Decay hc→γ η' and Evidence for hc→γ η

    NASA Astrophysics Data System (ADS)

    Ablikim, M.; Achasov, M. N.; Ai, X. C.; Albayrak, O.; Albrecht, M.; Ambrose, D. J.; Amoroso, A.; An, F. F.; An, Q.; Bai, J. Z.; Baldini Ferroli, R.; Ban, Y.; Bennett, D. W.; Bennett, J. V.; Bertani, M.; Bettoni, D.; Bian, J. M.; Bianchi, F.; Boger, E.; Boyko, I.; Briere, R. A.; Cai, H.; Cai, X.; Cakir, O.; Calcaterra, A.; Cao, G. F.; Cetin, S. A.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, H. Y.; Chen, J. C.; Chen, M. L.; Chen, S.; Chen, S. J.; Chen, X.; Chen, X. R.; Chen, Y. B.; Cheng, H. P.; Chu, X. K.; Cibinetto, G.; Dai, H. L.; Dai, J. P.; Dbeyssi, A.; Dedovich, D.; Deng, Z. Y.; Denig, A.; Denysenko, I.; Destefanis, M.; de Mori, F.; Ding, Y.; Dong, C.; Dong, J.; Dong, L. Y.; Dong, M. Y.; Dou, Z. L.; Du, S. X.; Duan, P. F.; Fan, J. Z.; Fang, J.; Fang, S. S.; Fang, X.; Fang, Y.; Farinelli, R.; Fava, L.; Fedorov, O.; Feldbauer, F.; Felici, G.; Feng, C. Q.; Fioravanti, E.; Fritsch, M.; Fu, C. D.; Gao, Q.; Gao, X. L.; Gao, X. Y.; Gao, Y.; Gao, Z.; Garzia, I.; Goetzen, K.; Gong, L.; Gong, W. X.; Gradl, W.; Greco, M.; Gu, M. H.; Gu, Y. T.; Guan, Y. H.; Guo, A. Q.; Guo, L. B.; Guo, R. P.; Guo, Y.; Guo, Y. P.; Haddadi, Z.; Hafner, A.; Han, S.; Hao, X. Q.; Harris, F. A.; He, K. L.; Held, T.; Heng, Y. K.; Hou, Z. L.; Hu, C.; Hu, H. M.; Hu, J. F.; Hu, T.; Hu, Y.; Huang, G. S.; Huang, J. S.; Huang, X. T.; Huang, X. Z.; Huang, Y.; Huang, Z. L.; Hussain, T.; Ji, Q.; Ji, Q. P.; Ji, X. B.; Ji, X. L.; Jiang, L. W.; Jiang, X. S.; Jiang, X. Y.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Johansson, T.; Julin, A.; Kalantar-Nayestanaki, N.; Kang, X. L.; Kang, X. S.; Kavatsyuk, M.; Ke, B. C.; Kiese, P.; Kliemt, R.; Kloss, B.; Kolcu, O. B.; Kopf, B.; Kornicer, M.; Kupsc, A.; Kühn, W.; Lange, J. S.; Lara, M.; Larin, P.; Leng, C.; Li, C.; Li, Cheng; Li, D. M.; Li, F.; Li, F. Y.; Li, G.; Li, H. B.; Li, H. J.; Li, J. C.; Li, Jin; Li, K.; Li, K.; Li, Lei; Li, P. R.; Li, Q. Y.; Li, T.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. N.; Li, X. Q.; Li, Y. B.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y. T.; Liao, G. R.; Lin, D. X.; Liu, B.; Liu, B. J.; Liu, C. X.; Liu, D.; Liu, F. H.; Liu, Fang; Liu, Feng; Liu, H. B.; Liu, H. H.; Liu, H. H.; Liu, H. M.; Liu, J.; Liu, J. B.; Liu, J. P.; Liu, J. Y.; Liu, K.; Liu, K. Y.; Liu, L. D.; Liu, P. L.; Liu, Q.; Liu, S. B.; Liu, X.; Liu, Y. B.; Liu, Z. A.; Liu, Zhiqing; Loehner, H.; Lou, X. C.; Lu, H. J.; Lu, J. G.; Lu, Y.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, T.; Luo, X. L.; Lyu, X. R.; Ma, F. C.; Ma, H. L.; Ma, L. L.; Ma, M. M.; Ma, Q. M.; Ma, T.; Ma, X. N.; Ma, X. Y.; Ma, Y. M.; Maas, F. E.; Maggiora, M.; Mao, Y. J.; Mao, Z. P.; Marcello, S.; Messchendorp, J. G.; Min, J.; Mitchell, R. E.; Mo, X. H.; Mo, Y. J.; Morales Morales, C.; Muchnoi, N. Yu.; Muramatsu, H.; Nefedov, Y.; Nerling, F.; Nikolaev, I. B.; Ning, Z.; Nisar, S.; Niu, S. L.; Niu, X. Y.; Olsen, S. L.; Ouyang, Q.; Pacetti, S.; Pan, Y.; Patteri, P.; Pelizaeus, M.; Peng, H. P.; Peters, K.; Pettersson, J.; Ping, J. L.; Ping, R. G.; Poling, R.; Prasad, V.; Qi, H. R.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, L. Q.; Qin, N.; Qin, X. S.; Qin, Z. H.; Qiu, J. F.; Rashid, K. H.; Redmer, C. F.; Ripka, M.; Rong, G.; Rosner, Ch.; Ruan, X. D.; Sarantsev, A.; Savrié, M.; Schoenning, K.; Schumann, S.; Shan, W.; Shao, M.; Shen, C. P.; Shen, P. X.; Shen, X. Y.; Sheng, H. Y.; Shi, M.; Song, W. M.; Song, X. Y.; Sosio, S.; Spataro, S.; Sun, G. X.; Sun, J. F.; Sun, S. S.; Sun, X. H.; Sun, Y. J.; Sun, Y. Z.; Sun, Z. J.; Sun, Z. T.; Tang, C. J.; Tang, X.; Tapan, I.; Thorndike, E. H.; Tiemens, M.; Ullrich, M.; Uman, I.; Varner, G. S.; Wang, B.; Wang, B. L.; Wang, D.; Wang, D. Y.; Wang, K.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, P.; Wang, P. L.; Wang, S. G.; Wang, W.; Wang, W. P.; Wang, X. F.; Wang, Y.; Wang, Y. D.; Wang, Y. F.; Wang, Y. Q.; Wang, Z.; Wang, Z. G.; Wang, Z. H.; Wang, Z. Y.; Wang, Z. Y.; Weber, T.; Wei, D. H.; Wei, J. B.; Weidenkaff, P.; Wen, S. P.; Wiedner, U.; Wolke, M.; Wu, L. H.; Wu, L. J.; Wu, Z.; Xia, L.; Xia, L. G.; Xia, Y.; Xiao, D.; Xiao, H.; Xiao, Z. J.; Xie, Y. G.; Xiu, Q. L.; Xu, G. F.; Xu, J. J.; Xu, L.; Xu, Q. J.; Xu, Q. N.; Xu, X. P.; Yan, L.; Yan, W. B.; Yan, W. C.; Yan, Y. H.; Yang, H. J.; Yang, H. X.; Yang, L.; Yang, Y. X.; Ye, M.; Ye, M. H.; Yin, J. H.; Yu, B. X.; Yu, C. X.; Yu, J. S.; Yuan, C. Z.; Yuan, W. L.; Yuan, Y.; Yuncu, A.; Zafar, A. A.; Zallo, A.; Zeng, Y.; Zeng, Z.; Zhang, B. X.; Zhang, B. Y.; Zhang, C.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J.; Zhang, J. J.; Zhang, J. L.; Zhang, J. Q.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, K.; Zhang, L.; Zhang, S. Q.; Zhang, X. Y.; Zhang, Y.; Zhang, Y. H.; Zhang, Y. N.; Zhang, Y. T.; Zhang, Yu; Zhang, Z. H.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, G.; Zhao, J. W.; Zhao, J. Y.; Zhao, J. Z.; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, Q. W.; Zhao, S. J.; Zhao, T. C.; Zhao, Y. B.; Zhao, Z. G.; Zhemchugov, A.; Zheng, B.; Zheng, J. P.; Zheng, W. J.; Zheng, Y. H.; Zhong, B.; Zhou, L.; Zhou, X.; Zhou, X. K.; Zhou, X. R.; Zhou, X. Y.; Zhu, K.; Zhu, K. J.; Zhu, S.; Zhu, S. H.; Zhu, X. L.; Zhu, Y. C.; Zhu, Y. S.; Zhu, Z. A.; Zhuang, J.; Zotti, L.; Zou, B. S.; Zou, J. H.; Besiii Collaboration

    2016-06-01

    A search for radiative decays of the P -wave spin singlet charmonium resonance hc is performed based on 4.48 ×108 ψ' events collected with the BESIII detector operating at the BEPCII storage ring. Events of the reaction channels hc→γ η' and γ η are observed with a statistical significance of 8.4 σ and 4.0 σ , respectively, for the first time. The branching fractions of hc→γ η' and hc→γ η are measured to be B (hc→γ η')=(1.52 ±0.27 ±0.29 )×10-3 and B (hc→γ η )=(4.7 ±1.5 ±1.4 )×10-4, respectively, where the first errors are statistical and the second are systematic uncertainties.

  16. Radiative corrections to the Dalitz plot of K{sub l3}{sup {+-}} decays

    SciTech Connect

    Juarez-Leon, C.; Martinez, A.; Neri, M.; Torres, J. J.; Flores-Mendieta, Ruben

    2011-03-01

    We calculate the model-independent radiative corrections to the Dalitz plot of K{sub l3}{sup {+-}} decays to the order of ({alpha}/{pi})(q/M{sub 1}), where q is the momentum transfer and M{sub 1} is the mass of the kaon. The final results are presented, first, with the triple integration over the variables of the bremsstrahlung photon ready to be performed numerically and, second, in an analytical form. These two forms are useful to cross-check on one another and with other calculations. This paper is organized to make it accessible and reliable in the analysis of the Dalitz plot of precision experiments and is not compromised to fixing the form factors at predetermined values. It is assumed that the real photons are kinematically discriminated. Otherwise, our results have a general model-independent applicability.

  17. Precision Measurement of the Radiative β Decay of the Free Neutron

    NASA Astrophysics Data System (ADS)

    Bales, M. J.; Alarcon, R.; Bass, C. D.; Beise, E. J.; Breuer, H.; Byrne, J.; Chupp, T. E.; Coakley, K. J.; Cooper, R. L.; Dewey, M. S.; Gardner, S.; Gentile, T. R.; He, D.; Mumm, H. P.; Nico, J. S.; O'Neill, B.; Thompson, A. K.; Wietfeldt, F. E.; RDK Collaboration, II

    2016-06-01

    The standard model predicts that, in addition to a proton, an electron, and an antineutrino, a continuous spectrum of photons is emitted in the β decay of the free neutron. We report on the RDK II experiment which measured the photon spectrum using two different detector arrays. An annular array of bismuth germanium oxide scintillators detected photons from 14 to 782 keV. The spectral shape was consistent with theory, and we determined a branching ratio of 0.00335 ±0.00005 [stat ]±0.00015 [syst ] . A second detector array of large area avalanche photodiodes directly detected photons from 0.4 to 14 keV. For this array, the spectral shape was consistent with theory, and the branching ratio was determined to be 0.00582 ±0.00023 [stat ]±0.00062 [syst ] . We report the first precision test of the shape of the photon energy spectrum from neutron radiative decay and a substantially improved determination of the branching ratio over a broad range of photon energies.

  18. An experiment for the precision measurement of the radiative decay mode of the neutron

    NASA Astrophysics Data System (ADS)

    Cooper, R. L.; Bass, C. D.; Beise, E. J.; Breuer, H.; Byrne, J.; Chupp, T. E.; Coakley, K. J.; Dewey, M. S.; Fisher, B. M.; Fu, C.; Gentile, T. R.; McGonagle, M.; Mumm, H. P.; Nico, J. S.; Thompson, A. K.; Wietfeldt, F. E.

    2009-12-01

    The familiar neutron decay into a proton, electron, and antineutrino can be accompanied by photons with sufficient energy to be detected. We recently reported the first observation of the radiative beta decay branch for the free neutron with photons of energy 15-340 keV. We performed the experiment in the bore of a superconducting magnet where electron, proton, and photon signals were measured. A bar of bismuth germanate scintillating crystal coupled to an avalanche photodiode served as the photon detector that operated in the cryogenic, high magnetic field environment. The branching ratio for this energy region was measured and is consistent with the theoretical calculation. An experiment is under way to measure the branching ratio with an improved precision of 1% relative standard uncertainty and to measure the photon energy spectrum. In this paper, the apparatus modifications to reduce the systematic uncertainties will be described. Central to these improvements is the development of a 12-element detector based on the original photon detector design that will improve the statistical sensitivity. During data acquisition, a detailed calibration program will be performed to improve the systematic uncertainties. The development of these modifications is currently under way, and the second run of the experiment commenced in July 2008.

  19. Radiative decays of the psi(3097) to two meson final states

    SciTech Connect

    Einsweiler, K.F.

    1984-05-01

    The MARK III detector operating at the SPEAR storage ring has acquired a sample of 2.7 x 10/sup 6/ produced psi(3097)'s. These events are used to investigate the radiative decays of the psi to two meson final states. Such decays are of topical interest because of the unusual QCD laboratory they provide - of particular interest is the possibility of observing glueball states. The process psi ..-->.. ..gamma pi../sup +/..pi../sup -/ is studied. The f(1270) tensor meson is observed and the helicity structure of its production is measured. The data indicate that helicity 2 is suppressed, in disagreement with lowest order QCD calculations. Evidence is presented for the first observation of the theta(1700) in the ..pi../sup +/..pi../sup -/ final state. The strong, but not complete, suppression of this state in the ..pi pi.. channel, combined with the absence of a J/sup P/ = 2/sup +/ signal in a recent MARK III analysis of psi ..-->.. ..gamma.. rho rho, suggest a very mysterious nature for the theta(1700). The process psi ..-->.. ..gamma..K/sup +/K/sup -/ is also studied. The f'(1515) tensor meson is observed with a branching ratio in agreement with the SU(3) symmetry prediction for the standard two gluon radiative decay diagram with no mixing corrections. The helicity structure of the f'(1515) is measured for the first time, and is found to be similar to that of the f(1270). The theta(1700) is observed with high statistics. Its spin and parity are measured, with the result that J/sup P/ = 2/sup +/ is preferred over J/sup P/ = 0/sup +/ at the 99.9% C.L. In addition, evidence is presented for a remarkable narrow state, designated the xi(2220). Its parameters are measured to be: m = 2.218 +- 0.003 +- 0.010 GeV, GAMMA less than or equal to 0.040 GeV at 95% C.L., and BR(psi ..-->.. ..gamma..xi(2220))BR(xi(2220) ..-->.. K/sup +/K/sup -/) = (5.7 +- 1.9 +- 1.4) x 10/sup -5/.

  20. Radiative Decay Engineering 7: Tamm State-Coupled Emission Using a Hybrid Plasmonic-Photonic Structure

    PubMed Central

    Badugu, Ramachandram; Descrovi, Emiliano; Lakowicz, Joseph R.

    2014-01-01

    There is a continuing need to increase the brightness and photostability of fluorophores for use in biotechnology, medical diagnostics and cell imaging. One approach developed during the past decade is to use metallic surfaces and nanostructures. It is now known that excited state fluorophores display interactions with surface plasmons, which can increase the radiative decay rates, modify the spatial distribution of emission and result in directional emission. One important example is Surface Plasmon-Coupled Emission (SPCE). In this phenomenon the fluorophores at close distances from a thin metal film, typically silver, display emission over a small range of angles into the substrate. A disadvantage of SPCE is that the emission occur at large angles relative to the surface normal, and at angles which are larger than the critical angle for the glass substrate. The large angles make it difficult to collect all the coupled emission and have prevented use of SPCE with high-throughput and/or array applications. In the present report we describe a simple multi-layer metal-dielectric structure which allows excitation with light that is perpendicular (normal) to the plane and provides emission within a narrow angular distribution that is normal to the plane. This structure consist of a thin silver film on top of a multi-layer dielectric Bragg grating, with no nanoscale features except for the metal or dielectric layer thicknesses. Our structure is designed to support optical Tamm states, which are trapped electromagnetic modes between the metal film and the underlying Bragg grating. We used simulations with the transfer matrix method to understand the optical properties of Tamm states and localization of the modes or electric fields in the structure. Tamm states can exist with zero in-plane wavevector components and can be created without the use of a coupling prism. We show that fluorophores on top of the metal film can interact with the Tamm state under the metal film

  1. Effect of Proton Radiation on the Kinetics of Phosphorescence Decay in the Ceramic Material ZnS-Cu

    SciTech Connect

    Kuchakova, T.A.; Vesna, G.V.; Makara, V.A.

    2004-11-01

    The results of studying the dose dependences of the decay kinetics of phosphorescence excited by X-ray radiation in luminescent ZnS-Cu ceramic material before and after irradiation with 50-MeV protons are considered. An anomalous variation in the exponent of the hyperbolic phosphorescence curves was observed experimentally as the accumulated light sum increased. It is found from an analysis of the data obtained that two processes are involved in the decay: one of these is monomolecular and corresponds to the first-order kinetics; the other is bimolecular and corresponds to the second-order kinetics. Transitions of charge carriers delocalized from traps occur at the nonradiative-recombination centers induced by proton radiation. Recombination of these charge carriers at the emission centers in the course of decay is described by the second-order kinetics.

  2. Understanding and eliminating non-radiative decay in organic-inorganic perovskites (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Stranks, Samuel D.; de Quilettes, Dane

    2016-09-01

    Organic-inorganic perovskites such as CH3NH3PbI3 are highly promising materials for a variety of optoelectronic applications, with certified power conversion efficiencies in solar cells already exceeding 21% and promising applications in light-emitting diodes, lasers and photodetectors also emerging. A key enabling property of the perovskites is their high photoluminescence quantum efficiency, suggesting that these materials could in principle approach the thermodynamic device efficiency limits in which all recombination is radiative. However, non-radiative recombination sites are present which vary heterogeneously from grain to grain and limit device performance. Here, I will present results where we probe the local photophysics of neat CH3NH3PbI3 perovskite films using confocal photoluminescence (PL) measurements and correlate the observations with the local chemistry of the grains using energy-dispersive X-ray spectroscopy (EDX) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). We investigate the connection between grains that are bright or dark in emission and the local Pb:I ratios at the surface and through the grains. We also examine how the photophysics, local chemistry and non-radiative decay pathways change slowly over time under illumination. Our results reveal a "photo-induced cleaning" arising from a redistribution of iodide content in the films, giving strong evidence for photo-induced ion migration. These slow transient effects appear to be related to anomalous hysteresis phenomena observed in full solar cells. I will discuss how immobilizing ions, reducing trap densities and achieving homogenous stoichiometries could suppress hysteresis effects and lead to devices approaching the efficiency limits.

  3. Radiative decay of self-trapped excitons in CaMoO4 and MgMoO4 crystals

    NASA Astrophysics Data System (ADS)

    Mikhailik, V. B.; Kraus, H.; Itoh, M.; Iri, D.; Uchida, M.

    2005-11-01

    Spectroscopic properties of CaMoO4 and MgMoO4 crystals were studied in view of their application to cryogenic scintillation detectors. Luminescence spectra and the luminescence decay kinetics were measured over a wide range of temperatures (8-300 K). For the first time we measured time-resolved luminescence spectra of CaMoO4. In addition to the green emission arising from the triplet state of self-trapped excitons (STEs), a new band at around 430 nm with a decay time constant 10 ± 3 ns was observed at T = 8 K. This emission is assigned to the radiative decay of a singlet STE. The relaxation of electronic excitations in the crystals under study is discussed on the basis of our current understanding of their electronic structures and a configuration coordinate model for the radiative decay of STEs. The model includes adiabatic potential energy surfaces (APESs) associated with singlet and triplet states and explains the variation of the luminescence kinetics with temperature as a result of a re-distribution in the population of these states. Thus, judging from the change of the singlet STE emission due to temperature variation, we infer the existence of an energy barrier between the singlet and triplet APESs. The multi-exponential character of the decay of the triplet emission can be understood assuming that the relevant radiative transitions originate from different minima of the triplet APES. Non-radiative energy transfer processes control the population of these states, resulting in thermal variation of the intensities of the different emission components.

  4. Relativistic electron acceleration and decay time scales in the inner and outer radiation belts: SAMPEX

    NASA Technical Reports Server (NTRS)

    Baker, D. N.; Blake, J. B.; Callis, L. B.; Cummings, J. R.; Hovestadt, D.; Kanekal, S.; Klecker, B.; Mewaldt, R. A.; Zwickl, R. D.

    1994-01-01

    High-energy electrons have been measured systematically in a low-altitude (520 x 675 km), nearly polar (inclination = 82 deg) orbit by sensitive instruments onboard the Solar, Anomalous, and Magnetospheric Particle Explorer (SAMPEX). Count rate channels with electron energy thresholds ranging from 0.4 MeV to 3.5 MeV in three different instruments have been used to examine relativistic electron variations as a function of L-shell parameter and time. A long run of essentially continuous data (July 1992 - July 1993) shows substantial acceleration of energetic electrons throughout much of the magnetosphere on rapid time scales. This acceleration appears to be due to solar wind velocity enhancements and is surprisingly large in that the radiation belt 'slot' region often is filled temporarily and electron fluxes are strongly enhanced even at very low L-values (L aprroximately 2). A superposed epoch analysis shows that electron fluxes rise rapidly for 2.5 is approximately less than L is approximately less than 5. These increases occur on a time scale of order 1-2 days and are most abrupt for L-values near 3. The temporal decay rate of the fluxes is dependent on energy and L-value and may be described by J = Ke-t/to with t(sub o) approximately equals 5-10 days. Thus, these results suggest that the Earth's magnetosphere is a cosmic electron accelerator of substantial strength and efficiency.

  5. Search for the Radiative Decays B→ργ and B0→ωγ

    NASA Astrophysics Data System (ADS)

    Aubert, B.; Barate, R.; Boutigny, D.; Gaillard, J.-M.; Hicheur, A.; Karyotakis, Y.; Lees, J. P.; Robbe, P.; Tisserand, V.; Zghiche, A.; Palano, A.; Pompili, A.; Chen, J. C.; Qi, N. D.; Rong, G.; Wang, P.; Zhu, Y. S.; Eigen, G.; Ofte, I.; Stugu, B.; Abrams, G. S.; Borgland, A. W.; Breon, A. B.; Brown, D. N.; Button-Shafer, J.; Cahn, R. N.; Charles, E.; Day, C. T.; Gill, M. S.; Gritsan, A. V.; Groysman, Y.; Jacobsen, R. G.; Kadel, R. W.; Kadyk, J.; Kerth, L. T.; Kolomensky, Yu. G.; Kral, J. F.; Kukartsev, G.; Leclerc, C.; Levi, M. E.; Lynch, G.; Mir, L. M.; Oddone, P. J.; Orimoto, T. J.; Pripstein, M.; Roe, N. A.; Romosan, A.; Ronan, M. T.; Shelkov, V. G.; Telnov, A. V.; Wenzel, W. A.; Harrison, T. J.; Hawkes, C. M.; Knowles, D. J.; Penny, R. C.; Watson, A. T.; Watson, N. K.; Deppermann, T.; Goetzen, K.; Koch, H.; Lewandowski, B.; Pelizaeus, M.; Peters, K.; Schmuecker, H.; Steinke, M.; Barlow, N. R.; Bhimji, W.; Boyd, J. T.; Chevalier, N.; Cottingham, W. N.; Mackay, C.; Wilson, F. F.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; Thiessen, D.; Kyberd, P.; McKemey, A. K.; Blinov, V. E.; Bukin, A. D.; Golubev, V. B.; Ivanchenko, V. N.; Kravchenko, E. A.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Yushkov, A. N.; Best, D.; Chao, M.; Kirkby, D.; Lankford, A. J.; Mandelkern, M.; McMahon, S.; Mommsen, R. K.; Roethel, W.; Stoker, D. P.; Buchanan, C.; Hadavand, H. K.; Hill, E. J.; Macfarlane, D. B.; Paar, H. P.; Rahatlou, Sh.; Schwanke, U.; Sharma, V.; Berryhill, J. W.; Campagnari, C.; Dahmes, B.; Kuznetsova, N.; Levy, S. L.; Long, O.; Lu, A.; Mazur, M. A.; Richman, J. D.; Verkerke, W.; Beringer, J.; Eisner, A. M.; Heusch, C. A.; Lockman, W. S.; Schalk, T.; Schmitz, R. E.; Schumm, B. A.; Seiden, A.; Turri, M.; Walkowiak, W.; Williams, D. C.; Wilson, M. G.; Albert, J.; Chen, E.; Dorsten, M. P.; Dubois-Felsmann, G. P.; Dvoretskii, A.; Hitlin, D. G.; Narsky, I.; Porter, F. C.; Ryd, A.; Samuel, A.; Yang, S.; Jayatilleke, S.; Mancinelli, G.; Meadows, B. T.; Sokoloff, M. D.; Barillari, T.; Blanc, F.; Bloom, P.; Clark, P. J.; Ford, W. T.; Nauenberg, U.; Olivas, A.; Rankin, P.; Roy, J.; Smith, J. G.; van Hoek, W. C.; Zhang, L.; Harton, J. L.; Hu, T.; Soffer, A.; Toki, W. H.; Wilson, R. J.; Zhang, J.; Altenburg, D.; Brandt, T.; Brose, J.; Colberg, T.; Dickopp, M.; Dubitzky, R. S.; Hauke, A.; Lacker, H. M.; Maly, E.; Müller-Pfefferkorn, R.; Nogowski, R.; Otto, S.; Schubert, K. R.; Schwierz, R.; Spaan, B.; Wilden, L.; Bernard, D.; Bonneaud, G. R.; Brochard, F.; Cohen-Tanugi, J.; Thiebaux, Ch.; Vasileiadis, G.; Verderi, M.; Khan, A.; Lavin, D.; Muheim, F.; Playfer, S.; Swain, J. E.; Tinslay, J.; Bozzi, C.; Piemontese, L.; Sarti, A.; Treadwell, E.; Anulli, F.; Baldini-Ferroli, R.; Calcaterra, A.; de Sangro, R.; Falciai, D.; Finocchiaro, G.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Zallo, A.; Buzzo, A.; Contri, R.; Crosetti, G.; Lo Vetere, M.; Macri, M.; Monge, M. R.; Passaggio, S.; Pastore, F. C.; Patrignani, C.; Robutti, E.; Santroni, A.; Tosi, S.; Bailey, S.; Morii, M.; Aspinwall, M. L.; Bowerman, D. A.; Dauncey, P. D.; Egede, U.; Eschrich, I.; Morton, G. W.; Nash, J. A.; Sanders, P.; Taylor, G. P.; Grenier, G. J.; Lee, S.-J.; Mallik, U.; Cochran, J.; Crawley, H. B.; Lamsa, J.; Meyer, W. T.; Prell, S.; Rosenberg, E. I.; Yi, J.; Davier, M.; Grosdidier, G.; Höcker, A.; Laplace, S.; Le Diberder, F.; Lepeltier, V.; Lutz, A. M.; Petersen, T. C.; Plaszczynski, S.; Schune, M. H.; Tantot, L.; Wormser, G.; Bionta, R. M.; Brigljević, V.; Cheng, C. H.; Lange, D. J.; Wright, D. M.; Bevan, A. J.; Fry, J. R.; Gabathuler, E.; Gamet, R.; Kay, M.; Payne, D. J.; Sloane, R. J.; Touramanis, C.; Back, J. J.; Bellodi, G.; Harrison, P. F.; Shorthouse, H. W.; Strother, P.; Vidal, P. B.; Cowan, G.; Flaecher, H. U.; George, S.; Green, M. G.; Kurup, A.; Marker, C. E.; McMahon, T. R.; Ricciardi, S.; Salvatore, F.; Vaitsas, G.; Winter, M. A.; Brown, D.; Davis, C. L.; Allison, J.; Barlow, R. J.; Forti, A. C.; Hart, P. A.; Jackson, F.; Lafferty, G. D.; Lyon, A. J.; Weatherall, J. H.; Williams, J. C.; Farbin, A.; Jawahery, A.; Kovalskyi, D.; Lae, C. K.; Lillard, V.; Roberts, D. A.; Blaylock, G.; Dallapiccola, C.; Flood, K. T.; Hertzbach, S. S.; Kofler, R.; Koptchev, V. B.; Moore, T. B.; Staengle, H.; Willocq, S.; Cowan, R.; Sciolla, G.; Taylor, F.; Yamamoto, R. K.; Mangeol, D. J.; Milek, M.; Patel, P. M.; Lazzaro, A.; Palombo, F.; Bauer, J. M.; Cremaldi, L.; Eschenburg, V.; Godang, R.; Kroeger, R.; Reidy, J.; Sanders, D. A.; Summers, D. J.; Zhao, H. W.; Hast, C.; Taras, P.; Nicholson, H.; Cartaro, C.; Cavallo, N.; de Nardo, G.; Fabozzi, F.; Gatto, C.; Lista, L.; Paolucci, P.; Piccolo, D.; Sciacca, C.; Baak, M. A.; Raven, G.; Losecco, J. M.; Gabriel, T. A.; Brau, B.; Pulliam, T.; Brau, J.; Frey, R.; Iwasaki, M.; Potter, C. T.; Sinev, N. B.; Strom, D.; Torrence, E.; Colecchia, F.; Dorigo, A.; Galeazzi, F.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simonetto, F.; Stroili, R.; Tiozzo, G.; Voci, C.; Benayoun, M.; Briand, H.; Chauveau, J.; David, P.; de La Vaissière, Ch.; del Buono, L.; Hamon, O.; Leruste, Ph.; Ocariz, J.; Pivk, M.; Roos, L.; Stark, J.; T'jampens, S.; Manfredi, P. F.; Re, V.; Gladney, L.; Guo, Q. H.; Panetta, J.; Angelini, C.; Batignani, G.; Bettarini, S.; Bondioli, M.; Bucci, F.; Calderini, G.; Carpinelli, M.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Marchiori, G.; Martinez-Vidal, F.; Morganti, M.; Neri, N.; Paoloni, E.; Rama, M.; Rizzo, G.; Sandrelli, F.; Walsh, J.; Haire, M.; Judd, D.; Paick, K.; Wagoner, D. E.; Danielson, N.; Elmer, P.; Lu, C.; Miftakov, V.; Olsen, J.; Smith, A. J.; Varnes, E. W.; Bellini, F.; Cavoto, G.; del Re, D.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Leonardi, E.; Mazzoni, M. A.; Morganti, S.; Pierini, M.; Piredda, G.; Safai Tehrani, F.; Serra, M.; Voena, C.; Christ, S.; Wagner, G.; Waldi, R.; Adye, T.; de Groot, N.; Franek, B.; Geddes, N. I.; Gopal, G. P.; Olaiya, E. O.; Xella, S. M.; Aleksan, R.; Emery, S.; Gaidot, A.; Ganzhur, S. F.; Giraud, P.-F.; Hamel de Monchenault, G.; Kozanecki, W.; Langer, M.; London, G. W.; Mayer, B.; Schott, G.; Vasseur, G.; Yeche, Ch.; Zito, M.; Purohit, M. V.; Weidemann, A. W.; Yumiceva, F. X.; Aston, D.; Bartoldus, R.; Berger, N.; Boyarski, A. M.; Buchmueller, O. L.; Convery, M. R.; Coupal, D. P.; Dong, D.; Dorfan, J.; Dujmic, D.; Dunwoodie, W.; Field, R. C.; Glanzman, T.; Gowdy, S. J.; Grauges-Pous, E.; Hadig, T.; Halyo, V.; Hryn'ova, T.; Innes, W. R.; Jessop, C. P.; Kelsey, M. H.; Kim, P.; Kocian, M. L.; Langenegger, U.; Leith, D. W.; Luitz, S.; Luth, V.; Lynch, H. L.; Marsiske, H.; Menke, S.; Messner, R.; Muller, D. R.; O'Grady, C. P.; Ozcan, V. E.; Perazzo, A.; Perl, M.; Petrak, S.; Ratcliff, B. N.; Robertson, S. H.; Roodman, A.; Salnikov, A. A.; Schindler, R. H.; Schwiening, J.; Simi, G.; Snyder, A.; Soha, A.; Stelzer, J.; Su, D.; Sullivan, M. K.; Tanaka, H. A.; Va'Vra, J.; Wagner, S. R.; Weaver, M.; Weinstein, A. J.; Wisniewski, W. J.; Wright, D. H.; Young, C. C.; Burchat, P. R.; Meyer, T. I.; Roat, C.; Ahmed, S.; Ernst, J. A.; Bugg, W.; Krishnamurthy, M.; Spanier, S. M.; Eckmann, R.; Kim, H.; Ritchie, J. L.; Schwitters, R. F.; Izen, J. M.; Kitayama, I.; Lou, X. C.; Ye, S.; Bianchi, F.; Bona, M.; Gallo, F.; Gamba, D.; Borean, C.; Bosisio, L.; della Ricca, G.; Dittongo, S.; Grancagnolo, S.; Lanceri, L.; Poropat, P.; Vitale, L.; Vuagnin, G.; Panvini, R. S.; Banerjee, Sw.; Brown, C. M.; Fortin, D.; Jackson, P. D.; Kowalewski, R.; Roney, J. M.; Band, H. R.; Dasu, S.; Datta, M.; Eichenbaum, A. M.; Hu, H.; Johnson, J. R.; Liu, R.; di Lodovico, F.; Mohapatra, A. K.; Pan, Y.; Prepost, R.; Sekula, S. J.; von Wimmersperg-Toeller, J. H.; Wu, J.; Wu, S. L.; Yu, Z.; Neal, H.

    2004-03-01

    A search of the exclusive radiative decays B→ρ(770)γ and B0→ω(782)γ is performed on a sample of about 84×106 BB¯ events collected by the BABAR detector at the SLAC PEP-II asymmetric-energy e+e- storage ring. No significant signal is seen in any of the channels. We set upper limits on the branching fractions B of B(B0→ρ0γ)<1.2×10-6, B(B+→ρ+γ)<2.1×10-6, and B(B0→ωγ)<1.0×10-6 at 90% confidence level (C.L.). Using the assumption that Γ(B→ργ)=Γ(B+→ρ+γ)=2×Γ(B0→ρ0γ), we find the combined limit B(B→ργ)<1.9×10-6, corresponding to B(B→ργ)/B(B→K*γ)<0.047 at 90% C.L.

  6. Branching Fractions and CP-Violating Asymmetries in Radiative B Decays to eta K gamma

    SciTech Connect

    Aubert, B.

    2008-05-14

    The authors present measurements of the CP-violation parameters S and C for the radiative decay B{sup 0} {yields} {eta}K{sub S}{sup 0}{gamma}; for B {yields} {eta}K{gamma} they also measure the branching fractions and for B{sup +} {yields} {eta}K{sup +}{gamma} the time-integrated charge asymmetry {Alpha}{sub ch}. The data, collected with the BABAR detector at the Stanford Linear Accelerator Center, represent 465 x 10{sup 6} B{bar B} pairs produced in e{sup +}e{sup -} annihilation. The results are S = -0.18{sub -0.46}{sup +0.49} {+-} 0.12, C = -0.32{sub -0.39}{sup +0.40} {+-} 0.07, {Beta}(B{sup 0} {yields} {eta}K{sup 0}{gamma}) = (7.1{sub -2.0}{sup +2.1} {+-} 0.4) x 10{sup -6}, {Beta}(B{sup +} {yields} {eta}K{sup +}{gamma}) = (7.7 {+-} 1.0 {+-} 0.4) x 10{sup -6}, and {Alpha}{sub ch} = (-9.0{sub -9.8}{sup +10.4} {+-} 1.4) x 10{sup -2}. The first error quoted is statistical and the second systematic.

  7. Temperature and magnetic-field dependence of radiative decay in colloidal germanium quantum dots.

    PubMed

    Robel, István; Shabaev, Andrew; Lee, Doh C; Schaller, Richard D; Pietryga, Jeffrey M; Crooker, Scott A; L Efros, Alexander; Klimov, Victor I

    2015-04-08

    We conduct spectroscopic and theoretical studies of photoluminescence (PL) from Ge quantum dots (QDs) fabricated via colloidal synthesis. The dynamics of late-time PL exhibit a pronounced dependence on temperature and applied magnetic field, which can be explained by radiative decay involving two closely spaced, slowly emitting exciton states. In 3.5 nm QDs, these states are separated by ∼1 meV and are characterized by ∼82 μs and ∼18 μs lifetimes. By using a four-band formalism, we calculate the fine structure of the indirect band-edge exciton arising from the electron-hole exchange interaction and the Coulomb interaction of the Γ-point hole with the anisotropic charge density of the L-point electron. The calculations suggest that the observed PL dynamics can be explained by phonon-assisted recombination of excitons thermally distributed between the lower-energy "dark" state with the momentum projection J = ± 2 and a higher energy "bright" state with J = ± 1. A fairly small difference between lifetimes of these states is due to their mixing induced by the exchange term unique to crystals with a highly symmetric cubic lattice such as Ge.

  8. Determination of the b-quark Mass and Nonperturbative parameters in Semileptonic and Radiative Penguin Decays at BaBar

    SciTech Connect

    Tackmann, Kerstin; collaboration, for the BABAR

    2008-01-23

    Knowing the mass of the b-quark is essential to the study of the structure and decays of B mesons as well as to future tests of the Higgs mechanism of mass generation. We present recent preliminary measurements of the b-quark mass and related nonperturbative parameters from moments of kinematic distributions in charmed and charmless semileptonic and radiative penguin B decays. Their determination from charmless semileptonic B decays is the first measurement in this mode. The data were collected by the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -}-collider at the Stanford Linear Accelerator Center at a center-of-momentum energy of 10:58 GeV.

  9. Flavor Changing Neutral Coupling Mediated Radiative Top Quark Decays at Next-to-Leading Order in QCD

    SciTech Connect

    Drobnak, Jure; Kamenik, Jernej F.; Fajfer, Svjetlana

    2010-06-25

    We compute the branching ratios for the rare top quark decays t{yields}c{gamma} and t{yields}cZ mediated by effective flavor changing neutral couplings at next-to-leading order in QCD, including the effects due to operator mixing. After resumming contributions of the order of [{alpha}{sub s}log({Lambda}/m{sub t})]{sup n}, where {Lambda} is the scale at which the effective operators are generated, using renormalization group methods, we compute finite matrix element corrections and study the effects of experimental kinematic cuts on the extracted branching ratios. We find that the t{yields}c{gamma} decay can also be used to probe the effective operators mediating t{yields}cg processes, since the latter can naturally contribute 10% or more to the radiative decay. Conversely, any experimental signal of t{yields}cg would indicate a natural lower bound on t{yields}cZ, {gamma}.

  10. Search for Di-Muon Decays of a Light Scalar Higgs Boson in Radiative Upsilon(1S) Decays

    SciTech Connect

    Prasad, Vindhyawasini

    2013-08-01

    We search for di-muon decays of a low-mass Higgs boson (A0) in the fully reconstructed decay chain of Υ(2S, 3S ) → π+π-Υ(1S ), Υ(1S ) → γA0, A0 → μ+μ+. The A0 is predicted by several extensions of the Standard Model (SM), including the Next-to-Minimal Supersymmetric Standard Model (NMSSM). NMSSM introduces a CP-odd light Higgs boson whose mass could be less than 10 GeV/c2. The data samples used in this analysis contain 92.8 × 106 Υ(2S ) and 116.8 × 106 Υ(3S ) events collected by the BABAR detector. The Υ(1S ) sample is selected by tagging the pion pair in the Υ(2S, 3S ) → π+π-Υ(1S ) transitions. We find no evidence for A0 production and set 90% confidence level (C.L.) upper limits on the product branching fraction B(Υ(1S ) → γA0) × B(A0 → μ+μ-) in the range of (0.28 - 9.7) × 10-6 for 0.212 ≤ mA0 ≤ 9.20 GeV/c2. We also combine our results with previous BABAR results of Υ(2S, 3S ) → γA0, A0 → μ+μ- to set limits on the effective coupling ( fΥ) of the b-quark to the A0, f 2 Υ × B(A0 → μ+μ-), at the level of (0.29- 40) × 10-6 for 0.212 ≤ mA0 ≤ 9.2 GeV/c2.

  11. New decay branches of the radiative capture reaction {sup 12}C({sup 16}O,{gamma}){sup 28}Si

    SciTech Connect

    Lebhertz, D.; Courtin, S.; Haas, F.; Salsac, M.-D.; Beck, C.; Michalon, A.; Rousseau, M.; Marley, P. L.; Glover, R. G.; Kent, P. E.; Hutcheon, D. A.; Davis, C.; Pearson, J. E.

    2009-01-28

    Resonances in the {sup 12}C({sup 16}O,{gamma}){sup 28}Si radiative capture process at energies around the Coulomb barrier have been probed using the very selective 0 deg. Dragon spectrometer at Triumf and its associated BGO {gamma}-array. For the first time the full level scheme involved in this process has been measured and shows previously unobserved {gamma}-decay to doorway states around 11 MeV in {sup 28}Si.

  12. Testing the Standard Model with Radiative Penguin Decays at BaBar

    SciTech Connect

    Tuggle, J; /Maryland U.

    2008-04-22

    The author discusses two recent results in b {yields} s{gamma} decays from BABAR. The first is a measurement of the branching fraction and photon energy spectrum in the B meson frame of the decay B {yields} X{sub s{gamma}}. The second result probes the photon polarization via time-dependent CP violation in neutral B decays to K*{sup 0}{gamma}.

  13. Experimental search for radiative decays of the pentaquark baryon {Theta}{sup +}(1540)

    SciTech Connect

    Barmin, V. V.; Asratyan, A. E.; Borisov, V. S.; Curceanu, C.; Davidenko, G. V.; Dolgolenko, A. G.; Guaraldo, C.; Kubantsev, M. A.; Larin, I. F.; Matveev, V. A.; Shebanov, V. A.; Shishov, N. N.; Sokolov, L. I.; Tumanov, G. K.; Verebryusov, 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{sup 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.

  14. Radiative Penguin Decays of B Mesons: Measurements of B to K* gamma, B to K2* gamma, and Search for B0 to phi gamma

    SciTech Connect

    Bauer, J.

    2005-01-03

    Electromagnetic radiative penguin decays of the B meson were studied with the BaBar detector at SLAC's PEP-II asymmetric-energy B Factory. Branching fractions and isospin asymmetry of the decay B {yields} K*{gamma}, branching fractions of B {yields} K*{sub 2}(1430){gamma}, and a search for B{sup 0} {yields} {phi}{gamma} are presented. The decay rates may be enhanced by contributions from non-standard model processes.

  15. Radioactive decay.

    PubMed

    Groch, M W

    1998-01-01

    When a parent radionuclide decays to its daughter radionuclide by means of alpha, beta, or isomeric transition, the decay follows an exponential form, which is characterized by the decay constant lambda. The decay constant represents the probability per unit time that a single radioatom will decay. The decay equation can be used to provide a useful expression for radionuclide decay, the half-life, the time when 50% of the radioatoms present will have decayed. Radiotracer half-life has direct implications in nuclear imaging, radiation therapy, and radiation safety because radionuclide half-life affects the ability to evaluate tracer kinetics and create appropriate nuclear images and also affects organ, tumor, and whole-body radiation dose. The number of radioatoms present in a sample is equal to the activity, defined as the number of transitions per unit time, divided by the decay constant; the mass of radioatoms present in a sample can be calculated to determine the specific activity (activity per unit mass). The dynamic relationship between the number of parent and daughter atoms present over time may lead to radioactive equilibrium, which takes two forms--secular and transient--and has direct relevance to generator-produced radionuclides.

  16. 12C(16O,γ)28Si radiative capture: Structural and statistical aspects of the γ decay

    NASA Astrophysics Data System (ADS)

    Lebhertz, D.; Courtin, S.; Haas, F.; Jenkins, D. G.; Simenel, C.; Salsac, M.-D.; Hutcheon, D. A.; Beck, C.; Cseh, J.; Darai, J.; Davis, C.; Glover, R. G.; Goasduff, A.; Kent, P. E.; Levai, G.; Marley, P. L.; Michalon, A.; Pearson, J. E.; Rousseau, M.; Rowley, N.; Ruiz, C.

    2012-03-01

    The heavy-ion radiative capture reaction 12C(16O,γ)28Si has been studied at three energies Ec.m.=8.5, 8.8, and 9 MeV which are close to the Coulomb barrier. The weak radiative capture process has been identified by measuring the 28Si recoils in the highly selective 0∘ spectrometer DRAGON at TRIUMF (Vancouver). The coincident γ rays have been recorded in the associated BGO array. This has allowed a complete measurement of the γ spectrum and the relative strength of all decay pathways. An important part of the decay through quasibound states close to the particle threshold and the feeding of bound states with particular deformation have been identified for the first time. Comparisons with Monte Carlo simulations allowed the extraction of the full experimental radiative capture cross section. Our results suggest an important contribution of spins Jπ=5- and 6+ in the entrance channel. The surprisingly large cross sections from 12 μb at Ec.m.=8.5 MeV to 25 μb at Ec.m.=9.0 MeV for the heavy-ion radiative capture process are discussed in terms of the interplay between statistical and structural aspects of the process.

  17. Investigation of photoneutron and capture gamma-ray production in Pb and W under irradiation from 16N decay radiation

    NASA Astrophysics Data System (ADS)

    Kebwaro, Jeremiah Monari; Zhao, Yaolin; He, Chaohui

    2015-09-01

    Lead and tungsten are potential alternative materials for shielding reactor ex-core components with high 16N activity when available space limits application of concrete. Since the two materials are vulnerable to photonuclear reactions, the nature and intensity of the secondary radiation resulting from (γ,n) and (n,γ) reactions when 16N decay radiation interact with these materials need to be well known for effective shielding design. In this study the MCNP code was used to calculate the photoneutron and capture gamma-ray spectra in the two materials when irradiated by 16N decay radiation. It was observed that some of the photoneutrons generated in the two materials lie in the low-energy range which is considered optimum for (n,γ) reactions. Lead is more transparent to the photoneutrons when compared to tungsten. The calculations also revealed that the bremsstrahlung generated by the beta spectrum was not sufficient to trigger any additional photoneutrons. Both energetic and less energetic capture gamma-rays are observed when photoneutrons interact with nuclei of the two materials. Depending on the strength of the 16N source term, the secondary radiation could affect the effectiveness of the shield and need to be considered during design.

  18. An amplitude analysis of the pi0pi0 system produced in radiative J/psi decays

    NASA Astrophysics Data System (ADS)

    Bennett, Jake Vernon

    Despite many years of study, a complete understanding of the interactions of quarks and gluons within hadronic states remains elusive. Quantum Chromodynamics (QCD) has long predicted the possibility of states in which gluonic excitations can contribute to the characteristics of the state (a hybrid) or even take the place of constituent quarks altogether (a glueball), yet no incontrovertible evidence yet exists. This is partially due to the nature of the low mass spectrum, in which broad, overlapping states make experimental methods challenging. Recent technological improvements and high statistics data sets now enable a rigorous study of regions in which experimentalists may perform fundamental tests of QCD. This dissertation presents one such study, focusing on the pi 0pi0 spectrum. Particular emphasis is placed on the scalar meson spectrum (JPC = 0++), wherein the lightest glueball state is expected. An amplitude analysis of the pi0pi0 system produced in radiative J/psi decays is presented. A mass independent analysis of the (1.3106 +/- 0.0072) x 10 9 J/psi decays collected by the BESIII detector at BEPCII in Beijing, China is repeated under different model assumptions and experimental conditions. Additionally, the branching ratio of radiative J/psi decays to pi0pi0 is measured to be (1.147+/-0.002+/-0.042) x 10-3, where the first error is statistical and the second is systematic. This is the first measurement of this reaction.

  19. Exclusive weak radiative Higgs decays in the standard model and beyond

    NASA Astrophysics Data System (ADS)

    Alte, Stefan; König, Matthias; Neubert, Matthias

    2016-12-01

    We perform a detailed study of the exclusive Higgs decays h → MZ and h → MW, where M is a pseudoscalar or vector meson, using the QCD factorization approach. We allow for the presence of new-physics effects in the form of modified Higgs couplings to gauge bosons and fermions, including the possibility of flavor-changing Higgs couplings. We show that the decays h → VZ exhibit a strong sensitivity to the effective CP-even and CP-odd hγZ couplings. When combined with a measurement of the h → γZ decay rate, this can be used to extract these couplings up to a sign ambiguity in the CP-odd coefficient. Some of the h → MW decay modes can be used to probe for flavor-violating Higgs couplings involving the top quark.

  20. Volume effects in the decay of free radicals in organic crystals. [cobalt 60 gamma radiation

    SciTech Connect

    Markaryan, R.E.; Kovarskii, A.L.; Tshetinin, V.G. )

    1991-09-01

    The decay kinetics of the free radicals produced by {gamma}-irradiation of single crystals of organic dicarboxylic acids is studied at hydrostatic pressures up to 200 MPa. Correlation is established between the reaction's activation parameters (V{sup *} and E{sup *}) and the crystals macrocharacteristics - the compressibility and thermal expansion coefficients. A common equation is proposed to describe the variation of the radical decay rate constant with temperature and pressure in malonic, succinic, adipic, glutaric, suberic, and sebacic acids.

  1. Rare And Radiative B Meson Decays From the BaBar Experiment

    SciTech Connect

    Stelzer, J.; /SLAC

    2006-08-28

    Since its start in 1999 the BABAR experiment has collected a vast amount of data. Electron-positron collisions at the energy of the {Upsilon}(4S) resonance have produced about 240 million coherent B{sup 0}{bar B}{sup 0} and B{sup +}B{sup -} pairs, opening the doors for exploration of rare B meson decays. An overview of the electroweak penguin physics program of BABAR is given, the analysis of two specific decays is presented in detail.

  2. Radiative corrections of O(α ) to B- → V0 ℓ - bar{ν }_{ℓ } decays

    NASA Astrophysics Data System (ADS)

    Tostado, S. L.; Castro, G. López

    2016-09-01

    The O(α ) electromagnetic radiative corrections to the B^- → V^0 ℓ ^- bar{ν }_{ℓ } ( V is a vector meson and ℓ a charged lepton) decay rates are evaluated using the cutoff method to regularize virtual corrections and incorporating intermediate resonance states in the real-photon amplitude to extend the region of validity of the soft-photon approximation. The electromagnetic and weak form factors of hadrons are assumed to vary smoothly over the energies of virtual and real photons under consideration. The cutoff dependence of radiative corrections upon the scale Λ that separates the long- and short-distance regimes is found to be mild and is considered as an uncertainty of the calculation. Owing to partial cancellations of electromagnetic corrections evaluated over the three- and four-body regions of phase space, the photon-inclusive corrected rates are found to be dominated by the short-distance contribution. These corrections will be relevant for a precise determination of the b quark mixing angles by testing isospin symmetry when measurements of semileptonic rates of charged and neutral B mesons at the few percent level become available. For completeness, we also provide numerical values of radiative corrections in the three-body region of the Dalitz plot distributions of these decays.

  3. Constraining |V(td)|/|V(ts)| Using Radiative Penguin B -> V(K*/rho/omega)gamma Decays

    SciTech Connect

    Tan, Ping; /Wisconsin U., Madison

    2006-03-08

    Exclusive radiative penguin B decays, B {yields} (K*{sup 0}/K*{sup +}) and B {yields} ({rho}/{omega}){gamma}, are flavor-changing neutral-current (FCNC) processes. Studies of these decays are of special interest in testing Standard Model (SM) predictions and searching for other beyond-the-SM FCNC interactions. Using 89 x 10{sup 6} B{bar B} pairs from BABAR, we measure the branching fraction ({Beta}), CP-asymmetry ({Alpha}), and isospin asymmetry ({Delta}{sub 0-}) of B {yields} (K*{sup 0}/K*{sup +}){gamma} as follows: {Beta}(B{sup 0} {yields} K*{sup 0}{gamma}) = 3.92 {+-} 0.20(stat.) {+-} 0.24(syst.); {Beta}(B{sup +} {yields} K*{sup +}{gamma}) = 3.87 {+-} 0.28(stat.) {+-} 0.26(syst.); {Alpha}(B {yields} K*{gamma}) = -0.013 {+-} 0.36(stat.) {+-} 0.10(syst.); {Delta}{sub 0-}(B {yields} K*{gamma}) = 0.050 {+-} 0.045(stat.) {+-} 0.028(syst.) {+-} 0.024(R{sup +/0}). The 90% confidence intervals for the CP-asymmetry and the isospin-asymmetry in the B {yields} K*{gamma} decay are given as: -0.074 < {Alpha}(B {yields} K*{gamma}) < 0.049, -0.046 < {Delta}{sub 0-} (B {yields} K*{gamma}) < 0.146. We also search for B {yields} ({rho}/{omega}){gamma} decays using 211 x 10{sup 6} B{bar B} pairs from BABAR. No evidence for these decays is found. We set the upper limits at 90% confidence level for these decays: {Beta}(B{sup 0} {yields} {rho}{sup 0}{gamma}) < 0.4 x 10{sup -6}; {Beta}(B{sup +}{yields} {rho}{sup =}{gamma}) < 1.8 x 10{sup -6}; {Beta}(B{sup 0} {yields} {omega}{gamma}) < 1.0 x 10{sup -6}; {bar {Beta}}(B {yields} ({rho}/{omega}){gamma}) < 1.2 x 10{sup -6}. These results are in good agreement with the SM predictions. The branching fractions of these decays are then used to constrain the ratio |V{sub td}|/|V{sub ts}|.

  4. Atomic radiations in the decay of medical radioisotopes: a physics perspective.

    PubMed

    Lee, B Q; Kibédi, T; Stuchbery, A E; Robertson, K A

    2012-01-01

    Auger electrons emitted in nuclear decay offer a unique tool to treat cancer cells at the scale of a DNA molecule. Over the last forty years many aspects of this promising research goal have been explored, however it is still not in the phase of serious clinical trials. In this paper, we review the physical processes of Auger emission in nuclear decay and present a new model being developed to evaluate the energy spectrum of Auger electrons, and hence overcome the limitations of existing computations.

  5. Radiative capture studies of the electromagnetic decays of highly excited states

    SciTech Connect

    Snover, K.A.

    1980-01-01

    Selected examples of interesting E1, M1, and E2 resonance studies in (p,..gamma..) and (..cap alpha..,..gamma..) reactions are discussed. These include a unique determination of E1 amplitudes in the /sup 12/C(P,..gamma../sub 0/)/sup 13/N reaction, E2 strength in light nuclei, M1 decays to the ground states and to the excited O/sup +/ states of the doubly magic /sup 16/O and /sup 40/Ca nuclei, second harmonic E1 resonances in (p,..gamma..), and M1 ..gamma..-decay of stretched particle-hole states in /sup 16/O and /sup 28/Si.

  6. Atomic Radiations in the Decay of Medical Radioisotopes: A Physics Perspective

    PubMed Central

    Lee, B. Q.; Kibédi, T.; Stuchbery, A. E.; Robertson, K. A.

    2012-01-01

    Auger electrons emitted in nuclear decay offer a unique tool to treat cancer cells at the scale of a DNA molecule. Over the last forty years many aspects of this promising research goal have been explored, however it is still not in the phase of serious clinical trials. In this paper, we review the physical processes of Auger emission in nuclear decay and present a new model being developed to evaluate the energy spectrum of Auger electrons, and hence overcome the limitations of existing computations. PMID:22924061

  7. Charge-exchange x-ray spectra: Evidence for significant contributions from radiative decays of doubly excited states

    NASA Astrophysics Data System (ADS)

    Ali, R.; Beiersdorfer, P.; Harris, C. L.; Neill, P. A.

    2016-01-01

    Charge-exchange collisions of slow Ne+10 ions with He, Ne, and Ar targets were studied with simultaneous x-ray and cold-target recoil-ion-momentum spectroscopy proving the contribution of several mechanisms to the radiative stabilization of apparent (4,4) doubly excited states for He and Ne targets and of (5,6) states for Ar. In particular, the stabilization efficiency of the mechanism of dynamic auto-transfer to Rydberg states is confirmed. Moreover, we present evidence for direct radiative decays of (4,4) states populated in collisions with He, which is an experimental indication of the population of so-called unnatural-parity states in such collisions. These mechanisms lead to the emission of x-rays that have considerably higher energies than those predicted by current spectral models and may explain recent observations of anomalously large x-ray emission from Rydberg levels.

  8. Novel nonperturbative approach for radiative B¯0(B¯s0)→J /ψ γ decays

    NASA Astrophysics Data System (ADS)

    Geng, Li-Sheng; Oset, Eulogio

    2016-07-01

    Radiative B¯ 0(B¯s 0)→J /ψ γ decays provide an interesting case to test our understanding of (non)perturbative QCD and eventually to probe physics beyond the standard model. Recently, the LHCb Collaboration reported an upper bound, updating the results of the BABAR Collaboration. Previous theoretical predictions based on QCD factorization or perturbative QCD have shown large variations due to different treatment of nonfactorizable contributions and meson-photon transitions. In this paper, we report on a novel approach to estimate the decay rates, which is based on a recently proposed model for B decays and the vector meson dominance hypothesis, widely tested in the relevant energy regions. The predicted branching ratios are Br [B¯ 0→J /ψ γ ]=(3.50 ±0.34-0.63+1.12)×10-8 and Br [B¯s 0→J /ψ γ ]=(7.20 ±0.68-1.30+2.31)×10-7 . The first uncertainty is systematic and the second is statistical, originating from the experimental B¯s 0→J /ψ ϕ branching ratio.

  9. Phenomenological study on the wino radiative decay in anomalous U(1){sup '} models

    SciTech Connect

    Fucito, Francesco; Lionetto, Andrea; Pacifici, Daniel Ricci; Racioppi, Antonio

    2010-12-01

    An extension of the standard model by at least one extra U(1) gauge symmetry has been investigated by many authors. In this paper we explore the possibility that this extra U(1) is anomalous. One possible signature of this model could be given by the photons produced in the decays of the next to lightest supersymmetric particle into the lightest supersymmetric particle.

  10. Radiatively corrected lepton energy distributions in top quark decays t→ bW +→ b( ℓ + ν ℓ ) and t→ bH +→ b( τ + ν τ ) and single-charged prong energy distributions from subsequent τ + decays

    NASA Astrophysics Data System (ADS)

    Ali, Ahmed; Kuraev, Eduard A.; Bystritskiy, Yury M.

    2010-06-01

    We calculate the QED and QCD radiative corrections to the charged lepton energy distributions in the dominant semileptonic decays of the top quark t→ bW +→ b( ℓ + ν ℓ ) ( ℓ= e, μ, τ) in the standard model (SM), and for the decay t→ bH +→ b( τ + ν τ ) in an extension of the SM having a charged Higgs boson H ± with m_{H^{±}}decays. As the τ + leptons arising from the decays W +→ τ + ν τ and H +→ τ + ν τ are predominantly left- and right-polarised, respectively, influencing the energy distributions of the decay products in the subsequent decays of the τ +, we work out the effect of the radiative corrections on such distributions in the dominant (one-charged prong) decay channels tau+toπ+bar{ν}_{tau},ρ+bar{ν}_{tau},a1+bar{ν}_{tau} and ell+ν_{ell}bar{ν}_{tau}. The inclusive π + energy spectra in the decay chains tto b(W+,H+)to b(tau+ν_{tau})to b(π+bar{ν}_{tau}ν_{tau}+X) are calculated, which can help in searching for the induced H ± effects at the Tevatron and the LHC.

  11. High-energy electrons from the muon decay in orbit: Radiative corrections

    SciTech Connect

    Szafron, Robert; Czarnecki, Andrzej

    2015-12-07

    We determine the Ο(α) correction to the energy spectrum of electrons produced in the decay of muons bound in atoms. We focus on the high-energy end of the spectrum that constitutes a background for the muon-electron conversion and will be precisely measured by the upcoming experiments Mu2e and COMET. As a result, the correction suppresses the background by about 20%.

  12. New Measurement of the {pi}{sup 0} Radiative Decay Width

    SciTech Connect

    Larin, I.; McNulty, D.; Prok, Y.; Bernstein, A. M.; Kowalski, S.; Clinton, E.; Martel, P.; Miskimen, R.; Wood, M.; Ambrozewicz, P.; Ahmidouch, A.; Benton, L.; Danagoulian, S.; Demirchyan, R.; Gasparian, A.; Hardy, K.; Mtingwa, S.; Overby, S.; Payen, M.; Pedroni, R.

    2011-04-22

    High precision measurements of the differential cross sections for {pi}{sup 0} photoproduction at forward angles for two nuclei, {sup 12}C and {sup 208}Pb, have been performed for incident photon energies of 4.9-5.5 GeV to extract the {pi}{sup 0}{yields}{gamma}{gamma} decay width. The experiment was done at Jefferson Lab using the Hall B photon tagger and a high-resolution multichannel calorimeter. The {pi}{sup 0}{yields}{gamma}{gamma} decay width was extracted by fitting the measured cross sections using recently updated theoretical models for the process. The resulting value for the decay width is {Gamma}({pi}{sup 0}{yields}{gamma}{gamma})=7.82{+-}0.14(stat){+-}0.17(syst) eV. With the 2.8% total uncertainty, this result is a factor of 2.5 more precise than the current Particle Data Group average of this fundamental quantity, and it is consistent with current theoretical predictions.

  13. Corrected Article: "Experimental observation of nonspherically-decaying radiation from a rotating superluminal source" [J. Appl. Phys. 96, 4614 (2004)

    NASA Astrophysics Data System (ADS)

    Ardavan, A.; Hayes, W.; Singleton, J.; Ardavan, H.; Fopma, J.; Halliday, D.

    2004-12-01

    We describe the experimental implementation of a superluminal (i.e., faster than light in vacuo) polarization current distribution that both oscillates and undergoes centripetal acceleration. Theoretical treatments predict that the radiation emitted by each volume element of the superluminally moving distribution pattern will comprise a Čerenkov-like envelope with two sheets that meet along a cusp. Correspondingly, the emission from the experimental machine is found to be tightly beamed in both the azimuthal and polar directions. The beaming is frequency independent and has a sharply defined and unchanging geometry determined only by the speed and path of the moving distribution pattern, i.e., by the parameters governing the structure of the Čerenkov-like envelopes. In addition, over a restricted range of angles, we detect the presence of cusps in the emitted radiation. These, which are due to the focusing of wave fronts on a propagating space curve, result in the reception, during a short time period, of radiation emitted over a considerably longer period of (retarded) source time. The intensity of the radiation at these angles was observed to decline more slowly with increasing distance from the source than would the emission from a conventional antenna. The angular distribution of the emitted radiation and the properties associated with the cusps are in good quantitative agreement with theoretical models of superluminal sources once the effect of reflections from the earth's surface are taken into account. In particular, the prediction that the beaming and the slow decay should extend into the far zone has been tested to several hundred Fresnel distances (Rayleigh ranges). The excellent agreement between the theoretical calculations and the data suggests that the apparatus achieves precise and reproducible control of the polarization current and that similar machines could be of general interest for studying and utilizing the novel effects associated with

  14. Radiative transfer theory for the fractal structure and power-law decay characteristics of short-period seismograms

    NASA Astrophysics Data System (ADS)

    Sato, Haruo; Fukushima, Rintaro

    2013-12-01

    For short period S-wave seismograms of an earthquake, the maximum amplitude decreases according to a power of traveltime, and the coda amplitude also decreases according to a power of lapse time measured from the earthquake origin time. The radiative transfer theory has been often used for the envelope synthesis of complex seismograms composed of scattered waves due to random heterogeneities in the Earth medium; however, the conventional theory, which supposes uniform distributions of scatterers (heterogeneities) and intrinsic absorbers, predicts that both the ballistic term amplitude and the coda wave amplitude exponentially decrease with time increasing in addition to the geometrical decay. In order to explain their power-law characteristics, this paper proposes the radiative transfer theory for a fractally random and homogeneous distribution of isotropic scatterers and intrinsic absorbers with fractal dimension D ≤ 3 in the 3-D space: the number density of scatterers/absorbers in a sphere of radius r is proportional to rD - 3 for distance r ≫ rc but constant for r ≪ rc, where the corner distance rc is introduced to avoid divergence at a small r. The case of D = 3 corresponds to the conventional uniform distribution. For the case of D = 2, the theory well predicts that the mean square (MS) amplitude of the ballistic-wave decreases according to a power of traveltime and the MS amplitude of coda waves decreases according to a power of lapse time measured from the origin time, where each power is controlled by the scattering coefficient, intrinsic absorption coefficient and corner distance. For the case of D = 1, the ballistic-wave MS amplitude decay is the inverse square of time and the coda decay is much faster. As a preliminary work, fixing D = 2 as a priori choice, we analyse S-seismogram envelopes of a local earthquake in Japan. The case study shows that the radiative transfer theory for a fractal scattering medium is useful for the study of the

  15. On the origin of the pion-decay radiation in the 1982 June 3 solar flare

    NASA Technical Reports Server (NTRS)

    Ramaty, R.; Murphy, R. J.; Dermer, C. D.

    1987-01-01

    The June 3, 1982 flare produced a wealth of observed gamma-ray, energetic particle, and neutron emissions. It is shown that the predictions of an interaction model developed for the June 3 flare by Murphy, Dermer, and Ramaty (1987) compare favorably with new data on the time-dependent flux on pion-decay emission from this flare. It is concluded that the particles which produced the bulk of the pions could have the same origin as the particle observed in interplanetary space from the June 3 flare.

  16. Solving the Crisis in Big-Bang Nucleosynthesis by the Radiative Decay of an Exotic Particle

    NASA Astrophysics Data System (ADS)

    Holtmann, Erich; Kawasaki, Masahiro; Moroi, Takeo

    1996-10-01

    We discuss a new mechanism which can solve the crisis in standard big-bang nucleosynthesis. A long-lived particle X \\(104 sec<~τX<~106 sec\\) which decays into photon(s) will induce cascade photons, and destroy significant amounts of D and 3He without destroying 4He or too much 7Li. We numerically investigate this process and derive a constraint on the properties of X such that the theoretical values of the primordial light-element abundances agree with observation. We also present some candidates for the unstable particle X.

  17. Vector-meson-dominance model for radiative decays involving light scalar mesons.

    PubMed

    Black, Deirdre; Harada, Masayasu; Schechter, Joseph

    2002-05-06

    We study a vector-dominance model which predicts quite a large number of currently interesting decay amplitudes of the types S-->gammagamma, V-->Sgamma, and S-->Vgamma, where S and V denote scalar and vector mesons, in terms of three parameters. As an application, the model makes it easy to study in detail a recent proposal to boost the ratio Gamma(phi-->f(0)gamma)/Gamma(phi-->a(0)(0)gamma) by including the isospin violating a(0)(0)-f(0) mixing. However, we find that this effect is actually small in our model.

  18. Measurement of inclusive radiative B-meson decays with a photon energy threshold of 1.7 GeV.

    PubMed

    Limosani, A; Aihara, H; Arinstein, K; Aushev, T; Bakich, A M; Balagura, V; Barberio, E; Bay, A; Belous, K; Bischofberger, M; Bondar, A; Bozek, A; Bracko, M; Browder, T E; Chang, P; Chao, Y; Chen, A; Cheon, B G; Choi, Y; Dalseno, J; Danilov, M; Drutskoy, A; Dungel, W; Eidelman, S; Goldenzweig, P; Golob, B; Ha, H; Hayashii, H; Hoshi, Y; Hou, W-S; Hyun, H J; Inami, K; Itoh, R; Iwasaki, Y; Julius, T; Kah, D H; Kim, H O; Kim, S K; Kim, Y I; Kim, Y J; Kinoshita, K; Ko, B R; Korpar, S; Kreps, M; Krizan, P; Krokovny, P; Kuhr, T; Kumar, R; Kwon, Y-J; Kyeong, S-H; Lesiak, T; Li, J; Liu, C; Liventsev, D; Louvot, R; Matyja, A; Miyabayashi, K; Miyata, H; Miyazaki, Y; Mizuk, R; Mori, T; Nakao, M; Nakazawa, H; Nishida, S; Nishimura, K; Nitoh, O; Nozaki, T; Ogawa, S; Ohshima, T; Okuno, S; Ozaki, H; Pakhlova, G; Park, C W; Park, H; Piilonen, L E; Rozanska, M; Sahoo, H; Sakai, Y; Schneider, O; Schümann, J; Schwanda, C; Schwartz, A J; Senyo, K; Sevior, M E; Shapkin, M; Shebalin, V; Shen, C P; Shiu, J-G; Singh, J B; Stanic, S; Staric, M; Sumisawa, K; Sumiyoshi, T; Suzuki, S; Taylor, G N; Teramoto, Y; Trabelsi, K; Tsuboyama, T; Uehara, S; Unno, Y; Uno, S; Urquijo, P; Ushiroda, Y; Varner, G; Varvell, K E; Vervink, K; Wang, C H; Wang, M-Z; Wang, P; Watanabe, Y; Wedd, R; Wicht, J; Won, E; Yabsley, B D; Yamamoto, H; Yamashita, Y; Zhang, Z P; Zivko, T; Zupanc, A

    2009-12-11

    Using 605 fb(-1) of data collected at the Upsilon(4S) resonance we present a measurement of the inclusive radiative B-meson decay channel, B-->X(s)gamma. For the lower photon energy thresholds of 1.7, 1.8, 1.9, and 2.0 GeV, as defined in the rest frame of the B meson, we measure the partial branching fraction and the mean and variance of the photon energy spectrum. At the 1.7 GeV threshold we obtain the partial branching fraction BF(B-->X(s)}gamma)=(3.45+/-0.15+/-0.40)x10(-4), where the errors are statistical and systematic.

  19. Measurement of Inclusive Radiative B-Meson Decays with a Photon Energy Threshold of 1.7 GeV

    NASA Astrophysics Data System (ADS)

    Limosani, A.; Aihara, H.; Arinstein, K.; Aushev, T.; Bakich, A. M.; Balagura, V.; Barberio, E.; Bay, A.; Belous, K.; Bischofberger, M.; Bondar, A.; Bozek, A.; Bračko, M.; Browder, T. E.; Chang, P.; Chao, Y.; Chen, A.; Cheon, B. G.; Choi, Y.; Dalseno, J.; Danilov, M.; Drutskoy, A.; Dungel, W.; Eidelman, S.; Goldenzweig, P.; Golob, B.; Ha, H.; Hayashii, H.; Hoshi, Y.; Hou, W.-S.; Hyun, H. J.; Inami, K.; Itoh, R.; Iwasaki, Y.; Julius, T.; Kah, D. H.; Kim, H. O.; Kim, S. K.; Kim, Y. I.; Kim, Y. J.; Kinoshita, K.; Ko, B. R.; Korpar, S.; Kreps, M.; Križan, P.; Krokovny, P.; Kuhr, T.; Kumar, R.; Kwon, Y.-J.; Kyeong, S.-H.; Lesiak, T.; Li, J.; Liu, C.; Liventsev, D.; Louvot, R.; Matyja, A.; Miyabayashi, K.; Miyata, H.; Miyazaki, Y.; Mizuk, R.; Mori, T.; Nakao, M.; Nakazawa, H.; Nishida, S.; Nishimura, K.; Nitoh, O.; Nozaki, T.; Ogawa, S.; Ohshima, T.; Okuno, S.; Ozaki, H.; Pakhlova, G.; Park, C. W.; Park, H.; Piilonen, L. E.; Rozanska, M.; Sahoo, H.; Sakai, Y.; Schneider, O.; Schümann, J.; Schwanda, C.; Schwartz, A. J.; Senyo, K.; Sevior, M. E.; Shapkin, M.; Shebalin, V.; Shen, C. P.; Shiu, J.-G.; Singh, J. B.; Stanič, S.; Starič, M.; Sumisawa, K.; Sumiyoshi, T.; Suzuki, S.; Taylor, G. N.; Teramoto, Y.; Trabelsi, K.; Tsuboyama, T.; Uehara, S.; Unno, Y.; Uno, S.; Urquijo, P.; Ushiroda, Y.; Varner, G.; Varvell, K. E.; Vervink, K.; Wang, C. H.; Wang, M.-Z.; Wang, P.; Watanabe, Y.; Wedd, R.; Wicht, J.; Won, E.; Yabsley, B. D.; Yamamoto, H.; Yamashita, Y.; Zhang, Z. P.; Zivko, T.; Zupanc, A.

    2009-12-01

    Using 605fb-1 of data collected at the Υ(4S) resonance we present a measurement of the inclusive radiative B-meson decay channel, B→Xsγ. For the lower photon energy thresholds of 1.7, 1.8, 1.9, and 2.0 GeV, as defined in the rest frame of the B meson, we measure the partial branching fraction and the mean and variance of the photon energy spectrum. At the 1.7 GeV threshold we obtain the partial branching fraction BF(B→Xsγ)=(3.45±0.15±0.40)×10-4, where the errors are statistical and systematic.

  20. Measurements of the production of P-wave charmonium states through radiative decays at the ATLAS experiment

    NASA Astrophysics Data System (ADS)

    Marcisovsky, Michal

    2014-04-01

    The production cross sections of the χc1 and χc2 charmonium states are measured in pp collisions at √s = 7 TeV using 4.5 fb-1 of integrated luminosity recorded by the ATLAS detector at the LHC. The χc states are reconstructed via the radiative decay χc → J/ψ(μ+μ-)γ, where the photons are reconstructed using γ → e+ e- conversion in the detector material. Differential production cross sections for prompt and non-prompt χc1,2 are presented, as well as the fraction of inclusive J/ψ produced by feed-down from the χc states. The results are compared with a range of theoretical predictions. The branching fraction of ℬ (B+ → χc1K+) is measured using the same dataset and χc event selection.

  1. Roles of Interfering Radiation Emitted from Decaying Pulses Obeying Soliton Equations Belonging to the Ablowitz-Kaup-Newell-Segur Systems

    NASA Astrophysics Data System (ADS)

    Fujishima, Hironobu; Yajima, Tetsu

    2015-06-01

    The nonlinear Schrödinger (NLS) equation under the box-type initial condition, which models general multiple pulses deviating from pure solitons, is analyzed. Following the approximation by splitting the initial pulse into many small bins [G. Boffetta and A. R. Osborne, http://dx.doi.org/10.1016/0021-9991(92)90370-E, J. Comp. Phys. 102, 252 (1992)], we can analyze the Zakharov-Shabat eigenvalue problem to construct transfer matrices connecting the Jost functions in each interval without direct numerical computation. We can obtain analytical expressions for the scattering data that describe interfering radiation emitted from initial pulses. The number of solitons that appear in the final stage is predicted theoretically, and the condition generating an unusual wave such as a double-pole soliton is derived. Numerical analyses under box-type initial conditions are also performed to show that the interplay between the tails from decaying pulses can affect the asymptotic profile.

  2. Observation of D0→ρ0γ and Search for C P Violation in Radiative Charm Decays

    NASA Astrophysics Data System (ADS)

    Nanut, T.; Zupanc, A.; Adachi, I.; Aihara, H.; Al Said, S.; Asner, D. M.; Aulchenko, V.; Aushev, T.; Ayad, R.; Babu, V.; Badhrees, I.; Bakich, A. M.; Bansal, V.; Behera, P.; Bhardwaj, V.; Biswal, J.; Bondar, A.; Bozek, A.; Bračko, M.; Browder, T. E.; Červenkov, D.; Chekelian, V.; Chen, A.; Cheon, B. G.; Chistov, R.; Cho, K.; Choi, S.-K.; Choi, Y.; Cinabro, D.; Dash, N.; Di Carlo, S.; Doležal, Z.; Dutta, D.; Eidelman, S.; Farhat, H.; Fast, J. E.; Ferber, T.; Fulsom, B. G.; Gaur, V.; Gabyshev, N.; Garmash, A.; Gillard, R.; Goldenzweig, P.; Golob, B.; Hayasaka, K.; Hayashii, H.; Hou, W.-S.; Iijima, T.; Inami, K.; Inguglia, G.; Ishikawa, A.; Iwasaki, Y.; Jacobs, W. W.; Jaegle, I.; Joffe, D.; Joo, K. K.; Julius, T.; Kaliyar, A. B.; Kang, K. H.; Kawasaki, T.; Kim, D. Y.; Kim, J. B.; Kim, K. T.; Kim, M. J.; Kim, S. H.; Kinoshita, K.; Kodyš, P.; Korpar, S.; Krokovny, P.; Kuhr, T.; Kulasiri, R.; Kuzmin, A.; Kwon, Y.-J.; Lange, J. S.; Lee, I. S.; Li, C. H.; Li, L.; Li, Y.; Li Gioi, L.; Libby, J.; Liventsev, D.; Lubej, M.; Masuda, M.; Matsuda, T.; Matvienko, D.; Miyabayashi, K.; Miyata, H.; Mizuk, R.; Mohanty, G. B.; Moon, H. K.; Nakao, M.; Nath, K. J.; Nayak, M.; Nisar, N. K.; Nishida, S.; Ogawa, S.; Okuno, S.; Pakhlov, P.; Pakhlova, G.; Pal, B.; Park, C.-S.; Park, C. W.; Park, H.; Paul, S.; Pedlar, T. K.; Pesántez, L.; Pestotnik, R.; Petrič, M.; Piilonen, L. E.; Prasanth, K.; Pulvermacher, C.; Rauch, J.; Ritter, M.; Rostomyan, A.; Sakai, Y.; Sandilya, S.; Santelj, L.; Sanuki, T.; Sato, Y.; Savinov, V.; Schlüter, T.; Schneider, O.; Schnell, G.; Schwanda, C.; Schwartz, A. J.; Seino, Y.; Senyo, K.; Seon, O.; Sevior, M. E.; Shebalin, V.; Shen, C. P.; Shibata, T.-A.; Shiu, J.-G.; Shwartz, B.; Solovieva, E.; Stanič, S.; Starič, M.; Strube, J. F.; Stypula, J.; Sumiyoshi, T.; Takizawa, M.; Tamponi, U.; Tenchini, F.; Trabelsi, K.; Uchida, M.; Uno, S.; Ushiroda, Y.; Varner, G.; Vinokurova, A.; Vorobyev, V.; Vossen, A.; Wang, C. H.; Wang, M.-Z.; Wang, P.; Watanabe, Y.; Widmann, E.; Won, E.; Yamaoka, J.; Yamashita, Y.; Yelton, J.; Zhang, Z. P.; Zhilich, V.; Zhukova, V.; Zhulanov, V.; Belle Collaboration

    2017-02-01

    We report the first observation of the radiative charm decay D0→ρ0γ and the first search for C P violation in decays D0→ρ0γ , ϕ γ , and K¯ *0 (892 )γ , using a data sample of 943 fb-1 collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. The branching fraction is measured to be B (D0→ρ0γ ) =(1.77 ±0.30 ±0.07 )×10-5 , where the first uncertainty is statistical and the second is systematic. The obtained C P asymmetries AC P(D0→ρ0γ ) =+0.056 ±0.152 ±0.006 , AC P(D0→ϕ γ ) =-0.094 ±0.066 ±0.001 , and AC P(D0→K¯ *0γ ) =-0.003 ±0.020 ±0.000 are consistent with no C P violation. We also present an improved measurement of the branching fractions B (D0→ϕ γ ) =(2.76 ±0.19 ±0.10 )×10-5 and B (D0→K¯ *0γ ) =(4.66 ±0.21 ±0.21 )×10-4 .

  3. Observation of D^{0}→ρ^{0}γ and Search for CP Violation in Radiative Charm Decays.

    PubMed

    Nanut, T; Zupanc, A; Adachi, I; Aihara, H; Al Said, S; Asner, D M; Aulchenko, V; Aushev, T; Ayad, R; Babu, V; Badhrees, I; Bakich, A M; Bansal, V; Behera, P; Bhardwaj, V; Biswal, J; Bondar, A; Bozek, A; Bračko, M; Browder, T E; Červenkov, D; Chekelian, V; Chen, A; Cheon, B G; Chistov, R; Cho, K; Choi, S-K; Choi, Y; Cinabro, D; Dash, N; Di Carlo, S; Doležal, Z; Dutta, D; Eidelman, S; Farhat, H; Fast, J E; Ferber, T; Fulsom, B G; Gaur, V; Gabyshev, N; Garmash, A; Gillard, R; Goldenzweig, P; Golob, B; Hayasaka, K; Hayashii, H; Hou, W-S; Iijima, T; Inami, K; Inguglia, G; Ishikawa, A; Iwasaki, Y; Jacobs, W W; Jaegle, I; Joffe, D; Joo, K K; Julius, T; Kaliyar, A B; Kang, K H; Kawasaki, T; Kim, D Y; Kim, J B; Kim, K T; Kim, M J; Kim, S H; Kinoshita, K; Kodyš, P; Korpar, S; Krokovny, P; Kuhr, T; Kulasiri, R; Kuzmin, A; Kwon, Y-J; Lange, J S; Lee, I S; Li, C H; Li, L; Li, Y; Li Gioi, L; Libby, J; Liventsev, D; Lubej, M; Masuda, M; Matsuda, T; Matvienko, D; Miyabayashi, K; Miyata, H; Mizuk, R; Mohanty, G B; Moon, H K; Nakao, M; Nath, K J; Nayak, M; Nisar, N K; Nishida, S; Ogawa, S; Okuno, S; Pakhlov, P; Pakhlova, G; Pal, B; Park, C-S; Park, C W; Park, H; Paul, S; Pedlar, T K; Pesántez, L; Pestotnik, R; Petrič, M; Piilonen, L E; Prasanth, K; Pulvermacher, C; Rauch, J; Ritter, M; Rostomyan, A; Sakai, Y; Sandilya, S; Santelj, L; Sanuki, T; Sato, Y; Savinov, V; Schlüter, T; Schneider, O; Schnell, G; Schwanda, C; Schwartz, A J; Seino, Y; Senyo, K; Seon, O; Sevior, M E; Shebalin, V; Shen, C P; Shibata, T-A; Shiu, J-G; Shwartz, B; Solovieva, E; Stanič, S; Starič, M; Strube, J F; Stypula, J; Sumiyoshi, T; Takizawa, M; Tamponi, U; Tenchini, F; Trabelsi, K; Uchida, M; Uno, S; Ushiroda, Y; Varner, G; Vinokurova, A; Vorobyev, V; Vossen, A; Wang, C H; Wang, M-Z; Wang, P; Watanabe, Y; Widmann, E; Won, E; Yamaoka, J; Yamashita, Y; Yelton, J; Zhang, Z P; Zhilich, V; Zhukova, V; Zhulanov, V

    2017-02-03

    We report the first observation of the radiative charm decay D^{0}→ρ^{0}γ and the first search for CP violation in decays D^{0}→ρ^{0}γ, ϕγ, and K[over ¯]^{*0}(892)γ, using a data sample of 943  fb^{-1} collected with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. The branching fraction is measured to be B(D^{0}→ρ^{0}γ)=(1.77±0.30±0.07)×10^{-5}, where the first uncertainty is statistical and the second is systematic. The obtained CP asymmetries A_{CP}(D^{0}→ρ^{0}γ)=+0.056±0.152±0.006, A_{CP}(D^{0}→ϕγ)=-0.094±0.066±0.001, and A_{CP}(D^{0}→K[over ¯]^{*0}γ)=-0.003±0.020±0.000 are consistent with no CP violation. We also present an improved measurement of the branching fractions B(D^{0}→ϕγ)=(2.76±0.19±0.10)×10^{-5} and B(D^{0}→K[over ¯]^{*0}γ)=(4.66±0.21±0.21)×10^{-4}.

  4. Astrophysical data on 5 eV to 1 keV radiation from the radiative decay of fundamental particles - Current limits and prospects for improvement

    NASA Technical Reports Server (NTRS)

    Bowyer, Stuart; Malina, Roger F.

    1986-01-01

    Line emission from the decay of fundamental particles, integrated over cosmological distances, can give rise to detectable spectral features in the diffuse astronomical background between 5 eV and 1 keV. Spectroscopic observations may allow these features to be separated from line emission from the numerous local sources of radiation. The current observational status and existing evidence for such features are reviewed. No definitive detections of nongalactic line features have been made. Several local sources of background mask the features at many wavelengths and confuse the interpretation of the data. No systematic spectral observations have been carried out to date. Upcoming experiments which can be expected to provide significantly better constraints on the presence of spectral features in the diffuse background from 5 eV to 1 keV are reviewed.

  5. The Radiative Decay of Green and Red Photoluminescent Phosphors: An Undergraduate Kinetics Experiment for Materials Chemistry

    ERIC Educational Resources Information Center

    Esposti, C. Degli; Bizzocchi, L.

    2008-01-01

    This article describes a laboratory experiment that allows the students to investigate the radiative properties of the green and red emitting phosphors that are employed in commercial fluorescent lamps. Making use of a spectrofluorometer, students first record the emission spectrum of a fluorescent lamp under normal operating conditions, and then…

  6. Photogenerated excitons in plain core CdSe nanocrystals with unity radiative decay in single channel: the effects of surface and ligands.

    PubMed

    Gao, Yuan; Peng, Xiaogang

    2015-04-01

    A systematic and reproducible method was developed to study the decay dynamics of an exciton, a photogenerated electron-hole pair, in semiconductor nanocrystals in solution. Results revealed that the excitons in plain core CdSe nanocrystals in either zinc-blende or wurtzite or mixed lattice structures could be reproducibly prepared to decay radiatively in unity quantum yield and in single channel. The single-channel lifetime was found to increase monotonically by increasing size of the CdSe nanocrystals, with zinc-blende ones increasing in a relatively slow pace. Surface inorganic stoichiometry was found to be a sensitive parameter to affect the exciton decay dynamics for all crystal structures with different sizes. Excess Se (Cd) sites on the surface were found to induce short (long) lifetime channels for the excitons. Both types of traps reduced the quantum yield of the radiative decay of the excitons, and the hole traps associated with Se sites were nearly not emissive. With optimal surface inorganic stoichiometry, primary amines were identified as "ideal" organic ligands for CdSe core nanocrystals to achieve unity radiative decay of excitons in single channel in comparison to other types of neutral ligands commonly applied in the field.

  7. Observation of chicJ radiative decays to light vector mesons.

    PubMed

    Bennett, J V; 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; Tan, B J Y; 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; 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; Tatishvili, G; Vogel, H; 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

    2008-10-10

    Using a total of 2.74 x 10(7) decays of the psi(2S) collected with the CLEO-c detector, we present a study of chi(cJ)-->gammaV, where V=rho(0), omega, phi. The transitions chi(c1)-->gammarho(0 and chi(c1)-->gammaomega are observed with B(chi(c1)-->gammarho(0))=(2.43+/-0.19+/-0.22) x 10(-4) and B(chi(c1)-->gammaomega)=(8.3+/-1.5+/-1.2) x 10(-5). In the chi(c1)-->gammarho(0) transition, the final state meson is dominantly longitudinally polarized. Upper limits on the branching fractions of other chi(cJ) states to light vector mesons are presented.

  8. Exclusive radiative Higgs decays as probes of light-quark Yukawa couplings

    NASA Astrophysics Data System (ADS)

    König, Matthias; Neubert, Matthias

    2015-08-01

    We present a detailed analysis of the rare exclusive Higgs boson decays into a single vector meson and a photon and investigate the possibility of using these processes to probe the light-quark Yukawa couplings. We work with an effective Lagrangian with modified Higgs couplings to account for possible new-physics effects in a model-independent way. The h → Vγ decay rate is governed by the destructive interference of two amplitudes, one of which involves the Higgs coupling to the quark anti-quark pair inside the vector meson. We derive this amplitude at next-to-leading order in α s using QCD factorization, including the resummation of large logarithmic corrections and accounting for the effects of flavor mixing. The high factorization scale μ ˜ m h ensures that our results are rather insensitive to the hadronic parameters characterizing the light-cone distribution amplitude of the vector meson. The second amplitude arises from the loop-induced effective hγγ * and hγZ * couplings, where the off-shell gauge boson converts into the vector meson. We devise a strategy to eliminate theoretical uncertainties related to this amplitude to almost arbitrary precision. This opens up the possibility to probe for modifications of the c- and b-quark Yukawa couplings and modifications of the s-quark Yukawa coupling in the high-luminosity LHC run. In particular, we show that measurements of the ratios Br( h → Υ( nS) γ)/Br( h → γγ) and can provide complementary information on the real and imaginary parts of the b-quark Yukawa coupling. More accurate measurements would be possible at a future 100 TeV proton-proton collider.

  9. Analysis of the vertices {Omega}{sub Q}*{Omega}{sub Q{phi}} and radiative decays {Omega}{sub Q}*{yields}{Omega}{sub Q{gamma}}

    SciTech Connect

    Wang Zhigang

    2010-02-01

    In this article, we study the vertices {Omega}{sub Q}*{Omega}{sub Q{phi}} with the light-cone QCD sum rules, then assume the vector meson dominance of the intermediate {phi}(1020), and calculate the radiative decays {Omega}{sub Q}*{yields}{Omega}{sub Q{gamma}}.

  10. Self-consistent solitons for vacuum decay in radiatively generated potentials

    NASA Astrophysics Data System (ADS)

    Garbrecht, Björn; Millington, Peter

    2015-12-01

    We use a Green's function approach in order to develop a method for calculating the tunneling rate between radiatively generated nondegenerate vacua. We apply this to a model that exhibits spontaneous symmetry breaking via the Coleman-Weinberg mechanism, where we determine the self-consistent tunneling configuration and illustrate the impact of gradient effects that arise from accounting for the underlying space-time inhomogeneity.

  11. Reply to Comments on ``Generation of focused, nonspherically decaying pulses of electromagnetic radiation''

    NASA Astrophysics Data System (ADS)

    Ardavan, H.

    2000-08-01

    The criticism made by Hannay [preceding Comment, Phys. Rev. E 62, 3008 (2000)] is unfounded since the steps, familiar from the subluminal regime, that are taken in his argument are not mathematically permissible when the distribution pattern of the source is moving and has volume elements that approach the observer with the speed of light and zero acceleration along the radiation direction. In the superluminal regime, the retarded time is a multivalued function of the observation time and so the retarded potential for the radiation from a localized source cannot be represented, as Hannay assumes, by an integral over all space whose integrand entails a differentiable retarded distribution of the source density. Contrary to what is claimed by Hewish [Comment in this issue, Phys. Rev. E 62, 3007 (2000)], moreover, there is no discrepancy between conventional antenna theory and the analysis that appears in Phys. Rev. E 58, 6659 (1998). The characteristics of the new type of emission predicted by this analysis, and received from pulsars, differ from those of the radiation that is produced by known leaky waveguides because there are at present no antennas in which the emitting electric current is both volume-distributed and has the time dependence of a traveling wave with an accelerated superluminal motion.

  12. Search for a light C P -odd Higgs boson in radiative decays of J /ψ

    NASA Astrophysics Data System (ADS)

    Ablikim, M.; Achasov, M. N.; Ai, X. C.; Albayrak, O.; Albrecht, M.; Ambrose, D. J.; Amoroso, A.; An, F. F.; An, Q.; Bai, J. Z.; Baldini Ferroli, R.; Ban, Y.; Bennett, D. W.; Bennett, J. V.; Bertani, M.; Bettoni, D.; Bian, J. M.; Bianchi, F.; Boger, E.; Boyko, I.; Briere, R. A.; Cai, H.; Cai, X.; Cakir, O.; Calcaterra, A.; Cao, G. F.; Cetin, S. A.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, H. Y.; Chen, J. C.; Chen, M. L.; Chen, S. J.; Chen, X.; Chen, X. R.; Chen, Y. B.; Cheng, H. P.; Chu, X. K.; Cibinetto, G.; Dai, H. L.; Dai, J. P.; Dbeyssi, A.; Dedovich, D.; Deng, Z. Y.; Denig, A.; Denysenko, I.; Destefanis, M.; de Mori, F.; Ding, Y.; Dong, C.; Dong, J.; Dong, L. Y.; Dong, M. Y.; Dou, Z. L.; Du, S. X.; Duan, P. F.; Fan, J. Z.; Fang, J.; Fang, S. S.; Fang, X.; Fang, Y.; Fava, L.; Feldbauer, F.; Felici, G.; Feng, C. Q.; Fioravanti, E.; Fritsch, M.; Fu, C. D.; Gao, Q.; Gao, X. L.; Gao, X. Y.; Gao, Y.; Gao, Z.; Garzia, I.; Goetzen, K.; Gong, W. X.; Gradl, W.; Greco, M.; Gu, M. H.; Gu, Y. T.; Guan, Y. H.; Guo, A. Q.; Guo, L. B.; Guo, Y.; Guo, Y. P.; Haddadi, Z.; Hafner, A.; Han, S.; Harris, F. A.; He, K. L.; Held, T.; Heng, Y. K.; Hou, Z. L.; Hu, C.; Hu, H. M.; Hu, J. F.; Hu, T.; Hu, Y.; Huang, G. M.; Huang, G. S.; Huang, J. S.; Huang, X. T.; Huang, Y.; Hussain, T.; Ji, Q.; Ji, Q. P.; Ji, X. B.; Ji, X. L.; Jiang, L. W.; Jiang, X. S.; Jiang, X. Y.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Johansson, T.; Julin, A.; Kalantar-Nayestanaki, N.; Kang, X. L.; Kang, X. S.; Kavatsyuk, M.; Ke, B. C.; Kiese, P.; Kliemt, R.; Kloss, B.; Kolcu, O. B.; Kopf, B.; Kornicer, M.; Kühn, W.; Kupsc, A.; Lange, J. S.; Lara, M.; Larin, P.; Leng, C.; Li, C.; Li, Cheng; Li, D. M.; Li, F.; Li, F. Y.; Li, G.; Li, H. B.; Li, J. C.; Li, Jin; Li, K.; Li, K.; Li, Lei; Li, P. R.; Li, T.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. M.; Li, X. N.; Li, X. Q.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y. T.; Liao, G. R.; Lin, D. X.; Liu, B. J.; Liu, C. X.; Liu, D.; Liu, F. H.; Liu, Fang; Liu, Feng; Liu, H. B.; Liu, H. H.; Liu, H. H.; Liu, H. M.; Liu, J.; Liu, J. B.; Liu, J. P.; Liu, J. Y.; Liu, K.; Liu, K. Y.; Liu, L. D.; Liu, P. L.; Liu, Q.; Liu, S. B.; Liu, X.; Liu, Y. B.; Liu, Z. A.; Liu, Zhiqing; Loehner, H.; Lou, X. C.; Lu, H. J.; Lu, J. G.; Lu, Y.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, T.; Luo, X. L.; Lyu, X. R.; Ma, F. C.; Ma, H. L.; Ma, L. L.; Ma, Q. M.; Ma, T.; Ma, X. N.; Ma, X. Y.; Maas, F. E.; Maggiora, M.; Mao, Y. J.; Mao, Z. P.; Marcello, S.; Messchendorp, J. G.; Min, J.; Mitchell, R. E.; Mo, X. H.; Mo, Y. J.; Morales Morales, C.; Muchnoi, N. Yu.; Muramatsu, H.; Nefedov, Y.; Nerling, F.; Nikolaev, I. B.; Ning, Z.; Nisar, S.; Niu, S. L.; Niu, X. Y.; Olsen, S. L.; Ouyang, Q.; Pacetti, S.; Pan, Y.; Patteri, P.; Pelizaeus, M.; Peng, H. P.; Peters, K.; Pettersson, J.; Ping, J. L.; Ping, R. G.; Poling, R.; Prasad, V.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, L. Q.; Qin, N.; Qin, X. S.; Qin, Z. H.; Qiu, J. F.; Rashid, K. H.; Redmer, C. F.; Ripka, M.; Rong, G.; Rosner, Ch.; Ruan, X. D.; Santoro, V.; Sarantsev, A.; Savrié, M.; Schoenning, K.; Schumann, S.; Shan, W.; Shao, M.; Shen, C. P.; Shen, P. X.; Shen, X. Y.; Sheng, H. Y.; Song, W. M.; Song, X. Y.; Sosio, S.; Spataro, S.; Sun, G. X.; Sun, J. F.; Sun, S. S.; Sun, Y. J.; Sun, Y. Z.; Sun, Z. J.; Sun, Z. T.; Tang, C. J.; Tang, X.; Tapan, I.; Thorndike, E. H.; Tiemens, M.; Ullrich, M.; Uman, I.; Varner, G. S.; Wang, B.; Wang, B. L.; Wang, D.; Wang, D. Y.; Wang, K.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, P.; Wang, P. L.; Wang, S. G.; Wang, W.; Wang, W. P.; Wang, X. F.; Wang, Y. D.; Wang, Y. F.; Wang, Y. Q.; Wang, Z.; Wang, Z. G.; Wang, Z. H.; Wang, Z. Y.; Weber, T.; Wei, D. H.; Wei, J. B.; Weidenkaff, P.; Wen, S. P.; Wiedner, U.; Wolke, M.; Wu, L. H.; Wu, Z.; Xia, L.; Xia, L. G.; Xia, Y.; Xiao, D.; Xiao, H.; Xiao, Z. J.; Xie, Y. G.; Xiu, Q. L.; Xu, G. F.; Xu, L.; Xu, Q. J.; Xu, X. P.; Yan, L.; Yan, W. B.; Yan, W. C.; Yan, Y. H.; Yang, H. J.; Yang, H. X.; Yang, L.; Yang, Y.; Yang, Y. Y.; Ye, M.; Ye, M. H.; Yin, J. H.; Yu, B. X.; Yu, C. X.; Yu, J. S.; Yuan, C. Z.; Yuan, W. L.; Yuan, Y.; Yuncu, A.; Zafar, A. A.; Zallo, A.; Zeng, Y.; Zeng, Z.; Zhang, B. X.; Zhang, B. Y.; Zhang, C.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J. J.; Zhang, J. L.; Zhang, J. Q.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, K.; Zhang, L.; Zhang, X. Y.; Zhang, Y.; Zhang, Y. H.; Zhang, Y. N.; Zhang, Y. T.; Zhang, Yu; Zhang, Z. H.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, G.; Zhao, J. W.; Zhao, J. Y.; Zhao, J. Z.; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, Q. W.; Zhao, S. J.; Zhao, T. C.; Zhao, Y. B.; Zhao, Z. G.; Zhemchugov, A.; Zheng, B.; Zheng, J. P.; Zheng, W. J.; Zheng, Y. H.; Zhong, B.; Zhou, L.; Zhou, X.; Zhou, X. K.; Zhou, X. R.; Zhou, X. Y.; Zhu, K.; Zhu, K. J.; Zhu, S.; Zhu, S. H.; Zhu, X. L.; Zhu, Y. C.; Zhu, Y. S.; Zhu, Z. A.; Zhuang, J.; Zotti, L.; Zou, B. S.; Zou, J. H.; Besiii Collaboration

    2016-03-01

    We search for a light Higgs boson A0 in the fully reconstructed decay chain of J /ψ →γ A0 , A0→μ+μ- using (225.0 ±2.8 )×106 J /ψ events collected by the BESIII experiment. The A0 is a hypothetical C P -odd light Higgs boson predicted by many extensions of the Standard Model including two spin-0 doublets plus an extra singlet. We find no evidence for A0 production and set 90% confidence-level upper limits on the product branching fraction B (J /ψ →γ A0)×B (A0→μ+μ-) in the range of (2.8 - 495.3 )×10-8 for 0.212 ≤mA0≤3.0 GeV /c2 . The new limits are five times below our previous results, and the nature of the A0 is constrained to be mostly singlet.

  13. Test of the linear-NO threshold theory of radiation carcinogenesis for inhaled radon decay products

    SciTech Connect

    Cohen, B.L.

    1995-02-01

    Data on lung cancer mortality rates vs. average radon concentration in homes for 1,601 U.S. counties are used to test the linear-no threshold theory. The widely recognized problems with ecological studies, as applied to this work, are addressed extensively. With or without corrections for variations in smoking prevalence, there is a strong tendency for lung cancer rates to decrease with increasing radon exposure, in sharp contrast to the increase expected from the theory. The discrepancy in slope is about 20 standard deviations. It is shown that uncertainties in lung cancer rates, radon exposures, and smoking prevalence are not important and that confounding by 54 socioeconomic factors, by geography, and by altitude and climate can explain only a small fraction of the discrepancy. Effects of known radon-smoking prevalence correlations-rural people have higher radon levels and smoke less than urban people, and smokers are exposed to less radon than non-smokers-are calculated and found to be trivial. In spite of extensive efforts, no potential explanation for the discrepancy other than failure of the linear-no threshold theory for carcinogenesis from inhaled radon decay products could be found. 46 refs., 2 figs., 7 tabs.

  14. Radiative decay engineering 5: metal-enhanced fluorescence and plasmon emission

    PubMed Central

    Lakowicz, Joseph R.

    2009-01-01

    Metallic particles and surfaces display diverse and complex optical properties. Examples include the intense colors of noble metal colloids, surface plasmon resonance absorption by thin metal films, and quenching of excited fluorophores near the metal surfaces. Recently, the interactions of fluorophores with metallic particles and surfaces (metals) have been used to obtain increased fluorescence intensities, to develop assays based on fluorescence quenching by gold colloids, and to obtain directional radiation from fluorophores near thin metal films. For metal-enhanced fluorescence it is difficult to predict whether a particular metal structure, such as a colloid, fractal, or continuous surface, will quench or enhance fluorescence. In the present report we suggest how the effects of metals on fluorescence can be explained using a simple concept, based on radiating plasmons (RPs). The underlying physics may be complex but the concept is simple to understand. According to the RP model, the emission or quenching of a fluorophore near the metal can be predicted from the optical properties of the metal structures as calculated from electrodynamics, Mie theory, and/or Maxwell’s equations. For example, according to Mie theory and the size and shape of the particle, the extinction of metal colloids can be due to either absorption or scattering. Incident energy is dissipated by absorption. Far-field radiation is created by scattering. Based on our model small colloids are expected to quench fluorescence because absorption is dominant over scattering. Larger colloids are expected to enhance fluorescence because the scattering component is dominant over absorption. The ability of a metal’s surface to absorb or reflect light is due to wavenumber matching requirements at the metal–sample interface. Wavenumber matching considerations can also be used to predict whether fluorophores at a given distance from a continuous planar surface will be emitted or quenched. These

  15. Heavy quark signals from radiative corrections to the Z{sup '} boson decay in 3-3-1 models

    SciTech Connect

    Martinez, R.; Ochoa, F.

    2009-10-01

    One-loop corrections to the Z{sup '} decay width are derived and analyzed in the framework of the general form of the 3-3-1 models. We identify two important sources of corrections: oblique corrections associated to the Z{sup '} propagator through vacuum polarizations induced by virtual particle-antiparticle pairs of new heavy quarks J, and vertex corrections to the Z{sup '}qq vertex through virtual exchange of new K{sup Q{sub 1,2}} gauge bosons. Fixing a specific renormalization scheme, we obtain dominant oblique corrections that exhibit a quadratic dependence on the J quark mass, which are absorbed into two oblique parameters: a global parameter {rho}{sub f}{sup '} which modify the Z{sup '} decay width, and a parameter {kappa}{sub f}{sup '} that define effective Z{sup '} couplings. Numerical results in an specific 3-3-1 model gives a strong contribution of the oblique corrections from about 1.3% in the d(s) quark channel to 10.5% in the neutrino channel, for m{sub J}=2 TeV. The vertex corrections contribute to the oblique corrections up to 1.4% for the same channel and m{sub J} value. For pp collisions at the CERN LHC collider, we find that the corrections significantly modify the shape of the cross section distributions for e{sup +}e{sup -} and tt final states, where the distributions including the radiative corrections increases up to 1.23 times the tree-level distribution for the dielectron events and to 1.07 for the top events when m{sub J}=3 TeV.

  16. Modeling of Iron K Lines: Radiative and Auger Decay Data for Fe II-Fe IX

    NASA Technical Reports Server (NTRS)

    Palmeri, P.; Mendoza, C.; Kallman, T. R.; Bautista, M. A.; Melendez, M.

    2003-01-01

    A detailed analysis of the radiative and Auger de-excitation channels of K-shell vacancy states in Fe II-Fe IX has been carried out. Level energies, wavelengths, A-values, Auger rates and fluorescence yields have been calculated for the lowest fine-structure levels populated by photoionization of the ground state of the parent ion. Different branching ratios, namely K alpha 2/K alpha 1, K beta/K alpha, KLM/KLL, KMM/KLL, and the total K-shell fluorescence yields, omega(sub k), obtained in the present work have been compared with other theoretical data and solid-state measurements, finding good general agreement with the latter. The Kalpha 2/K alpha l ratio is found to be sensitive to the excitation mechanism. From these comparisons it has been possible to estimate an accuracy of approx.10% for the present transition probabilities.

  17. Modeling of iron K lines: Radiative and Auger decay data for Fe II-Fe IX

    NASA Astrophysics Data System (ADS)

    Palmeri, P.; Mendoza, C.; Kallman, T. R.; Bautista, M. A.; Meléndez, M.

    2003-10-01

    A detailed analysis of the radiative and Auger de-excitation channels of K-shell vacancy states in Fe II-Fe IX has been carried out. Level energies, wavelengths, A-values, Auger rates and fluorescence yields have been calculated for the lowest fine-structure levels populated by photoionization of the ground state of the parent ion. Different branching ratios, namely Kalpha2 /Kalpha1, Kbeta/Kalpha, KLM/KLL, KMM/KLL, and the total K-shell fluorescence yields, omegaK, obtained in the present work have been compared with other theoretical data and solid-state measurements, finding good general agreement with the latter. The Kalpha2/Kalpha1 ratio is found to be sensitive to the excitation mechanism. From these comparisons it has been possible to estimate an accuracy of ~ 10% for the present transition probabilities. Tables 3 and 4 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/410/359

  18. Updated Next-to-Next-to-Leading-Order QCD Predictions for the Weak Radiative B-Meson Decays.

    PubMed

    Misiak, M; Asatrian, H M; Boughezal, R; Czakon, M; Ewerth, T; Ferroglia, A; Fiedler, P; Gambino, P; Greub, C; Haisch, U; Huber, T; Kamiński, M; Ossola, G; Poradziński, M; Rehman, A; Schutzmeier, T; Steinhauser, M; Virto, J

    2015-06-05

    Weak radiative decays of the B mesons belong to the most important flavor changing processes that provide constraints on physics at the TeV scale. In the derivation of such constraints, accurate standard model predictions for the inclusive branching ratios play a crucial role. In the current Letter we present an update of these predictions, incorporating all our results for the O(α_{s}^{2}) and lower-order perturbative corrections that have been calculated after 2006. New estimates of nonperturbative effects are taken into account, too. For the CP- and isospin-averaged branching ratios, we find B_{sγ}=(3.36±0.23)×10^{-4} and B_{dγ}=(1.73_{-0.22}^{+0.12})×10^{-5}, for E_{γ}>1.6 GeV. Both results remain in agreement with the current experimental averages. Normalizing their sum to the inclusive semileptonic branching ratio, we obtain R_{γ}≡(B_{sγ}+B_{dγ})/B_{cℓν}=(3.31±0.22)×10^{-3}. A new bound from B_{sγ} on the charged Higgs boson mass in the two-Higgs-doublet-model II reads M_{H^{±}}>480 GeV at 95% C.L.

  19. High-energy positrons and gamma radiation from decaying constituents of a two-component dark atom model

    NASA Astrophysics Data System (ADS)

    Belotsky, K.; Khlopov, M.; Kouvaris, C.; Laletin, M.

    2015-09-01

    We study a two-component dark matter candidate inspired by the minimal walking technicolor (WTC) model. Dark matter consists of a dominant strongly interactive massive particle (SIMP)-like dark atom component made of bound states between primordial helium nuclei and a doubly charged technilepton and a small WIMP-like component made of another dark atom bound state between a doubly charged technibaryon and a technilepton. This scenario is consistent with direct search experimental findings because the dominant SIMP component interacts too strongly to reach the depths of current detectors with sufficient energy to recoil and the WIMP-like component is too small to cause significant amount of events. In this context, a metastable technibaryon that decays to e+e+, μ+μ+ and τ+τ+ can, in principle, explain the observed positron excess by AMS-02 and PAMELA, while being consistent with the photon flux observed by FERMI/LAT. We scan the parameters of the model and we find the best possible fit to the latest experimental data. We find that there is a small range of parameter space that this scenario can be realized under certain conditions regarding the cosmic ray propagation and the final state radiation (FSR). This range of parameters fall inside the region where the current run of large hadron collider (LHC) can probe, and therefore it will soon be possible to either verify or exclude conclusively this model of dark matter.

  20. Radiative decays of radially excited mesons {pi}{sup 0'}, {rho}{sup 0'}, and {omega}{sup '} in the Nambu-Jona-Lasinio model

    SciTech Connect

    Kuraev, E. A.; Volkov, M. K.; Arbuzov, A. B.

    2010-12-15

    Radiative decays {pi}{sup 0}({pi}{sup 0'}){yields}{gamma}+{gamma}, {pi}{sup 0'{yields}{rho}0}({omega})+{gamma}, {rho}{sup 0'}({omega}{sup '}){yields}{pi}{sup 0}+{gamma}, and {rho}{sup 0'}({omega}{sup '}){yields}{pi}{sup 0'}+{gamma} are considered in the framework of the SU(2)xSU(2) Nambu-Jona-Lasinio (NJL) model. Radially excited mesons are described with the help of a simple polynomial form factor. In spite of mixing of the ground and excited meson states in this model, the decay widths of {pi}{sup 0{yields}{gamma}}+{gamma} and {rho}{sup 0}({omega}){yields}{pi}{sup 0}+{gamma} are found to be in good agreement with experimental data, as in the standard NJL model. Our predictions for decay widths of radially excited mesons can be verified in future experiments.

  1. Radiative corrections to the Dalitz plot of charged and neutral baryon semileptonic decays with angular correlation between polarized emitted baryons and charged lepton

    SciTech Connect

    Manriquez, J. J. Torres; Martinez, A.; Neri, M.; Garcia, A.

    2008-07-02

    Because of the near future work of the NA48 experimental group, we have calculated the radiative corrections (RC) to the Dalitz plot of baryon semileptonic decays with angular correlation between polarized emitted baryons and charged leptons. This work covers the two cases, charged and neutral decaying baryons, and it is restricted to the so called three body region of the Dalitz plot. Also it is specialized at the c.m. frame of the emitted baryon. We consider terms up to ({alpha}/ product )(q/M{sub 1}){sup 0}, where q is the momentum transfer and M{sub 1} is the mass of the decaying baryon, and neglect terms of the order ({alpha}/ product )(q/M{sub 1}){sup n}, n = 1,2,.... The analytical expressions displayed are ready to obtain numerical results, suitable for a model-independent experimental analysis.

  2. An analytical method for estimating the {sup 14}N nuclear quadrupole resonance parameters of organic compounds with complex free induction decays for radiation effects studies

    SciTech Connect

    Iselin, L.H.

    1992-12-31

    The use of {sup 14}N nuclear quadrupole resonance (NQR) as a radiation dosimetry tool has only recently been explored. An analytical method for analyzing {sup 14}N NQR complex free induction decays is presented with the background necessary to conduct pulsed NQR experiments. The {sup 14}N NQR energy levels and possible transitions are derived in step-by-step detail. The components of a pulsed NQR spectrometer are discussed along with the experimental techniques for conducting radiation effects experiments using the spectrometer. Three data analysis techniques -- the power spectral density Fourier transform, state space singular value decomposition (HSVD), and nonlinear curve fitting (using the downhill simplex method of global optimization and the Levenberg-Marquart method) -- are explained. These three techniques are integrated into an analytical method which uses these numerical techniques in this order to determine the physical NQR parameters. Sample data sets of urea and guanidine sulfate data are used to demonstrate how these methods can be employed to analyze both simple and complex free induction decays. By determining baseline values for biologically significant organics, radiation effects on the NQR parameters can be studied to provide a link between current radiation dosimetry techniques and the biological effects of radiation.

  3. Massive Neutrino Decay Driven Radiative Instabilities, Sub-Structure Survival in Galaxy Clusters and a Nested - Particle-Mesh Code

    NASA Astrophysics Data System (ADS)

    Splinter, Randall John

    1995-01-01

    I have performed a series of studies concerning the clustering of mass on large scales in the universe, with the goal being an increased understanding of the role of various processes in the formation of structure in the universe. One of the first dark matter candidates was the massive neutrino. In this section I investigate the role of a radiative decay mode for a massive neutrino species, and its impact on structure formation. By reviving a concept known as "mock gravity" I attempt to provide seed masses for eventual galaxy formation in a Hot Dark Matter universe. I show that mock gravity is ineffective at generating seed masses for galaxy formation; the ionization rate is too large and the universe becomes fully ionized well before the radiation pressure can have any effect on the clumping of matter. The final section of this thesis presents a series of N-body experiments which are aimed at understanding the theoretical sources of substructure in galaxy clusters. I perform a series of simulations using a variety of power law initial conditions to generate our cluster data sets. From there I use the statistical methods developed by Bird to analyze the subsequent survival of the sub-structures. I find that for a high omega universe that a significant number of clusters should exhibit sub-structure for very long periods of time after their formation. To test whether the sub-structure results are dependent upon the resolution of the N-body code I develop a nested-grid code for use in performing high resolution studies of gravitational instability. In the next section I present an N-body code which features a nested-grid technology. This nested-grid method allows me to extend both the force and mass resolution of a traditional particle-mesh type code. This code will prove extremely useful for studying problems in large-scale structure formation where one is focusing on highly non -linear objects, and hence force and mass resolution are at a premium. In this chapter I

  4. A comparison of radiative capture with decay gamma-ray method in bore hole logging for economic minerals

    USGS Publications Warehouse

    Senftle, F.E.; Moxham, R.M.; Tanner, A.B.

    1972-01-01

    The recent availability of borehole logging sondes employing a source of neutrons and a Ge(Li) detector opens up the possibility of analyzing either decay or capture gamma rays. The most efficient method for a given element can be predicted by calculating the decay-to-capture count ratio for the most prominent peaks in the respective spectra. From a practical point of view such a calculation must be slanted toward short irradiation and count times at each station in a borehole. A simplified method of computation is shown, and the decay-to-capture count ratio has been calculated and tabulated for the optimum value in the decay mode irrespective of the irradiation time, and also for a ten minute irradiation time. Based on analysis of a single peak in each spectrum, the results indicate the preferred technique and the best decay or capture peak to observe for those elements of economic interest. ?? 1972.

  5. Search for a light Higgs boson decaying to two gluons or ss̄ in the radiative decays of Υ(1S)

    DOE PAGES

    Lees, J. P.; Poireau, V.; Tisserand, V.; ...

    2013-08-06

    We search for the decay Υ(1S)→γA⁰, A⁰→gg or ss̄, where A⁰ is the pseudoscalar light Higgs boson predicted by the next-to-minimal supersymmetric Standard Model. We use a sample of (17.6±0.3)×10⁶ Υ(1S) mesons produced in the BABAR experiment via e⁺e⁻→Υ(2S)→π⁺π⁻Υ(1S). We see no significant signal and set 90%-confidence-level upper limits on the product branching fraction B(Υ(1S)→γA⁰)·B(A⁰→gg or ss̄) ranging from 10⁻⁶ to 10⁻² for A⁰ masses in the range 0.5–9.0 GeV/c².

  6. The Observation of the Weak Radiative Hyperon Decay Ξ°→Λ°π°γ at KTeV/E799, Fermilab

    SciTech Connect

    Ping, Huican

    2005-01-01

    The large sample of Ξ° hyperons available at KTeV 799 provides an opportunity to search for the Weak Radiative Hyperon Decay Ξ° → Λ°π°γ. We present a branching fraction measurement of Ξ° → Λ°π°γ based on the E799-II experiment data-taking in 1999 at KTeV, Fermilab. We used the principal decay of Ξ° → Λ°π where Λ decays to a proton and a π- as the flux normalization mode. This is the first observation of this interesting decay mode. Four candidate events are found in the data. The branching ratio at 90% confidence level has been measured to be (1.67-0.80+1.45(stat.) ± 0.50(syst.)) x 10-5 or (1.67-0.69+1.16(stat.) ± 0.50(syst.)) x 10-5 at 68.27% confidence level.

  7. Low-LET and high-LET radiation action of {sup 125}I decays in DNA: Effect of cysteamine on micronucleus formation and cell killing

    SciTech Connect

    Hofer, K.G.; Bao, S.P.

    1995-02-01

    Chinese hamster ovary cells were pulse-labeled with {sup 125}I-iododeoxyuridine during early S phase, and cell samples were harvested 30 min or 5 h after labeling. The samples were frozen (with or without 25 mM cysteamine) and stored at -196{degrees}C for accumulation of {sup 125}I decays. X-ray control experiments were performed at 37{degrees}C and -196{degrees}C. Aliquots of cells were plated for evaluating micronucleus formation and cell survival. The results demonstrated a striking shift in micronucleus formation and cell death with time after labeling. Cells frozen 30 min after labeling exhibited effects typical of low-LET radiation, but cells frozen 5 h after labeling showed a response characteristic of high-LET radiation. Cysteamine provided protection against the effects of {sup 125}I during the initial phase of effects characteristic of low-LET radiation, but no protection was seen during the phase characteristic of high-LET radiation. When cell survival was evaluated as a function of micronucleus frequency rather than dose in decays/cell, the survival curves for all treatment groups became superimposed. Previous work using the same experimental system had failed to show a direct link between {sup 125}I-induced DNA double-strand breaks and cell death. These findings are consistent with the hypothesis that DNA damage may not be the sole mechanism for cell killing and that damage to higher-order structures in the cell nucleus may contribute to (or modify) radiation-induced cell death. 50 refs., 7 figs.

  8. Search for a light Higgs resonance in radiative decays of the ϒ (1 S ) with a charm tag

    NASA Astrophysics Data System (ADS)

    Lees, J. P.; Poireau, V.; Tisserand, V.; Grauges, E.; Palano, A.; Eigen, G.; Stugu, B.; Brown, D. N.; Kerth, L. T.; Kolomensky, Yu. G.; Lee, M. J.; Lynch, G.; Koch, H.; Schroeder, T.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; So, R. Y.; Khan, A.; Blinov, V. E.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Kravchenko, E. A.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Todyshev, K. Yu.; Lankford, A. J.; Dey, B.; Gary, J. W.; Long, O.; Franco Sevilla, M.; Hong, T. M.; Kovalskyi, D.; Richman, J. D.; West, C. A.; Eisner, A. M.; Lockman, W. S.; Panduro Vazquez, W.; Schumm, B. A.; Seiden, A.; Chao, D. S.; Cheng, C. H.; Echenard, B.; Flood, K. T.; Hitlin, D. G.; Miyashita, T. S.; Ongmongkolkul, P.; Porter, F. C.; Röhrken, M.; Andreassen, R.; Huard, Z.; Meadows, B. T.; Pushpawela, B. G.; Sokoloff, M. D.; Sun, L.; Bloom, P. C.; Ford, W. T.; Gaz, A.; Smith, J. G.; Wagner, S. R.; Ayad, R.; Toki, W. H.; Spaan, B.; Bernard, D.; Verderi, M.; Playfer, S.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cibinetto, G.; Fioravanti, E.; Garzia, I.; Luppi, E.; Piemontese, L.; Santoro, V.; Calcaterra, A.; de Sangro, R.; Finocchiaro, G.; Martellotti, S.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rama, M.; Zallo, A.; Contri, R.; Monge, M. R.; Passaggio, S.; Patrignani, C.; Bhuyan, B.; Prasad, V.; Adametz, A.; Uwer, U.; Lacker, H. M.; Mallik, U.; Chen, C.; Cochran, J.; Prell, S.; Ahmed, H.; Gritsan, A. V.; Arnaud, N.; Davier, M.; Derkach, D.; Grosdidier, G.; Le Diberder, F.; Lutz, A. M.; Malaescu, B.; Roudeau, P.; Stocchi, A.; Wormser, G.; Lange, D. J.; Wright, D. M.; Coleman, J. P.; Fry, J. R.; Gabathuler, E.; Hutchcroft, D. E.; Payne, D. J.; Touramanis, C.; Bevan, A. J.; Di Lodovico, F.; Sacco, R.; Cowan, G.; Brown, D. N.; Davis, C. L.; Denig, A. G.; Fritsch, M.; Gradl, W.; Griessinger, K.; Hafner, A.; Schubert, K. R.; Barlow, R. J.; Lafferty, G. D.; Cenci, R.; Hamilton, B.; Jawahery, A.; Roberts, D. A.; Cowan, R.; Cheaib, R.; Patel, P. M.; Robertson, S. H.; Neri, N.; Palombo, F.; Cremaldi, L.; Godang, R.; Summers, D. J.; Simard, M.; Taras, P.; De Nardo, G.; Onorato, G.; Sciacca, C.; Raven, G.; Jessop, C. P.; LoSecco, J. M.; Honscheid, K.; Kass, R.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simi, G.; Simonetto, F.; Stroili, R.; Akar, S.; Ben-Haim, E.; Bomben, M.; Bonneaud, G. R.; Briand, H.; Calderini, G.; Chauveau, J.; Leruste, Ph.; Marchiori, G.; Ocariz, J.; Biasini, M.; Manoni, E.; Rossi, A.; Angelini, C.; Batignani, G.; Bettarini, S.; Carpinelli, M.; Casarosa, G.; Chrzaszcz, M.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Oberhof, B.; Paoloni, E.; Rizzo, G.; Walsh, J. J.; Lopes Pegna, D.; Olsen, J.; Smith, A. J. S.; Anulli, F.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Pilloni, A.; Piredda, G.; Bünger, C.; Dittrich, S.; Grünberg, O.; Hess, M.; Leddig, T.; Voß, C.; Waldi, R.; Adye, T.; Olaiya, E. O.; Wilson, F. F.; Emery, S.; Vasseur, G.; Aston, D.; Bard, D. J.; Cartaro, C.; Convery, M. R.; Dorfan, J.; Dubois-Felsmann, G. P.; Dunwoodie, W.; Ebert, M.; Field, R. C.; Fulsom, B. G.; Graham, M. T.; Hast, C.; Innes, W. R.; Kim, P.; Leith, D. W. G. S.; Lindemann, D.; Luitz, S.; Luth, V.; Lynch, H. L.; MacFarlane, D. B.; Muller, D. R.; Neal, H.; Perl, M.; Pulliam, T.; Ratcliff, B. N.; Roodman, A.; Schindler, R. H.; Snyder, A.; Su, D.; Sullivan, M. K.; Va'vra, J.; Wisniewski, W. J.; Wulsin, H. W.; Purohit, M. V.; Wilson, J. R.; Randle-Conde, A.; Sekula, S. J.; Bellis, M.; Burchat, P. R.; Puccio, E. M. T.; Alam, M. S.; Ernst, J. A.; Gorodeisky, R.; Guttman, N.; Peimer, D. R.; Soffer, A.; Spanier, S. M.; Ritchie, J. L.; Schwitters, R. F.; Izen, J. M.; Lou, X. C.; Bianchi, F.; De Mori, F.; Filippi, A.; Gamba, D.; Lanceri, L.; Vitale, L.; Martinez-Vidal, F.; Oyanguren, A.; Villanueva-Perez, P.; Albert, J.; Banerjee, Sw.; Beaulieu, A.; Bernlochner, F. U.; Choi, H. H. F.; King, G. J.; Kowalewski, R.; Lewczuk, M. J.; Lueck, T.; Nugent, I. M.; Roney, J. M.; Sobie, R. J.; Tasneem, N.; Gershon, T. J.; Harrison, P. F.; Latham, T. E.; Band, H. R.; Dasu, S.; Pan, Y.; Prepost, R.; Wu, S. L.; BaBar Collaboration

    2015-04-01

    A search is presented for the decay ϒ (1 S )→γ A0 , A0→c c ¯, where A0 is a candidate for the C P -odd Higgs boson of the next-to-minimal supersymmetric standard model. The search is based on data collected with the BABAR detector at the ϒ (2 S ) resonance. A sample of ϒ (1 S ) mesons is selected via the decay ϒ (2 S )→π+π-ϒ (1 S ) . The A0→c c ¯ decay is identified through the reconstruction of hadronic D0, D+, and D*(2010 )+ meson decays. No significant signal is observed. The measured 90% confidence-level upper limits on the product branching fraction B (ϒ (1 S )→γ A0)×B (A0→c c ¯ ) range from 7.4 ×10-5 to 2.4 ×10-3 for A0 masses from 4.00 to 8.95 GeV /c2 and 9.10 to 9.25 GeV /c2 , where the region between 8.95 and 9.10 GeV /c2 is excluded because of background from ϒ (2 S )→γ χb J(1 P ) , χb J(1 P )→γ ϒ (1 S ) decays.

  9. Search for Invisible Decays of a Light Scalar in Radiative Transitions Y(3S)->gamma A0

    SciTech Connect

    Aubert, B

    2008-11-05

    We search for a light scalar particle produced in single-photon decays of the {Upsilon}(3S) resonance through the process {Upsilon}(3S) {yields} {gamma} + A{sup 0}, A{sup 0} {yields} invisible. Such an object appears in Next-to-Minimal Supersymmetric extensions of the Standard Model, where a light CP-odd Higgs boson naturally couples strongly to b-quarks. If, in addition, there exists a light, stable neutralino, decays of A{sup 0} could be preferentially to an invisible final state. We search for events with a single high-energy photon and a large missing mass, consistent with a 2-body decay of {Upsilon}(3S). We find no evidence for such processes in a sample of 122 x 10{sup 6} {Upsilon}(3S) decays collected by the BABAR collaboration at the PEP-II B-factory, and set 90% C.L. upper limits on the branching fraction {Beta}({Upsilon}(3S) {yields} {gamma}A{sup 0}) x {Beta}(A{sup 0} {yields} invisible) at (0.7-31) x 10{sup -6} in the mass range m{sub A{sup 0}} {le} 7.8 GeV. The results are preliminary.

  10. Search for a light Higgs resonance in radiative decays of the Y(1S) with a charm tag

    SciTech Connect

    Lees, J. P.

    2015-04-10

    In this study, a search is presented for the decay Υ(1S)→γA0, A0 → cc¯, where A0 is a candidate for the CP-odd Higgs boson of the next-to-minimal supersymmetric standard model. The search is based on data collected with the BABAR detector at the Υ(2S) resonance. A sample of Υ(1S) mesons is selected via the decay Υ(2S) → π+π Υ(1S). The A0 → cc¯ decay is identified through the reconstruction of hadronic D0, D+, and D*(2010)+ meson decays. No significant signal is observed. The measured 90% confidence-level upper limits on the product branching fraction B(Υ(1S) → γA0)×B(A0 → cc¯) range from 7.4×10–5 to 2.4×10–3 for A0 masses from 4.00 to 8.95 GeV/c2 and 9.10 to 9.25 GeV/c2, where the region between 8.95 and 9.10 GeV/c2 is excluded because of background from Υ(2S) → γχbJ(1P), χbJ(1P) → γΥ(1S) decays.

  11. Radiative corrections to the three-body region of the Dalitz plot of baryon semileptonic decays with angular correlation between polarized emitted baryons and charged leptons: The initial-baryon rest frame case

    SciTech Connect

    Juarez-Leon, C.; Martinez, A.; Neri, M.; Torres, J. J.; Flores-Mendieta, Ruben; Garcia, A.

    2009-03-01

    We complement the results for the radiative corrections to the s-circumflex{sub 2}{center_dot}l-circumflex angular correlation of baryon semileptonic decays of Neri et al.[Phys. Rev. D 78, 054018 (2008)] with the final results in the rest frame of the decaying baryon. In addition, we present an analytical result which was not possible to obtain in Neri et al.'s work.

  12. Search for radiative penguin decays B(+)-->rho(+)gamma, B(0)-->rho(0)gamma, and B(0)-->omegagamma.

    PubMed

    Aubert, B; Barate, R; Boutigny, D; Couderc, F; Gaillard, J-M; Hicheur, A; Karyotakis, Y; Lees, J P; Tisserand, V; Zghiche, A; Palano, A; Pompili, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Borgland, A W; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Shelkov, V G; Wenzel, W A; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Morgan, S E; Watson, A T; Fritsch, M; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Steinke, M; Boyd, J T; Chevalier, N; Cottingham, W N; Kelly, M P; Latham, T E; Wilson, F F; Cuhadar-Donszelmann, T; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Thiessen, D; Khan, A; Kyberd, P; Teodorescu, L; Blinov, A E; Blinov, V E; Druzhinin, V P; Golubev, V B; Ivanchenko, V N; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Yushkov, A N; Best, D; Bruinsma, M; Chao, M; Eschrich, I; Kirkby, D; Lankford, A J; Mandelkern, M; Mommsen, R K; Roethel, W; Stoker, D P; Buchanan, C; Hartfiel, B L; Foulkes, S D; Gary, J W; Shen, B C; Wang, K; Del Re, D; Hadavand, H K; Hill, E J; Macfarlane, D B; Paar, H P; Rahatlou, Sh; Sharma, V; Berryhill, J W; Campagnari, C; Dahmes, B; Long, O; Lu, A; Mazur, M A; Richman, J D; Verkerke, W; Beck, T W; Eisner, A M; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dubois-Felsmann, G P; Dvoretskii, A; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Yang, S; Jayatilleke, S; Mancinelli, G; Meadows, B T; Sokoloff, M D; Abe, T; Blanc, F; Bloom, P; Chen, S; Ford, W T; Nauenberg, U; Olivas, A; Rankin, P; Smith, J G; Zhang, J; Zhang, L; Chen, A; Harton, J L; Soffer, A; Toki, W H; Wilson, R J; Zeng, Q L; Altenburg, D; Brandt, T; Brose, J; Dickopp, M; Feltresi, E; Hauke, A; Lacker, H M; Müller-Pfefferkorn, R; Nogowski, R; Otto, S; Petzold, A; Schubert, J; Schubert, K R; Schwierz, R; Spaan, B; Sundermann, J E; Bernard, D; Bonneaud, G R; Brochard, F; Grenier, P; Schrenk, S; Thiebaux, Ch; Vasileiadis, G; Verderi, M; Bard, D J; Clark, P J; Lavin, D; Muheim, F; Playfer, S; Xie, Y; Andreotti, M; Azzolini, V; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Piemontese, L; Sarti, A; Treadwell, E; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Patteri, P; Peruzzi, I M; Piccolo, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Crosetti, G; Vetere, M Lo; Macri, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Bailey, S; Brandenburg, G; Chaisanguanthum, K S; Morii, M; Won, E; Dubitzky, R S; Langenegger, U; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Gaillard, J R; Morton, G W; Nash, J A; Nikolich, M B; Taylor, G P; Charles, M J; Grenier, G J; Mallik, U; Cochran, J; Crawley, H B; Lamsa, J; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Yi, J; Biasini, M; Covarelli, R; Pioppi, M; Davier, M; Giroux, X; Grosdidier, G; Höcker, A; Laplace, S; Diberder, F Le; Lepeltier, V; Lutz, A M; Petersen, T C; Plaszczynski, S; Schune, M H; Tantot, L; Wormser, G; Cheng, C H; Lange, D J; Simani, M C; Wright, D M; Bevan, A J; Chavez, C A; Coleman, J P; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; Hutchcroft, D E; Parry, R J; Payne, D J; Sloane, R J; Touramanis, C; Back, J J; Cormack, C M; Harrison, P F; Lodovico, F Di; Mohanty, G B; Brown, C L; Cowan, G; Flack, R L; Flaecher, H U; Green, M G; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Winter, M A; Brown, D; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Hart, P A; Hodgkinson, M C; Lafferty, G D; Lyon, A J; Williams, J C; Farbin, A; Hulsbergen, W D; Jawahery, A; Kovalskyi, D; Lae, C K; Lillard, V; Roberts, D A; Blaylock, G; Dallapiccola, C; Flood, K T; Hertzbach, S S; Kofler, R; Koptchev, V B; Moore, T B; Saremi, S; Staengle, H; Willocq, S; Cowan, R; Sciolla, G; Sekula, S J; Taylor, F; Yamamoto, R K; Mangeol, D J J; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Taras, P; Nicholson, H; Cavallo, N; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M; Bulten, H; Raven, G; Snoek, H L; Wilden, L; Jessop, C P; Losecco, J M; Allmendinger, T; Gan, K K; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Pulliam, T; Rahimi, A M; Ter-Antonyan, R; Wong, Q K; Brau, J; Frey, R; Igonkina, O; Potter, C T; Sinev, N B; Strom, D; Torrence, E; Colecchia, F; Dorigo, A; Galeazzi, F; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Tiozzo, G; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; de la Vaissière, Ch; Buono, L Del; Hamon, O; John, M J J; Leruste, Ph; Malcles, J; Ocariz, J; Pivk, M; Roos, L; T'jampens, S; Therin, G; Manfredi, P F; Re, V; Behera, P K; Gladney, L; Guo, Q H; Panetta, J; Angelini, C; Batignani, G; Bettarini, S; Bondioli, M; Bucci, F; Calderini, G; Carpinelli, M; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Martinez-Vidal, F; Morganti, M; Neri, N; Paoloni, E; Rama, M; Rizzo, G; Sandrelli, F; Walsh, J; Haire, M; Judd, D; Paick, K; Wagoner, D E; Danielson, N; Elmer, P; Lau, Y P; Lu, C; Miftakov, V; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Gioi, L Li; Mazzoni, M A; Morganti, S; Pierini, M; Piredda, G; Tehrani, F Safai; Voena, C; Christ, S; Wagner, G; Waldi, R; Adye, T; Groot, N De; Franek, B; Geddes, N I; Gopal, G P; Olaiya, E O; Aleksan, R; Emery, S; Gaidot, A; Ganzhur, S F; Giraud, P-F; de Monchenault, G Hamel; Kozanecki, W; Legendre, M; London, G W; Mayer, B; Schott, G; Vasseur, G; Yèche, Ch; Zito, M; Purohit, M V; Weidemann, A W; Wilson, J R; Yumiceva, F X; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmueller, O L; Claus, R; Convery, M R; Cristinziani, M; Nardo, G De; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W; Elsen, E E; Fan, S; Field, R C; Glanzman, T; Gowdy, S J; Hadig, T; Halyo, V; Hast, C; Hryn'ova, T; Innes, W R; Kelsey, M H; Kim, P; Kocian, M L; Leith, D W G S; Libby, J; Luitz, S; Luth, V; Lynch, H L; Marsiske, H; Messner, R; Muller, D R; O'grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Petrak, S; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Simi, G; Snyder, A; Soha, A; Stelzer, J; Su, D; Sullivan, M K; Va'vra, J; Wagner, S R; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Young, C C; Burchat, P R; Edwards, A J; Meyer, T I; Petersen, B A; Roat, C; Ahmed, S; Alam, M S; Ernst, J A; Saeed, M A; Saleem, M; Wappler, F R; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Kim, H; Ritchie, J L; Satpathy, A; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Bona, M; Gallo, F; Gamba, D; Bosisio, L; Cartaro, C; Cossutti, F; Ricca, G Della; Dittongo, S; Grancagnolo, S; Lanceri, L; Poropat, P; Vitale, L; Vuagnin, G; Panvini, R S; Banerjee, Sw; Brown, C M; Fortin, D; Jackson, P D; Kowalewski, R; Roney, J M; Sobie, R J; Band, H R; Cheng, B; Dasu, S; Datta, M; Eichenbaum, A M; Graham, M; Hollar, J J; Johnson, J R; Kutter, P E; Li, H; Liu, R; Mihalyi, A; Mohapatra, A K; Pan, Y; Prepost, R; Tan, P; von Wimmersperg-Toeller, J H; Wu, J; Wu, S L; Yu, Z; Greene, M G; Neal, H

    2005-01-14

    A search for the decays B-->rho(770)gamma and B0-->omega(782)gamma is performed on a sample of 211 x 10(6) Upsilon(4S)-->BB events collected by the BABAR detector at the SLAC PEP-II asymmetric-energy e(+)e(-) storage ring. No evidence for the decays is seen. We set the following limits on the individual branching fractions: B(B+-->rho(+)gamma)<1.8 x 10(-6), B(B0-->rho(0)gamma)<0.4 x 10(-6), and B(B0-->omegagamma)<1.0 x 10(-6) at the 90% confidence level. We use the quark model to limit the combined branching fraction B [B-->(rho/omega)gamma]<1.2 x 10(-6), from which we determine a constraint on the ratio of Cabibbo-Kobayashi-Maskawa matrix elements |V(td)|/|V(ts)|.

  13. Impact of radiation processing on quality during storage and post-refrigeration decay of plum (Prunus domestica L.) cv. Santaroza

    NASA Astrophysics Data System (ADS)

    Hussain, Peerzada R.; Dar, Mohd A.; Wani, Ali M.

    2013-04-01

    Gamma irradiation treatment was tested for maintaining storage quality and extending the shelf life of plum fruit. Matured green plums were irradiated in the dose range of 0.2-1.5 kGy and stored under ambient (temperature 25±2 °C, RH 70%) and refrigerated (temperature 3±1 °C, RH 80%) conditions. Studies revealed that irradiation treatment significantly (p≤0.05) maintained the storage quality of plum fruit under ambient as well as refrigerated conditions. Positive correlations (r=0.88) existed between the irradiation doses and firmness retention under both the storage conditions. In samples irradiated at 1.0 kGy, 1.2 kGy and 1.5 kGy, no microbial load was detected up to 8 and 12 days of ambient storage. Dose range of 1.2-1.5 kGy significantly inhibited the decaying of plums up to 16 days of ambient storage. Irradiation in combination with refrigeration prevented the decaying of plums up to 35 days as against the 12.5% decay in un-irradiated control samples. Irradiation dose of 1.2-1.5 kGy also gave an extension of 8 days during additional ambient storage of the plums at 25±2 °C, RH 70% following 35 days of refrigeration.

  14. Radiative corrections to the decays K{sub L}{sup 0} {r_arrow} e{sup +}e{sup {minus}} and K{sub L}{sup 0} {r_arrow} {mu}{sup +} {mu}{sup {minus}}

    SciTech Connect

    Dicus, D.A.; Repko, W.W.

    1998-12-31

    The authors calculate the rates and lepton ({ell}) invariant mass distributions for decays of the form 0{sup {minus}+} {r_arrow} {ell}{sup +}{ell}{sup {minus}}{gamma}, which are important radiative corrections to the purely leptonic decays 0{sup {minus}+} {r_arrow} {ell}{sup +}{ell}{sup {minus}}. The approach uses the loop diagrams which arise by including the two photon intermediate state and they retain the imaginary parts of the loops--a radiative extension of the unitarity bound for the process. These results are compared with those obtained using a model in which the meson couples directly to the leptons.

  15. Measurement of Branching Fractions in Radiative BDecays to eta K gamma and Search for B Decays to eta' K gamma

    SciTech Connect

    Aubert, B.

    2006-03-31

    The authors present measurements of the B {yields} {eta}K{gamma} branching fractions and upper limits for the B {yields} {eta}'K{gamma} branching fractions. For B{sup +} {yields} {eta}K{sup +}{gamma} they also measure the time-integrated charge asymmetry. The data sample, collected with the BABAR detector at the Stanford Linear Accelerator Center, represents 232 x 10{sup 6} produced B{bar B} pairs. The results for branching fractions and upper limits at 90% C.L. in units of 10{sup -6} are: {Beta}(B{sup 0} {yields} {eta}K{sup 0}{gamma}) = 11.3{sub -2.6}{sup +2.8} {+-} 0.6, {Beta}(B{sup +} {yields} {eta}K{sup +}{gamma}) = 10.0 {+-} 1.3 {+-} 0.5, {Beta}(B{sup 0} {yields} {eta}'K{sup 0}{gamma}) < 6.6, {Beta}(B{sup +} {yields} {eta}'K{sup +}{gamma}) < 4.2. The charge asymmetry in the decay B{sup +} {yields} {eta}K{sup +}{gamma} is {Alpha}{sub ch} = -0.09 {+-} 0.12 {+-} 0.01. The first errors are statistical and the second systematic.

  16. Tooth Decay

    MedlinePlus

    You call it a cavity. Your dentist calls it tooth decay or dental caries. They're all names for a hole in your tooth. The cause of tooth decay is plaque, a sticky substance in your mouth made up mostly of germs. Tooth decay starts in the outer layer, called the enamel. Without ...

  17. Conservation laws, radiative decay rates, and excited state localization in organometallic complexes with strong spin-orbit coupling.

    PubMed

    Powell, B J

    2015-06-30

    There is longstanding fundamental interest in 6-fold coordinated d(6) (t(2g)(6)) transition metal complexes such as [Ru(bpy)3](2+) and Ir(ppy)3, particularly their phosphorescence. This interest has increased with the growing realisation that many of these complexes have potential uses in applications including photovoltaics, imaging, sensing, and light-emitting diodes. In order to design new complexes with properties tailored for specific applications a detailed understanding of the low-energy excited states, particularly the lowest energy triplet state, T1, is required. Here we describe a model of pseudo-octahedral complexes based on a pseudo-angular momentum representation and show that the predictions of this model are in excellent agreement with experiment - even when the deviations from octahedral symmetry are large. This model gives a natural explanation of zero-field splitting of T1 and of the relative radiative rates of the three sublevels in terms of the conservation of time-reversal parity and total angular momentum modulo two. We show that the broad parameter regime consistent with the experimental data implies significant localization of the excited state.

  18. Symmetry control of radiative decay in linear polyenes: low barriers for isomerization in the S1 state of hexadecaheptaene.

    PubMed

    Christensen, Ronald L; Galinato, Mary Grace I; Chu, Emily F; Fujii, Ritsuko; Hashimoto, Hideki; Frank, Harry A

    2007-02-14

    The room temperature absorption and emission spectra of the 4-cis and all-trans isomers of 2,4,6,8,10,12,14-hexadecaheptaene are almost identical, exhibiting the characteristic dual emissions S1-->S0 (21Ag- --> 11Ag-) and S2-->S0 (11Bu+ --> 11Ag-) noted in previous studies of intermediate length polyenes and carotenoids. The ratio of the S1-->S0 and S2-->S0 emission yields for the cis isomer increases by a factor of approximately 15 upon cooling to 77 K in n-pentadecane. In contrast, for the trans isomer this ratio shows a 2-fold decrease with decreasing temperature. These results suggest a low barrier for conversion between the 4-cis and all-trans isomers in the S1 state. At 77 K, the cis isomer cannot convert to the more stable all-trans isomer in the 21Ag- state, resulting in the striking increase in its S1-->S0 fluorescence. These experiments imply that the S1 states of longer polyenes have local energy minima, corresponding to a range of conformations and isomers, separated by relatively low (2-4 kcal) barriers. Steady state and time-resolved optical measurements on the S1 states in solution thus may sample a distribution of conformers and geometric isomers, even for samples represented by a single, dominant ground state structure. Complex S1 potential energy surfaces may help explain the complicated S2-->S1 relaxation kinetics of many carotenoids. The finding that fluorescence from linear polyenes is so strongly dependent on molecular symmetry requires a reevaluation of the literature on the radiative properties of all-trans polyenes and carotenoids.

  19. Radiative Penguin Decays at the BaBar Experiment B to K*gamma, B to rho gamma, B to omega gamma and B to X_s gamma

    SciTech Connect

    Grauges, E.

    2004-12-08

    A review of the results obtained from the analysis of the B meson decays that involve Radiative Penguin processes, recorded at the BaBar experiment at the Stanford Linear Accelerator Center PEP-II B-Factory, is presented. The physics interest of these processes and their SM prediction are discussed briefly. The most relevant selection techniques used in the analysis are described before quoting the latest results made public by the BaBar collaboration as of July 2003.

  20. Penguin and rare decays in BABAR

    NASA Astrophysics Data System (ADS)

    Akar, Simon; Babar Collaboration

    2014-11-01

    We present recent results from the BABAR Collaboration on radiative decays. These include searches for new physics via measurements of several observables such as the time- dependent CP asymmetry in B0 → K0Sπ-π+γ exclusive decays, as well as direct CP asymmetries and branching fractions in B → Xsγ and B → Xsl+l- inclusive decays.

  1. Beauty baryon decays: a theoretical overview

    NASA Astrophysics Data System (ADS)

    Wang, Yu-Ming

    2014-11-01

    I overview the theoretical status and recent progress on the calculations of beauty baryon decays focusing on the QCD aspects of the exclusive semi-leptonic Λb → plμ decay at large recoil and theoretical challenges of radiative and electro-weak penguin decays Λb → Λγ,Λl+l-.

  2. Radiation

    NASA Video Gallery

    Outside the protective cocoon of Earth's atmosphere, the universe is full of harmful radiation. Astronauts who live and work in space are exposed not only to ultraviolet rays but also to space radi...

  3. Radiation Therapy (For Parents)

    MedlinePlus

    ... temporary, it can be permanent. Sore Mouth and Tooth Decay The tissues of the mouth may be sore ... and there may be an increased risk of tooth decay if a child received radiation therapy to the ...

  4. Radiative decay probabilities of the (2s{sup 2}2p{sub 1/2}{sup 5}3s{sub 1/2}){sub J=0} level in neonlike ions

    SciTech Connect

    Beiersdorfer, P.; Obst, M.; Safronova, U. I.

    2011-01-15

    The radiative decay rates of the (2s{sup 2}2p{sub 1/2}{sup 5}3s{sub 1/2}){sub J=0} level in neonlike ions have been calculated for nuclear charges ranging from Z=10 to Z=110. The calculations include the magnetic dipole decay to the (2s{sup 2}2p{sub 3/2}{sup 5}3s{sub 1/2}){sub J=1} level, which is shown to be the dominant decay branch in low-Z and very-high-Z ions, as well as the two-electron, one-photon decays to the (2s{sup 2}2p{sub 3/2}{sup 5}3p{sub 1/2}){sub J=1} and (2s{sup 2}2p{sub 3/2}{sup 5}3p{sub 3/2}){sub J=1} levels, which dominate near Z=50. We also take into account a small magnetic quadrupole decay branch to the (2s{sup 2}2p{sub 3/2}{sup 5}3s{sub 1/2}){sub J=2} level and calculate the total radiative lifetime of the (2s{sup 2}2p{sub 1/2}{sup 5}3s{sub 1/2}){sub J=0} level. The resulting values span over 15 orders of magnitude, and much of this range is accessible with modern atomic lifetime measurement techniques. In particular, we calculate a value of 1.6x10{sup 4} s{sup -1} for the radiative decay rate of the (2s{sup 2}2p{sub 1/2}{sup 5}3s{sub 1/2}){sub J=0} level in Fe XVII and show that the corresponding magnetic dipole transition has a measurable spectral intensity for electron densities below about 1x10{sup 13} cm{sup -3}.

  5. Radioactive decay data tables

    SciTech Connect

    Kocher, D.C.

    1981-01-01

    The estimation of radiation dose to man from either external or internal exposure to radionuclides requires a knowledge of the energies and intensities of the atomic and nuclear radiations emitted during the radioactive decay process. The availability of evaluated decay data for the large number of radionuclides of interest is thus of fundamental importance for radiation dosimetry. This handbook contains a compilation of decay data for approximately 500 radionuclides. These data constitute an evaluated data file constructed for use in the radiological assessment activities of the Technology Assessments Section of the Health and Safety Research Division at Oak Ridge National Laboratory. The radionuclides selected for this handbook include those occurring naturally in the environment, those of potential importance in routine or accidental releases from the nuclear fuel cycle, those of current interest in nuclear medicine and fusion reactor technology, and some of those of interest to Committee 2 of the International Commission on Radiological Protection for the estimation of annual limits on intake via inhalation and ingestion for occupationally exposed individuals.

  6. Yukawa radiative corrections to the triple self-couplings of neutral CP-even Higgs bosons and to the H {sup {yields}} hh decay rate within the minimal supersymmetric standard model

    SciTech Connect

    Philippov, Yu. P.

    2007-07-15

    Within the minimal supersymmetric standard model, four self-couplings, {lambda}{sub hhh}, {lambda}{sub hhH}, {lambda}{sub hHH}, and {lambda}{sub HHH}, and the decay rate {gamma}(H {sup {yields}} hh) are calculated with allowance for one-loop corrections induced by the contribution of the t, b, and c quarks, the {tau} lepton, and the corresponding superpartners and with the aid of the on-shell renormalization scheme. An analysis of the dependences of these features on tan{beta} and the mass of the A Higgs boson, M{sub A}, shows that, in a specific region of the model-parameter space, the calculated corrections can make a significant contribution to the couplings and decay rate in the one-loop approximation. The inclusion of the radiative corrections in question is mandatory in reconstructing the Higgs potential.

  7. Top decays in extended models

    SciTech Connect

    Gaitan, R.; Miranda, O. G.; Cabral-Rosetti, L. G.

    2009-04-20

    Top quark decays are interesting as a mean to test the Standard Model (SM) predictions. The Cabbibo-Kobayashi-Maskawa (CKM)-suppressed process t{yields}cWW, and the rare decays t{yields}cZ, t{yields}H{sup 0}+c, and t{yields}c{gamma} an excellent window to probe the predictions of theories beyond the SM. We evaluate the flavor changing neutral currents (FCNC) decay t{yields}H{sup 0}+c in the context of Alternative Left-Right symmetric Models (ALRM) with extra isosinglet heavy fermions; the FCNC decays may place at tree level and are only supressed by the mixing between ordinary top and charm quarks. We also comment on the decay process t{yields}c+{gamma}, which involves radiative corrections.

  8. Photoproduction and Decay of Light Mesons in CLAS

    SciTech Connect

    Amaryan, Moskov Jamalovich

    2013-08-01

    We present preliminary experimental results on photoproduction and decay of light mesons measured with CLAS setup at JLAB . This include Dalitz decay of pseudoscalar and vector mesons, radiative decay of pseudoscalar mesons as well hadronic decays of pseudoscalar and vector mesons. The collected high statistics in some of decay channels exceeds the world data by an order of magnitude and some other decay modes are observed for the first time. It is shown how the CLAS data will improve the world data on transition form factors of light mesons, Dalitz plot analyses, branching ratios of rare decay modes and other fundamental properties potentially accessible through the light meson decays.

  9. Experimental Status of b -> s(d) gamma Decays

    SciTech Connect

    Di Lodovico, F

    2004-02-05

    Radiative penguin decays provide an indirect probe for physics beyond the Standard Model and contribute to the determination of the CKM matrix elements. Copious quantities of B mesons produced at the B-Factories permit precision measurements of radiative penguin decays. We review the experimental status of the radiative penguin processes b {yields} s(d){gamma}.

  10. PHYSICAL FACTORS AND DOSIMETRY IN THE MARSHALL ISLAND RADIATION EXPOSURES

    DTIC Science & Technology

    FALLOUT, *RADIATION HAZARDS, *RADIOCHEMISTRY, DOSE RATE, PERSONNEL, RADIATION, RADIATION MONITORS, DOSAGE , EXPOSURE (PHYSIOLOGY), EXPOSURE METERS, EXPERIMENTAL DATA, ENERGY, TIME, GAMMA RAY SPECTROSCOPY, BETA DECAY, PHOTONS.

  11. Decoherence delays false vacuum decay

    NASA Astrophysics Data System (ADS)

    Bachlechner, Thomas C.

    2013-05-01

    We show that gravitational interactions between massless thermal modes and a nucleating Coleman-de Luccia bubble may lead to efficient decoherence and strongly suppress metastable vacuum decay for bubbles that are small compared to the Hubble radius. The vacuum decay rate including gravity and thermal photon interactions has the exponential scaling \\Gamma \\sim \\Gamma _{CDL}^{2}, where ΓCDL is the Coleman-de Luccia decay rate neglecting photon interactions. For the lowest metastable initial state an efficient quantum Zeno effect occurs due to thermal radiation of temperatures as low as the de Sitter temperature. This strong decoherence effect is a consequence of gravitational interactions with light external mode. We argue that efficient decoherence does not occur for the case of Hawking-Moss decay. This observation is consistent with requirements set by Poincaré recurrence in de Sitter space.

  12. Threshold enhancement phenomena in Y(4260) decays

    NASA Astrophysics Data System (ADS)

    Liu, Xiao-Hai

    2014-04-01

    We investigate several strong and radiative decay modes of Y(4260), by assuming that Y(4260) either is a D1\\bar {D} molecular state, or has sizeable couplings with D0 \\bar {D}* and D1' \\bar {D}. In such ansatzes, obvious threshold enhancements or narrow cusp structures appear quite naturally without introducing a genuine resonance. And we emphasize that the radiative decay modes may be useful for studying D(*)\\bar {D}S-wave scattering.

  13. Observation of large-scale density cavities and parametric-decay instabilities in the high-altitude discrete auroral ionosphere under pulsed electromagnetic radiation.

    PubMed

    Wong, A Y; Chen, J; Lee, L C; Liu, L Y

    2009-03-13

    A large density cavity that measured 2000 km across and 500 km in height was observed by DEMETER and Formosat/COSMIC satellites in temporal and spatial relation to a new mode of propagation of electromagnetic (em) pulses between discrete magnetic field-aligned auroral plasmas to high altitudes. Recorded positive plasma potential from satellite probes is consistent with the expulsion of electrons in the creation of density cavities. High-frequency decay spectra support the concept of parametric instabilities fed by free energy sources.

  14. Observation of Large-Scale Density Cavities and Parametric-Decay Instabilities in the High-Altitude Discrete Auroral Ionosphere under Pulsed Electromagnetic Radiation

    SciTech Connect

    Wong, A. Y.; Chen, J.; Lee, L. C.; Liu, L. Y.

    2009-03-13

    A large density cavity that measured 2000 km across and 500 km in height was observed by DEMETER and Formosat/COSMIC satellites in temporal and spatial relation to a new mode of propagation of electromagnetic (em) pulses between discrete magnetic field-aligned auroral plasmas to high altitudes. Recorded positive plasma potential from satellite probes is consistent with the expulsion of electrons in the creation of density cavities. High-frequency decay spectra support the concept of parametric instabilities fed by free energy sources.

  15. Baryon semileptonic decays: the Mexican contribution

    SciTech Connect

    Flores-Mendieta, Ruben; Martinez, Alfonso

    2006-09-25

    We give a detailed account of the techniques to compute radiative corrections in baryon semileptonic decays developed over the years by Mexican collaborations. We explain how the method works by obtaining an expression for the Dalitz plot of semileptonic decays of polarized baryons including radiative corrections to order O({alpha}q/{pi}M1), where q is the four-momentum transfer and M1 is the mass of the decaying baryon. From here we compute the totally integrated spin angular asymmetry coefficient of the emitted baryon and compare its value with other results.

  16. Neutron-Induced Partial Cross Section Measurements on Cu, Ge and Pb at En = 8 and 12 MeV for Background Radiation in 0νββ Decay Experiments

    NASA Astrophysics Data System (ADS)

    Kwan, E.; Esterline, J. H.; Fallin, B.; Howell, C. R.; Hutcheson, A.; Kidd, M. F.; Tonchev, A.; Tornow, W.; Angell, C.; Karwowski, H.; Kelley, J.; Mei, D.; Hilderbrand, S.; Masters, D. B.; Pedroni, R. S.; Weisel, G. J.

    2008-04-01

    The search for the existence of 0νββ decay plays an important role in the uncovering of physics beyond the standard model. The detection of such decay would confirm that neutrinos are Majorana particles. The large lifetimes (i.e.,T1/2(^76Ge) > 10^25 y) and the corresponding long measuring times require extensive understanding of background radiation induced by neutron interactions with shielding and detector materials. For example, neutron induced γ-ray transitions in Pb and Cu and their escape peaks could interfere with the identification of the 2039 keV signature of 0νββ in the case of ^ 76Ge. Thus, it is necessary to determine the yields from possible background sources. The neutron-induced partial cross sections for γ-ray transitions in Cu, enriched ^76 Ge, and Pb were measured at TUNL using an array of HPGe detectors at En=8 and 12 MeV. The experimental setup and preliminary results will be presented.Supported by DOE Grants DE-FG02-97ER41033 & DE- FG02-97ER41042.

  17. New experimental results on neutrino mixing and decay.

    NASA Astrophysics Data System (ADS)

    Oberauer, L.; von Feilitzsch, F.; Hagner, C.; Kempf, G.; Mößbauer, R. L.; Declais, Y.; Kajfasz, E.

    The search for neutrino decay is a sensitive method to look for very small neutrino mixing parameter. The authors report about the status of an decay experiment performed at a reactor in Bugey and present preliminary new experimental limits on the coupling of a heavy neutrino to the electron state. Additionally new experimental lifetime bounds on the radiative decay mode are given. Rigid laboratory limits on this decay mode for the hypothetical 17 keV neutrino are presented. Limits on the radiative decay of a 17 keV neutrino obtained from the supernova SN 1987A are discussed.

  18. An amplitude analyses of the K K-bar system (M < 2 GeV/C{sup 2}) produced in J/{Psi} radiative decay

    SciTech Connect

    Chen, Liang-Ping

    1991-11-01

    Using the 5.8 {times} 10{sup 6} J/{psi} events collected by the MARK 3 experiment on the SPEAR e{sup +}e{sup {minus}} storage ring at SLAC, a mass independent amplitude analysis of the J/{psi} {yields} {gamma} K{sub s}K{sub s} and J/{psi} {yields} K{sup +}K{sup {minus}} decays is presented. For K{bar K} systems having mass less than 2 GeV/c{sup 2}, the efficiency-corrected spherical harmonic moments of the J/{psi} joint decay angular distribution are measured. Fits are then performed in each independent mass interval in order to extract the underlying helicity amplitude structure; amplitudes describing K{bar K} systems of spin zero and spin two are included simultaneously. For the first time, a large spin zero component in the {theta}(1720) mass region is observed; consistent results are obtained for the data samples corresponding to the individual decay modes. This structure is attributed to the production of an S wave resonance, the f{sub 0}(1710), of mass and width M = 1710 {plus_minus} 10 MeV/c{sup 2}, {Gamma} = 186 {plus_minus} 30 MeV/c{sup 2}, respectively, with branching fraction Bf(J/{psi} {yields} {gamma}f{sub 0}, f{sub 0} {yields} K{bar K}) = (6.47 {plus_minus} 1.14 {plus_minus} 0.84) {times} 10{sup {minus}4}. A small amount ({approximately}24%) of spin two component in this mass region cannot be ruled out with the present statistics. These results revise the previous conclusion that the {theta}(1720) is a spin two resonance, a result obtained on the basis of spin hypothesis tests, which assumed that either pure spin zero or pure spin two states contribute in this mass region, but not both. The previous measurements of the f{sub 2}{prime} (1525) have been refined in the present analysis because of the simultaneous inclusion of spin zero and spin two amplitudes in the fit.

  19. An amplitude analyses of the K K-bar system (M < 2 GeV/C sup 2 ) produced in J/. Psi. radiative decay

    SciTech Connect

    Chen, Liang-Ping.

    1991-11-01

    Using the 5.8 {times} 10{sup 6} J/{psi} events collected by the MARK 3 experiment on the SPEAR e{sup +}e{sup {minus}} storage ring at SLAC, a mass independent amplitude analysis of the J/{psi} {yields} {gamma} K{sub s}K{sub s} and J/{psi} {yields} K{sup +}K{sup {minus}} decays is presented. For K{bar K} systems having mass less than 2 GeV/c{sup 2}, the efficiency-corrected spherical harmonic moments of the J/{psi} joint decay angular distribution are measured. Fits are then performed in each independent mass interval in order to extract the underlying helicity amplitude structure; amplitudes describing K{bar K} systems of spin zero and spin two are included simultaneously. For the first time, a large spin zero component in the {theta}(1720) mass region is observed; consistent results are obtained for the data samples corresponding to the individual decay modes. This structure is attributed to the production of an S wave resonance, the f{sub 0}(1710), of mass and width M = 1710 {plus minus} 10 MeV/c{sup 2}, {Gamma} = 186 {plus minus} 30 MeV/c{sup 2}, respectively, with branching fraction Bf(J/{psi} {yields} {gamma}f{sub 0}, f{sub 0} {yields} K{bar K}) = (6.47 {plus minus} 1.14 {plus minus} 0.84) {times} 10{sup {minus}4}. A small amount ({approximately}24%) of spin two component in this mass region cannot be ruled out with the present statistics. These results revise the previous conclusion that the {theta}(1720) is a spin two resonance, a result obtained on the basis of spin hypothesis tests, which assumed that either pure spin zero or pure spin two states contribute in this mass region, but not both. The previous measurements of the f{sub 2}{prime} (1525) have been refined in the present analysis because of the simultaneous inclusion of spin zero and spin two amplitudes in the fit.

  20. Spin-forbidden radiative decay rates from the 3 {sup 3}P{sub 1,2} and 3 {sup 1}P{sub 1} states of helium

    SciTech Connect

    Morton, Donald C.; Drake, G. W. F.

    2011-04-15

    We have calculated atomic helium spontaneous decay rates and absorption oscillator strengths for the spin-forbidden transitions from 3 {sup 3}P{sub 1,2} and 3 {sup 1}P{sub 1} to all lower {sup 1}S{sub 0} and {sup 3}S{sub 1} states. In particular we found A{sub 10}=44.33(4) s{sup -1} for the E1 transition 3 {sup 3}P{sub 1}-1 {sup 1}S{sub 0} and 0.1147(1) s{sup -1} for the M2 transition 3 {sup 3}P{sub 2}-1 {sup 1}S{sub 0}.

  1. Measurement of the branching fractions of radiative leptonic τ decays τ → ℓγν anti-ν (ℓ=e,μ) at BABAR

    SciTech Connect

    Oberhof, Benjamin

    2015-04-29

    We perform a measurement of the branching fractions for τ → ℓγν anti ν, (ℓ = e, μ) decays for a minimum photon energy of 10 MeV in the τ rest frame using 430 fb-1 of e+e- collisions collected at the center-of-mass energy of the Υ(4S) resonance with the BABAR detector at the PEP-II storage rings. We find B(τ → μγνν) = (3.69±0.03±0.10)×103 and B(τ → eγνν) = (1.847 ± 0.015 ± 0.052) × 10-2 where the first quoted error is statistical and the second is systematic. These results represent a substantial improvement with respect to existing measurements for both channels.

  2. Lepton flavor violating quarkonium decays

    NASA Astrophysics Data System (ADS)

    Hazard, Derek E.; Petrov, Alexey A.

    2016-10-01

    We argue that lepton flavor violating (LFV) decays M →ℓ1ℓ¯ 2 of quarkonium states M with different quantum numbers could be used to put constraints on the Wilson coefficients of effective operators describing LFV interactions at low energy scales. We note that restricted kinematics of the two-body quarkonium decays allows us to select operators with particular quantum numbers, significantly reducing the reliance on the single operator dominance assumption that is prevalent in constraining parameters of the effective LFV Lagrangian. We shall also argue that studies of radiative lepton flavor violating M →γ ℓ1ℓ¯ 2 decays could provide important complementary access to those effective operators.

  3. Semileptonic Decays

    SciTech Connect

    Luth, Vera G.; /SLAC

    2012-10-02

    The following is an overview of the measurements of the CKM matrix elements |V{sub cb}| and |V{sub ub}| that are based on detailed studies of semileptonic B decays by the BABAR and Belle Collaborations and major advances in QCD calculations. In addition, a new and improved measurement of the ratios R(D{sup (*)}) = {Beta}({bar B} {yields} D{sup (*)}{tau}{sup -}{bar {nu}}{sub {tau}})/{Beta}({bar B} {yields} D{sup (*)}{ell}{sup -}{bar {nu}}{sub {ell}}) is presented. Here D{sup (*)} refers to a D or a D* meson and {ell} is either e or {mu}. The results, R(D) = 0.440 {+-} 0.058 {+-} 0.042 and R(D*) = 0.332 {+-} 0.024 {+-} 0.018, exceed the Standard Model expectations by 2.0{sigma} and 2.7{sigma}, respectively. Taken together, they disagree with these expectations at the 3.4{sigma} level. The excess of events cannot be explained by a charged Higgs boson in the type II two-Higgs-doublet model.

  4. Evidence for Orbital Decay of RX J1914.4+2456: Gravitational Radiation and the Nature of the X-Ray Emission

    NASA Technical Reports Server (NTRS)

    Strohmayer, Tod E.; White, Nicholas E. (Technical Monitor)

    2002-01-01

    RX J1914.4+2456 is a candidate double-degenerate binary (AM CVn) with a putative 569 s orbital period. If this identification is correct, then it has one of the shortest binary orbital periods known, and gravitational radiation should drive the orbital evolution and mass transfer if the binary is semi-detached. Here we report the results of a coherent timing study of the archival ROSAT data for RX J1914.4+2456. We performed a phase coherent timing analysis using all five ROSAT observations spanning a four-year period. We demonstrate that all the data can be phase connected, and we show that the 1.756 mHz orbital frequency is increasing at a rate of 1.5 +/- 0.4 x 10(exp -17) Hz/s consistent with the expected loss of angular momentum from the binary system via gravitational radiation. In addition to providing evidence for the emission of gravitational waves, our measurement of the orbital v(dot) constrains models for the X-ray emission and the nature of the secondary. If stable mass accretion drives the X-ray flux, then a positive v(dot) is inconsistent with a degenerate donor. A helium burning dwarf is compatible if indeed such systems can have periods as short as that of RX J1914.4+2456, an open theoretical question. Our measurement of a positive v(dot) is consistent with the unipolar induction model of Wu et al. which does not require accretion to drive the X-ray flux. We discuss how future timing measurements of RX J1914.4+2456 (and systems like it) with for example, Chandra and XMM-Newton, can provide a unique probe of the interaction between mass loss and gravitational radiation. We also discuss the importance of such measurements in the context of gravitational wave detection from space, such as is expected in the future with the LISA mission.

  5. Intramolecular vibrational redistribution in the non-radiative excited state decay of uracil in the gas phase: an ab initio molecular dynamics study.

    PubMed

    Carbonniere, Philippe; Pouchan, Claude; Improta, Roberto

    2015-05-07

    We report a study of intramolecular vibrational distribution (IVR) occurring in the electronic ground state of uracil (S0) in the gas phase, following photoexcitation in the lowest energy bright excited state (Sπ) and decay through the ethylene-like Sπ/S0 Conical Intersection (CI-0π). To this aim we have performed 20 independent ab initio molecular dynamics simulations starting from CI-0π (ten of them with 1 eV kinetic energy randomly distributed over the different molecular degrees of freedom) and 10 starting from the ground state minimum (Franck-Condon, FC, point), with the excess kinetic energy equal to the energy gap between CI-0π and the FC point. The simulations, exploiting PBE0/6-31G(d) calculations, were performed over an overall period of 10 ps. A thorough statistical analysis of the variation of the geometrical parameters of uracil during the simulation time and of the distribution of the kinetic energy among the different vibrational degrees of freedom provides a consistent picture of the IVR process. In the first 0-200 fs the structural dynamics involve mainly the recovery of the average planarity. In the 200-600 fs time range, a substantial activation of CO and NH degrees of freedom is observed. After 500-600 fs most of the geometrical parameters reach average values similar to those found after 10 ps, though the system cannot be considered to be in equilibrium yet.

  6. Searching the Inclusive Lepton + Photon + Missing E(T) + b-quark Signature for Radiative Top Quark Decay and Non-Standard-Model Processes

    SciTech Connect

    Aaltonen, T.; Adelman, Jahred A.; Akimoto, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, Dante E.; Anastassov, A.; Annovi, Alberto; Antos, Jaroslav; Apollinari, G.; Apresyan, A.; /Purdue U. /Waseda U.

    2009-06-01

    In a search for new phenomena in a signature suppressed in the standard model of elementary particles (SM), we compare the inclusive production of events containing a lepton ({ell}), a photon ({gamma}), significant transverse momentum imbalance (E{sub T}), and a jet identified as containing a b-quark, to SM predictions. The search uses data produced in proton-antiproton collisions at {radical}s = 1.96 TeV corresponding to 1.9 fb{sup -1} of integrated luminosity taken with the CDF detector at the Fermilab Tevatron. We find 28 {ell}{gamma}bE{sub T} events versus an expectation of 31.0{sub -3.5}{sup +4.1} events. If we further require events to contain at least three jets and large total transverse energy, simulations predict that the largest SM source is top-quark pair production with an additional radiated photon, t{bar t} + {gamma}. In the data we observe 16 t{bar t}{gamma} candidate events versus an expectation from non-top-quark SM sources of 11.2{sub -2.1}{sup +2.3}. Assuming the difference between the observed number and the predicted non-top-quark total is due to SM top quark production, we estimate the t{bar t} cross section to be 0.15 {+-} 0.08 pb.

  7. Searching the inclusive ℓγE̸T+b-quark signature for radiative top quark decay and non-standard-model processes

    NASA Astrophysics Data System (ADS)

    Aaltonen, T.; Adelman, J.; Akimoto, T.; Álvarez 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.; Badgett, W.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartsch, V.; Bauer, G.; Beauchemin, P.-H.; Bedeschi, F.; 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.; Burke, S.; Burkett, K.; Busetto, G.; Bussey, P.; Buzatu, A.; Byrum, K. L.; Cabrera, S.; Calancha, C.; 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.; Choudalakis, G.; Chuang, S. H.; 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.; Cordelli, M.; Cortiana, G.; 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.; Derwent, P. F.; di Canto, A.; 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.; Frank, M. J.; Franklin, M.; Freeman, J. C.; Frisch, H. J.; Furic, I.; Gallinaro, M.; Galyardt, J.; Garberson, F.; Garcia, J. E.; Garfinkel, A. F.; Garosi, P.; 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.; Happacher, F.; Hara, K.; Hare, D.; Hare, M.; Harper, S.; Harr, R. F.; Harris, R. M.; Hartz, M.; Hatakeyama, K.; Hays, C.; Heck, M.; Heijboer, A.; 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.; 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.; Knuteson, B.; Ko, B. R.; 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.; 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.; Lucchesi, D.; Luci, C.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lyons, L.; Lys, J.; Lysak, R.; 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.; Mathis, M.; 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.; Morlock, 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.; 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.; Palencia, E.; Papadimitriou, V.; Papaikonomou, A.; Paramonov, 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.; 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.; 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.; Saltó, O.; Santi, L.; Sarkar, S.; 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.; 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.; Spreitzer, T.; 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.; 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.; 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.; Vallecorsa, S.; van Remortel, N.; Varganov, A.; Vataga, E.; Vázquez, F.; Velev, G.; Vellidis, C.; Vidal, M.; Vidal, R.; Vila, I.; Vilar, R.; Vine, T.; 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., III; 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.; Wright, T.; Wu, X.; Würthwein, F.; Xie, S.; 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.; Zanello, L.; Zanetti, A.; Zhang, X.; Zheng, Y.; Zucchelli, S.

    2009-07-01

    We compare the inclusive production of events containing a lepton (ℓ), a photon (γ), significant transverse momentum imbalance (E̸T), and a jet identified as containing a b-quark, to SM predictions. The search uses data produced in proton-antiproton collisions at s=1.96TeV corresponding to 1.9fb-1 of integrated luminosity taken with the CDF detector. We find 28 ℓγbE̸T events versus an expectation of 31.0-3.5+4.1 events. If we further require events to contain at least three jets and large total transverse energy, the largest SM source is radiative top-quark pair production, t tmacr +γ. In the data we observe 16 t tmacr γ candidate events versus an expectation from SM sources of 11.2-2.1+2.3. Assuming the difference between the observed number and the predicted non-top-quark total of 6.8-2.0+2.2 is due to SM top-quark production, we estimate the t tmacr γ cross section to be 0.15±0.08pb.

  8. The program RADLST (Radiation Listing)

    SciTech Connect

    Burrows, T.W.

    1988-02-29

    The program RADLST (Radiation Listing) is designed to calculate the nuclear and atomic radiations associated with the radioactive decay of nuclei. It uses as its primary input nuclear decay data in the Evaluated Nuclear Structure Data File (ENSDF) format. The code is written in FORTRAN 77 and, with a few exceptions, is consistent with the ANSI standard. 65 refs.

  9. Analytical properties of the plasmon decay profile in a periodic metal-nanoparticle chain.

    PubMed

    Fung, Kin Hung; Tang, Ross Chin Hang; Chan, C T

    2011-06-15

    We show that the spatial decay of plasmons in a periodic metal-nanoparticle chain is composed of exponential and power-law decays. Our results show a high level of similarity between the absorptive and radiative decay channels. By analyzing the poles (and the corresponding residues) of the generating function for the lattice Green's function, we explain the details of the spatial decay profile. We also present an analytical formula for the decay profile.

  10. Resolvability of positron decay channels

    SciTech Connect

    Fluss, M.J.; Howell, R.H.; Rosenberg, I.J.; Meyer, P.

    1985-03-07

    Many data analysis treatments of positron experiments attempt to resolve two or more positron decay or exist channels which may be open simultaneously. Examples of the need to employ such treatments of the experimental results can be found in the resolution of the constituents of a defect ensemble, or in the analysis of the complex spectra which arise from the interaction of slow positrons at or near the surfaces of solids. Experimental one- and two-dimensional angular correlation of annihilation radiation experiments in Al single crystals have shown that two defect species (mono- and divacancies) can be resolved under suitable conditions. Recent experiments at LLNL indicate that there are a variety of complex exit channels open to positrons interacting at surfaces, and ultimely these decay channels must also be suitably resolved from one another. 6 refs., 4 figs.

  11. Baryonic B Decays

    NASA Astrophysics Data System (ADS)

    Chistov, R.

    2016-02-01

    In this talk the decays of B-mesons into baryons are discussed. Large mass of B-meson makes possible the decays of the type B → baryon (+mesons). Experimental observations and measurements of these decays at B-factories Belle and BaBar have stimulate the development of theoretical models in this field. We briefly review the experimental results together with the current theoretical models which describe baryonic B decays.

  12. The large scale microwave background anisotropy in decaying particle cosmology

    SciTech Connect

    Panek, M.

    1987-06-01

    We investigate the large-scale anisotropy of the microwave background radiation in cosmological models with decaying particles. The observed value of the quadrupole moment combined with other constraints gives an upper limit on the redshift of the decay z/sub d/ < 3-5. 12 refs., 2 figs.

  13. Radiation detection system

    DOEpatents

    Franks, Larry A.; Lutz, Stephen S.; Lyons, Peter B.

    1981-01-01

    A radiation detection system including a radiation-to-light converter and fiber optic wave guides to transmit the light to a remote location for processing. The system utilizes fluors particularly developed for use with optical fibers emitting at wavelengths greater than about 500 nm and having decay times less than about 10 ns.

  14. Detection of radon decay products in rainwater

    SciTech Connect

    Baker, S.I.

    1999-11-01

    The Argonne National Laboratory-East (ANL-E) Environmental Radiation Monitoring System measures and records ambient radiation levels and provides detection capability for radon decay products in rain clouds. These decay products in rainwater tracked into a facility on the shoes of workers can cause false alarms from hand and shoe monitors. The monitors at ANL-E can easily detect the radon decay products, and the 19.6 and 26.8 min half-lives of the beta-particle emitters are long enough in many cases for sufficient activity to still be present to initiate a contamination alarm when the shoes are checked for radioactivity. The Environmental Radiation Monitoring System provides a warning when precipitation contains elevated levels of radon decay products. It is based on a prototype developed at the Super Collider Laboratory, During its first year of operation there were nine alarms from radon decay products with an alarm trigger point set at 30% greater than background. The alarms occurred at both monitoring stations, which are approximately 1,000 m apart, indicating large diameter radon clouds. The increases in background were associated with low atmospheric pressure. There was no correlation with radon released from the coal-burning steam plant on the site. Alarms also occurred when short-lived accelerator-produced radioactivity in the exhaust stack plume passed over the NaI(TI) detector in one of the stations. The 450 MeV proton accelerator near the station produced {sup 12}C, {sup 13}N, and {sup 15}O by spallation of air nuclei. The gamma-ray spectrum from the plume from the accelerator exhaust stack was dominated by the 511 keV annihilation gamma rays from decay of these radionuclides. These gamma rays were easily distinguished from the 609 keV, 1,120 keV, and 1,764 keV gamma rays emitted by the radon decay products.

  15. Bremsstrahlung in {alpha} Decay Reexamined

    SciTech Connect

    Boie, H.; Scheit, H.; Jentschura, U. D.; Koeck, F.; Lauer, M.; Schwalm, D.; Milstein, A. I.; Terekhov, I. S.

    2007-07-13

    A high-statistics measurement of bremsstrahlung emitted in the {alpha} decay of {sup 210}Po has been performed, which allows us to follow the photon spectra up to energies of {approx}500 keV. The measured differential emission probability is in good agreement with our theoretical results obtained within the quasiclassical approximation as well as with the exact quantum mechanical calculation. It is shown that, due to the small effective electric dipole charge of the radiating system, a significant interference between the electric dipole and quadrupole contributions occurs, which is altering substantially the angular correlation between the {alpha} particle and the emitted photon.

  16. On stimulated radiation of black holes

    SciTech Connect

    Ridky, Jan

    2009-10-27

    The Unruh's thermal state in the vicinity of the event horizon of the black hole provides conditions where impinging particles can radiate other particles. The subsequent decays eventually lead to observable radiation of photons and neutrinos. Such radiation can be induced even by massive particles with gravitational interaction only. The hadronic particles would induce {approx}30 MeV gamma radiation from {pi}{sup 0} decays.

  17. Trapping of radiation in plasmas

    SciTech Connect

    Riley, M.E.; Alford, W.J.

    1995-06-01

    The authors analyze the problem of radiation trapping (imprisonment) by the method of Holstein. The process is described by an integrodifferential equation which shows that the effective radiative decay rate of the system depends on the size and the shape of the active medium. Holstein obtains a global decay rate for a particular geometry by assuming that the radiating excited species evolves into a steady state spatial mode. The authors derive a new approximation for the trapped decay which has a space dependent decay rate and is easy to implement in a detailed computer simulation of a plasma confined within an arbitrary geometry. They analyze the line shapes that are relevant to a near-atmospheric-pressure mixture of He and Xe. This line-shape analysis can be utilized in either the Holstein formulae or the space-dependent decay approximation.

  18. Re-ionization and decaying dark matter

    NASA Technical Reports Server (NTRS)

    Dodelson, Scott; Jubas, Jay M.

    1991-01-01

    Gunn-Peterson tests suggest that the Universe was reionized after the standard recombination epoch. A systematic treatment is presented of the ionization process by deriving the Boltzmann equations appropriate to this regime. A compact solution for the photon spectrum is found in terms of the ionization ratio. These equations are then solved numerically for the Decaying Dark Matter scenario, wherein neutrinos with mass of order 30 eV radiatively decay producing photons which ionize the intergalactic medium. It was found that the neutrino mass and lifetime are severely constrained by Gunn-Peterson tests, observations of the diffuse photon spectrum in the ultraviolet regime, and the Hubble parameter.

  19. RARE DECAYS INCLUDING PENGUINS

    SciTech Connect

    Eigen, G

    2003-12-04

    The authors present a preliminary measurement of the exclusive charmless semileptonic B decays, B {yields} {rho}{ell}{nu}, and the extraction of the CKM parameters V{sub ub}. IN a data sample of 55 x 10{sup 6} B{bar B} events they measure a branching fraction of {Beta}(B {yields} {rho}{ell}{nu}) = (3.39 {+-} 0.44{sub stat} {+-} 0.52{sub sys} {+-} 0.60{sub th}) x 10{sup -4} yielding |V{sub ub}| = (3.69 {+-} 0.23{sub stat} {+-} 0.27{sub sys -0.59th}{sup +0.40}) x 10{sup -3}. Next, they report on a preliminary study of the radiative penguin modes B {yields} K{ell}{sup +}{ell}{sup -} and B {yields} K*{ell}{sup +}{ell}{sup -}. In a data sample of 84 x 10{sup 6} B{bar B} events they observe a significant signal (4.4{sigma}) in B {yields} K{ell}{sup +}{ell}{sup -}, yielding a branching fraction of {Beta}(B {yields} K{ell}{sup +}{ell}{sup -}) = (0.78{sub -0.20-0.18}{sup +0.24+0.11}) x 10{sup -6}. In B {yields} K*{ell}{sup +}{ell}{sup -} the observed yield is not yet significant (2.8{sigma}), yielding an upper limit of the branching fraction of {Beta}(B {yields} K*{ell}{sup +}{ell}{sup -}) 3.0 x 10{sup -6} {at} 90% confidence level. Finally, they summarize preliminary results of searches for B {yields} {rho}({omega}){gamma}, B{sup +} {yields} K{sup +} {nu}{bar {nu}} and B{sup 0} {yields} {ell}{sup +}{ell}{sup -}.

  20. Radioactive Decay - An Analog.

    ERIC Educational Resources Information Center

    McGeachy, Frank

    1988-01-01

    Presents an analog of radioactive decay that allows the student to grasp the concept of half life and the exponential nature of the decay process. The analog is devised to use small, colored, plastic poker chips or counters. Provides the typical data and a graph which supports the analog. (YP)

  1. Inflaton dark matter from incomplete decay

    NASA Astrophysics Data System (ADS)

    Bastero-Gil, Mar; Cerezo, Rafael; Rosa, João G.

    2016-05-01

    We show that the decay of the inflaton field may be incomplete, while nevertheless successfully reheating the Universe and leaving a stable remnant that accounts for the present dark matter abundance. We note, in particular, that since the mass of the inflaton decay products is field dependent, one can construct models, endowed with an appropriate discrete symmetry, where inflaton decay is kinematically forbidden at late times and only occurs during the initial stages of field oscillations after inflation. We show that this is sufficient to ensure the transition to a radiation-dominated era and that inflaton particles typically thermalize in the process. They eventually decouple and freeze out, yielding a thermal dark matter relic. We discuss possible implementations of this generic mechanism within consistent cosmological and particle physics scenarios, for both single-field and hybrid inflation.

  2. Trion decay in colloidal quantum dots.

    PubMed

    Jha, Praket P; Guyot-Sionnest, Philippe

    2009-04-28

    Using charged films of colloidal CdSe/CdS core/shell quantum dots of approximately 3.5 to 4.5 nm core diameters and 0.6 to 1.2 nm thick CdS shells, the radiative and nonradiative decay of the negatively charged exciton, the trion T-, are measured. The T- radiative rate is faster than the exciton by a factor of 2.2 +/- 0.4 and estimated at approximately 10 ns. The T- lifetime is approximately 0.7-1.5 ns for the samples measured and is longer than the biexciton lifetime by a factor or 7.5 +/- 1.7.

  3. RARE KAON DECAYS.

    SciTech Connect

    LITTENBERG, L.

    2005-07-19

    Lepton flavor violation (LFV) experiments have probed sensitivities corresponding to mass scales of well over 100 TeV, making life difficult for models predicting accessible LFV in kaon decay and discouraging new dedicated experiments of this type.

  4. Charmless B Decays

    SciTech Connect

    Gradl, Wolfgang; /Edinburgh U.

    2007-03-06

    Rare charmless hadronic B decays are a good testing ground for the standard model. The dominant amplitudes contributing to this class of B decays are CKM suppressed tree diagrams and b {yields} s or b {yields} d loop diagrams (''penguins''). These decays can be used to study interfering standard model (SM) amplitudes and CP violation. They are sensitive to the presence of new particles in the loops, and they provide valuable information to constrain theoretical models of B decays. The B factories BABAR at SLAC and Belle at KEK produce B mesons in the reaction e{sup +}e{sup -} {yields} {Upsilon}(4S) {yields} B{bar B}. So far they have collected integrated luminosities of about 406 fb{sup -1} and 600 fb{sup -1}, respectively. The results presented here are based on subsets of about 200-500 fb{sup -1} and are preliminary unless a journal reference is given.

  5. Decay of long-lived particles in the early universe

    NASA Technical Reports Server (NTRS)

    Silk, J.; Stebbins, A.

    1983-01-01

    It is pointed out that radiative decay of massive fermions can distort the cosmic background radiation. The present investigation is concerned with a study of decay lifetimes in the range from 10 to 100,000 years. Attention is given to the physics involved in determining the effect of radiative decay of massive fermions on observed photon backgrounds. The case of particles which decoupled when the effective number of species in equilibrium was in the range from 50 to 100 is considered, and constraints on particle masses and lifetimes are placed on the basis of observed photon fluxes. This approach provides results with special applications to particles predicted by supersymmetry theories and to right-handed neutrinos. Implications for galaxy formation are also discussed.

  6. Radiation Education Activities | RadTown USA | | US EPA

    EPA Pesticide Factsheets

    2017-03-28

    EPA's Radiation Education Activities are designed to help increase awareness and understanding of radiation concepts among middle and high school students. The activities introduce basic concepts of radiation, non-ionizing and ionizing radiation, radiation protection, radioactive atoms and radioactive decay.

  7. Diffuse gamma rays from WIMP decay and annihilation.

    NASA Astrophysics Data System (ADS)

    Kamionkowski, M.

    The author discusses contributions to the diffuse gamma-ray background from decay and annihilation of weakly interacting massive particles (WIMPs). He first reviews the calculation of the cosmological abundance of a WIMP and shows that it is simply related to the cross section for annihilation of the WIMP into lighter particles. The diffuse extragalactic background radiation (DEBRA) from WIMP decay is then discussed. It is shown how observational upper limits to the DEBRA can be used to constrain properties of WIMPs that decay to photons, and the author presents additional new constraints that unitarity of the annihilation cross section imposes on such particles.

  8. Penguin and rare decays in BaBar

    SciTech Connect

    Akar, Simon

    2015-04-29

    We present recent results from the BABAR Collaboration on radiative decays. These include searches for new physics via measurements of several observables such as the time- dependent CP asymmetry in B0 → K0Sπ π+γ exclusive decays, as well as direct CP asymmetries and branching fractions in B → Xsγ and B → Xs+ inclusive decays.

  9. Enhanced Electroweak Penguin Amplitude in B{yields}VV Decays

    SciTech Connect

    Beneke, M.; Rohrer, J.; Yang, D.

    2006-04-14

    We discuss a novel electromagnetic penguin contribution to the transverse helicity amplitudes in B decays to two vector mesons, which is enhanced by two powers of m{sub B}/{lambda} relative to the standard penguin amplitudes. This leads to unique polarization signatures in penguin-dominated decay modes such as B{yields}{rho}K* similar to polarization effects in the radiative decay B{yields}K*{gamma} and offers new opportunities to probe the magnitude and chirality of flavor-changing neutral current couplings to photons.

  10. Prospects for studying penguin decays in LHCb experiments

    SciTech Connect

    Barsuk, S. Ya. Pakhlova, G. V. Belyaev, I. M.

    2006-04-15

    Investigation of loop penguin decays of beauty hadrons seems promising in testing the predictions of the Standard Model of electroweak and strong interactions and in seeking new phenomena beyond the Standard Model. The possibility of studying the radiative penguin decays B{sup 0} {sup {yields}} K*{sup 0}{gamma}, B{sup 0}{sub s} {sup {yields}} {phi}{gamma}, and B{sup 0} {sup {yields}} {omega}{gamma} and the gluonic penguin decays B{sup 0} {sup {yields}} {phi}K{sup 0}{sub S} and B{sup 0}{sub s} {sup {yields}} {phi}{phi} in LHCb experiments is discussed.

  11. Decay of superdeformed bands

    SciTech Connect

    Carpenter, M.P.; Khoo, T.L.; Lauritsen, T.

    1995-12-31

    One of the major challenges in the study of superdeformation is to directly connect the large number of superdeformed bands now known to the yrast states. In this way, excitation energies, spins and parities can be assigned to the levels in the second well which is essential to establish the collective and single-particle components of these bands. This paper will review some of the progress which has been made to understand the decay of superdeformed bands using the new arrays including the measurement of the total decay spectrum and the establishment of direct one-step decays from the superdeformed band to the yrast line in {sup 194}Hg. 42 refs., 5 figs.

  12. Suppressed Charmed B Decay

    SciTech Connect

    Snoek, Hella Leonie

    2009-06-02

    This thesis describes the measurement of the branching fractions of the suppressed charmed B0 → D*- a0+ decays and the non-resonant B0 → D*- ηπ+ decays in approximately 230 million Υ(4S) → B$\\bar{B}$ events. The data have been collected with the BABAR detector at the PEP-II B factory at the Stanford Linear Accelerator Center in California. Theoretical predictions of the branching fraction of the B0 → D*- a{sub 0}+ decays show large QCD model dependent uncertainties. Non-factorizing terms, in the naive factorization model, that can be calculated by QCD factorizing models have a large impact on the branching fraction of these decay modes. The predictions of the branching fractions are of the order of 10-6. The measurement of the branching fraction gives more insight into the theoretical models. In general a better understanding of QCD models will be necessary to conduct weak interaction physics at the next level. The presence of CP violation in electroweak interactions allows the differentiation between matter and antimatter in the laws of physics. In the Standard Model, CP violation is incorporated in the CKM matrix that describes the weak interaction between quarks. Relations amongst the CKM matrix elements are used to present the two relevant parameters as the apex of a triangle (Unitarity Triangle) in a complex plane. The over-constraining of the CKM triangle by experimental measurements is an important test of the Standard Model. At this moment no stringent direct measurements of the CKM angle γ, one of the interior angles of the Unitarity Triangle, are available. The measurement of the angle γ can be performed using the decays of neutral B mesons. The B0 → D*- a0+ decay is sensitive to the angle γ and, in comparison to the current decays that are being employed, could significantly

  13. Flavor changing nucleon decay

    NASA Astrophysics Data System (ADS)

    Maekawa, Nobuhiro; Muramatsu, Yu

    2017-04-01

    Recent discovery of neutrino large mixings implies the large mixings in the diagonalizing matrices of 5 bar fields in SU (5) grand unified theory (GUT), while the diagonalizing matrices of 10 fields of SU (5) are expected to have small mixings like Cabibbo-Kobayashi-Maskawa matrix. We calculate the predictions of flavor changing nucleon decays (FCND) in SU (5), SO (10), and E6 GUT models which have the above features for mixings. We found that FCND can be the main decay mode and play an important role to test GUT models.

  14. Search for the decay

    NASA Astrophysics Data System (ADS)

    Aaij, R.; Adeva, B.; Adinolfi, M.; Affolder, A.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Anderson, J.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Aquines Gutierrez, O.; Archilli, F.; d'Argent, P.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Bachmann, S.; Back, J. J.; Badalov, A.; Baesso, C.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Batozskaya, V.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Bel, L. J.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Benton, J.; Berezhnoy, A.; Bernet, R.; Bertolin, A.; Bettler, M.-O.; van Beuzekom, M.; Bien, A.; Bifani, S.; Bird, T.; Birnkraut, A.; Bizzeti, A.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Bondar, A.; Bondar, N.; Bonivento, W.; Borghi, S.; Borsato, M.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Braun, S.; Brett, D.; Britsch, M.; Britton, T.; Brodzicka, J.; Brook, N. H.; Bursche, A.; Buytaert, J.; Cadeddu, S.; Calabrese, R.; Calvi, M.; Calvo Gomez, M.; Campana, P.; Campora Perez, D.; Capriotti, L.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carniti, P.; Carson, L.; Carvalho Akiba, K.; Casanova Mohr, R.; Casse, G.; Cassina, L.; Castillo Garcia, L.; Cattaneo, M.; Cauet, Ch.; Cavallero, G.; Cenci, R.; Charles, M.; Charpentier, Ph.; Chefdeville, M.; Chen, S.; Cheung, S.-F.; Chiapolini, N.; Chrzaszcz, M.; Cid Vidal, X.; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coco, V.; Cogan, J.; Cogneras, E.; Cogoni, V.; Cojocariu, L.; Collazuol, G.; Collins, P.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coombes, M.; Coquereau, S.; Corti, G.; Corvo, M.; Couturier, B.; Cowan, G. A.; Craik, D. C.; Crocombe, A.; Cruz Torres, M.; Cunliffe, S.; Currie, R.; D'Ambrosio, C.; Dalseno, J.; David, P. N. Y.; Davis, A.; De Bruyn, K.; De Capua, S.; De Cian, M.; De Miranda, J. M.; De Paula, L.; De Silva, W.; De Simone, P.; Dean, C.-T.; Decamp, D.; Deckenhoff, M.; Del Buono, L.; Déléage, N.; Derkach, D.; Deschamps, O.; Dettori, F.; Dey, B.; Di Canto, A.; Di Ruscio, F.; Dijkstra, H.; Donleavy, S.; Dordei, F.; Dorigo, M.; Dosil Suárez, A.; Dossett, D.; Dovbnya, A.; Dreimanis, K.; Dujany, G.; Dupertuis, F.; Durante, P.; Dzhelyadin, R.; Dziurda, A.; Dzyuba, A.; Easo, S.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; El Rifai, I.; Elsasser, Ch.; Ely, S.; Esen, S.; Evans, H. M.; Evans, T.; Falabella, A.; Färber, C.; Farinelli, C.; Farley, N.; Farry, S.; Fay, R.; Ferguson, D.; Fernandez Albor, V.; Ferrari, F.; Ferreira Rodrigues, F.; Ferro-Luzzi, M.; Filippov, S.; Fiore, M.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fol, P.; Fontana, M.; Fontanelli, F.; Forty, R.; Francisco, O.; Frank, M.; Frei, C.; Frosini, M.; Fu, J.; Furfaro, E.; Gallas Torreira, A.; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; García Pardiñas, J.; Garofoli, J.; Garra Tico, J.; Garrido, L.; Gascon, D.; Gaspar, C.; Gastaldi, U.; Gauld, R.; Gavardi, L.; Gazzoni, G.; Geraci, A.; Gerick, D.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gianelle, A.; Gianì, S.; Gibson, V.; Giubega, L.; Gligorov, V. V.; Göbel, C.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gotti, C.; Grabalosa Gándara, M.; Graciani Diaz, R.; Granado Cardoso, L. A.; Graugés, E.; Graverini, E.; Graziani, G.; Grecu, A.; Greening, E.; Gregson, S.; Griffith, P.; Grillo, L.; Grünberg, O.; Gui, B.; Gushchin, E.; Guz, Yu.; Gys, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hall, S.; Hamilton, B.; Hampson, T.; Han, X.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Harrison, J.; He, J.; Head, T.; Heijne, V.; Hennessy, K.; Henrard, P.; Henry, L.; Hernando Morata, J. A.; van Herwijnen, E.; Heß, M.; Hicheur, A.; Hill, D.; Hoballah, M.; Hombach, C.; Hulsbergen, W.; Humair, T.; Hussain, N.; Hutchcroft, D.; Hynds, D.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jaeger, A.; Jalocha, J.; Jans, E.; Jawahery, A.; Jing, F.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Jurik, N.; Kandybei, S.; Kanso, W.; Karacson, M.; Karbach, T. M.; Karodia, S.; Kelsey, M.; Kenyon, I. R.; Kenzie, M.; Ketel, T.; Khanji, B.; Khurewathanakul, C.; Klaver, S.; Klimaszewski, K.; Kochebina, O.; Kolpin, M.; Komarov, I.; Koopman, R. F.; Koppenburg, P.; Korolev, M.; Kravchuk, L.; Kreplin, K.; Kreps, M.; Krocker, G.; Krokovny, P.; Kruse, F.; Kucewicz, W.; Kucharczyk, M.; Kudryavtsev, V.; Kurek, K.; Kvaratskheliya, T.; La Thi, V. N.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lambert, D.; Lambert, R. W.; Lanfranchi, G.; Langenbruch, C.; Langhans, B.; Latham, T.; Lazzeroni, C.; Le Gac, R.; van Leerdam, J.; Lees, J.-P.; Lefèvre, R.; Leflat, A.; Lefrançois, J.; Leroy, O.; Lesiak, T.; Leverington, B.; Li, Y.; Likhomanenko, T.; Liles, M.; Lindner, R.; Linn, C.; Lionetto, F.; Liu, B.; Lohn, S.; Longstaff, I.; Lopes, J. H.; Lucchesi, D.; Lucio Martinez, M.; Luo, H.; Lupato, A.; Luppi, E.; Lupton, O.; Machefert, F.; Maciuc, F.; Maev, O.; Malde, S.; Malinin, A.; Manca, G.; Mancinelli, G.; Manning, P.; Mapelli, A.; Maratas, J.; Marchand, J. F.; Marconi, U.; Marin Benito, C.; Marino, P.; Märki, R.; Marks, J.; Martellotti, G.; Martinelli, M.; Martinez Santos, D.; Martinez Vidal, F.; Martins Tostes, D.; Massafferri, A.; Matev, R.; Mathad, A.; Mathe, Z.; Matteuzzi, C.; Matthieu, K.; Mauri, A.; Maurin, B.; Mazurov, A.; McCann, M.; McCarthy, J.; McNab, A.; McNulty, R.; Meadows, B.; Meier, F.; Meissner, M.; Merk, M.; Milanes, D. A.; Minard, M.-N.; Mitzel, D. S.; Molina Rodriguez, J.; Monteil, S.; Morandin, M.; Morawski, P.; Mordà, A.; Morello, M. J.; Moron, J.; Morris, A. B.; Mountain, R.; Muheim, F.; Müller, J.; Müller, K.; Müller, V.; Mussini, M.; Muster, B.; Naik, P.; Nakada, T.; Nandakumar, R.; Nasteva, I.; Needham, M.; Neri, N.; Neubert, S.; Neufeld, N.; Neuner, M.; Nguyen, A. D.; Nguyen, T. D.; Nguyen-Mau, C.; Niess, V.; Niet, R.; Nikitin, N.; Nikodem, T.; Ninci, D.; Novoselov, A.; O'Hanlon, D. P.; Oblakowska-Mucha, A.; Obraztsov, V.; Ogilvy, S.; Okhrimenko, O.; Oldeman, R.; Onderwater, C. J. G.; Osorio Rodrigues, B.; Otalora Goicochea, J. M.; Otto, A.; Owen, P.; Oyanguren, A.; Palano, A.; Palombo, F.; Palutan, M.; Panman, J.; Papanestis, A.; Pappagallo, M.; Pappalardo, L. L.; Parkes, C.; Passaleva, G.; Patel, G. D.; Patel, M.; Patrignani, C.; Pearce, A.; Pellegrino, A.; Penso, G.; Pepe Altarelli, M.; Perazzini, S.; Perret, P.; Pescatore, L.; Petridis, K.; Petrolini, A.; Petruzzo, M.; Picatoste Olloqui, E.; Pietrzyk, B.; Pilař, T.; Pinci, D.; Pistone, A.; Playfer, S.; Plo Casasus, M.; Poikela, T.; Polci, F.; Poluektov, A.; Polyakov, I.; Polycarpo, E.; Popov, A.; Popov, D.; Popovici, B.; Potterat, C.; Price, E.; Price, J. D.; Prisciandaro, J.; Pritchard, A.; Prouve, C.; Pugatch, V.; Puig Navarro, A.; Punzi, G.; Qian, W.; Quagliani, R.; Rachwal, B.; Rademacker, J. H.; Rakotomiaramanana, B.; Rama, M.; Rangel, M. S.; Raniuk, I.; Rauschmayr, N.; Raven, G.; Redi, F.; Reichert, S.; Reid, M. M.; dos Reis, A. C.; Ricciardi, S.; Richards, S.; Rihl, M.; Rinnert, K.; Rives Molina, V.; Robbe, P.; Rodrigues, A. B.; Rodrigues, E.; Rodriguez Lopez, J. A.; Rodriguez Perez, P.; Roiser, S.; Romanovsky, V.; Romero Vidal, A.; Rotondo, M.; Rouvinet, J.; Ruf, T.; Ruiz, H.; Ruiz Valls, P.; Saborido Silva, J. J.; Sagidova, N.; Sail, P.; Saitta, B.; Salustino Guimaraes, V.; Sanchez Mayordomo, C.; Sanmartin Sedes, B.; Santacesaria, R.; Santamarina Rios, C.; Santovetti, E.; Sarti, A.; Satriano, C.; Satta, A.; Saunders, D. M.; Savrina, D.; Schiller, M.; Schindler, H.; Schlupp, M.; Schmelling, M.; Schmelzer, T.; Schmidt, B.; Schneider, O.; Schopper, A.; Schune, M.-H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Semennikov, A.; Sepp, I.; Serra, N.; Serrano, J.; Sestini, L.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Shevchenko, V.; Shires, A.; Silva Coutinho, R.; Simi, G.; Sirendi, M.; Skidmore, N.; Skillicorn, I.; Skwarnicki, T.; Smith, E.; Smith, E.; Smith, J.; Smith, M.; Snoek, H.; Sokoloff, M. D.; Soler, F. J. P.; Soomro, F.; Souza, D.; Souza De Paula, B.; Spaan, B.; Spradlin, P.; Sridharan, S.; Stagni, F.; Stahl, M.; Stahl, S.; Steinkamp, O.; Stenyakin, O.; Sterpka, F.; Stevenson, S.; Stoica, S.; Stone, S.; Storaci, B.; Stracka, S.; Straticiuc, M.; Straumann, U.; Stroili, R.; Sun, L.; Sutcliffe, W.; Swientek, K.; Swientek, S.; Syropoulos, V.; Szczekowski, M.; Szczypka, P.; Szumlak, T.; T'Jampens, S.; Tekampe, T.; Teklishyn, M.; Tellarini, G.; Teubert, F.; Thomas, C.; Thomas, E.; van Tilburg, J.; Tisserand, V.; Tobin, M.; Todd, J.; Tolk, S.; Tomassetti, L.; Tonelli, D.; Topp-Joergensen, S.; Torr, N.; Tournefier, E.; Tourneur, S.; Trabelsi, K.; Tran, M. T.; Tresch, M.; Trisovic, A.; Tsaregorodtsev, A.; Tsopelas, P.; Tuning, N.; Ukleja, A.; Ustyuzhanin, A.; Uwer, U.; Vacca, C.; Vagnoni, V.; Valenti, G.; Vallier, A.; Vazquez Gomez, R.; Vazquez Regueiro, P.; Vázquez Sierra, C.; Vecchi, S.; Velthuis, J. J.; Veltri, M.; Veneziano, G.; Vesterinen, M.; Viaud, B.; Vieira, D.; Vieites Diaz, M.; Vilasis-Cardona, X.; Vollhardt, A.; Volyanskyy, D.; Voong, D.; Vorobyev, A.; Vorobyev, V.; Voß, C.; de Vries, J. A.; Waldi, R.; Wallace, C.; Wallace, R.; Walsh, J.; Wandernoth, S.; Wang, J.; Ward, D. R.; Watson, N. K.; Websdale, D.; Weiden, A.; Whitehead, M.; Wiedner, D.; Wilkinson, G.; Wilkinson, M.; Williams, M.; Williams, M. P.; Williams, M.; Wilson, F. F.; Wimberley, J.; Wishahi, J.; Wislicki, W.; Witek, M.; Wormser, G.; Wotton, S. A.; Wright, S.; Wyllie, K.; Xie, Y.; Xu, Z.; Yang, Z.; Yuan, X.; Yushchenko, O.; Zangoli, M.; Zavertyaev, M.; Zhang, L.; Zhang, Y.; Zhelezov, A.; Zhokhov, A.; Zhong, L.

    2015-08-01

    A search for decays is performed using 3 .0 fb1- of pp collision data recorded by the LHCb experiment during 2011 and 2012. The f 0(980) meson is reconstructed through its decay to the π + π - final state in the mass window 900 MeV /c 2 < m( π + π -) < 1080 MeV /c 2. No significant signal is observed. The first upper limits on the branching fraction of are set at 90 % (95 %) confidence level. [Figure not available: see fulltext.

  15. Sound decay of notes from acoustic guitars

    NASA Astrophysics Data System (ADS)

    Galazen, Erika; Nordberg, Joni; Huber, Thomas M.

    2005-09-01

    The acoustic guitar produces tones by transferring energy from the strings, through the bridge to the top plate, back, and air cavity of the guitar. The vibrations are ultimately radiated into the air as sound. The air-cavity and body resonances of the guitar play an important role in both the tone and the sustain (the time it takes notes to decay) produced by the guitar. To study the relationship between resonances of the guitar and the sustain of notes, the resonance frequencies were measured using a mechanical shaker attached to the body of the guitar and laser Doppler vibrometer to measure its vibration. A string was tuned to different frequencies and plucked. The decay of the note was measured with an electromagnetic pickup that measured the vibration of the string, a vibrometer to measure vibration of the top plate, and microphones located inside and outside the guitar. As expected, when the fundamental frequency of the string was near one of the resonances of the guitar, the decay rate was faster (shorter sustain) than when the string was between resonances. The relationship between the decay rates of the different parts of the system will also be discussed.

  16. Decay Time of Cathodoluminescence

    ERIC Educational Resources Information Center

    Kraftmakher, Yaakov

    2009-01-01

    Simple measurements of the decay time of cathodoluminescence are described. Cathodoluminescence is used in many devices, including computer monitors, oscilloscopes, radar displays and television tubes. The experimental setup is simple and easy to build. Two oscilloscopes, a function generator, and a fast photodiode are needed for the experiments.…

  17. Anatomy of decays

    NASA Astrophysics Data System (ADS)

    Bel, Lennaert; De Bruyn, Kristof; Fleischer, Robert; Mulder, Mick; Tuning, Niels

    2015-07-01

    The decays B {/d 0} → D {/d -} D {/d +} and B {/s 0} → D {/s -} D {/s +} probe the CP-violating mixing phases ϕ d and ϕ s , respectively. The theoretical uncertainty of the corresponding determinations is limited by contributions from penguin topologies, which can be included with the help of the U-spin symmetry of the strong interaction. We analyse the currently available data for B {/d, s 0} → D {/d, s -} D {/d, s +} decays and those with similar dynamics to constrain the involved non-perturbative parameters. Using further information from semileptonic B {/d 0} → D {/d -} ℓ + ν ℓ decays, we perform a test of the factorisation approximation and take non-factorisable SU(3)-breaking corrections into account. The branching ratios of the B {/d 0} → D {/d -} D {/d +}, B {/s 0} → D {/s -} D {/d +} and B {/s 0} → D {/s -} D {/s +}, B {/d 0} → D {/d -} D {/s +} decays show an interesting pattern which can be accommodated through significantly enhanced exchange and penguin annihilation topologies. This feature is also supported by data for the B {/s 0} → D {/d -} D {/d +} channel. Moreover, there are indications of potentially enhanced penguin contributions in the B {/d 0} → D {/d -} D {/d +} and B {/s 0} → D {/s -} D {/s +} decays, which would make it mandatory to control these effects in the future measurements of ϕ d and ϕ s . We discuss scenarios for high-precision measurements in the era of Belle II and the LHCb upgrade.

  18. Interatomic Coulombic decay in a He dimer: Ab initio potential-energy curves and decay widths

    SciTech Connect

    Kolorenc, Premysl; Kryzhevoi, Nikolai V.; Sisourat, Nicolas; Cederbaum, Lorenz S.

    2010-07-15

    The energy gained by either of the two helium atoms in a helium dimer through simultaneous ionization and excitation can be efficiently transferred to the other helium atom, which then ionizes. The respective relaxation process called interatomic Coulombic decay (ICD) is the subject of the present paper. Specifically, we are interested in ICD of the lowest of the ionized excited states, namely, the He{sup +}(n=2)He states, for which we calculated the relevant potential-energy curves and the interatomic decay widths. The full-configuration interaction method was used to obtain the potential-energy curves. The decay widths were computed by utilizing the Fano ansatz, Green's-function methods, and the Stieltjes imaging technique. The behavior of the decay widths with the interatomic distance is examined and is elucidated, whereby special emphasis is given to the asymptotically large interatomic separations. Our calculations show that the electronic ICD processes dominate over the radiative decay mechanisms over a wide range of interatomic distances. The ICD in the helium dimer has recently been measured by Havermeier et al. [Phys. Rev. Lett. 104, 133401 (2010)]. The impact of nuclear dynamics on the ICD process is extremely important and is discussed by Sisourat et al. [Nat. Phys. 6, 508 (2010)] based on the ab initio data computed in the present paper.

  19. Observational consequences of dark energy decay

    NASA Astrophysics Data System (ADS)

    Pen, Ue-Li; Zhang, Pengjie

    2014-03-01

    We consider the generic scenario of dark energy that arises through the latent heat of a hidden sector first-order cosmological phase transition. This field could account for the extra radiation degree of freedom suggested by the CMB. We present the bubble nucleation solution for the viscous limit. The decay rate of the field is constrained by published kSZ data. This model may provide an explanation of current excess ISW correlations. Cross correlation of current and future surveys can further constrain or test the parameter space. The decay model is plausibly in the observable range and avoids anthropic problems. This class of models is not well constrained by the popular dark energy figure of merit.

  20. Symmetry relations in nucleon decay

    NASA Astrophysics Data System (ADS)

    Hurlbert, Anya; Wilczek, Frank

    1980-05-01

    Some experimental consequences of the structure of the effective hamiltonian for nucleon decay are presented. New results concern relations among inclusive decay rates, a striking test of the kinship hypothesis involving μ+ polarization, and soft π theorems.

  1. Renormalization-scale uncertainty in the decay rate of false vacuum

    NASA Astrophysics Data System (ADS)

    Endo, Motoi; Moroi, Takeo; Nojiri, Mihoko M.; Shoji, Yutaro

    2016-01-01

    We study radiative corrections to the decay rate of false vacua, paying particular attention to the renormalization-scale dependence of the decay rate. The decay rate exponentially depends on the bounce action. The bounce action itself is renormalization-scale dependent. To make the decay rate scale-independent, radiative corrections, which are due to the field fluctuations around the bounce, have to be included. We show quantitatively that the inclusion of the fluctuations suppresses the scale dependence, and hence is important for the precise calculation of the decay rate. We also apply our analysis to a supersymmetric model and show that the radiative corrections are important for the Higgs-stau system with charge breaking minima.

  2. Nuclear Properties and Decay Data Chart of Nuclides.

    SciTech Connect

    OSORIO, V. B.

    2008-04-04

    Version 00 NUCHART displays nuclear decay data graphically on a PC and, includes a search routine for assigning gamma-ray energies to radionuclides. The numerical data included in NUCHART were taken from the online database "NUDAT" Version of March 1994. The following information is presented: (1) Nuclide information: for each nuclide, abundance, mass excess, (main) decay mode, half-life and uncertainty, branching ratio, decay Q; (2) decay radiation: for each nuclide, tables of radiation energy, intensity and equivalent dose for the 5 most intense decay radiations of beta+, beta-, conversion electrons, gammas, alphas and x-rays, including electron Augers; (3) adopted gammas: for each nuclide, table containing energy, relative intensity, energy level of the main gamma lines and year of publication in Nuclear Data Sheets; (4) search gamma energies: for a specified interval of gamma energies all know gamma lines and their nuclides are displayed; the database contains 132,000 gamma lines; (5) a search mode by specific nuclide is also available. For the latest data and online tools for viewing the data, see NuDat 2.4 on the NNDC and IAEA NDS websites: http://www.nndc.bnl.gov/ and http://www-nds.iaea.org/.

  3. Theory of weak hypernuclear decay

    SciTech Connect

    Dubach, J.F.; Feldman, G.B.; Holstein, B.R. |; de la Torre, L.

    1996-07-01

    The weak nomesonic decay of {Lambda}-hypernuclei is studied in the context of a one-meson-exchange model. Predictions are made for the decay rate, the {ital p}/{ital n} stimulation ratio and the asymmetry in polarized hypernuclear decay. Copyright {copyright} 1996 Academic Press, Inc.

  4. B Decays Involving Light Mesons

    SciTech Connect

    Eschrich, Ivo Gough; /UC, Irvine

    2007-01-09

    Recent BABAR results for decays of B-mesons to combinations of non-charm mesons are presented. This includes B decays to two vector mesons, B {yields} {eta}{prime}({pi}, K, {rho}) modes, and a comprehensive Dalitz Plot analysis of B {yields} KKK decays.

  5. Interatomic Coulombic Decay of HeNe dimers after ionization and excitation of He and Ne

    NASA Astrophysics Data System (ADS)

    Sann, H.; Havermeier, T.; Kim, H.-K.; Sturm, F.; Trinter, F.; Waitz, M.; Zeller, S.; Ulrich, B.; Meckel, M.; Voss, S.; Bauer, T.; Schneider, D.; Schmidt-Böcking, H.; Wallauer, R.; Schöffler, M.; Williams, J. B.; Dörner, R.; Jahnke, T.

    2017-01-01

    We study the decay of a helium/neon dimer after ionization and simultaneous excitation of either the neon or the helium atom using Cold Target Recoil Ion Momentum Spectroscopy (COLTRIMS). We find that, depending on the decaying state, either direct Interatomic Coulombic Decay (ICD) (i.e. mediated by a virtual photon exchange), exchange ICD (mediated by electron exchange) or radiative charge transfer occurs. The corresponding channels are identified.

  6. Rare top quark decays in Alternative Left-Right Symmetric Models

    SciTech Connect

    Gaitan, R.; Miranda, O. G.; Cabral-Rosetti, L. G.

    2007-06-19

    We evaluate the flavor changing neutral currents (FCNC) decay t {yields} H0 + c in the context of Alternative Left-Right symmetric Models (ALRM) with extra isosinglet heavy fermions; the FCNC decays may place at tree level and are only supressed by the mixing between ordinary top and charm quarks. We also comment on the decay process t {yields} c + {gamma}, which involves radiative corrections.

  7. Preliminary Therapy Evaluation of 225Ac-DOTA-c(RGDyK) Demonstrates that Cerenkov Radiation Derived from 225Ac Daughter Decay Can Be Detected by Optical Imaging for In Vivo Tumor Visualization

    PubMed Central

    Pandya, Darpan N.; Hantgan, Roy; Budzevich, Mikalai M.; Kock, Nancy D.; Morse, David L.; Batista, Izadora; Mintz, Akiva; Li, King C.; Wadas, Thaddeus J.

    2016-01-01

    The theranostic potential of 225Ac-based radiopharmaceuticals continues to increase as researchers seek innovative ways to harness the nuclear decay of this radioisotope for therapeutic and imaging applications. This communication describes the evaluation of 225Ac-DOTA-c(RGDyK) in both biodistribution and Cerenkov luminescence imaging (CLI) studies. Initially, La-DOTA-c(RGDyK) was prepared as a non-radioactive surrogate to evaluate methodologies that would contribute to an optimized radiochemical synthetic strategy and estimate the radioactive conjugate's affinity for αvβ3, using surface plasmon resonance spectroscopy. Surface plasmon resonance spectroscopy studies revealed the IC50 and Ki of La-DOTA-c(RGDyK) to be 33 ± 13 nM and 26 ± 11 nM, respectively, and suggest that the complexation of the La3+ ion to the conjugate did not significantly alter integrin binding. Furthermore, use of this surrogate allowed optimization of radiochemical synthesis strategies to prepare 225Ac-DOTA-c(RGDyK) with high radiochemical purity and specific activity similar to other 225Ac-based radiopharmaceuticals. This radiopharmaceutical was highly stable in vitro. In vivo biodistribution studies confirmed the radiotracer's ability to target αvβ3 integrin with specificity; specificity was detected in tumor-bearing animals using Cerenkov luminescence imaging. Furthermore, tumor growth control was achieved using non-toxic doses of the radiopharmaceutical in U87mg tumor-bearing nude mice. To our knowledge, this is the first report to describe the CLI of αvβ3+ tumors in live animals using the daughter products derived from 225Ac decay in situ. This concept holds promise to further enhance development of targeted alpha particle therapy. PMID:27022417

  8. Superallowed Fermi beta decay

    SciTech Connect

    Hardy, J. C.; Towner, I. S.

    1998-12-21

    Superallowed 0{sup +}{yields}0{sup +} nuclear beta decay provides a direct measure of the weak vector coupling constant, G{sub V}. We survey current world data on the nine accurately determined transitions of this type, which range from the decay of {sup 10}C to that of {sup 54}Co, and demonstrate that the results confirm conservation of the weak vector current (CVC) but differ at the 98% confidence level from the unitarity condition for the Cabibbo-Kobayashi-Maskawa (CKM) matrix. We examine the reliability of the small calculated corrections that have been applied to the data, and assess the likelihood of even higher quality nuclear data becoming available to confirm or deny the discrepancy. Some of the required experiments depend upon the availability of intense radioactive beams. Others are possible today.

  9. Decay Dynamics of Tumors

    PubMed Central

    2016-01-01

    The fractional cell kill is a mathematical expression describing the rate at which a certain population of cells is reduced to a fraction of itself. We investigate the mathematical function that governs the rate at which a solid tumor is lysed by a cell population of cytotoxic lymphocytes. We do it in the context of enzyme kinetics, using geometrical and analytical arguments. We derive the equations governing the decay of a tumor in the limit in which it is plainly surrounded by immune cells. A cellular automaton is used to test such decay, confirming its validity. Finally, we introduce a modification in the fractional cell kill so that the expected dynamics is attained in the mentioned limit. We also discuss the potential of this new function for non-solid and solid tumors which are infiltrated with lymphocytes. PMID:27310010

  10. Project 8 Phase II: Improved beta decay electrons reconstruction

    NASA Astrophysics Data System (ADS)

    Guigue, Mathieu; Project 8 Collaboration

    2017-01-01

    The Project 8 collaboration aims to measure the absolute neutrino mass scale using a cyclotron radiation emission spectroscopy technique on the beta decays of tritium. The second phase of the project will measure a differential spectrum of tritium beta decays and extract the tritium endpoint value with an eV or sub-eV scale precision. Monoenergetic electrons emitted by gaseous 83mKr atoms can be used to determine the coefficient between the cyclotron frequency and the electron energy and to optimize the instrument configuration for the tritium measurement. We present the progress on the processing of the electron cyclotron radiation signal to reconstruct the beta decay spectrum of krypton and tritium.

  11. Complex decay patterns in atomic core photoionization disentangled by ion-recoil measurements

    SciTech Connect

    Guillemin, Renaud; Bomme, Cedric; Marin, Thierry; Journel, Loic; Marchenko, Tatiana; Kushawaha, Rajesh K.; Piancastelli, Maria Novella; Simon, Marc; Trcera, Nicolas

    2011-12-15

    Following core 1s ionization and resonant excitation of argon atoms, we measure the recoil energy of the ions due to momentum conservation during the emission of Auger electrons. We show that such ion momentum spectroscopy can be used to disentangle to some degree complex decay patterns, involving both radiative and nonradiative decays.

  12. New studies of allowed pion and muon decays

    NASA Astrophysics Data System (ADS)

    Počanić, D.; Palladino, A.; Alonzi, L. P.; Baranov, V. A.; Bertl, W.; Bychkov, M.; Bystritsky, Yu. M.; Frlež, E.; Kalinnikov, V. A.; Khomutov, N. V.; Korenchenko, A. S.; Korenchenko, S. M.; Korolija, M.; Kozlowski, T.; Kravchuk, N. P.; Kuchinsky, N. A.; Lehman, M. C.; Mekterović, D.; Munyangabe, E.; Mzhavia, D.; Robmann, P.; Rozhdestvensky, A. M.; Shkarovskiy, S. N.; Straumann, U.; Supek, I.; Truöl, P.; Tsamalaidze, Z.; van der Schaaf, A.; Velicheva, E. P.; Volnykh, V. P.

    2013-10-01

    Building on the rare pion and muon decay results of the PIBETA experiment, the PEN collaboration has undertaken a precise measurement of Bπe2≡Re/μπ, the π+ → e+ν(γ) decay branching ratio, at the Paul Scherrer Institute, to reduce the present 40× experimental precision lag behind theory to ˜6 - 7×. Because of large helicity suppression, Re/μπ is uniquely sensitive to contributions from non-(V - A) physics, making this decay a particularly suitable subject of study. Even at current precision, the experimental value of Bπe2 provides the most accurate test of lepton universality available. During runs in 2008-10, PEN has accumulated over 2 × 107 πe2 events; a comprehensive maximum-likelihood analysis is currently under way. The new data will also lead to improved precision of the earlier PIBETA results on radiative π and μ decays.

  13. Charmless b decays at CDF

    SciTech Connect

    Donega, Mauro; /Geneva U.

    2005-07-01

    The authors report on the charmless B decays measurements performed on 180 pb{sup -1} of data collected with the CDF II detector at the Fermilab Tevatron collider. This paper describes: the first observation of the decay mode B{sub s} {yields} K{sup +}K{sup -} and the measurement of the direct Cp asymmetry in the ({bar B}){sub d} {yields} K{sup {+-}}{pi}{sup {-+}} decay; the first evidence of the decay mode B{sub s} {yields} {phi}{phi} and the branching ratio and Cp asymmetry for the B{sup {+-}} {yields} {phi}K{sup {+-}} decay.

  14. Non-exponential and oscillatory decays in quantum mechanics

    SciTech Connect

    Peshkin, Murray; Volya, Alexander; Zelevinsky, Vladimir

    2014-08-07

    The quantum-mechanical theory of the decay of unstable states is revisited. We show that the decay is non-exponential both in the short-time and long-time limits using a more physical definition of the decay rate than the one usually used. We report results of numerical studies based on Winter's model that may elucidate qualitative features of exponential and non-exponential decay more generally. The main exponential stage is related to the formation of a radiating state that maintains the shape of its wave function with exponentially diminishing normalization. We discuss situations where the radioactive decay displays several exponents. The transient stages between different regimes are typically accompanied by interference of various contributions and resulting oscillations in the decay curve. The decay curve can be fully oscillatory in a two-flavor generalization of Winter's model with some values of the parameters. We consider the implications of that result for models of the oscillations reported by GSI.

  15. Radiative and Electroweak Penguins at Belle

    NASA Astrophysics Data System (ADS)

    Hyun, HyoJung

    2010-02-01

    Radiative and electroweak penguin decays of B mesons are a sensitive probe of new physics beyond the Standard Model. We study the inclusive and exclusive radiative and electroweak penguin decays of B meson and also search an exotic particle seen by the HyperCP experiment. The measurements are based on a large data sample of 605 fb-1 containing 657 millions BB¯ pairs collected at the Υ(4S) with the Belle detector at the KEKB energy asymmetric e+e- collider.

  16. Is radioactive decay really exponential?

    NASA Astrophysics Data System (ADS)

    Aston, P. J.

    2012-03-01

    Radioactive decay of an unstable isotope is widely believed to be exponential. This view is supported by experiments on rapidly decaying isotopes but is more difficult to verify for slowly decaying isotopes. The decay of 14C can be calibrated over a period of 12550 years by comparing radiocarbon dates with dates obtained from dendrochronology. It is well known that this approach shows that radiocarbon dates of over 3000 years are in error, which is generally attributed to past variation in atmospheric levels of 14C. We note that predicted atmospheric variation (assuming exponential decay) does not agree with results from modelling, and that theoretical quantum mechanics does not predict exact exponential decay. We give mathematical arguments that non-exponential decay should be expected for slowly decaying isotopes and explore the consequences of non-exponential decay. We propose an experimental test of this prediction of non-exponential decay for 14C. If confirmed, a foundation stone of current dating methods will have been removed, requiring a radical reappraisal both of radioisotope dating methods and of currently predicted dates obtained using these methods.

  17. E6 Gamma Decay

    SciTech Connect

    Brown, B. Alex; Rae, W. D. M.

    2011-05-06

    Rare electric hexacontatetrapole (E6) transitions are studied in the full (f{sub 7/2},f{sub 5/2},p{sub 3/2},p{sub 1/2}) shell-model basis. Comparison of theory to the results from the gamma decay in {sup 53}Fe and from inelastic electron scattering on {sup 52}Cr provides unique and interesting tests of the valence wavefunctions, the models used for energy density functionals and into the origin of effective charge.

  18. Rare B Decays

    SciTech Connect

    Jackson, P.D.; /Victoria U.

    2006-02-24

    Recent results from Belle and BaBar on rare B decays involving flavor-changing neutral currents or purely leptonic final states are presented. Measurements of the CP asymmetries in B {yields} K*{gamma} and b {yields} s{gamma} are reported. Also reported are updated limits on B{sup +} {yields} K{sup +}{nu}{bar {nu}}, B{sup +} {yields} {tau}{sup +}{nu}, B{sup +} {yields} {mu}{sup +}{nu} and the recent measurement of B {yields} X{sub s}{ell}{sup +}{ell}{sup -}.

  19. Rare decays and CP asymmetries in charged B decays

    SciTech Connect

    Deshpande, N.G.

    1991-01-01

    The theory of loop induced rare decays and the rate asymmetry due to CP violation in charged B Decays in reviewed. After considering b {yields} s{gamma} and b {yields} se{sup +}e{sup {minus}} decays, the asymmetries for pure penguin process are estimated first. A larger asymmetry can result in those modes where a tree diagram and a penguin diagram interfere, however these estimates are necessarily model dependent. Estimates of Cabbibo suppressed penguins are also considered.

  20. Wood decay at sea

    NASA Astrophysics Data System (ADS)

    Charles, François; Coston-Guarini, Jennifer; Guarini, Jean-Marc; Fanfard, Sandrine

    2016-08-01

    The oceans and seas receive coarse woody debris since the Devonian, but the kinetics of wood degradation remains one of many unanswered questions about the fate of driftwood in the marine environment. A simple gravimetric experiment was carried out at a monitoring station located at the exit of a steep, forested Mediterranean watershed in the Eastern Pyrenees. The objective was to describe and quantify, with standardized logs (in shape, structure and constitution), natural degradation of wood in the sea. Results show that the mass decrease of wood logs over time can be described by a sigmoidal curve. The primary process of wood decay observed at the monitoring station was due to the arrival and installation of wood-boring species that consumed more than half of the total wood mass in six months. Surprisingly, in a region where there is little remaining wood marine infrastructure, "shipworms", i.e. xylophagous bivalves, are responsible for an important part of this wood decay. This suggests that these communities are maintained probably by a frequent supply of a large quantity of riparian wood entering the marine environment adjacent to the watershed. By exploring this direct link between terrestrial and marine ecosystems, our long term objective is to determine how these supplies of terrestrial organic carbon can sustain wood-based marine communities as it is observed in the Mediterranean Sea.

  1. Constraining decaying dark matter with Fermi LAT gamma-rays

    SciTech Connect

    Zhang, Le; Sigl, Günter; Weniger, Christoph; Maccione, Luca; Redondo, Javier E-mail: christoph.weniger@desy.de E-mail: redondo@mppmm.mpg.de

    2010-06-01

    High energy electrons and positrons from decaying dark matter can produce a significant flux of gamma rays by inverse Compton off low energy photons in the interstellar radiation field. This possibility is inevitably related with the dark matter interpretation of the observed PAMELA and FERMI excesses. The aim of this paper is providing a simple and universal method to constrain dark matter models which produce electrons and positrons in their decay by using the Fermi LAT gamma-ray observations in the energy range between 0.5 GeV and 300 GeV. We provide a set of universal response functions that, once convolved with a specific dark matter model produce the desired constraints. Our response functions contain all the astrophysical inputs such as the electron propagation in the galaxy, the dark matter profile, the gamma-ray fluxes of known origin, and the Fermi LAT data. We study the uncertainties in the determination of the response functions and apply them to place constraints on some specific dark matter decay models that can well fit the positron and electron fluxes observed by PAMELA and Fermi LAT. To this end we also take into account prompt radiation from the dark matter decay. We find that with the available data decaying dark matter cannot be excluded as source of the PAMELA positron excess.

  2. Rare B Decays at Babar

    SciTech Connect

    Palombo, Fernando; Collaboration, for the BABAR

    2009-01-12

    The author presents some of the most recent BABAR measurements for rare B decays. These include rate asymmetries in the B decays to K{sup (*)}l{sup +}l{sup -} and K{sup +}{pi}{sup -} and branching fractions in the B decays to l{sup +}{nu}{sub l}, K{sub 1}(1270){sup +}{pi}{sup -} and K{sub 1}(1400){sup +}{pi}{sup -}. The author also reports a search for the B{sup +} decay to K{sub S}{sup 0}K{sub S}{sup 0}{pi}{sup +}.

  3. Adriatic seiche decay and energy loss to the Mediterranean

    NASA Astrophysics Data System (ADS)

    Cerovečki, Ivana; Orlić, Mirko; Hendershott, Myrl C.

    1997-12-01

    A salient feature of sea level records from the Adriatic Sea is the frequent occurrence of energetic seiches of period about 21 h. Once excited by a sudden wind event, such seiches often persist for days. They lose energy either to friction within the Adriatic, or by radiation through Otranto Strait into the Mediterranean. The free decay time of the dominant (lowest mode) seiche was determined from envelopes of handpassed sea level residuals from three locations (Bakar, Split and Dubrovnik) along the Croatian coast during twelve seiche episodes between 1963 and 1986 by taking into consideration only time intervals when the envelopes decreased exponentially in time, when the modelled effects of along-basin winds were smaller than the error of estimation of decay time from the envelopes and when across-basin winds were small. The free decay time thus obtained was 3.2±0.5 d. This value is consonant with the observed width of the spectral peak. The decay caused by both bottom friction and radiation was included in a one dimensional variable cross section shallow water model of the Adriatic. Bottom friction is parameterized by the coefficient k appearing in the linearized bottom stress term ρ0u (where u is the along-basin velocity and ρ0 the fluid density). The coefficient k is constrained by values obtained from linearization of the quadratic bottom stress law using estimates of near bottom currents associated with the seiche, with wind driven currents, with tides and with wind waves. Radiation is parameterized by the coefficient f appearing in the open strait boundary condition ζ = auh/ c (where ζ is sea level, h is depth and c is phase speed). This parameterization of radiation provides results comparable to allowing the Adriatic to radiate into an unbounded half plane ocean. Repeated runs of the model delineate the dependence of model free seiche decay time on k and a, and these plus the estimates of k allow estimation of a. The principle conclusions of this

  4. Radiation Effects on the Sorption and Mobilization of Radionuclide during Transport through the Geosphere

    SciTech Connect

    L.M. Wang; R.C. Eqing; K.F. Hayes

    2004-03-14

    Site restoration activities at DOE facilities and the permanent disposal of nuclear waste inevitably involve understanding the behavior of materials in a radiation field. Radionuclide decay and the associated radiation fields lead to physical and chemical changes that can degrade or enhance important material properties. Alpha-decay of the actinide elements and beta-decay of the fission products lead to atomic-scale changes in materials (radiation damage and transmutation).

  5. Gravitino decay and the cosmic gamma-ray background

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1986-01-01

    It is argued that the cosmic gamma-ray background (CGB) spectrum does not exhibit evidence for the decay of light gravitinos, in contradiction to the suggestion by Olive and Silk (1985), who observed a bump near 1 MeV in the CGB radiation spectrum. It is suggested that better fits to the CGB spectrum would be provided by mechanisms generating a power-law spectrum which is flattened below about 2 MeV. Olive and Silk maintain that the decays of a long-lived particle such as the gravitino may be responsible for features in the gamma-ray spectrum near 1 MeV.

  6. Effects of vacuum fluctuation suppression on atomic decay rates

    SciTech Connect

    Ford, L.H.; Roman, Thomas A.

    2011-08-15

    Highlights: > Excited atoms are shot through a cavity containing an electromagnetic field. > Cavity is in the lowest mode in a non-classical state. > Such a state can suppress the decay rate of the atoms in certain situations. > We show that this effect can be correlated with periods of negative energy density. - Abstract: The use of atomic decay rates as a probe of sub-vacuum phenomena will be studied. Because electromagnetic vacuum fluctuations are essential for radiative decay of excited atomic states, decay rates can serve as a measure of the suppression of vacuum fluctuations in non-classical states, such as squeezed vacua. In such states, the renormalized expectation value of the square of the electric field or the energy density can be periodically negative, representing suppression of vacuum fluctuations. We explore the extent to which atomic decays can be used to measure the mean squared electric field or energy density. We consider a scheme in which atoms in an excited state transit a closed cavity whose lowest mode contains photons in a non-classical state. A crucial feature of our analysis is that we do not employ the rotating wave approximation. The change in the decay probability of the atom in the cavity due to the non-classical state can, under certain circumstances, serve as a measure of the mean squared electric field or energy density in the cavity. We make some estimates of the magnitude of this effect, which indicate that an experimental test might be possible, although very challenging.

  7. Accelerated Decay of Radioisotopes

    DTIC Science & Technology

    2013-01-01

    00-01 -2013 Technical June20 l l-June 2012 4 . TITLE AND SUBTITLE Sa. CONTRACT NUMBER DTRA MIPR 11-2362M Accelerated Decay of Radioisotopes Sb...268 x E +2 4.788 026 x E -2 6.894 757 4.535 924 x E -1 4.214 011 x E -2 1.601 846 x E +1 1.000 000 x E -2 2.579 760 x E - 4 1.000 000 x E -8...c a y o f R a d i o i s o t o p e s " P r o p o s a l # B R C A L L 0 7 - N - 2 - 0 0 4 7 I l l u s t r a t i o n o f \\ P F R P a s p o

  8. Neutrinoless Double Beta Decay

    NASA Astrophysics Data System (ADS)

    Fiorini, Ettore

    2007-06-01

    The recent results showing the presence of neutrino oscillations clearly indicate that the difference between the squared mass of neutrinos of different flavors is different from zero, but are unable to determine the nature and the absolute value of the neutrino mass. Neutrinoless double beta decay (DBD) is at present the most powerful tool to ascertain if the neutrino is a Majorana particle and to determine under this condition the absolute value of its mass. The results already obtained in this lepton violating process will be reported and the two presently running DBD experiments briefly discussed. The future second generation experiments will be reviewed with special emphasis to those already partially approved. In conclusion the peculiar and interdisciplinary nature of these searches will be stressed in their exciting aim to discover if neutrino is Dirac or Majorana particle.

  9. Double beta decay: Calorimeters

    NASA Astrophysics Data System (ADS)

    Brofferio, Chiara

    2008-11-01

    Calorimeters or, with a more specific definition, low temperature detectors, have been used by now for more than 15 years in Double Beta Decay (DBD) searches, with excellent results: they compete with Ge diodes for the rank of detectors with the highest sensitivity to the effective neutrino mass, which is defined as a linear combination of the neutrino mass eigenvalues. After a brief introduction to the argument, with some notes on DBD and on bolometers, an update on the now closed experiment CUORICINO and on its successor, CUORE, is given. The fundamental role of background is then revealed and commented, introducing in this way the importance of the specific experiment now under construction, CUORE-0, that will precede CUORE to help optimizing the struggle against surface background. The possible future of this technique is then commented, quoting important R&D studies that are going on, for active shielding bolometers and for scintillating bolometers coupled with light detecting bolometers.

  10. Decay of oscillating universes

    NASA Astrophysics Data System (ADS)

    Mithani, Audrey Todhunter

    2016-08-01

    It has been suggested by Ellis et al that the universe could be eternal in the past, without beginning. In their model, the "emergent universe'' exists forever in the past, in an "eternal'' phase before inflation begins. We will show that in general, such an "eternal'' phase is not possible, because of an instability due to quantum tunneling. One candidate model, the "simple harmonic universe'' has been shown by Graham et al to be perturbatively stable; we find that it is unstable with respect to quantum tunneling. We also investigate the stability of a distinct oscillating model in loop quantum cosmology with respect to small perturbations and to quantum collapse. We find that the model has perturbatively stable and unstable solutions, with both types of solutions occupying significant regions of the parameter space. All solutions are unstable with respect to collapse by quantum tunneling to zero size. In addition, we investigate the effect of vacuum corrections, due to the trace anomaly and the Casimir effect, on the stability of an oscillating universe with respect to decay by tunneling to the singularity. We find that these corrections do not generally stabilize an oscillating universe. Finally, we determine the decay rate of the oscillating universe. Although the wave function of the universe lacks explicit time dependence in canonical quantum cosmology, time evolution may be present implicitly through the semiclassical superspace variables, which themselves depend on time in classical dynamics. Here, we apply this approach to the simple harmonic universe, by extending the model to include a massless, minimally coupled scalar field φ which has little effect on the dynamics but can play the role of a "clock''.

  11. Soudan 2 nucleon decay experiment

    SciTech Connect

    Thron, J.L.

    1986-01-01

    The Soudan 2 nucleon decay experiment consists of a 1.1 Kton fine grained iron tracking calorimeter. It has a very isotropic detection structure which along with its flexible trigger will allow detection of multiparticle and neutrino proton decay modes. The detector has now entered its construction stage.

  12. Theoretical understanding of charm decays

    SciTech Connect

    Bigi, I.I.

    1986-08-01

    A detailed description of charm decays has emerged. The various concepts involved are sketched. Although this description is quite successful in reproducing the data the chapter on heavy flavour decays is far from closed. Relevant questions like on th real strength of weak annihilation, Penguin operators, etc. are still unanswered. Important directions in future work, both on the experimental and theoretical side are identified.

  13. Charm and bottom semileptonic decays

    NASA Astrophysics Data System (ADS)

    O'donnell, Patrick J.; Turan, Gürsevil

    1997-07-01

    We review the present status of theoretical attempts to calculate the semileptonic charm and bottom decays and then present a calculation of these decays in the light-front frame at the kinematic point q2=0. This allows us to evaluate the form factors at the same value of q2, even though the allowed kinematic ranges for charm and bottom decays are very different. Also, at this kinematic point the decay is given in terms of only one form factor A0(0). For the ratio of the decay rates given by the E653 collaboration we show that the determination of the ratio of the Cabibbo-Kobayashi-Maskawa matrix elements is consistent with that obtained from the unitarity constraint, though a new measurement by the E687 Collaboration is about two standard deviations too high. At present, though, the unitarity method still has greater accuracy. Since comparisons of the semileptonic decays into ρ and either electrons or muons will be available soon from the E791 Fermilab experiment, we also look at the massive muon case. We show that for a range of q2 the SU(3)F symmetry breaking is small even though the contributions of the various helicity amplitudes becomes more complicated. For B decays, the decay B-->K*ll¯ at q2=0 involves an extra form factor coming from the photon contribution and so is not amenable to the same kind of analysis, leaving only the decay B-->K*νν¯ as a possibility. As the mass of the decaying particle increases we note that the SU(3) symmetry becomes badly broken at q2=0.

  14. Radiation dosimetry.

    PubMed Central

    Cameron, J

    1991-01-01

    This article summarizes the basic facts about the measurement of ionizing radiation, usually referred to as radiation dosimetry. The article defines the common radiation quantities and units; gives typical levels of natural radiation and medical exposures; and describes the most important biological effects of radiation and the methods used to measure radiation. Finally, a proposal is made for a new radiation risk unit to make radiation risks more understandable to nonspecialists. PMID:2040250

  15. Decay of negative muons bound in {sup 27}Al

    SciTech Connect

    Grossheim, A.; Bayes, R.; Faszer, W.; Fujiwara, M. C.; Gill, D. R.; Gumplinger, P.; Henderson, R. S.; Hillairet, A.; Hu, J.; Marshall, G. M.; Mischke, R. E.; Olchanski, K.; Olin, A.; Openshaw, R.; Poutissou, J.-M.; Poutissou, R.; Sheffer, G.; Shin, B.; Bueno, J. F.; Hasinoff, M. D.

    2009-09-01

    We present the first measurement of the energy spectrum up to 70 MeV of electrons from the decay of negative muons after they become bound in {sup 27}Al atoms. The data were taken with the TWIST apparatus at TRIUMF. We find a muon lifetime of (864.6{+-}1.2) ns, in agreement with earlier measurements. The asymmetry of the decay spectrum is consistent with zero, indicating that the atomic capture has completely depolarized the muons. The measured momentum spectrum is in reasonable agreement with theoretical predictions at the higher energies, but differences around the peak of the spectrum indicate the need for O({alpha}) radiative corrections to the calculations. The present measurement is the most precise measurement of the decay spectrum of muons bound to any nucleus.

  16. Decays of heavy vector mesons in the quark confinement model

    NASA Astrophysics Data System (ADS)

    Ivanov, M. A.; Valit, Yu. M.

    1995-12-01

    We analyze the radiative and hadronic decays of vector heavy mesons within the relativistic quark model with confined light quarks. The only adjustable parameters in this approach are the values of constituent masses of heavy quarks ( M c and M b). We adjust them using the available experimental data from CLEO and ARGUS-collaborations for the D *→ Dγ and D *→ Dπ branching ratios. It is found that the value of M c varies approximately in the interval 1.3 GeV< M c<1.65 GeV. We give the predictions for the absolute values of decay widths and compare our results with those obtained in other approaches. Also we consider the heavy quark limit M Q→∞ with E=M H-MQ=const for the decay amplitudes.

  17. Measurements of the Decay KL→e+e-μ+μ-

    NASA Astrophysics Data System (ADS)

    Alavi-Harati, A.; Alexopoulos, T.; Arenton, M.; Arisaka, K.; Barbosa, R. F.; Barker, A. R.; Barrio, M.; Bellantoni, L.; Bellavance, A.; Blucher, E.; Bock, G. J.; Bown, C.; Bright, S.; Cheu, E.; Coleman, R.; Corcoran, M. D.; Cox, B.; Erwin, A. R.; Escobar, C. O.; Ford, R.; Glazov, A.; Golossanov, A.; Gouffon, P.; Graham, J.; Hamm, J.; Hanagaki, K.; Hsiung, Y. B.; Huang, H.; Jejer, V.; Jensen, D. A.; Kessler, R.; Kobrak, H. G.; Kotera, K.; Ladue, J.; Lai, N.; Ledovskoy, A.; McBride, P. L.; Monnier, E.; Nelson, K. S.; Nguyen, H.; Prasad, V.; Qi, X. R.; Quinn, B.; Ramberg, E. J.; Ray, R. E.; Santos, E.; Senyo, K.; Shanahan, P.; Shields, J.; Slater, W.; Solomey, N.; Swallow, E. C.; Taegar, S. A.; Tesarek, R. J.; Toale, P. A.; Tripathi, A.; Tschirhart, R.; Wah, Y. W.; Wang, J.; White, H. B.; Whitmore, J.; Wilking, M.; Winstein, B.; Winston, R.; Worcester, E. T.; Yamanaka, T.; Zukanovich, R. F.

    2003-04-01

    The KTeV experiment at Fermilab has isolated a total of 132events from the rare decay KL→e+e-μ+μ- , with an estimated background of 0.8events. The branching ratio of this mode is determined to be [2.69±0.24(stat)±0.12(syst)]×10-9, with a radiative cutoff of M2eeμμ /M2K>0.95. The first measurement using this mode of the parameter α from the D’Ambrosio-Isidori-Portolès (DIP) model of the KLγ*γ* vertex yields a result of -1.59±0.37, consistent with values obtained from other decay modes. Because of the limited statistics, no sensitivity is found to the DIP parameter β. We use this decay mode to set limits on CP and lepton violation.

  18. Measurements of the Decay KL-->e+ e- mu+ mu-.

    PubMed

    Alavi-Harati, A; Alexopoulos, T; Arenton, M; Arisaka, K; Barbosa, R F; Barker, A R; Barrio, M; Bellantoni, L; Bellavance, A; Blucher, E; Bock, G J; Bown, C; Bright, S; Cheu, E; Coleman, R; Corcoran, M D; Cox, B; Erwin, A R; Escobar, C O; Ford, R; Glazov, A; Golossanov, A; Gouffon, P; Graham, J; Hamm, J; Hanagaki, K; Hsiung, Y B; Huang, H; Jejer, V; Jensen, D A; Kessler, R; Kobrak, H G E; Kotera, K; LaDue, J; Lai, N; Ledovskoy, A; McBride, P L; Monnier, E; Nelson, K S; Nguyen, H; Prasad, V; Qi, X R; Quinn, B; Ramberg, E J; Ray, R E; Santos, E; Senyo, K; Shanahan, P; Shields, J; Slater, W; Solomey, N; Swallow, E C; Taegar, S A; Tesarek, R J; Toale, P A; Tripathi, A; Tschirhart, R; Wah, Y W; Wang, J; White, H B; Whitmore, J; Wilking, M; Winstein, B; Winston, R; Worcester, E T; Yamanaka, T; Zukanovich, R F

    2003-04-11

    The KTeV experiment at Fermilab has isolated a total of 132 events from the rare decay K(L)-->e+ e- mu+ mu-, with an estimated background of 0.8 events. The branching ratio of this mode is determined to be [2.69+/-0.24(stat)+/-0.12(syst)]x10(-9), with a radiative cutoff of M(2)(ee mu mu)/M(2)(K)>0.95. The first measurement using this mode of the parameter alpha from the D'Ambrosio-Isidori-Portolès (DIP) model of the K(L)gamma*gamma* vertex yields a result of -1.59+/-0.37, consistent with values obtained from other decay modes. Because of the limited statistics, no sensitivity is found to the DIP parameter beta. We use this decay mode to set limits on CP and lepton violation.

  19. Non-exponential decay of dark localized surface plasmons.

    PubMed

    Ginzburg, Pavel; Zayats, Anatoly V

    2012-03-12

    It is shown that the decay of the weakly coupled to radiation (dark) modes of subwavelength plasmonic nanostructures is strongly nonexponential. Their lifetime is overestimated by conventional exponential relaxation time obtained in the standard Markovian approximation. These effects are manifestations of the strong dispersion and near-field feedback. The developed theoretical framework introduces an ensemble of local relaxation degrees of freedom coupled to plasmonic mode in order to describe its decay due to material losses. The macroscopic description of the decay process leads to the specific memory function of the system, evaluated from the modal and material dispersions of the plasmonic nanostructure. Proper knowledge of the relaxation behavior is vital for various applications relying on light-matter interactions of emitters with nanoscale objects, such as fluorescence manipulation, bio-imaging, sensing, spasers, sub-diffraction optics, Raman scattering, and quantum optics.

  20. Semileptonic and leptonic B decays, circa 2016

    NASA Astrophysics Data System (ADS)

    Ricciardi, Giulia

    2017-02-01

    We summarize the status of semileptonic and leptonic B decays, including |Vcb| and |Vub| exclusive and inclusive determinations, decays to excited states of the charm meson spectrum and decays into τ leptons.

  1. Primordial nucleosynthesis with decaying particles. I - Entropy-producing decays. II - Inert decays

    NASA Technical Reports Server (NTRS)

    Scherrer, Robert J.; Turner, Michael S.

    1988-01-01

    The effect of a nonrelativistic particle X, which decays out of equilibrium, on primordial nucleosynthesis is investigated, including both the energy density of the X particle and the electromagnetic entropy production from its decay. The results are parametrized in terms of the X particle lifetime and the density parameter rm(X), where m(X) is the X particle mass and r is the ratio of X number density to photon number density prior to nucleosynthesis. The results rule out particle lifetimes greater than 1-10 s for large values of rm(X). The question of a decaying particle which produces no electromagnetic entropy in the course of its decay is addressed, and particles which produce both entropy and an inert component in their decay are discussed.

  2. Double Beta Decay

    NASA Astrophysics Data System (ADS)

    Fiorini, Ettore

    2010-12-01

    Almost exactly seventy years ago and only one year before his tragic disappearance the ingenious idea of Ettore Majorana is becoming one of the most important step in the development of fundamental physics. The problem of the nature of the neutrino, namely if it is a massless Dirac particle different from its antineutrino or a Majorana particle with finite mass, is discussed. In fact the recent results showing the presence of neutrino oscillations clearly indicates that the difference between the squared mass of neutrinos of different flavours is finite. Neutrinoless double beta decay (DBD) is at present the most powerful tool to determine the effective value of the mass of a Majorana neutrino. The results already obtained in this lepton violating process will be reported and the two presently running DBD experiments briefly discussed. The future second generation experiments will be reviewed with special emphasis to those already at least partially approved. In conclusion the peculiar and interdisciplinary nature of these searches will be stressed in their exciting aim to discover if neutrino is indeed a Majorana particle.

  3. Decay of Solar Active Regions

    NASA Technical Reports Server (NTRS)

    Hathaway, David H.; Choudhary, Debi Prasad

    2005-01-01

    We examine the record of sunspot group areas observed over a period of 100 years to determine the rate of decay of solar active regions. We exclude observations of groups when they are more than 60deg in longitude from the central meridian and only include data when at least three days of observations are available following the date of maximum area for a spot group's disk passage. This leaves data for some 24,000 observations of active region decay. We find that the decay rate is a constant 20 microHem/day for spots smaller than about 200 microHem (about the size of a supergranule). This decay rate increases linearly to about 90 microHem/day for spots with areas of 1000 microHem. We find no evidence for significant variations in active region decay from one solar cycle to another. However, we do find that the decay rate is slower at lower latitudes. This gives a slower decay rate during the declining phase of sunspot cycles.

  4. Nonleptonic Bc→VV decays

    NASA Astrophysics Data System (ADS)

    Kar, Susmita; Dash, P. C.; Priyadarsini, M.; Naimuddin, Sk.; Barik, N.

    2013-11-01

    We study the exclusive nonleptonic Bc→VV decays, within the factorization approximation, in the framework of the relativistic independent quark model, based on a confining potential in the scalar-vector harmonic form. The weak form factors are extracted from the overlap integral of meson wave functions derived in the relativistic independent quark model. The predicted branching ratios for different Bc-meson decays are obtained in a wide range, from a tiny value of O(10-6) for Bc→D*D(s)* to a large value of 24.32% for Bc→Bs*ρ-, in general agreement with other dynamical-quark-model predictions. The decay modes Bc→Bs*ρ- and Bc→B*ρ- with high branching ratios of 24.32% and 1.73%, respectively, obtained in this model should be detectable at the LHC and Tevatron in the near future. The b→c, u induced decays are predicted predominantly in the longitudinal mode, whereas the c¯→s¯, d¯ induced decays are obtained in a slightly higher transverse mode. The CP-odd fractions (R⊥) for different decay modes are predicted and those for color-favored Bc→D*D*, D*Ds* decays indicate significant CP violation in this sector.

  5. Virus decay and its causes in coastal waters.

    PubMed

    Noble, R T; Fuhrman, J A

    1997-01-01

    Recent evidence suggests that viruses play an influential role within the marine microbial food web. To understand this role, it is important to determine rates and mechanisms of virus removal and degradation. We used plaque assays to examine the decay of infectivity in lab-grown viruses seeded into natural seawater. The rates of loss of infectivity of native viruses from Santa Monica Bay and of nonnative viruses from the North Sea in the coastal seawater of Santa Monica Bay were determined. Viruses were seeded into fresh seawater that had been pretreated in various ways: filtration with a 0.2-(mu)m-pore-size filter to remove organisms, heat to denature enzymes, and dissolved organic matter enrichment to reconstitute enzyme activity. Seawater samples were then incubated in full sunlight, in the dark, or under glass to allow partitioning of causative agents of virus decay. Solar radiation always resulted in increased rates of loss of virus infectivity. Virus isolates which are native to Santa Monica Bay consistently degraded more slowly in full sunlight in untreated seawater (decay ranged from 4.1 to 7.2% h(sup-1)) than nonnative marine bacteriophages which were isolated from the North Sea (decay ranged from 6.6 to 11.1% h(sup-1)). All phages demonstrated susceptibility to degradation by heat-labile substances, as heat treatment reduced the decay rates to about 0.5 to 2.0% h(sup-1) in the dark. Filtration reduced decay rates by various amounts, averaging 20%. Heat-labile, high-molecular-weight dissolved material (>30 kDa, probably enzymes) appeared responsible for about 1/5 of the maximal decay. Solar radiation was responsible for about 1/3 to 2/3 of the maximal decay of nonnative viruses and about 1/4 to 1/3 of that of the native viruses, suggesting evolutionary adaptation to local light levels. Our results suggest that sunlight is an important contributing factor to virus decay but also point to the significance of particles and dissolved substances in seawater.

  6. Decays of the b quark

    NASA Astrophysics Data System (ADS)

    Thorndike, Edward H.; Poling, Ronald A.

    1988-01-01

    Recent experimental results on the decay of b-flavored hadrons are reviewed. Substantial progress has been made in the study of exclusive and inclusive B-meson decays, as well as in the theoretical understanding of these processes. The two most prominent developments are the continuing failure to observe evidence of decays of the b quark to a u quark rather than a c quark, and the surprisingly high level of B 0- overlineB0 mi xing which has recently been reported by the ARGUS collaboration. Notwithstanding these results, we conclude that the health of the Standard Model is excellent.

  7. Tensor interactions and τ decays

    NASA Astrophysics Data System (ADS)

    Godina Nava, J. J.; López Castro, G.

    1995-09-01

    We study the effects of charged tensor weak currents on the strangeness-changing decays of the τ lepton. First, we use the available information on the K+e3 form factors to obtain B(τ--->K-π0ντ)~10-4 when the Kπ system is produced in an antisymmetric tensor configuration. Then we propose a mechanism for the direct production of the K*2(1430) in τ decays. Using the current upper limit on this decay we set a bound on the symmetric tensor interactions.

  8. Glueball decay in holographic QCD

    SciTech Connect

    Hashimoto, Koji; Tan, C.-I; Terashima, Seiji

    2008-04-15

    Using holographic QCD based on D4-branes and D8-anti-D8-branes, we have computed couplings of glueballs to light mesons. We describe glueball decay by explicitly calculating its decay widths and branching ratios. Interestingly, while glueballs remain less well understood both theoretically and experimentally, our results are found to be consistent with the experimental data for the scalar glueball candidate f{sub 0}(1500). More generally, holographic QCD predicts that decay of any glueball to 4{pi}{sup 0} is suppressed, and that mixing of the lightest glueball with qq mesons is small.

  9. Slow Interatomic Coulombic Decay of Multiply Excited Neon Clusters

    NASA Astrophysics Data System (ADS)

    Iablonskyi, D.; Nagaya, K.; Fukuzawa, H.; Motomura, K.; Kumagai, Y.; Mondal, S.; Tachibana, T.; Takanashi, T.; Nishiyama, T.; Matsunami, K.; Johnsson, P.; Piseri, P.; Sansone, G.; Dubrouil, A.; Reduzzi, M.; Carpeggiani, P.; Vozzi, C.; Devetta, M.; Negro, M.; Calegari, F.; Trabattoni, A.; Castrovilli, M. C.; Faccialà, D.; Ovcharenko, Y.; Möller, T.; Mudrich, M.; Stienkemeier, F.; Coreno, M.; Alagia, M.; Schütte, B.; Berrah, N.; Kuleff, A. I.; Jabbari, G.; Callegari, C.; Plekan, O.; Finetti, P.; Spezzani, C.; Ferrari, E.; Allaria, E.; Penco, G.; Serpico, C.; De Ninno, G.; Nikolov, I.; Diviacco, B.; Di Mitri, S.; Giannessi, L.; Prince, K. C.; Ueda, K.

    2016-12-01

    Ne clusters (˜5000 atoms ) were resonantly excited (2 p →3 s ) by intense free electron laser (FEL) radiation at FERMI. Such multiply excited clusters can decay nonradiatively via energy exchange between at least two neighboring excited atoms. Benefiting from the precise tunability and narrow bandwidth of seeded FEL radiation, specific sites of the Ne clusters were probed. We found that the relaxation of cluster surface atoms proceeds via a sequence of interatomic or intermolecular Coulombic decay (ICD) processes while ICD of bulk atoms is additionally affected by the surrounding excited medium via inelastic electron scattering. For both cases, cluster excitations relax to atomic states prior to ICD, showing that this kind of ICD is rather slow (picosecond range). Controlling the average number of excitations per cluster via the FEL intensity allows a coarse tuning of the ICD rate.

  10. Radiative B Meson Decay as a Probe of Physics Beyond the Standard Model: Time-Dependent CP Violation in B0 → K0S π0 γ and the B → Φ K γ Branching Fraction

    SciTech Connect

    Joseph Marion Tuggle IV

    2009-01-01

    The author presents measurements of radiative B meson decays to the final states Ks0π0γ and KΦγ based on data collected at the Υ(4S) resonance with the BABAR detector at the PEP-II e+e- collider at SLAC. In a data sample of 467 million B$\\bar{B}$ pairs, the time-dependent CP asymmetry in B0 → Ks0π0γ decays is measured in two regions of Ks00 invariant mass. In the K* region, 0.8 < m(Ks0π0) < 1.0 GeV/c2, we find SK*γ = -0.03 ± 0.29 ± 0.03 and CK*γ = -0.14 ± 0.16 ± 0.03; in the range 1.1 < m(Ks0π0) < 1.8 GeV/c2, they find SKs0π0γ = -0.78 ± 0.59 ± 0.09 and C Ks0π0γ = -0.36 ± 0.33 ± 0.04. With a sample of 228 million B$\\bar{B}$ pairs they measure the branching fraction β(B+ → K+Φγ) = (3.5 ± 0.6 ± 0.4) x 10-6 and set the limit β(B0→ K0Φγ) < 2.7 x 10-6 at 90% confidence level. The direct CP asymmetry in B+ → K+Φγ is found to be A CP = (-26 ±14 ± 5)%. In each case the uncertainties are statistical and systematic, respectively.

  11. Mass spectra and decays of ground and orbitally excited cb¯ states in nonrelativistic quark model

    NASA Astrophysics Data System (ADS)

    Monteiro, Antony Prakash; Bhat, Manjunath; Vijaya Kumar, K. B.

    2017-02-01

    The complete spectrum of cb¯ states is obtained in a phenomenological nonrelativistic quark model (NRQM), which consists of a confinement potential and one gluon exchange potential (OGEP) as effective quark-antiquark potential. We make predictions for the radiative decay (E1 and M1) widths and weak decay widths of cb¯ states in the framework of NRQM formalism.

  12. Precision Measurement of Nuclear Electron Capture Decay

    NASA Astrophysics Data System (ADS)

    Koltick, David; Liu, Shih-Chieh; Wang, Haoyu; Heim, Jordan; Nistor, Jonathan

    2017-01-01

    The method of accurately measuring the radioactive decay constant of a isotope by measuring the decay rate as a function of time requires that both the detector and environment be stable over time periods comparable to the life-time of the isotope. In addition statistical accuracy requires initial counting rates be high but limited by the dead time capability of the data collection system and the detectors double-event resolving time. A High Purity Germanium (HPGe) spectrometer, sensitive to radiation from 3-KeV to over 3-MeV, has been built to measure radioactive decay constants to a level of 10-5 10-6 at a location only 6 meters from the core of the High Flux Isotope Reactor located at Oak Ridge National Laboratory. Such accuracy requires understanding of, background, signal-processing algorithms, and both the double and triple event pile-up in the observed spectrum. The approach taken is to fit the collected energy spectrum with invariant shapes, independent of event rate. By fixing the source-detector geometry and environmental conditions, the invariant shapes are (1) ideal energy spectrum without pile-up and background, (2) the ideal double event pile-up spectrum, (3) the ideal triple event pile-up spectrum, and (4) the stable background spectrum. A method is presented that finds these ideal shapes using the collected data in situ. Taking this approach the HPGe detector photopeak shape in the absence of background and pile-up is presented showing associated structure over a range of 7 orders of magnitude.

  13. Lepton flavor violating {tau} and B decays and heavy neutrinos

    SciTech Connect

    He Xiaogang

    2004-12-01

    We study lepton flavor violating (LFV) {tau} and B decays in models with heavy neutrinos to constrain the mixing matrix parameters U{sub {tau}}{sub N}. We find that the best current constraints when the heavy neutrinos are purely left handed come from LFV radiative {tau} decay modes. To obtain competitive constraints in LFV B decay, it is necessary to probe b{yields}X{sub s}{tau}{sup {+-}}e{sup {+-}} at the 10{sup -7} level. When the heavy neutrinos have both left- and right-handed couplings, the mixing parameters can be constrained by studying LFV B decay modes and LFV {tau} decay into three charged leptons. We find that the branching ratios B({tau}{sup {+-}}{yields}l{sub 1}{sup {+-}}l{sub 2}{sup {+-}}l{sub 3}{sup {+-}}), B(B{sub s}{yields}{tau}{sup {+-}}e{sup {+-}}) and B(b{yields}X{sub s}l{sub 1}{sup {+-}}l{sub 2}{sup {+-}}) need to be probed at the 10{sup -8} level in order to constrain the mixing parameters beyond what is known from unitarity.

  14. A model for multiexponential tryptophan fluorescence intensity decay in proteins.

    PubMed Central

    Bajzer, Z; Prendergast, F G

    1993-01-01

    Tryptophan fluorescence intensity decay in proteins is modeled by multiexponential functions characterized by lifetimes and preexponential factors. Commonly, multiple conformations of the protein are invoked to explain the recovery of two or more lifetimes from the experimental data. However, in many proteins the structure seems to preclude the possibility of multiple conformers sufficiently different from one another to justify such an inference. We present here another plausible multiexponential model based on the assumption that an energetically excited donor surrounded by N acceptor molecules decays by specific radiative and radiationless relaxation processes, and by transferring its energy to acceptors present in or close to the protein matrix. If interactions between the acceptors themselves and back energy transfer are neglected, we show that the intensity decay function contain 2N exponential components characterized by the unperturbed donor lifetime, by energy transfer rates and a probability of occurrence for the corresponding process. We applied this model to the fluorescence decay of holo- and apoazurin, ribonuclease T1, and the reduced single tryptophan mutant (W28F) of thioredoxin. Use of a multiexponential model for the analysis of the fluorescence intensity decay can therefore be justified, without invoking multiple protein conformations. Images FIGURE 1 PMID:8312471

  15. The Search for Proton Decay.

    ERIC Educational Resources Information Center

    Marshak, Marvin L.

    1984-01-01

    Provides the rationale for and examples of experiments designed to test the stability of protons and bound neutrons. Also considers the unification question, cosmological implications, current and future detectors, and current status of knowledge on proton decay. (JN)

  16. CP violation in K decays

    SciTech Connect

    Gilman, F.J.

    1989-05-01

    Recent theoretical and experimental progress on the manifestation of CP violation in K decays, and toward understanding whether CP violation originates in a phase, or phases, in the weak mixing matrix of quarks is reviewed. 23 refs., 10 figs.

  17. Questions Students Ask: Beta Decay.

    ERIC Educational Resources Information Center

    Koss, Jordan; Hartt, Kenneth

    1988-01-01

    Answers a student's question about the emission of a positron from a nucleus. Discusses the problem from the aspects of the uncertainty principle, beta decay, the Fermi Theory, and modern physics. (YP)

  18. Nuclear decay data files of the Dosimetry Research Group

    SciTech Connect

    Eckerman, K.F.; Westfall, R.J.; Ryman, J.C.; Cristy, M.

    1993-12-01

    This report documents the nuclear decay data files used by the Dosimetry Research Group at Oak Ridge National Laboratory and the utility DEXRAX which provides access to the files. The files are accessed, by nuclide, to extract information on the intensities and energies of the radiations associated with spontaneous nuclear transformation of the radionuclides. In addition, beta spectral data are available for all beta-emitting nuclides. Two collections of nuclear decay data are discussed. The larger collection contains data for 838 radionuclides, which includes the 825 radionuclides assembled during the preparation of Publications 30 and 38 of the International Commission on Radiological Protection (ICRP) and 13 additional nuclides evaluated in preparing a monograph for the Medical Internal Radiation Dose (MIRD) Committee of the Society of Nuclear Medicine. The second collection is composed of data from the MIRD monograph and contains information for 242 radionuclides. Abridged tabulations of these data have been published by the ICRP in Publication 38 and by the Society of Nuclear Medicine in a monograph entitled ``MIRD: Radionuclide Data and Decay Schemes.`` The beta spectral data reported here have not been published by either organization. Electronic copies of the files and the utility, along with this report, are available from the Radiation Shielding Information Center at Oak Ridge National Laboratory.

  19. CP violation in sbottom decays

    NASA Astrophysics Data System (ADS)

    Deppisch, Frank F.; Kittel, Olaf

    2010-06-01

    We study CP asymmetries in two-body decays of bottom squarks into charginos and top quarks. These asymmetries probe the SUSY CP phases of the sbottom and the chargino sector in the Minimal Supersymmetric Standard Model (MSSM). We identify the MSSM parameter space where the CP asymmetries are sizeable. As a result, potentially detectable CP asymmetries in sbottom decays are found, which motivates further detailed experimental studies for probing the SUSY CP phases at the LHC.

  20. Continuum-state and bound-state β--decay rates of the neutron

    NASA Astrophysics Data System (ADS)

    Faber, M.; Ivanov, A. N.; Ivanova, V. A.; Marton, J.; Pitschmann, M.; Serebrov, A. P.; Troitskaya, N. I.; Wellenzohn, M.

    2009-09-01

    For the β--decay of the neutron we analyze the continuum-state and bound-state decay modes. We calculate the decay rates, the electron energy spectrum for the continuum-state decay mode, and angular distributions of the decay probabilities for the continuum-state and bound-state decay modes. The theoretical results are obtained for the new value for the axial coupling constant gA=1.2750(9), obtained recently by H. Abele [Prog. Part. Nucl. Phys. 60, 1 (2008)] from the fit of the experimental data on the coefficient of the correlation of the neutron spin and the electron momentum of the electron energy spectrum of the continuum-state decay mode. We take into account the contribution of radiative corrections and the scalar and tensor weak couplings. The calculated angular distributions of the probabilities of the bound-state decay modes of the polarized neutron can be used for the experimental measurements of the bound-state β--decays into the hyperfine states with total angular momentum F=1 and scalar and tensor weak coupling constants.

  1. Few body hypernuclear systems: Weak decays

    SciTech Connect

    Dover, C.B.

    1987-01-01

    The experimental and theoretical situation regarding mesonic and non-mesonic decays of light hypernuclei is reviewed. Although some models give reasonable results for pionic decays as well as the total weak decay rate, no existing approach explains, even qualitatively, the observed spin-isospin dependence of ..lambda..N ..-->.. NN non-mesonic weak decays. 31 refs., 2 figs.

  2. Dalitz plot analysis of three-body charmonium decays at BABAR

    NASA Astrophysics Data System (ADS)

    Palano, Antimo

    2016-05-01

    We present preliminary results on the measurement of the I=1/2 Kπ S-wave through a model independent partial wave analysis of ηc decays to KS0 K+π- and K+ K-π0 produced in two-photon interactions. We also perform a Dalitz plot analysis of the J/ψ decays to π+π-π0 and K+ K-π0 produced in the initial state radiation process.

  3. Spontaneous decay of an atom excited in a dense and disordered atomic ensemble: Quantum microscopic approach

    NASA Astrophysics Data System (ADS)

    Kuraptsev, A. S.; Sokolov, I. M.

    2014-07-01

    On the basis of general theoretical results developed previously [I. M. Sokolov et al., J. Exp. Theor. Phys. 112, 246 (2011), 10.1134/S106377611101016X], we analyze spontaneous decay of a single atom inside cold atomic clouds under conditions when the averaged interatomic separation is less than or comparable with the wavelength of quasiresonant radiation. Beyond the decay dynamics we analyze shifts of resonance as well as distortion of the spectral shape of the atomic transition.

  4. Radiation Therapy

    MedlinePlus

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Radiation Therapy KidsHealth > For Teens > Radiation Therapy A A ... how to cope with side effects. What Is Radiation Therapy? Cancer is a disease that causes cells ...

  5. Radiation Protection

    MedlinePlus

    Jump to main content US EPA United States Environmental Protection Agency Search Search Radiation Protection Share Facebook Twitter Google+ Pinterest Contact Us Radiation Protection Document Library View ...

  6. Atmospheric radiation

    SciTech Connect

    Harshvardhan, M.R. )

    1991-01-01

    Studies of atmospheric radiative processes are summarized for the period 1987-1990. Topics discussed include radiation modeling; clouds and radiation; radiative effects in dynamics and climate; radiation budget and aerosol effects; and gaseous absorption, particulate scattering and surface reflection. It is concluded that the key developments of the period are a defining of the radiative forcing to the climate system by trace gases and clouds, the recognition that cloud microphysics and morphology need to be incorporated not only into radiation models but also climate models, and the isolation of a few important unsolved theoretical problems in atmospheric radiation.

  7. Gamma-ray lines from novae. [relationship to radioactive decay and positron annihilation

    NASA Technical Reports Server (NTRS)

    Clayton, D. D.; Hoyle, F.

    1974-01-01

    An appropriate gamma-ray telescope could detect the gamma-rays associated with radioactive decays. The observable lines would be the annihilation radiation following the positron emission of N-13, O-14, O-15, and Na-22 and the 2.312-MeV line emitted following the O-14 decay and the 1.274-MeV line emitted following the Na-22 decay. The experimental possibility should be borne in mind for the occurrence of novae within a few kiloparsecs.

  8. c b \\xAF spectrum and decay properties with coupled channel effects

    NASA Astrophysics Data System (ADS)

    Monteiro, Antony Prakash; Bhat, Manjunath; Kumar, K. B. Vijaya

    2017-03-01

    The mass spectrum of c b ¯ states has been obtained using the phenomenological relativistic quark model (RQM) with coupled channel effects. The Hamiltonian used in the investigation has confinement potential and confined one gluon exchange potential (COGEP). In the frame work of the RQM, a study of magnetic dipole and electric dipole transitions and radiative decays of c b ¯ states has been made. The weak decay widths in the spectator quark approximation have been estimated. An overall agreement is obtained with the experimental masses and decay widths.

  9. Decay curve study in a standard electron capture decay

    SciTech Connect

    Nishimura, D.; Fukuda, M.; Kisamori, K.; Kuwada, Y.; Makisaka, K.; Matsumiya, R.; Matsuta, K.; Mihara, M.; Takagi, A.; Yokoyama, R.; Izumikawa, T.; Ohtsubo, T.; Suzuki, T.; Yamaguchi, T.

    2010-05-12

    We have searched for a time-modulated decay in a standard electron capture experiment for {sup 140}Pr, in order to confirm a report from GSI, where an oscillatory decay has been observed for hydrogen-like {sup 140}Pr and {sup 142}Pm ions in the cooler storage ring. {sup 140}Pr has been produced with the {sup 140}Ce(p, n) reaction by a pulsed proton beam accelerated from the Van de Graaff accelerator at Osaka University. Resultant time dependence of the K{sub a}lpha and K{sub b}eta X-ray intensities from the daughter shows no oscillatory behavior.

  10. Two surface plasmon decay of plasma oscillations

    SciTech Connect

    Kluge, T. Metzkes, J.; Zeil, K.; Bussmann, M.; Schramm, U.; Cowan, T. E.

    2015-06-15

    The interaction of ultra-intense lasers with solid foils can be used to accelerate ions to high energies well exceeding 60 MeV [Gaillard et al., Phys. Plasmas 18, 056710 (2011)]. The non-linear relativistic motion of electrons in the intense laser radiation leads to their acceleration and later to the acceleration of ions. Ions can be accelerated from the front surface, the foil interior region, and the foil rear surface (target normal sheath acceleration (TNSA), most widely used), or the foil may be accelerated as a whole if sufficiently thin (radiation pressure acceleration). Here, we focus on the most widely used mechanism for laser ion-acceleration of TNSA. Starting from perfectly flat foils, we show by simulations how electron filamentation at or inside the solid leads to spatial modulations in the ions. The exact dynamics depend very sensitively on the chosen initial parameters which has a tremendous effect on electron dynamics. In the case of step-like density gradients, we find evidence that suggests a two-surface-plasmon decay of plasma oscillations triggering a Raileigh-Taylor-like instability.

  11. New precise measurements of the Ξ→Λγ and Ξ→Σγ decay asymmetries

    NASA Astrophysics Data System (ADS)

    Batley, J. R.; Kalmus, G. E.; Lazzeroni, C.; Munday, D. J.; Patel, M.; Slater, M. W.; Wotton, S. A.; Arcidiacono, R.; Bocquet, G.; Ceccucci, A.; Cundy, D.; Doble, N.; Falaleev, V.; Gatignon, L.; Gonidec, A.; Grafström, P.; Kubischta, W.; Mikulec, I.; Norton, A.; Panzer-Steindel, B.; Rubin, P.; Wahl, H.; Goudzovski, E.; Hristov, P.; Kekelidze, V.; Litov, L.; Madigozhin, D.; Molokanova, N.; Potrebenikov, Yu.; Stoynev, S.; Zinchenko, A.; Monnier, E.; Swallow, E.; Winston, R.; Sacco, R.; Walker, A.; Baldini, W.; Gianoli, A.; Dalpiaz, P.; Frabetti, P. L.; Martini, M.; Petrucci, F.; Savrié, M.; Scarpa, M.; Calvetti, M.; Collazuol, G.; Iacopini, E.; Ruggiero, G.; Bizzeti, A.; Lenti, M.; Veltri, M.; Behler, M.; Eppard, K.; Eppard, M.; Hirstius, A.; Kleinknecht, K.; Koch, U.; Marouelli, P.; Masetti, L.; Moosbrugger, U.; Morales, C. Morales; Peters, A.; Wanke, R.; Winhart, A.; Dabrowski, A.; Martin, T. Fonseca; Velasco, M.; Cenci, P.; Lubrano, P.; Pepe, M.; Anzivino, G.; Imbergamo, E.; Lamanna, G.; Michetti, A.; Nappi, A.; Petrucci, M. C.; Piccini, M.; Valdata, M.; Cerri, C.; Fantechi, R.; Costantini, F.; Fiorini, L.; Giudici, S.; Pierazzini, G.; Sozzi, M.; Mannelli, I.; Cheshkov, C.; Cheze, J. B.; De Beer, M.; Debu, P.; Gouge, G.; Marel, G.; Mazzucato, E.; Peyaud, B.; Vallage, B.; Holder, M.; Maier, A.; Ziolkowski, M.; Biino, C.; Cartiglia, N.; Marchetto, F.; Pastrone, N.; Clemencic, M.; Lopez, S. Goy; Menichetti, E.; Wislicki, W.; Dibon, H.; Jeitler, M.; Markytan, M.; Neuhofer, G.; Widhalm, L.; NA48/1 Collaboration

    2010-10-01

    The decay asymmetries of the weak radiative hyperon decays Ξ→Λγ and Ξ→Σγ have been measured with high precision using data of the NA48/1 experiment at CERN. From about 52 000 Ξ→Λγ and 15 000 Ξ→Σγ decays, we obtain for the decay asymmetries α=-0.704±0.019±0.064 and α=-0.729±0.030±0.076, respectively. These results are in good agreement with previous experiments, but more precise.

  12. Factorization and dispersion relations for radiative leptonic B decay

    NASA Astrophysics Data System (ADS)

    Wang, Yu-Ming

    2016-09-01

    Applying the dispersion approach we compute perturbative QCD corrections to the power suppressed soft contribution of B → γℓν at leading twist. QCD factorization for the B → γ * form factors is demonstrated explicitly for the hard-collinear transverse polarized photon at one loop, with the aid of the method of regions. While the one-loop hard function is identical to the matching coefficient of the QCD weak current ūγ μ ⊥(1 - γ 5) b in soft-collinear effective theory, the jet function from integrating out the hard-collinear fluctuations differs from the corresponding one entering the factorization formula of B → γℓν, due to the appearance of an additional hard-collinear momentum mode. Furthermore, we evaluate the sub-leading power contribution to the B → γ form factors from the three-particle B-meson distribution amplitudes (DAs) at tree level, with the dispersion approach. The soft contribution to the B → γ form factors from the three-particle B-meson DAs is shown to be of the same power compared with the corresponding hard correction, in contrast to the two-particle counterparts. Numerically the next-to-leading-order QCD correction to the soft two-particle contribution in B → γ form factors will induce an approximately (10 ˜ 20)% shift to the tree-level contribution at λ B ( μ 0) = 354 MeV. Albeit of power suppression parametrically, the soft two-particle correction can decrease the leading power predictions for the B → γ form factors by an amount of (10 ˜ 30)% with the same value of λ B ( μ 0). Employing the phenomenological model of the three-particle B-meson DAs inspired by a QCD sum rule analysis, the three-particle contribution to the B → γ form factors is predicted to be of O (1%), at leading order in α s , with the default theory inputs. Finally, we explore theory constraints on the inverse moment of the leading-twist B-meson DA λ B from the recent Belle measurements of the partial branching fractions of B → γℓν, taking into account the newly computed contributions to the B → γ form factors at subleading power.

  13. EC decay of 244Bk

    NASA Astrophysics Data System (ADS)

    Sodaye, Suparna; Tripathi, R.; Sudarshan, K.; Sharma, S. K.; Pujari, P. K.; Palit, R.; Mukhopadhyay, S.

    2014-12-01

    Berkelium isotopes have been produced in 11B-induced reaction on 238U. The EC decay of 244Bk → 244Cm has been studied by carrying out the single and coincidence measurements of the γ-rays emitted during the de-excitation of the 244Cm levels. Radiochemical separations have been carried out to minimize the contribution from the fission products and target. The new half-life of 244Bk is obtained as 5.02 ± 0.03 h, which is close to the theoretically calculated value. The relative intensities of the decay γ-rays have been re-evaluated. Based on the coincidence measurements, a tentative partial level scheme for 244Bk → 244Cm decay has been proposed.

  14. Charmless B decays involving baryons

    NASA Astrophysics Data System (ADS)

    Gronau, Michael; Rosner, Jonathan L.

    1988-02-01

    Predictions are made for the fraction of B-meson decays involving specific final states of NN¯+nπ (n>=0), as functions of (a) decay dynamics, (b) models for multipion production, (c) the isospin of the final state, and (d) the ratio ||Vbu/Vbc|| of Kobayashi-Maskawa matrix elements. From recent observations of B+-->pp¯π+(+c.c.) and B0-->pp¯π+π- by the ARGUS Collaboration, it is concluded that ||Vbu/Vbc||>~0.08, similar to the ARGUS Collaboration's own estimate of 0.07. However, a more likely value for this ratio is near its present experimental upper limit. Predictions are made for further final states in NN¯+nπ and in other charmless B decays. We also comment briefly on prospects for observing CP violation in B-->NN¯+nπ.

  15. Studies of Ion Acoustic Decay

    SciTech Connect

    Drake, R.P.; Bauer, B.S.; Baker, K.L. |

    1994-03-07

    In this project, we advanced knowledge of Ion Acoustic Decay on several fronts. In this project, we have developed and demonstrated the capability to perform experimental and theoretical studies of the Ion Acoustic Decay Instability. We have at the same time demonstrated an improved capability to do multichannel spectroscopy and Thomson scattering. We made the first observations of the time-resolved second harmonic emission at several angles simultaneously, and the first observations of the emission both parallel and perpendicular to the electric field of the laser light. We used Thomson scattering to make the first observations of the plasma waves driven by acoustic decay in a warm plasma with long density scale lengths. We also advanced both the linear and the nonlinear theory of this instability. We are thus prepared to perform experiments to address this mechanism as needed for applications.

  16. Tunneling decay of false kinks

    NASA Astrophysics Data System (ADS)

    Dupuis, Éric; Gobeil, Yan; MacKenzie, Richard; Marleau, Luc; Paranjape, M. B.; Ung, Yvan

    2015-07-01

    We consider the decay of "false kinks," that is, kinks formed in a scalar field theory with a pair of degenerate symmetry-breaking false vacua in 1 +1 dimensions. The true vacuum is symmetric. A second scalar field and a peculiar potential are added in order for the kink to be classically stable. We find an expression for the decay rate of a false kink. As with any tunneling event, the rate is proportional to exp (-SE) where SE is the Euclidean action of the bounce describing the tunneling event. This factor varies wildly depending on the parameters of the model. Of interest is the fact that for certain parameters SE can get arbitrarily small, implying that the kink is only barely stable. Thus, while the false vacuum itself may be very long-lived, the presence of kinks can give rise to rapid vacuum decay.

  17. Heavy quark spectroscopy and decay

    SciTech Connect

    Schindler, R.H.

    1987-01-01

    The understanding of q anti q systems containing heavy, charmed, and bottom quarks has progressed rapidly in recent years, through steady improvements in experimental techniques for production and detection of their decays. These lectures are meant to be an experimentalist's review of the subject. In the first of two lectures, the existing data on the spectroscopy of the bound c anti c and b anti b systems will be discussed. Emphasis is placed on comparisons with the theoretical models. The second lecture covers the rapidly changing subject of the decays of heavy mesons (c anti q and b anti q), and their excited states. In combination, the spectroscopy and decays of heavy quarks are shown to provide interesting insights into both the strong and electroweak interactions of the heavy quarks. 103 refs., 39 figs.

  18. Decay of capillary wave turbulence.

    PubMed

    Deike, Luc; Berhanu, Michael; Falcon, Eric

    2012-06-01

    We report on the observation of freely decaying capillary wave turbulence on the surface of a fluid. The capillary wave turbulence spectrum decay is found to be self-similar in time with the same power law exponent as the one found in the stationary regime, in agreement with weak turbulence predictions. The amplitude of all Fourier modes are found to decrease exponentially with time at the same damping rate. The longest wavelengths involved in the system are shown to be damped by a viscous surface boundary layer. These long waves play the role of an energy source during the decay that sustains nonlinear interactions to keep capillary waves in a wave turbulent state.

  19. Electronic decay through carbon chains

    NASA Astrophysics Data System (ADS)

    Kuleff, Alexander I.

    2017-01-01

    Using the multielectron wave-packet propagation method the electronic decay of O2s vacancy in fluorinated cumulenones, OCnF2 , containing a chain of up to five carbons is traced in time and space. It is shown that in all studied cases this state decays non-locally by emitting an electron from the remote fluorines. Even in the pentatetraenone case, where the oxygen and the flourines are more than 7 Å apart, this non-local decay is extremely efficient, with a time constant of about 5 fs. The process can be viewed as an ultrafast energy transfer through the carbon chain and thus our systematic study allows to shed some light on the dependence of the time scale of the electron-correlation driven energy transfer through a medium.

  20. Pelvic radiation - discharge

    MedlinePlus

    Radiation of the pelvis - discharge; Cancer treatment - pelvic radiation; Prostate cancer - pelvic radiation; Ovarian cancer - pelvic radiation; Cervical cancer - pelvic radiation; Uterine cancer - pelvic radiation; Rectal cancer - ...

  1. Luminescence decay of porous silicon

    NASA Astrophysics Data System (ADS)

    Chen, X.; Uttamchandani, D.; Sander, D.; O'Donnell, K. P.

    1993-04-01

    The luminescence decay pattern of porous silicon samples prepared by electrochemical etching is characterised experimentally by a non-exponential profile, a strong dependence on temperature and an absence of spectral diffusion. We describe this luminescence as carrier-dopping-assisted recombination. Following the correlation function approach to non-dispersive transport developed by Scher and co-workers [Physics Today 41 (1991) 26], we suggest a simple derivation of analytical functions which accurately describes the anomalous luminescence decay of porous silicon, and show that this model includes exponential and Kohlrausch [Pogg. Ann. Phys. 119 (1863) 352] (stretched-exponential) relaxations as special cases.

  2. Decay Data Evaluation Project (DDEP): evaluation of the main 233Pa decay characteristics.

    PubMed

    Chechev, Valery P; Kuzmenko, Nikolay K

    2006-01-01

    The results of a decay data evaluation are presented for 233Pa (beta-) decay to nuclear levels in 233U. These evaluated data have been obtained within the Decay Data Evaluation Project using information published up to 2005.

  3. Radiative and Electroweak Penguins at Belle

    SciTech Connect

    Hyun, Hyo Jung

    2010-02-10

    Radiative and electroweak penguin decays of B mesons are a sensitive probe of new physics beyond the Standard Model. We study the inclusive and exclusive radiative and electroweak penguin decays of B meson and also search an exotic particle seen by the HyperCP experiment. The measurements are based on a large data sample of 605 fb{sup -1} containing 657 millions BB-bar pairs collected at the UPSILON(4S) with the Belle detector at the KEKB energy asymmetric e{sup +}e{sup -} collider.

  4. Short sound decay of ancient Chinese music bells

    NASA Astrophysics Data System (ADS)

    Pan, Jie; Li, Xiaodong; Tian, Jing; Lin, Tanran

    2002-12-01

    Ancient Chinese music bells, which have oval-like cross sections, possess the unique feature of a short sound-decay time that is especially suitable for music with fast tempo. Although recorded in the literature nearly 1000 years ago, this feature has never been truly understood. Recent damping measurement of oval pipes with different axial ratios suggested a challenging task for acousticians as the increase of the modal damping with the pipe's axial ratio is significant only when the pipe response is measured in air but not in vacuum. In this paper, the decrease of sound-decay time of oval pipes with the increased cross-section ovality is investigated. This is the first time that such short sound-decay feature is explained in terms of the rich sound radiation characteristics of the symmetric modes of music bells and the oval pipes. Finite element and boundary element methods are employed to explain how axial ratio significantly affects the normal velocity distribution, radiation efficiency, and directivity of acoustic modes.

  5. The Majorana Demonstrator Neutrinoless Double-beta Decay Experiment

    NASA Astrophysics Data System (ADS)

    Guiseppe, V. E.

    2012-03-01

    Neutrinoless double-beta decay searches play a major role in determining the nature of neutrinos, the existence of a lepton violating process, and the effective Majorana neutrino mass. The Majorana Collaboration is assembling an array of HPGe detectors to search for neutrinoless double-beta decay in ^76Ge. Our proposed method uses the well-established technique of searching for neutrinoless double-beta decay in high purity Ge-diode radiation detectors that play both roles of source and detector. The use of p-type point contact Ge detectors present advances in background rejection and a significantly lower energy threshold than conventional Ge detectors. The lower energy threshold opens up a broader and exciting physics program including searches for dark matter and axions concurrent with the double-beta decay search. Initially, Majorana is constructing a prototype module to demonstrate the potential of a future 1-tonne experiment. The status and potential physics reach of the Majorana Demonstrator module will be presented.

  6. New Results in Rare Allowed Muon and Pion Decays

    NASA Astrophysics Data System (ADS)

    Počanić, D.; Munyangabe, E.; Bychkov, M.; Alonzi, L. P.; Baranov, V. A.; Bertl, W.; Bystritsky, Yu. M.; Frlež, E.; Kalinnikov, V. A.; Khomutov, N. V.; Korenchenko, A. S.; Korenchenko, S. M.; Korolija, M.; Kozlowski, T.; Kravchuk, N. P.; Kuchinsky, N. A.; Lehman, M. C.; Mekterović, D.; Mzhavia, D.; Palladino, A.; Robmann, P.; Rozhdestvensky, A. M.; Supek, I.; Truöl, P.; Tsamalaidze, Z.; van der Schaaf, A.; Vandevender, B.; Velicheva, E. P.; Volnykh, V. P.

    2014-12-01

    Simple dynamics, few available decay channels, and highly controlled radiative and loop corrections, make pion and muon decays a sensitive means of exploring details of the underlying symmetries. We review the current status of the rare decays: π+ → e+ν (πe2), π+ → e+νγ (πe2γ), π+ → π0e+ν (πe3), and μ + -> e+ν \\bar {ν }γ . For the latter we report new preliminary values for the branching ratio B(Eγ > 10 MeV, θeγ > 30°) = 4.365 (9)stat (42)syst × 10-3, and the decay parameter \\bar {η } = 0.006 (17) stat (18) syst, both in excellent agreement with standard model predictions. We review recent measurements, particularly by the PIBETA and PEN experiments, and near-term prospects for improvement. These and other similar precise low energy studies complement modern collider results materially.

  7. Multiple photon emission in heavy particle decays

    NASA Technical Reports Server (NTRS)

    Asakimori, K.; Burnett, T. H.; Cherry, M. L.; Christl, M. J.; Dake, S.; Derrickson, J. H.; Fountain, W. F.; Fuki, M.; Gregory, J. C.; Hayashi, T.

    1994-01-01

    Cosmic ray interactions, at energies above 1 TeV/nucleon, in emulsion chambers flown on high altitude balloons have yielded two events showing apparent decays of a heavy particle into one charged particle and four photons. The photons converted into electron pairs very close to the decay vertex. Attempts to explain this decay topology with known particle decays are presented. Unless both events represent a b yields u transition, which is statistically unlikely, then other known decay modes for charmed or bottom particles do not account satisfactorily for these observations. This could indicate, possibly, a new decay channel.

  8. Natural circulation decay heat removal from an SP-100, 550 kWe power system for a lunar outpost

    NASA Technical Reports Server (NTRS)

    El-Genk, Mohamed S.; Xue, Huimin

    1992-01-01

    This research investigated the decay heat removal from the SP-100 reactor core of a 550-kWe power system for a lunar outpost by natural circulation of lithium coolant. A transient model that simulates the decay heat removal loop (DHRL) of the power system was developed and used to assess the system's decay heat removal capability. The effects of the surface area of the decay heat rejection radiator, the dimensions of the decay heat exchanger (DHE) flow duct, the elevation of the DHE, and the diameter of the rise and down pipes in the DHRL on the decay heat removal capability were examined. Also, to determine the applicability of test results at earth gravity to actual system performance on the lunar surface, the effect of the gravity constant (1 g and 1/6 g) on the thermal behavior of the system after shutdown was investigated.

  9. Fermi's β-DECAY Theory

    NASA Astrophysics Data System (ADS)

    Yang, Chen Ning

    2013-05-01

    Throughout his lifetime Enrico Fermi (1901-1954) had considered his 1934 β-decay theory as his most important contribution to theoretical physics. E. Segrè (1905-1989) had vividly written about an episode at the inception of that paper:1...

  10. Nuclear structure from radioactive decay

    SciTech Connect

    Wood, J.L.

    1990-09-30

    This report discusses the nuclear structure of the following isotopes as a result of radioactive decays: neutron-deficient iridium isotopes; neutron-deficient platinum isotopes; neutron-deficient gold isotopes; neutron-deficient mercury isotopes; neutron-deficient thallium isotopes; neutron-deficient lead isotopes; neutron-deficient promethium isotopes; and neutron-deficient samarium isotopes.

  11. Deconvolution method for fluorescence decays

    NASA Astrophysics Data System (ADS)

    Apanasovich, V. V.; Novikov, E. G.

    1990-09-01

    A new method for fluorescence decay deconvolution is offered. It has acceptable accuracy, high speed of deconvolution, and allows to estimate the number of exponentials. Some results of statistical experiments, using a simulation model of a pulsed fluorescence spectrometer, are introduced.

  12. Rare B decays at CDF

    SciTech Connect

    Farrington, Sinead M.; /Liverpool U.

    2006-10-01

    The confidence level limits of the CDF search for the B{sub s}{sup 0} and B{sub d}{sup 0} {yields} {mu}{sup +}{mu}{sup -} rare decays and the branching ratio measurement of B{sub s}{sup 0} {yields} D{sub s}{sup +} D{sub s}{sup -} are presented.

  13. Decay Studies of NEPTUNIUM-237.

    NASA Astrophysics Data System (ADS)

    Woods, S. A.

    Available from UMI in association with The British Library. Requires signed TDF. The decay of ^{237}Np (T_{1over2} = 2.14 times 10^6 years) has been investigated from singles and coincidence gamma-ray spectra acquired using Ge detectors and also from internal conversion electron spectra acquired using an iron-free, pi/2 double-focusing, beta-ray spectrometer. Such a long-lived nucleus has a very low specific activity which has previously made the determination of the internal conversion following its decay extremely difficult. In order to overcome this problem, the luminosity of the beta -ray spectrometer has been increased by utilising the multistrip source technique of Bergkvist in conjunction with a sixteen-element proportional counter. Twenty-four gamma-rays have been observed in the singles studies, with four additional gamma -rays observed in the coincidence studies alone, all of which have been placed in the level scheme of ^{233}Pa. The coincidence data also indicates the presence of two unobserved transitions of low energy. The absolute conversion coefficients and multipolarity of five gamma-ray transitions following the decay of ^{237} Np, together with those of seven gamma -ray transitions following the decay of the daughter nucleus, ^{233}Pa, have been determined and the levels of ^{233 }Pa assigned within the framework of the Nilsson Model.

  14. Review of tau lepton decays

    SciTech Connect

    Stoker, D.P.

    1991-07-01

    Measurements of the {tau} decay modes are reviewed and compared with the predictions of the Standard Model. While the agreement is generally good, the status of the 1-prong puzzle'' remains controversial and a discrepancy between the measured leptonic branching fractions and the {tau} lifetime persists. Prospects for precision measurements at a Tau-Charm Factory are also reviewed. 20 refs., 2 tabs.

  15. Family symmetries and proton decay

    SciTech Connect

    Murayama, Hitoshi |; Kaplan, D.B.

    1994-08-01

    The proton decay modes p {yields} K{sup 0}e{sup +} and p {yields} K{sup 0}{mu}{sup +} may be visible in certain supersymmetric theories, and if seen would provide evidence for new flavor physics at extremely short distances. These decay modes can arise from the dimension five operator (Q{sub 1}Q{sub 1}Q{sub 2}L{sub 1,2}), where Q{sub i} and L{sub i} are i{sup th} generation quark and lepton superfields respectively. Such an operator is not generated at observable levels due to gauge or Higgs boson exchange in a minimal GUT. However in theories that explain the fermion mass hierarchy, it may be generated at the Planck scale with a strength such that the decays p {yields} K{sup 0}{ell}{sup +} are both compatible with the proton lifetime and visible at Super-Kamiokande. Observable proton decay can even occur in theories without unification.

  16. Search for Rare B Meson Decays at the BABAR Experiment

    NASA Astrophysics Data System (ADS)

    Cheaib, R.; BABAR Collaboration

    2016-11-01

    b → s transitions are flavour-changing neutral current (FCNC) processes that play an important role in the search for physics beyond the Standard Model (SM). Contributions from virtual particles in the loop are predicted to deviate observables, such as the branching fraction, from their SM expectations. Using data from the BaBar experiment, we present the first search for the rare decay B + → K+ τ+τ-. The BABAR results on the measurement of the angular asymmetries of B → K* l + l -, where l = e or μ, are also reported. In addition, using a time-dependent analysis of B → K s 0π+π-γ, the mixing induced CP-asymmetry for the radiative FCNC decay, B → K s 0ργ, is measured, along with an amplitude analysis of the mKπ and mKππ spectrum.

  17. Nonradiative decay mechanism of fluoren-9-ylidene malononitrile ambipolar derivatives.

    PubMed

    Estrada, Leandro A; Cai, Xichen; Neckers, Douglas C

    2011-03-24

    We report recent results on the nonradiative decay (NRD) of fluoren-9-ylidene malononitrile (FM) ambipolar derivatives (FMDs). 2,7- and 3,6-disubstituted FMDs present distinctive photophysics. Charge separation was found dominant for excited state relaxation. The radiative decay (RD) is sensitive to changes in temperature and solvent medium only for the case of 3,6-FMDs. Excited state deactivation of carbazole-containing 3,6-FMD (CPAFM36) was exclusively nonradiative in polar solvents with excited state lifetimes shorter than 10 ps. The charge separation/recombination mechanism of the corresponding FMDs is suggested to fall in the inverted Marcus region of electron transfer. Given the electron-withdrawing properties of the FM unit, its ambipolar derivatives are suggested as potential candidates for air-stable organic thin-film transistors and molecular organic photovoltaics.

  18. Rapid Orbital Decay in Detached Binaries: Evidence for Circumbinary Disks

    NASA Astrophysics Data System (ADS)

    Chen, Wen-Cong; Podsiadlowski, Philipp

    2017-03-01

    Some short-period, detached binary systems have recently been reported as experiencing very rapid orbital decay, much faster than is expected from the angular-momentum loss caused by gravitational radiation alone. As these systems contain fully convective stars, magnetic braking is not believed to be operative, making the large orbital-period derivative puzzling. Here, we explore whether a resonant interaction between the binary and a surrounding circumbinary (CB) disk could account for the observed orbital decay. Our calculations indicate that the observed orbital-period derivatives in seven detached binaries can be produced by the resonant interaction between the binary and a CB disk if the latter has a mass in the range of {10}-4{--}{10}-2 {M}ȯ , which is of the same order as the inferred disk mass (∼ 2.4× {10}-4 {M}ȯ ) in the post-common-envelope binary NN Ser.

  19. Radiations from hot nuclei

    NASA Technical Reports Server (NTRS)

    Malik, F. Bary

    1993-01-01

    The investigation indicates that nuclei with excitation energy of a few hundred MeV to BeV are more likely to radiate hot nuclear clusters than neutrons. These daughter clusters could, furthermore, de-excite emitting other hot nuclei, and the chain continues until these nuclei cool off sufficiently to evaporate primarily neutrons. A few GeV excited nuclei could radiate elementary particles preferentially over neutrons. Impact of space radiation with materials (for example, spacecraft) produces highly excited nuclei which cool down emitting electromagnetic and particle radiations. At a few MeV excitation energy, neutron emission becomes more dominant than gamma-ray emission and one often attributes the cooling to take place by successive neutron decay. However, a recent experiment studying the cooling process of 396 MeV excited Hg-190 casts some doubt on this thinking, and the purpose of this investigation is to explore the possibility of other types of nuclear emission which might out-compete with neutron evaporation.

  20. Neutron beta decay studies with Nab

    NASA Astrophysics Data System (ADS)

    Baeßler, S.; Alarcon, R.; Alonzi, L. P.; Balascuta, S.; Barrón-Palos, L.; Bowman, J. D.; Bychkov, M. A.; Byrne, J.; Calarco, J. R.; Chupp, T.; Cianciolo, T. V.; Crawford, C.; Frlež, E.; Gericke, M. T.; Glück, F.; Greene, G. L.; Grzywacz, R. K.; Gudkov, V.; Harrison, D.; Hersman, F. W.; Ito, T.; Makela, M.; Martin, J.; McGaughey, P. L.; McGovern, S.; Page, S.; Penttilä, S. I.; Počanić, D.; Rykaczewski, K. P.; Salas-Bacci, A.; Tompkins, Z.; Wagner, D.; Wilburn, W. S.; Young, A. R.

    2013-10-01

    Precision measurements in neutron beta decay serve to determine the coupling constants of beta decay and allow for several stringent tests of the standard model. This paper discusses the design and the expected performance of the Nab spectrometer.

  1. Space Radiation

    NASA Technical Reports Server (NTRS)

    Wu, Honglu

    2006-01-01

    Astronauts receive the highest occupational radiation exposure. Effective protections are needed to ensure the safety of astronauts on long duration space missions. Increased cancer morbidity or mortality risk in astronauts may be caused by occupational radiation exposure. Acute and late radiation damage to the central nervous system (CNS) may lead to changes in motor function and behavior, or neurological disorders. Radiation exposure may result in degenerative tissue diseases (non-cancer or non-CNS) such as cardiac, circulatory, or digestive diseases, as well as cataracts. Acute radiation syndromes may occur due to occupational radiation exposure.

  2. Search for hadronic b-->u decays

    NASA Astrophysics Data System (ADS)

    Albrecht, H.; Gläser, R.; Harder, G.; Krüger, A.; Nilsson, A. W.; Nippe, A.; Oest, T.; Reidenbach, M.; Schäfer, M.; Schmidt-Parzefall, W.; Schröder, H.; Schulz, H. D.; Sefkow, F.; Wurth, R.; Appuhn, R. D.; Drescher, A.; Hast, C.; Herrera, G.; Kolanoski, H.; Lange, A.; Lindner, A.; Mankel, R.; Scheck, H.; Schweda, G.; Spaan, B.; Walther, A.; Wegener, D.; Paulini, M.; Reim, K.; Volland, U.; Wegener, H.; Funk, W.; Stiewe, J.; Werner, S.; Ball, S.; Gabriel, J. C.; Geyer, C.; Hölscher, A.; Hofmann, W.; Holzer, B.; Khan, S.; Spengler, J.; Charlesworth, C. E. K.; Edwards, K. W.; Frisken, W. R.; Kapitza, H.; Krieger, P.; Kutschke, R.; Macfarlene, D. B.; McLean, K. W.; Orr, R. S.; Parsons, J. A.; Patel, P. M.; Prentice, J. D.; Seidel, S. C.; Swain, J. D.; Tsipolitis, G.; Tzamariudaki, K.; Yoon, T.-S.; Ruf, T.; Schael, S.; Schubert, K. R.; Strahl, K.; Waldi, R.; Weseler, S.; Boštjančič, B.; Kernel, G.; Križan, P.; Križnič, E.; Cronström, H. I.; Jönsson, L.; Babaev, A.; Danilo, M.; Fominykh, B.; Golutvin, A.; Gorelov, I.; Lubimov, V.; Rostovtsev, A.; Semenov, A.; Semenov, S.; Shevchenko, V.; Soloshenko, V.; Tchistilin, V.; Tichomirov, I.; Zaitsev, Yu.; Childers, R.; Darden, C. W.; Argus Collaboration

    1990-05-01

    Using the ARGUS detector at the e +e - storage ring DORIS II at DESY, we searched for b→u transitions in exclusive hadronic B meson decays. A systematic analysis of B decays into pions has been performed for decay modes with 2-7 pions in the final state. In none of the decays a positive signal was observed. The upper limits obtained on various branching ratios are consistent with the current model predictions.

  3. QCD corrections to flavor changing neutral coupling mediated rare top quark decays

    SciTech Connect

    Drobnak, Jure; Kamenik, Jernej F.; Fajfer, Svjetlana

    2010-10-01

    Recently we have presented an analysis of flavor changing neutral coupling mediated radiative top quark decays at next-to-leading order in QCD. In the present paper we provide the details of the calculation of QCD corrections to t{yields}q{gamma} and t{yields}qZ decays within the effective theory approach including operator mixing. In particular, we calculate virtual matrix element corrections and the corresponding bremsstrahlung contributions. In the case of t{yields}q{gamma} we study the effects of kinematic cuts on the extracted branching ratios. Analytical formulas are given at all stages of the calculation. We find that the t{yields}q{gamma} decay can be used to probe also the effective operators mediating t{yields}qg processes, since these can naturally contribute 10% or more to the radiative decay, given typical experimental cuts on the decay kinematics at hadron colliders. Conversely, we argue that any positive experimental signal of the t{yields}qg process would indicate a natural lower bound on t{yields}q{gamma} decay rate.

  4. Dark radiation emerging after big bang nucleosynthesis?

    SciTech Connect

    Fischler, Willy; Meyers, Joel

    2011-03-15

    We show how recent data from observations of the cosmic microwave background may suggest the presence of additional radiation density which appeared after big bang nucleosynthesis. We propose a general scheme by which this radiation could be produced from the decay of nonrelativistic matter, we place constraints on the properties of such matter, and we give specific examples of scenarios in which this general scheme may be realized.

  5. Rare Z decays and new physics

    SciTech Connect

    Glover, E.W.N.

    1990-04-01

    Although the signatures for rare Z decays are often spectacular, the predicted standard model rates are usually extremely small. In many cases, however, rare decays are very sensitive to new phenomena and may lead to an observable rate. In this talk, I select some interesting rare decays and discuss how new physics might be identified. 25 refs., 4 figs., 2 tabs.

  6. Observation of Doppler broadening in β -delayed proton- γ decay

    DOE PAGES

    Schwartz, S. B.; Wrede, C.; Bennett, M. B.; ...

    2015-09-14

    Background: The Doppler broadening of gamma-ray peaks is due to nuclear recoil from beta-delayed nucleon emission can be used to measure the energies of the nucleons. This method has never been tested using beta-delayed proton emission or applied to a recoil heavier than A = 10. Purpose: To test and apply this Doppler broadening method using gamma-ray peaks from the P-26(beta p gamma)Al-25 decay sequence. Methods: A fast beam of P-26 was implanted into a planar Ge detector, which was used as a P-26 beta-decay trigger. The SeGA array of high-purity Ge detectors was used to detect gamma rays frommore » the P-26(beta p gamma)Al-25 decay sequence. Results: Radiative Doppler broadening in beta-delayed proton-gamma decay was observed for the first time. Moreover, the Doppler broadening analysis method was verified using the 1613-keV gamma-ray line for which the proton energies were previously known. The 1776-keV gamma ray de-exciting the 2720 keV Al-25 level was observed in P-26(beta p gamma)Al-25 decay for the first time and used to determine that the center-of-mass energy of the proton emission feeding the 2720-keV level is 5.1 +/- 1.0 (stat.) +/- 0.6 (syst.) MeV, corresponding to a Si-26 excitation energy of 13.3 +/- 1.0 (stat.) +/- 0.6 (syst.) MeV for the proton-emitting level. Conclusions: Finally, the Doppler broadening method has been demonstrated to provide practical measurements of the energies for beta-delayed nucleon emissions populating excited states of nuclear recoils at least as heavy as A = 25.« less

  7. Sequential Decays of the Υ''

    NASA Astrophysics Data System (ADS)

    Heintz, H.; Kaarsberg, T.; Lee-Franzini, J.; Lovelock, D. M. J.; Narain, M.; Schamberger, R. D.; Willins, J.; Yanagisawa, C.; Franzini, P.; Tuts, P. M.; Kanekal, S.; Wu, Q.-W.

    1991-03-01

    We have studied the decay chain Υ''-->χ'b(χb)γ-->Υ'(Υ)γγ-->μμ(ee)γγwith the CUSB II detector at the Cornell Electron Storage Ring. For a sample of 1.33×106 Υ'''s we find ~400 events. We measure branching ratios forχ'bJ-->Υ'(Υ)γ and, using calculated E1 rates, we derive total and hadronic widths of theχ'b states. From these widths we obtain values of as in the range between 0.13 and 0.21, in agreement with other determinations. We observe the suppressed decay Υ''-->χbγ. The measured branching ratio suggests that relativistic effects are important. We also determine the branching ratios for Υ''-->Υ'π0π0 to be (1.3+/-0.4+/-0.2)% andΥ''-->Υπ0π0 to be (1.8+/-0.3+/-0.2)%.

  8. Status of Pion Decay Experiments

    NASA Astrophysics Data System (ADS)

    Numao, T.

    2016-11-01

    The branching ratio of pion decays, {Re/}_μ = Γ ({{{π }}^ + } \\to {e^ + }ν + {e^ + }{{ν γ }})/Γ ({{{π }}^ + } \\to {{{μ }}^ + }ν + {{{μ }}^ + }ν {{γ }}), has provided a sensitive test of electron-muon universality in weak interactions. The uncertainty of the Standard Model prediction is at a 0.01% level. Although a recent measurement, Re /μ = (1.2344 ± 0.0023(stat) ± 0.0019(syst)) × 10-4, reduced the experimental uncertainty by a factor of two, there is room for improvement by more than an order of magnitude. The status of two {{{π }}^ + } \\to {e^ + }ν experiments at TRIUMF and PSI as well as related pion decay experiments is presented.

  9. Lattice study of semileptonic B decays: B¯-->Dlν¯ decays

    NASA Astrophysics Data System (ADS)

    Bowler, K. C.; Hazel, N. M.; Henty, D. S.; Hoeber, H.; Kenway, R. D.; Richards, D. G.; Shanahan, H. P.; Simone, J. N.; Lellouch, L.; Nieves, J.; Sachrajda, C. T.; Wittig, H.

    1995-11-01

    We present a study of semileptonic B¯-->Dlν¯ decays in quenched lattice QCD through a calculation of the matrix element on a 243×48 lattice at β=6.2, using an O(a)-improved fermion action. We perform the calculation for several values of the initial and final heavy-quark masses around the charm mass, and three values of the light-(anti)quark mass around the strange mass. Because the charm quark has a bare mass which is almost 1/3 the inverse lattice spacing, we study the ensuing mass-dependent discretization errors, and propose a procedure for subtracting at least some of them nonperturbatively. We extract the form factors h+ and h-. After radiative corrections, we find that h+ displays no dependence on the heavy-quark mass, enabling us to identify it with an Isgur-Wise function ξ. Interpolating the light-quark mass to that of the strange, we obtain an Isgur-Wise function relevant for B¯s-->D(*)slν¯ decays which has a slope -ξ's=1.2+2-2 (stat)+2-1 (syst) at zero recoil. An extrapolation to a massless light quark enables us to obtain an Isgur-Wise function relevant for B¯-->D(*)lν¯ decays. This function has a slope -ξu,d'=0.9+2-3 (stat)+4-2 (syst) at zero recoil. We observe a slight decrease in the magnitude of the central value of the slope as the mass of the light quark is reduced; given the errors, however, the significance of this observation is limited. We then use these functions, in conjunction with heavy-quark effective theory, to extract Vcb with no free parameters from the B¯-->D*lν¯ decay rate measured by the ALEPH, ARGUS, and CLEO Collaborations. Using the CLEO data, for instance, we obtain ||Vcb|| =0.037+1+2+4-1-2-1[0.99/1+βA1(1)]1/1 +δ21/mc, where δ21/mc is the power correction inversely proportional to the square of the charm quark mass, and βA1(1) is the relevant radiative correction at zero recoil. Here, the first set of errors is experimental, the second represents the statistical error, and the third

  10. Nuclear Decay Data: On-going Studies to Address and Improve Radionuclide Decay Characteristics

    NASA Astrophysics Data System (ADS)

    Nichols, Alan L.

    2005-05-01

    Representative decay data studies are described and reviewed, ranging from various measurement programmes to the maintenance of evaluated decay-data libraries. Gross beta-decay measurements are essential to address the decay-data requirements for short-lived fission products, well-defined half-lives are required in assessments of the storage of long-lived radionuclides in waste depositories, and improved decay data continue to be demanded in safeguards, to improve detector-calibration standards, and for medical and analytical applications. Such needs require the measurement of good quality decay data, along with multinational evaluations of decay schemes by means of agreed procedures.

  11. Optical spectroscopy and tooth decay

    NASA Astrophysics Data System (ADS)

    Misra, P.; De, T.; Singh, R.

    2005-11-01

    Optical spectroscopy in the ultraviolet, visible and mid-infrared spectral regions has been used to discriminate between healthy and diseased teeth of patients in the age range 15-75 years. Spectral scans of absorbance versus wavenumber and fluorescence intensity versus wavelength have been recorded and investigated for caries and periodontal disease. Such optical diagnostics can prove very useful in the early detection and treatment of tooth decay.

  12. Nuclear structure from radioactive decay

    SciTech Connect

    Wood, J.L.

    1991-09-30

    This report discusses nuclear structure from radioactive decay of the following: Neutron-Deficient Iridium Isotopes; Neutron-Deficient Platinum Isotopes; Neutron-Deficient Gold Isotopes; Neutron-Deficient Mercury Isotopes; Neutron-Deficient Thallium Isotopes; Neutron-Deficient Lead Isotopes; Neutron-Deficient Samarium Isotopes; Neutron-Deficient Promethium Isotopes; Neutron-Deficient Neodymium Isotopes; and Neutron-Deficient Praseodymium Isotopes. Also discussed are Nuclear Systematics and Models.

  13. Proton Decay Searches with DUNE

    NASA Astrophysics Data System (ADS)

    Wood, Kevin

    2017-01-01

    The Deep Underground Neutrino Experiment (DUNE) will be comprised of a beam line and near detector complex at Fermilab, Illinois as well as a massive far detector located 1300 km away at Sanford Underground Research Facility (SURF), South Dakota. To achieve its rich physics program, DUNE plans to construct a 40kt fiducial volume Liquid Argon Time Projection Chamber (LArTPC) far detector almost a mile underground. The size, location, and technology of the proposed far detector make it an attractive tool to search for proton decay, which has yet to be observed. Observation of such a rare event requires high sensitivity to the signal and high background rejection rate. A particular background of interest arises from cosmic muons interacting with rock surrounding the detector and producing a variety of particles which can enter the detector and leave signatures similar to that of proton decay. In order to keep this background to a reasonable level without sacrificing signal acceptance efficiency, precise tracking, made possible by the LArTPC technology, is required. Precise 3D localization of proton decay events relies on the detector's ability to identify the prompt emission of scintillation light from proton decay events as the t0-defining signal. Therefore, low background rate and high detection efficiency of this light are the crucial to the search. This work examines these characteristics in a detailed Monte Carlo simulation using DUNE`s far detector reference design and demonstrates a high signal efficiency while keeping the expected number of cosmogenic background events sufficiently low.

  14. Current double beta decay experiments

    NASA Astrophysics Data System (ADS)

    Giuliani, A.

    2005-01-01

    After an introduction about double beta decay and the deep connections between the lepton-violating channel and the neutrino properties, the most sensitive experimental approaches to the search for this rare nuclear transition are described. An overview of the experiments presently running is then given, with particular emphasis on the adopted techniques and their possible extrapolation to next-generation, higher-sensitivity experiments. The present situation about the experimental determination of the Majorana neutrino mass is presented and discussed.

  15. Theory of {tau} mesonic decays

    SciTech Connect

    Li, B.A.

    1997-02-01

    Studies of {tau} mesonic decays are presented. A mechanism for the axial-vector current at low energies is proposed. The VMD is used to treat the vector current. All the meson vertices of both normal parity and abnormal parity (Wess-Zumino-Witten anomaly) are obtained from an effective chiral theory of mesons. a{sub 1} dominance is found in the decay modes of the {tau} lepton: 3{pi}, f(1285){pi}. Both the {rho} and the a{sub 1} meson contribute to the decay {tau}{r_arrow}K{sup {asterisk}}K{nu}; it is found that the vector current is dominant. CVC is tested by studying e{sup +}e{sup {minus}}{r_arrow}{pi}{sup +}{pi}{sup {minus}}. The branching ratios of {tau}{r_arrow}{omega}{pi}{nu} and K{bar K}{nu} are calculated. In terms of a similar mechanism the {Delta}s=1 decay modes of the {tau} lepton are studied and K{sub a} dominance is found in {tau}{r_arrow}K{sup {asterisk}}{pi}{nu} and K{sup {asterisk}}{eta}{nu}. The suppression of {tau}{r_arrow}K{rho}{nu} is revealed. The branching ratio of {tau}{r_arrow}{eta}K{nu} is computed. As a test of this theory, the form factors of {pi}{r_arrow}e{gamma}{nu} and K{r_arrow}e{gamma}{nu} are determined. The theoretical results agree with data reasonably well. {copyright} {ital 1997} {ital The American Physical Society}

  16. Beta Decay in the Field of an Electromagnetic Wave and Experiments on Measuring the Neutrino Mass

    SciTech Connect

    Dorofeev, O.F.; Lobanov, A.E.

    2005-06-01

    Investigations of the effect of an electromagnetic wave field on the beta-decay process are used to analyze the tritium-decay experimental data on the neutrino mass. It is shown that the electromagnetic wave can distort the beta spectrum, shifting the end point to the higher energy region. This phenomenon is purely classical and it is associated with the electron acceleration in the radiation field. Since strong magnetic fields exist in setups for precise measurement of the neutrino mass, the indicated field can appear owing to the synchrotron radiation mechanism. The phenomenon under consideration can explain the experimentally observed anomalies in the spectrum of the decay electrons; in particular, the effect of the 'negative square of the neutrino mass'.

  17. Tunneling decay of false vortices

    NASA Astrophysics Data System (ADS)

    Lee, Bum-Hoon; Lee, Wonwoo; MacKenzie, Richard; Paranjape, M. B.; Yajnik, U. A.; Yeom, Dong-han

    2013-10-01

    We consider the decay of vortices trapped in the false vacuum of a theory of scalar electrodynamics in 2+1 dimensions. The potential is inspired by models with intermediate symmetry breaking to a metastable vacuum that completely breaks a U(1) symmetry, while in the true vacuum, the symmetry is unbroken. The false vacuum is unstable through the formation of true vacuum bubbles; however, the rate of decay can be extremely long. On the other hand, the false vacuum can contain metastable vortex solutions. These vortices contain the true vacuum inside in addition to a unit of magnetic flux and the appropriate topologically nontrivial false vacuum outside. We numerically establish the existence of vortex solutions which are classically stable; however, they can decay via tunneling. In general terms, they tunnel to a configuration which is a large, thin-walled vortex configuration that is now classically unstable to the expansion of its radius. We compute an estimate for the tunneling amplitude in the semiclassical approximation. We believe our analysis would be relevant to superconducting thin films or superfluids.

  18. Neutrino mass from triton decay

    NASA Astrophysics Data System (ADS)

    Weinheimer, Christian

    2006-07-01

    Since the discovery of neutrino flavor oscillation in different fields and by many different experiments we believe that neutrinos have non-vanishing masses in contrast to their current description within the Standard Model of particle physics. However, the absolute values of the neutrino masses, which are as important for particle physics as they are for cosmology and astrophysics, cannot be determined by oscillation experiments alone. There are a few ways to determine the neutrino mass scale, but the only model-independent method is the investigation of the electron energy spectrum of a β decay near its endpoint with tritium being the ideal isotope for the classical spectrometer set-up. The tritium β decay experiments at Mainz and Troitsk have recently been finished. At Mainz all relevant systematic uncertainties have been investigated by dedicated experiments yielding an upper limit of m(ν)<2.3eV/c (90% C.L.). The new Karlsruhe Tritium Neutrino Experiment (KATRIN) will enhance the sensitivity on the neutrino mass by an ultra-precise measurement of the tritium β decay spectrum near the endpoint by another order of magnitude down to 0.2 eV/c2 by using a very strong windowless gaseous molecular tritium source and a huge ultra-high resolution electrostatic spectrometer of MAC-E-Filter type. The recent achievements in test experiments show, that this very challenging experiment is feasible.

  19. β decay of 129Cd and excited states in 129In

    NASA Astrophysics Data System (ADS)

    Taprogge, J.; Jungclaus, A.; Grawe, H.; Nishimura, S.; Doornenbal, P.; Lorusso, G.; Simpson, G. S.; Söderström, P.-A.; Sumikama, T.; Xu, Z. Y.; Baba, H.; Browne, F.; Fukuda, N.; Gernhäuser, R.; Gey, G.; Inabe, N.; Isobe, T.; Jung, H. S.; Kameda, D.; Kim, G. D.; Kim, Y.-K.; Kojouharov, I.; Kubo, T.; Kurz, N.; Kwon, Y. K.; Li, Z.; Sakurai, H.; Schaffner, H.; Steiger, K.; Suzuki, H.; Takeda, H.; Vajta, Zs.; Watanabe, H.; Wu, J.; Yagi, A.; Yoshinaga, K.; Benzoni, G.; Bönig, S.; Chae, K. Y.; Coraggio, L.; Covello, A.; Daugas, J.-M.; Drouet, F.; Gadea, A.; Gargano, A.; Ilieva, S.; Kondev, F. G.; Kröll, T.; Lane, G. J.; Montaner-Pizá, A.; Moschner, K.; Mücher, D.; Naqvi, F.; Niikura, M.; Nishibata, H.; Odahara, A.; Orlandi, R.; Patel, Z.; Podolyák, Zs.; Wendt, A.

    2015-05-01

    The β decay of 129Cd, produced in the relativistic fission of a 238U beam, was experimentally studied at the RIBF facility at the RIKEN Nishina Center. From the γ radiation emitted after the β decays, a level scheme of 129In was established comprising 31 excited states and 69 γ -ray transitions. The experimentally determined level energies are compared to state-of-the-art shell-model calculations. The half-lives of the two β -decaying states in 129Cd were deduced and the β feeding to excited states in 129In were analyzed. It is found that, as in most cases in the Z <50 , N ≤82 region, both decays are dominated by the ν 0 g7 /2→π 0 g9 /2 Gamow-Teller transition, although the contribution of first-forbidden transitions cannot be neglected.

  20. b--> sl{sup +}l{sup {minus}} Decays in and Beyond the Standard Model

    SciTech Connect

    Hiller, Gudrun

    2000-08-11

    The authors briefly review the status of rare radiative and semileptonic b --> s(gamma,l{sup +}l{sup {minus}}), (l=e,mu) decays. They discuss possible signatures of new physics in these modes and emphasize the role of the exclusive channels. In particular, measurements of the Forward-Backward asymmetry in B -->K*l{sup +}l{sup {minus}} decays and its zero provide a clean test of the Standard Model, complementary to studies in b -->s gamma decays. Further, the Forward-Backward CP asymmetry in B --> K*l{sup +}l{sup {minus}} decays is sensitive to possible non-standard sources of CP violation mediated by Flavor changing neutral current Z-penguins.

  1. Constraints on hadronically decaying dark matter

    SciTech Connect

    Garny, Mathias; Ibarra, Alejandro; Tran, David E-mail: alejandro.ibarra@ph.tum.de

    2012-08-01

    We present general constraints on dark matter stability in hadronic decay channels derived from measurements of cosmic-ray antiprotons. We analyze various hadronic decay modes in a model-independent manner by examining the lowest-order decays allowed by gauge and Lorentz invariance for scalar and fermionic dark matter particles and present the corresponding lower bounds on the partial decay lifetimes in those channels. We also investigate the complementarity between hadronic and gamma-ray constraints derived from searches for monochromatic lines in the sky, which can be produced at the quantum level if the dark matter decays into quark-antiquark pairs at leading order.

  2. Leptonic decays of the Ds meson

    NASA Astrophysics Data System (ADS)

    ALEPH Collaboration; Heister, A.; Schael, S.; Barate, R.; De Bonis, I.; Decamp, D.; Goy, C.; Lees, J.-P.; Merle, E.; Minard, M.-N.; Pietrzyk, B.; Boix, G.; Bravo, S.; Casado, M. P.; Chmeissani, M.; Crespo, J. M.; Fernandez, E.; Fernandez-Bosman, M.; Garrido, Ll.; Graugés, E.; Martinez, M.; Merino, G.; Miquel, R.; Mir, Ll. M.; Pacheco, A.; Ruiz, H.; Colaleo, A.; Creanza, D.; de Palma, M.; Iaselli, G.; Maggi, G.; Maggi, M.; Nuzzo, S.; Ranieri, A.; Raso, G.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Tricomi, A.; Zito, G.; Huang, X.; Lin, J.; Ouyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Abbaneo, D.; Azzurri, P.; Buchmüller, O.; Cattaneo, M.; Cerutti, F.; Clerbaux, B.; Drevermann, H.; Forty, R. W.; Frank, M.; Gianotti, F.; Greening, T. C.; Hansen, J. B.; Harvey, J.; Hutchcroft, D. E.; Janot, P.; Jost, B.; Kado, M.; Mato, P.; Moutoussi, A.; Ranjard, F.; Rolandi, L.; Schlatter, D.; Schneider, O.; Sguazzoni, G.; Tejessy, W.; Teubert, F.; Valassi, A.; Videau, I.; Ward, J.; Badaud, F.; Falvard, A.; Gay, P.; Henrard, P.; Jousset, J.; Michel, B.; Monteil, S.; Montret, J.-C.; Pallin, D.; Perret, P.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Nilsson, B. S.; Wäänänen, A.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Vayaki, A.; Zachariadou, K.; Blondel, A.; Bonneaud, G.; Brient, J.-C.; Rougé, A.; Rumpf, M.; Swynghedauw, M.; Verderi, M.; Videau, H.; Ciulli, V.; Focardi, E.; Parrini, G.; Antonelli, A.; Antonelli, M.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Chiarella, V.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Passalacqua, L.; Pepe-Altarelli, M.; Spagnolo, P.; Halley, A.; Lynch, J. G.; Negus, P.; O'Shea, V.; Raine, C.; Thompson, A. S.; Wasserbaech, S.; Cavanaugh, R.; Dhamotharan, S.; Geweniger, C.; Hanke, P.; Hansper, G.; Hepp, V.; Kluge, E. E.; Putzer, A.; Sommer, J.; Stenzel, H.; Tittel, K.; Werner, S.; Wunsch, M.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Dornan, P. J.; Girone, M.; Marinelli, N.; Sedgbeer, J. K.; Thompson, J. C.; Ghete, V. M.; Girtler, P.; Kneringer, E.; Kuhn, D.; Rudolph, G.; Bouhova-Thacker, E.; Bowdery, C. K.; Finch, A. J.; Foster, F.; Hughes, G.; Jones, R. W. L.; Pearson, M. R.; Robertson, N. A.; Jakobs, K.; Kleinknecht, K.; Quast, G.; Renk, B.; Sander, H.-G.; Wachsmuth, H.; Zeitnitz, C.; Bonissent, A.; Carr, J.; Coyle, P.; Leroy, O.; Payre, P.; Rousseau, D.; Talby, M.; Ragusa, F.; David, A.; Dietl, H.; Ganis, G.; Hüttmann, K.; Lütjens, G.; Mannert, C.; Männer, W.; Moser, H.-G.; Settles, R.; Wiedenmann, W.; Wolf, G.; Boucrot, J.; Callot, O.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, Ph.; Jacholkowska, A.; Lefrançois, J.; Veillet, J.-J.; Yuan, C.; Bagliesi, G.; Boccali, T.; Foà, L.; Giammanco, A.; Giassi, A.; Ligabue, F.; Messineo, A.; Palla, F.; Sanguinetti, G.; Sciabà, A.; Tenchini, R.; Venturi, A.; Verdini, P. G.; Blair, G. A.; Cowan, G.; Green, M. G.; Medcalf, T.; Misiejuk, A.; Strong, J. A.; Teixeira-Dias, P.; von Wimmersperg-Toeller, J. H.; Clifft, R. W.; Edgecock, T. R.; Norton, P. R.; Tomalin, I. R.; Bloch-Devaux, B.; Colas, P.; Emery, S.; Kozanecki, W.; Lançon, E.; Lemaire, M.-C.; Locci, E.; Perez, P.; Rander, J.; Renardy, J.-F.; Roussarie, A.; Schuller, J.-P.; Schwindling, J.; Trabelsi, A.; Vallage, B.; Konstantinidis, N.; Litke, A. M.; Taylor, G.; Booth, C. N.; Cartwright, S.; Combley, F.; Lehto, M.; Thompson, L. F.; Affholderbach, K.; Böhrer, A.; Brandt, S.; Grupen, C.; Ngac, A.; Prange, G.; Sieler, U.; Giannini, G.; He, H.; Putz, J.; Rothberg, J.; Armstrong, S. R.; Berkelman, K.; Cranmer, K.; Ferguson, D. P. S.; Gao, Y.; González, S.; Hayes, O. J.; Hu, H.; Jin, S.; Kile, J.; McNamara, P. A.; Nielsen, J.; Pan, Y. B.; von Wimmersperg-Toeller, J. H.; Wiedenmann, W.; Wu, J.; Wu, Sau Lan; Wu, X.; Zobernig, G.; Dissertori, G.

    2002-02-01

    The purely leptonic decays Ds-->τν and Ds-->μν are studied in a sample of four million hadronic /Z decays collected with the ALEPH detector at the LEP e+e- collider from 1991 to 1995. The branching fractions are extracted from a combination of two analyses, one optimized to select Ds-->τν decays with /τ-->eνν¯ or /μνν¯, and the other optimized for Ds-->μν decays. The results are used to evaluate the Ds decay constant, within the Standard Model: fDs=[285+/-19(stat)+/-40(syst)] MeV.

  3. Radiological Dispersion Devices and Basic Radiation Science

    ERIC Educational Resources Information Center

    Bevelacqua, Joseph John

    2010-01-01

    Introductory physics courses present the basic concepts of radioactivity and an overview of nuclear physics that emphasizes the basic decay relationship and the various types of emitted radiation. Although this presentation provides insight into radiological science, it often fails to interest students to explore these concepts in a more rigorous…

  4. Search for monenergetic gamma rays from psi /3684/ decay

    NASA Technical Reports Server (NTRS)

    Simpson, J. W.; Beron, B. L.; Ford, R. L.; Hofstadter, R.; Howell, R. L.; Hughes, E. B.; Liberman, A. D.; Martin, T. W.; Oneill, L. H.; Hilger, E.

    1975-01-01

    Results are reported of a search for monoenergetic gamma rays with energies above 50 MeV arising from psi (3684) decay. The measurements were made by operating an electron-positron storage ring at a center-of-mass energy of 3684 MeV and detecting the secondary gamma rays with large-crystal NaI(T1) spectrometers. No significant evidence is found for the emission of such radiation, and upper limits are placed on such emissions for energies above 50 MeV.

  5. Searching for Decaying Axionlike Dark Matter from Clusters of Galaxies

    SciTech Connect

    Riemer-Soerensen, Signe; Hansen, Steen H.; Pedersen, Kristian; Zioutas, Konstantin; Dahle, Haakon; Liolios, Anastasios

    2007-09-28

    We constrain the lifetime of radiatively decaying dark matter in clusters of galaxies inspired by generic Kaluza-Klein axions, which have been invoked as a possible explanation for the solar coronal x-ray emission. These particles can be produced inside stars and remain confined by the gravitational potential of clusters. By analyzing x-ray observations of merging clusters, where gravitational lensing observations have identified massive, baryon poor structures, we derive the first cosmological lifetime constraint on this kind of particles of {tau} > or approx. 10{sup 23} sec.

  6. Polarization of photons emitted by decaying dark matter

    NASA Astrophysics Data System (ADS)

    Bonivento, W.; Gorbunov, D.; Shaposhnikov, M.; Tokareva, A.

    2017-02-01

    Radiatively decaying dark matter may be searched through investigating the photon spectrum of galaxies and galaxy clusters. We explore whether the properties of dark matter can be constrained through the study of a polarization state of emitted photons. Starting from the basic principles of quantum mechanics we show that the models of symmetric dark matter are indiscernible by the photon polarization. However, we find that the asymmetric dark matter consisted of Dirac fermions is a source of circularly polarized photons, calling for the experimental determination of the photon state.

  7. Mechanisms of fluorescence decays of colloidal CdSe-CdS/ZnS quantum dots unraveled by time-resolved fluorescence measurement.

    PubMed

    Xu, Hao; Chmyrov, Volodymyr; Widengren, Jerker; Brismar, Hjalmar; Fu, Ying

    2015-11-07

    By narrowing the detection bandpass and increasing the signal-to-noise ratio in measuring the time-resolved fluorescence decay spectrum of colloidal CdSe-CdS/ZnS quantum dots (QDs), we show that directly after the photoexcitation, the fluorescence decay spectrum is characterized by a single exponential decay, which represents the energy relaxation of the photogenerated exciton from its initial high-energy state to the ground exciton state. The fluorescence decay spectrum of long decay time is in the form of β/t(2), where β is the radiative recombination time of the ground-state exciton and t is the decay time. Our findings provide us with a direct and quantitative link between fluorescence decay measurement data and fundamental photophysics of QD exciton, thereby leading to a novel way of applying colloidal QDs to study microscopic, physical and chemical processes in many fields including biomedicine.

  8. Heavy flavor decay of Zgamma at CDF

    NASA Astrophysics Data System (ADS)

    Harrington-Taber, Timothy M.

    According to the Standard Model of particle physics, elementary particles interact via the exchange of mediator particles. The specific mediator particle depends on the force: gluons for the strong nuclear force, photons for the electromagnetic force, and W and Z bosons for the weak nuclear force. No quantum theory of gravity has been deemed adequate by the community at this time, and no gravity-mediating particle (graviton is the proposed name for such a particle) is included in the Standard Model. As gravity is much weaker than the other fundamental forces at the particle level, this does not currently pose practical difficulties for elementary particle physics. In order to specifically study W and Z bosons, it is necessary to generate high-energy beams of particles, which are collided, and whose collisions (hopefully) produce the 90 GeV required for Z boson production. Typically, electrons and protons are the particle of choice for these beams. In order to obtain the necessary energies, circular collider facilities have been the highest energy sites for years. As electrons radiate energy when in circular orbits, by the late 1980's proton colliders have been the primary choice for high-energy physics. One such collider, built at Fermilab National Accelerator Laboratory in Batavia, Illinois, was the Tevatron, which started operations in 1984 and finally shut down in 2011. The Tevatron collided protons with anti-protons with a center of mass energy of 1.96 TeV for ten years (2001-2011) after a series of upgrades known collectively as Run II. Of the two detectors at the Tevatron, this analysis considers events observed at the Collider Detector at Fermilab (CDF) during Run II. Results can be usefully cross-checked by the other detector, D0. This thesis includes a technical description of the silicon tracking system at the CDF detector, including an account of challenges encountered during its operation and some of the personal work done to assist in its continuing

  9. The use of decay rates to analyse the performance of railway track in rolling noise generation

    NASA Astrophysics Data System (ADS)

    Jones, C. J. C.; Thompson, D. J.; Diehl, R. J.

    2006-06-01

    Through the development and testing of theoretical models for rolling noise in the past, it has been well demonstrated that the rate of decay of vibration along the rail is closely linked to the noise performance of the track, since it controls the effective radiating length of the rail. The decay rates of vibration along the rail have long been used by researchers as an intermediate, measurable parameter by which to test and improve the accuracy of prediction models. Recently, it has been suggested that the decay rates should be used as a criterion for the selection of track for noise measurements that are part of the acceptance testing of interoperable trains in Europe. In this context, a more detailed understanding of the factors that affect the measurement of decay rates and a consistent approach to the data processing have become important topics. Here, a method is suggested for the calculation of decay rates from frequency response measurements. Different effects are shown in the measured decay rates of a ballasted track with mono-bloc sleepers, a slab track and a ballasted track with bi-bloc sleepers. In the last case, a model for a periodically supported track is used to study the effects observed. It is shown that a peak in the decay rate just above the pinned-pinned frequency may be overestimated because of the measurement procedure that has been used.

  10. Radiation Proctopathy

    PubMed Central

    Grodsky, Marc B.; Sidani, Shafik M.

    2015-01-01

    Radiation therapy is a widely utilized treatment modality for pelvic malignancies, including prostate cancer, rectal cancer, and cervical cancer. Given its fixed position in the pelvis, the rectum is at a high risk for injury secondary to ionizing radiation. Despite advances made in radiation science, up to 75% of the patients will suffer from acute radiation proctitis and up to 20% may experience chronic symptoms. Symptoms can be variable and include diarrhea, bleeding, incontinence, and fistulization. A multitude of treatment options exist. This article summarizes the latest knowledge relating to radiation proctopathy focusing on the vast array of treatment options. PMID:26034407

  11. Radiation dose estimates for radiopharmaceuticals

    SciTech Connect

    Stabin, M.G.; Stubbs, J.B.; Toohey, R.E.

    1996-04-01

    Tables of radiation dose estimates based on the Cristy-Eckerman adult male phantom are provided for a number of radiopharmaceuticals commonly used in nuclear medicine. Radiation dose estimates are listed for all major source organs, and several other organs of interest. The dose estimates were calculated using the MIRD Technique as implemented in the MIRDOSE3 computer code, developed by the Oak Ridge Institute for Science and Education, Radiation Internal Dose Information Center. In this code, residence times for source organs are used with decay data from the MIRD Radionuclide Data and Decay Schemes to produce estimates of radiation dose to organs of standardized phantoms representing individuals of different ages. The adult male phantom of the Cristy-Eckerman phantom series is different from the MIRD 5, or Reference Man phantom in several aspects, the most important of which is the difference in the masses and absorbed fractions for the active (red) marrow. The absorbed fractions for flow energy photons striking the marrow are also different. Other minor differences exist, but are not likely to significantly affect dose estimates calculated with the two phantoms. Assumptions which support each of the dose estimates appears at the bottom of the table of estimates for a given radiopharmaceutical. In most cases, the model kinetics or organ residence times are explicitly given. The results presented here can easily be extended to include other radiopharmaceuticals or phantoms.

  12. τ-→η(')π-ντγ decays as background in the search for second class currents

    NASA Astrophysics Data System (ADS)

    Guevara, A.; López-Castro, G.; Roig, P.

    2017-03-01

    Observation of τ-→η(')π-ντ decays at Belle-II would indicate either a manifestation of isospin symmetry breaking or genuine second class current (SCC) effects. The corresponding radiative τ-→η(')π-ντγ decay channels are not suppressed by G -parity considerations and may represent a serious background in searches of SCCs in the former. We compute the observables associated to these radiative decays using resonance chiral Lagrangians and conclude that vetoing photons with Eγ>100 MeV should get rid of this background in the Belle-II environment while searching for the τ-→η π-ντ channel. Similar considerations hold inconclusive for decays involving the η', given the theory's uncertainties in the prediction of the τ-→η'π-ντ branching ratio. Still, additional kinematics-based cuts should be able to suppress this background in the η' case to a negligible level.

  13. Rare beauty and charm decays at LHCb

    NASA Astrophysics Data System (ADS)

    Albrecht, Johannes

    2013-05-01

    Rare heavy flavor decays are an ideal place to search for the effects of potential new particles that modify the decay rates or the Lorentz structure of the decay vertices. The LHCb experiment, a dedicated heavy flavour experiment at the LHC at CERN. It has recorded the worlds largest sample of heavy meson and lepton decays. The status of the rare decay analyses with 1 fb-1 of √s = 7 TeV and 1.1 fb-1 of √s = 8 TeV of pp-collisions collected by the LHCb experiment in 2011 and 2012 is reviewed. The worlds most precise measurements of the angular structure of B0 → K*0μ+μ- and B+ → K+μ+μ- decays is discussed, as well as the isospin asymmetry measurement in B → K(*)μ+μ- decays. The first evidence for the very rare decay Bs0 → µ+µ- is presented together with the most stringent upper exclusion limits on the branching fraction of decays of B0, D0 and Ks0 mesons into two muons. This note finishes with the discussion of searches for lepton number and lepton flavor violating τ decays.

  14. Stellar structures and the enigma of pulsars rotation frequency decay

    NASA Astrophysics Data System (ADS)

    de Oliveira, H. O.; Marinho, R. M., Jr.; Maglhaes, N. S.

    2015-07-01

    Pulsars are astrophysical objects normally modelled as compact neutron stars that originated from the collapse of another star. This model, that we name canonical, assumes that pulsars are described by spherical magnetized dipoles that rotate, usually with the magnetic axis misaligned to the rotation axis. This misalignment would be responsible for the observation of radiation emitted in well-defined time intervals in a certain direction (lighthouse effect), the typical observational characteristic of this kind of star. It has been noticed that the rotation frequency of pulsars is slowly decaying with time (spin down), implying a gradual decrease of the rotational angular velocity (Ω). Such decay can be quantified by a dimensionless parameter called “braking index” (“n”), given by n = ΩΩ/(Ω)2, where a dot indicates a time derivative. The canonical model predicts that this index has one only value for all pulsars, equal to three. However, observational data indicate that actual braking indices are less than three, representing an enigma. The main goal of this research is the exploration of a more precise model for pulsars’ rotation frequency decay.

  15. Interatomic Coulombic decay cascades in multiply excited neon clusters

    PubMed Central

    Nagaya, K.; Iablonskyi, D.; Golubev, N. V.; Matsunami, K.; Fukuzawa, H.; Motomura, K.; Nishiyama, T.; Sakai, T.; Tachibana, T.; Mondal, S.; Wada, S.; Prince, K. C.; Callegari, C.; Miron, C.; Saito, N.; Yabashi, M.; Demekhin, Ph. V.; Cederbaum, L. S.; Kuleff, A. I.; Yao, M.; Ueda, K.

    2016-01-01

    In high-intensity laser light, matter can be ionized by direct multiphoton absorption even at photon energies below the ionization threshold. However on tuning the laser to the lowest resonant transition, the system becomes multiply excited, and more efficient, indirect ionization pathways become operative. These mechanisms are known as interatomic Coulombic decay (ICD), where one of the species de-excites to its ground state, transferring its energy to ionize another excited species. Here we show that on tuning to a higher resonant transition, a previously unknown type of interatomic Coulombic decay, intra-Rydberg ICD occurs. In it, de-excitation of an atom to a close-lying Rydberg state leads to electron emission from another neighbouring Rydberg atom. Moreover, systems multiply excited to higher Rydberg states will decay by a cascade of such processes, producing even more ions. The intra-Rydberg ICD and cascades are expected to be ubiquitous in weakly-bound systems exposed to high-intensity resonant radiation. PMID:27917867

  16. Interatomic Coulombic decay cascades in multiply excited neon clusters

    NASA Astrophysics Data System (ADS)

    Nagaya, K.; Iablonskyi, D.; Golubev, N. V.; Matsunami, K.; Fukuzawa, H.; Motomura, K.; Nishiyama, T.; Sakai, T.; Tachibana, T.; Mondal, S.; Wada, S.; Prince, K. C.; Callegari, C.; Miron, C.; Saito, N.; Yabashi, M.; Demekhin, Ph. V.; Cederbaum, L. S.; Kuleff, A. I.; Yao, M.; Ueda, K.

    2016-12-01

    In high-intensity laser light, matter can be ionized by direct multiphoton absorption even at photon energies below the ionization threshold. However on tuning the laser to the lowest resonant transition, the system becomes multiply excited, and more efficient, indirect ionization pathways become operative. These mechanisms are known as interatomic Coulombic decay (ICD), where one of the species de-excites to its ground state, transferring its energy to ionize another excited species. Here we show that on tuning to a higher resonant transition, a previously unknown type of interatomic Coulombic decay, intra-Rydberg ICD occurs. In it, de-excitation of an atom to a close-lying Rydberg state leads to electron emission from another neighbouring Rydberg atom. Moreover, systems multiply excited to higher Rydberg states will decay by a cascade of such processes, producing even more ions. The intra-Rydberg ICD and cascades are expected to be ubiquitous in weakly-bound systems exposed to high-intensity resonant radiation.

  17. Searching for Rapid Orbital Decay of WASP-18b

    NASA Astrophysics Data System (ADS)

    Wilkins, Ashlee N.; Delrez, Laetitia; Barker, Adrian J.; Deming, Drake; Hamilton, Douglas; Gillon, Michael; Jehin, Emmanuel

    2017-02-01

    The WASP-18 system, with its massive and extremely close-in planet, WASP-18b (M p = 10.3M J , a = 0.02 au, P = 22.6 hr), is one of the best-known exoplanet laboratories to directly measure Q‧, the modified tidal quality factor and proxy for efficiency of tidal dissipation, of the host star. Previous analysis predicted a rapid orbital decay of the planet toward its host star that should be measurable on the timescale of a few years, if the star is as dissipative as is inferred from the circularization of close-in solar-type binary stars. We have compiled published transit and secondary eclipse timing (as observed by WASP, TRAPPIST, and Spitzer) with more recent unpublished light curves (as observed by TRAPPIST and Hubble Space Telescope) with coverage spanning nine years. We find no signature of a rapid decay. We conclude that the absence of rapid orbital decay most likely derives from Q‧ being larger than was inferred from solar-type stars and find that Q‧ ≥ 1 × 106, at 95% confidence; this supports previous work suggesting that F stars, with their convective cores and thin convective envelopes, are significantly less tidally dissipative than solar-type stars, with radiative cores and large convective envelopes.

  18. Evidence for B→Kη'γ decays at Belle

    NASA Astrophysics Data System (ADS)

    Wedd, R.; Adachi, I.; Aihara, H.; Arinstein, K.; Aulchenko, V.; Bakich, A. M.; Balagura, V.; Barberio, E.; Bay, A.; Belous, K.; Bhardwaj, V.; Bischofberger, M.; Bondar, A.; Bozek, A.; Bračko, M.; Browder, T. E.; Chao, Y.; Chen, A.; Cheon, B. G.; Cho, I.-S.; Choi, Y.; Dalseno, J.; Dash, M.; Drutskoy, A.; Eidelman, S.; Epifanov, D.; Gabyshev, N.; Goldenzweig, P.; Ha, H.; Horii, Y.; Hoshi, Y.; Hou, W.-S.; Hyun, H. J.; Iijima, T.; Inami, K.; Ishikawa, A.; Itoh, R.; Iwasaki, M.; Kah, D. H.; Katayama, N.; Kawai, H.; Kawasaki, T.; Kim, H. O.; Kim, J. H.; Kim, Y. I.; Kim, Y. J.; Kinoshita, K.; Ko, B. R.; Križan, P.; Krokovny, P.; Kuhr, T.; Kumar, R.; Kuzmin, A.; Kwon, Y.-J.; Kyeong, S.-H.; Lee, M. J.; Lee, S.-H.; Lesiak, T.; Li, J.; Limosani, A.; Liu, C.; Liventsev, D.; Louvot, R.; Matyja, A.; McOnie, S.; Miyata, H.; Mizuk, R.; Mori, T.; Nagasaka, Y.; Nakao, M.; Nakazawa, H.; Natkaniec, Z.; Nishida, S.; Nitoh, O.; Ohshima, T.; Okuno, S.; Ozaki, H.; Pakhlov, P.; Pakhlova, G.; Park, C. W.; Park, H. K.; Park, K. S.; Pestotnik, R.; Piilonen, L. E.; Poluektov, A.; Sahoo, H.; Sakai, Y.; Schneider, O.; Schümann, J.; Senyo, K.; Sevior, M. E.; Shapkin, M.; Shebalin, V.; Shiu, J.-G.; Shwartz, B.; Singh, J. B.; Sokolov, A.; Stanič, S.; Starič, M.; Sumisawa, K.; Sumiyoshi, T.; Suzuki, S.; Taylor, G. N.; Teramoto, Y.; Trabelsi, K.; Uehara, S.; Unno, Y.; Uno, S.; Urquijo, P.; Usov, Y.; Varner, G.; Varvell, K. E.; Vervink, K.; Vinokurova, A.; Wang, C. H.; Wang, M.-Z.; Wang, P.; Watanabe, Y.; Wicht, J.; Won, E.; Yabsley, B. D.; Yamamoto, H.; Yamashita, Y.; Zhang, Z. P.; Zhilich, V.; Zhulanov, V.; Zivko, T.; Zupanc, A.; Zyukova, O.; Belle Collaboration

    2010-06-01

    We present the results of a search for the radiative decay B→Kη'γ and find evidence for B+→K+η'γ decays at the 3.3 standard deviation level with a partial branching fraction of (3.6±1.2±0.4)×10-6, where the first error is statistical and the second systematic. This measurement is restricted to the region of combined Kη' invariant mass less than 3.4GeV/c2. A 90% confidence level upper limit of 6.4×10-6 is obtained for the partial branching fraction of the decay B0→K0η'γ in the same Kη' invariant mass region. These results are obtained from a 605fb-1 data sample containing 657×106BB¯ pairs collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider.

  19. Decaying dark matter and the tension in σ8

    NASA Astrophysics Data System (ADS)

    Enqvist, Kari; Nadathur, Seshadri; Sekiguchi, Toyokazu; Takahashi, Tomo

    2015-09-01

    We consider decaying dark matter (DDM) as a resolution to the possible tension between cosmic microwave background (CMB) and weak lensing (WL) based determinations of the amplitude of matter fluctuations, σ8. We perform N-body simulations in a model where dark matter decays into dark radiation and develop an accurate fitting formula for the non-linear matter power spectrum, which enables us to test the DDM model by the combined measurements of CMB, WL and the baryon acoustic oscillation (BAO). We employ a Markov chain Monte Carlo analysis to examine the overlap of posterior distributions of the cosmological parameters, comparing CMB alone with WL+BAO. We find an overlap that is significantly larger in the DDM model than in the standard CDM model. This may be hinting at DDM, although current data is not constraining enough to unambiguously favour a non-zero dark matter decay rate Γ. From the combined CMB+WL data, we obtain a lower bound Γ-1>= 97 Gyr at 95 % C.L, which is less tight than the constraint from CMB alone.

  20. Structure and Decay at Rapid Proton Capture Waiting Points

    NASA Astrophysics Data System (ADS)

    Hove, D.; Garrido, E.; Jensen, A. S.; Fynbo, H. O. U.; Fedorov, D. V.; Zinner, N. T.

    2017-01-01

    We investigate the region of the nuclear chart around A ˜eq 70 from a three-body perspective, where we compute reaction rates for the radiative capture of two protons. One key quantity is here the photon dissociation cross section for the inverse process where two protons are liberated from the borromean nucleus by photon bombardment. We find a number of peaks at low photon energy in this cross section where each peak is located at the energy corresponding to population of a three-body resonance. Thus, for these energies the decay or capture processes proceed through these resonances. However, the next step in the dissociation process still has the option of following several paths, that is either sequential decay by emission of one proton at a time with an intermediate two-body resonance as stepping stone, or direct decay into the continuum of both protons simultaneously. The astrophysical reaction rate is obtained by folding of the cross section as function of energy with the occupation probability for a Maxwell-Boltzmann temperature distribution. The reaction rate is then a function of temperature, and of course depending on the underlying three-body bound state and resonance structures. We show that a very simple formula at low temperature reproduces the elaborate numerically computed reaction rate.

  1. Precursor decay in several aluminas

    NASA Astrophysics Data System (ADS)

    Murray, N. H.; Bourne, N. K.; Rosenberg, Z.

    1996-05-01

    Plate impact experiments were performed on three ceramics with alumina content varying from 88 to 99.9% using a 50 mm single stage gas gun. Tiles of ceramic with thicknesses varying from 2 to 12 mm were impacted above their Hugoniot Elastic Limits (HELs) and the rate dependent strength was investigated by monitoring the variation in amplitude of the elastic precursor with propagation distance. Stress levels in the target were recorded using manganin stress transducers and a 1 GS s-1 storage oscilloscope. All grades of alumina were found to exhibit some elastic precursor decay indicating strain rate sensitivity.

  2. Gravitational effects on inflaton decay

    SciTech Connect

    Ema, Yohei; Jinno, Ryusuke; Mukaida, Kyohei; Nakayama, Kazunori

    2015-05-22

    We point out that the inflaton inevitably couples to all non-conformally coupled matters gravitationally through an oscillation in the Hubble parameter or the cosmic scale factor. It leads to particle production during the inflaton oscillation regime, which is most efficient just after inflation. Moreover, the analysis is extended to the model with non-minimal inflaton couplings to gravity, in which the Hubble parameter oscillates more violently. We apply our results to the graviton production by the inflaton: gravitons are also produced just after inflation, but the non-minimal coupling does not induce inflaton decay into the graviton pair.

  3. Can neutrino decay-driven mock gravity save hot dark matter?

    NASA Technical Reports Server (NTRS)

    Splinter, Randall J.; Melott, Adrian L.

    1992-01-01

    The radiative decay of a 30 eV neutrino with a lifetime of order 10 exp 23-24 s has recently been shown to yield a satisfactory explanation of a wide range of problems in astrophysics. In this paper, it is investigated whether the photon flux generated by the radiative decay of a massive neutrino is capable of generating sufficient radiation pressure to cause a 'mock gravitational' collapse of primordial hydrogen clouds. It is shown that when using neutral hydrogen as a source of opacity for mock gravity the time scale for mock gravitational collapse is significantly larger than the expansion time scale. Thus, the model fails as a source of galactic seed perturbations. Furthermore, it is argued that nonlinear feedback mechanisms will be unable to increase the collapse rate of the cloud under mock gravity.

  4. Radiator technology

    NASA Technical Reports Server (NTRS)

    Juhasz, Albert J.

    1993-01-01

    Radiator technology is discussed in the context of the Civilian Space Technology Initiative's (CSTI's) high capacity power-thermal management project. The CSTI project is a subset of a project to develop a piloted Mars nuclear electric propulsion (NEP) vehicle. The following topics are presented in vugraph form: advanced radiator concepts; heat pipe codes and testing; composite materials; radiator design and integration; and surface morphology.

  5. Hawking radiation

    NASA Astrophysics Data System (ADS)

    Parentani, Renaud; Spindel, Philippe

    2011-12-01

    Hawking radiation is the thermal radiation predicted to be spontaneously emitted by black holes. It arises from the steady conversion of quantum vacuum fluctuations into pairs of particles, one of which escaping at infinity while the other is trapped inside the black hole horizon. It is named after the physicist Stephen Hawking who derived its existence in 1974. This radiation reduces the mass of black holes and is therefore also known as black hole evaporation.

  6. On the decay of homogeneous isotropic turbulence

    NASA Astrophysics Data System (ADS)

    Skrbek, L.; Stalp, Steven R.

    2000-08-01

    Decaying homogeneous, isotropic turbulence is investigated using a phenomenological model based on the three-dimensional turbulent energy spectra. We generalize the approach first used by Comte-Bellot and Corrsin [J. Fluid Mech. 25, 657 (1966)] and revised by Saffman [J. Fluid Mech. 27, 581 (1967); Phys. Fluids 10, 1349 (1967)]. At small wave numbers we assume the spectral energy is proportional to the wave number to an arbitrary power. The specific case of power 2, which follows from the Saffman invariant, is discussed in detail and is later shown to best describe experimental data. For the spectral energy density in the inertial range we apply both the Kolmogorov -5/3 law, E(k)=Cɛ2/3k-5/3, and the refined Kolmogorov law by taking into account intermittency. We show that intermittency affects the energy decay mainly by shifting the position of the virtual origin rather than altering the power law of the energy decay. Additionally, the spectrum is naturally truncated due to the size of the wind tunnel test section, as eddies larger than the physical size of the system cannot exist. We discuss effects associated with the energy-containing length scale saturating at the size of the test section and predict a change in the power law decay of both energy and vorticity. To incorporate viscous corrections to the model, we truncate the spectrum at an effective Kolmogorov wave number kη=γ(ɛ/v3)1/4, where γ is a dimensionless parameter of order unity. We show that as the turbulence decays, viscous corrections gradually become more important and a simple power law can no longer describe the decay. We discuss the final period of decay within the framework of our model, and show that care must be taken to distinguish between the final period of decay and the change of the character of decay due to the saturation of the energy containing length scale. The model is applied to a number of experiments on decaying turbulence. These include the downstream decay of turbulence in

  7. Analysis of the B{yields}K{sub 2} (1430) l{sup +}l{sup -} decay

    SciTech Connect

    Choudhury, S. R.; Cornell, A. S.; Gaur, Naveen

    2010-05-01

    We present an analysis of the decay process B{yields}K{sub 2}(1430)l{sup +}l{sup -}, where this process has all the features of the related and well investigated process B{yields}K*(890)l{sup +}l{sup -}, with theoretically comparable branching ratios. The differential decay rate as well as the forward-backward asymmetry are worked out, where the sensitivity of these to possible right-handed couplings for the related b{yields}s radiative decay are also investigated.

  8. Beta decay of 99Tcm

    NASA Astrophysics Data System (ADS)

    Alburger, D. E.; Richards, P.; Ku, T. H.

    1980-02-01

    The emission of β rays from 6.02-h 99Tcm has been detected with an intermediate-image magnetic spectrometer. β-ray components with end-point energies of 434.8+/-2.6 keV (β0) to the 99Ru ground state and 346.7+/-2.0 keV (β1) to the 90-keV state were found with intensities per decay of (1.0+/-0.3) × 10-5 for β0 and (2.6+/-0.5) × 10-5 for β1. In the Kurie plot analysis the unique first-forbidden "α" shape was assumed for β0 and an allowed shape was assumed for β1. Values of f1t=9.39+/-0.11 for β0 and f0t=8.66+/-0.08 for β1 were derived. γ rays of 322, 233, and 140 keV were observed in a calibrated Ge(Li) detector with relative source intensities of I322:I233:I140=(1.13+/-0.09)×10-6:(0.95+/-0.17)×10-7:1.000. The total β-ray branching of 3.7 × 10-5 results in a negligible correction to dosage calculations in the use of 99Tcm for diagnostic nuclear medicine. RADIOACTIVITY 99Tcm: measured Eβ, Iβ, and Iγ magnetic spectrometer, Ge(Li); deduced decay scheme.

  9. Bs decays at the Tevatron

    SciTech Connect

    Giurgiu, Gavril; /Johns Hopkins U.

    2010-09-01

    The authors present measurements of the branching ratio and of the polarization amplitudes in charmless B{sub s} {yields} {phi}{phi} decays using data corresponding to 2.9 fb{sup -1} of integrated luminosity, collected by the CDF experiment at the Tevatron. The branching ratio in B{sub s} {yields} {phi}{phi} decays is measured relative to the normalization mode B{sub s} {yields} J/{Psi}{phi} be {Beta}(B{sub s} {yields} {phi}{phi})/{Beta}(B{sub s} {yields} J/{Psi}{phi}) = [1.78 {+-} 0.14(stat) {+-} 0.20(syst)] x 10{sup -2}. Using the experimental value of {Beta}(B{sub s} {yields} J/{Psi}{phi}) they determine the B{sub s} {yields} {phi}{phi} branching ratio {Beta}(B{sub s} {yields} {phi}{phi}) = 2.40 {+-} 0.21(stat) {+-} 0.27(syst) {+-} 0.82(BR) x 10{sup -5}. The polarization fractions are measured for the first time in this analysis and found to be: |A{sub 0}|{sup 2} = 0.348 {+-} 0.041(stat) {+-} 0.021(syst); |A{sub {parallel}}|{sup 2} = 0.287 {+-} 0.043(stat) {+-} 0.011(syst); and |A{sub {perpendicular}}|{sup 2} = 0.365 {+-} 0.044(stat) {+-} 0.027(syst).

  10. Correlation between thermoluminescence and radiation damage in bismuth germanate

    SciTech Connect

    Melcher, C.L.

    1985-02-01

    Thermoluminescence properties of bismuth germanate and their relationship to radiation damage characteristics have been investigated. Thermoluminescence and radiation damage in bismuth germanate display several similar properties including similar responses as a function of radiation dose, similar saturation levels, and similar decay times. Also a correlation was found between the thermoluminescence sensitivities and radiation damage sensitivities of four different crystals. The traps responsible for the radiation damage and those which store the thermoluminescence signal appear to be either closely related or actually the same traps. Four trapping centers can be seen in the thermoluminescence glow curves. The depth of the dominant trap is 1.1 eV. 10 references.

  11. Localized pulses exhibiting a missilelike slow decay.

    PubMed

    Shaarawi, Amr M; Maged, Maha A; Besieris, Ioannis M; Hashish, Essam

    2006-08-01

    We investigate the quasi-missile behavior of known localized wave solutions, such as the modified power spectrum and splash pulses. We demonstrate that source-free localized waves can exhibit slow decay rates analogous to Wu's missile solutions, which are characterized by an amplitude decay rate slower than 1/R over an unlimited range. When excited from a finite aperture, the missilelike decay is not exhibited by all localized waves showing such behavior in the source-free situation. On the other hand, localized wave missiles generated from a finite aperture have peaks that exhibit quasi-missile decay. In an extended intermediate range between the near- and the far-field regions, these pulses decay at a rate slower than 1/R before switching to the usual 1/R decay.

  12. Localized pulses exhibiting a missilelike slow decay

    NASA Astrophysics Data System (ADS)

    Shaarawi, Amr M.; Maged, Maha A.; Besieris, Ioannis M.; Hashish, Essam

    2006-08-01

    We investigate the quasi-missile behavior of known localized wave solutions, such as the modified power spectrum and splash pulses. We demonstrate that source-free localized waves can exhibit slow decay rates analogous to Wu's missile solutions, which are characterized by an amplitude decay rate slower than 1/R over an unlimited range. When excited from a finite aperture, the missilelike decay is not exhibited by all localized waves showing such behavior in the source-free situation. On the other hand, localized wave missiles generated from a finite aperture have peaks that exhibit quasi-missile decay. In an extended intermediate range between the near- and the far-field regions, these pulses decay at a rate slower than 1/R before switching to the usual 1/R decay.

  13. Exclusive hadronic decays of B mesons

    NASA Astrophysics Data System (ADS)

    Hölscher, Andreas

    1991-06-01

    The recent experimental results on exclusive hadronic decays of B mesons obtained by the ARGUS collaboration are presented in the talk. The results include exclusive hadronic decays involving a b → c transition, namely B decays with a D, D ∗ plus several pions and B decays to J/ψ or ψ' mesons plus Kaons have been studied. The measurements of branching ratios for two-body B decays involving a J/ψ or ψ' meson are of wide interest in the light of proposals for the study of CP violation in future experiments. The branching ratios are compared with the predictions of the model of Bauer, Stech and Wirbel and with a model of A.V. Dobrovolskaya. Using the cleanest decay channels, the masses and mass difference of the charged and neutral B meson are obtained. This mass difference is then compared with the mass splitting in other isospinmultipletts and with theoretical models.

  14. Decay Study of {sup 257}Rf

    SciTech Connect

    Qian, J.; Heinz, A.; Winkler, R.; Janssens, R. V. F.; Khoo, T. L.; Seweryniak, D.; Peterson, D.; Back, B. B.; Carpenter, M. P.; Greene, J. P.; Jiang, C. L.; Kondev, F. G.; Lauritsen, T.; Lister, C. J.; Pardo, R. C.; Robinson, A.; Scott, R.; Vondrasek, R.; Wang, X.; Zhu, S.

    2009-03-04

    The isotope {sup 257}Rf was produced in the fusion-evaporation reaction {sup 208}Pb({sup 50}Ti, n){sup 257}Rf. Reaction products were separated by the Argonne Fragment Mass Analyzer. Radioactive decay and spontaneous fission of {sup 257}Rf and its decay products were investigated. An isomeric state in {sup 257}Rf, with a half-life of 160{sub -31}{sup 42} {mu}S, was discovered by detecting internal conversion electrons followed by alpha decays. It is interpreted as a three-quasiparticle high-K isomer. A second group of internal-conversion electrons which were succeeded by alpha decay, with a half-life of 4.1{sub -1.3}{sup +2.4} s, was observed. These events might originate from the decay of excited states in {sup 257}Lr, populated by electron-capture decay of {sup 257}Rf, or from another isomer in {sup 257}Rf.

  15. Dark decay of the top quark

    SciTech Connect

    Kong, Kyoungchul; Lee, Hye -Sung; Park, Myeonghun

    2014-04-01

    We suggest top quark decays as a venue to search for light dark force carriers. Top quark is the heaviest particle in the standard model whose decays are relatively poorly measured, allowing sufficient room for exotic decay modes from new physics. A very light (GeV scale) dark gauge boson (Z') is a recently highlighted hypothetical particle that can address some astrophysical anomalies as well as the 3.6 σ deviation in the muon g-2 measurement. We present and study a possible scenario that top quark decays as t → b W + Z's. This is the same as the dominant top quark decay (t → b W) accompanied by one or multiple dark force carriers. The Z' can be easily boosted, and it can decay into highly collimated leptons (lepton-jet) with large branching ratio. In addition, we discuss the implications for the Large Hadron Collider experiments including the analysis based on the lepton-jets.

  16. Nanoscintillators for radiation detection

    NASA Astrophysics Data System (ADS)

    Hall, Ryan Gregory

    In the search for faster, more effective methods for detection of and protection against radiological weapons, advances in materials for radiation detection are a critical component of any successful strategy. This work focuses on producing inexpensive, but highly sensitive, nanoparticle alternatives to existing single-crystal installations. Attention is given to particular types of promising inorganic scintillators: LaF3, yttrium-aluminum-garnet (YAG), and SrF2, each one an inorganic host doped with additional elements that encourage luminescent decay and increase effective Z-value. I examine the possible routes to synthesize these compounds, and the difficulties and benefits of each method. After synthesizing these materials, testing was performed to determine comparative performance against each other and commercial solutions, identify structural and compositional characteristics, and explore routes for fixing the scintillators into a detector assembly. The unifying goal is to develop a scintillating material suitable for consistent dosimetry and radio-isotope identification applications.

  17. Spectroscopy of element 115 decay chains

    SciTech Connect

    Rudolph, Dirk; Forsberg, U.; Golubev, P.; Sarmiento, L. G.; Yakushev, A.; Andersson, L.-L.; Di Nitto, A.; Duehllmann, Ch. E.; Gates, J. M.; Gregorich, K. E.; Gross, Carl J; Hessberger, F. P.; Herzberg, R.-D; Khuyagbaatar, J.; Kratz, J. V.; Rykaczewski, Krzysztof Piotr; Schaedel, M.; Aberg, S.; Ackermann, D.; Block, M.; Brand, H.; Carlsson, B. G.; Cox, D.; Derkx, X.; Eberhardt, K.; Even, J.; Fahlander, C.; Gerl, J.; Jaeger, E.; Kindler, B.; Krier, J.; Kojouharov, I.; Kurz, N.; Lommel, B.; Mistry, A.; Mokry, C.; Nitsche, H.; Omtvedt, J. P.; Papadakis, P.; Ragnarsson, I.; Runke, J.; Schaffner, H.; Schausten, B.; Thoerle-Pospiech, P.; Torres, T.; Traut, T.; Trautmann, N.; Tuerler, A.; Ward, A.; Ward, D. E.; Wiehl, N.

    2013-01-01

    A high-resolution a, X-ray and -ray coincidence spectroscopy experiment was conducted at the GSI Helmholtzzentrum fu r Schwerionenforschung. Thirty correlated a-decay chains were detected following the fusion-evaporation reaction 48Ca + 243Am. The observations are consistent with previous assignments of similar decay chains to originate from element Z = 115. The data includes first candidates of fingerprinting the decay step Mt --> Bh with characteristic X rays. For the first time, precise spectroscopy allows the derivation of excitation schemes of isotopes along the decay chains starting with elements Z > 112. Comprehensive Monte-Carlo simulations accompany the data analysis. Nuclear structure models provide a first level interpretation.

  18. Unique forbidden beta decays and neutrino mass

    SciTech Connect

    Dvornický, Rastislav; Šimkovic, Fedor

    2015-10-28

    The measurement of the electron energy spectrum in single β decays close to the endpoint provides a direct determination of the neutrino masses. The most sensitive experiments use β decays with low Q value, e.g. KATRIN (tritium) and MARE (rhenium). We present the theoretical spectral shape of electrons emitted in the first, second, and fourth unique forbidden β decays. Our findings show that the Kurie functions for these unique forbidden β transitions are linear in the limit of massless neutrinos like the Kurie function of the allowed β decay of tritium.

  19. Leptonic Decay of J/Ψ

    NASA Astrophysics Data System (ADS)

    Liu, Bo; Shen, Peng-nian; Huan-qing, Jing; Chiang Huan, Ching

    1998-12-01

    A more realistic non-relativistic quark-quark potential in the thermal and dense medium is proposed and used to study the laptonic decay of J/Ψ. The laptonic decay property of J/Ψ in the hot and dense matter depends on the form of the binding potential. The decay width in this potential case is much sensitive to the temperature than that in the Karsch's potential case, especially in the lower temperature region. In both cases, the decay widths decreased with the increasing temperature and density. The resultant critical temperature of 200 MeV is consistent with the lattice quantum chromodynamics finding.

  20. Tensor mesons produced in tau lepton decays

    SciTech Connect

    Lopez Castro, G.; Munoz, J. H.

    2011-05-01

    Light tensor mesons (T=a{sub 2}, f{sub 2} and K{sub 2}*) can be produced in decays of {tau} leptons. In this paper we compute the branching ratios of {tau}{yields}T{pi}{nu} decays by assuming the dominance of intermediate virtual states to model the form factors involved in the relevant hadronic matrix elements. The exclusive f{sub 2}(1270){pi}{sup -} decay mode turns out to have the largest branching ratio, of O(10{sup -4}). Our results indicate that the contribution of tensor meson intermediate states to the three-pseudoscalar channels of {tau} decays are rather small.

  1. Holographic decays of large-spin mesons

    NASA Astrophysics Data System (ADS)

    Peeters, Kasper; Sonnenschein, Jacob; Zamaklar, Marija

    2006-02-01

    We study the decay process of large-spin mesons in the context of the gauge/string duality, using generic properties of confining backgrounds and systems with flavour branes. In the string picture, meson decay corresponds to the quantum-mechanical process in which a string rotating on the IR ``wall'' fluctuates, touches a flavour brane and splits into two smaller strings. This process automatically encodes flavour conservation as well as the Zweig rule. We show that the decay width computed in the string picture is in remarkable agreement with the decay width obtained using the phenomenological Lund model.

  2. Radioactive Decay: Audio Data Collection

    ERIC Educational Resources Information Center

    Struthers, Allan

    2009-01-01

    Many phenomena generate interesting audible time series. This data can be collected and processed using audio software. The free software package "Audacity" is used to demonstrate the process by recording, processing, and extracting click times from an inexpensive radiation detector. The high quality of the data is demonstrated with a simple…

  3. Radiation Therapy

    MedlinePlus

    ... can watch you during the procedure. As you go through radiation treatment, you may feel like you're all ... treatment. Avoid exposing the treated area to the sun during the weeks you're getting radiation therapy. And when the treatment's over, wear sunscreen ...

  4. Understanding Radiation.

    ERIC Educational Resources Information Center

    Department of Energy, Washington, DC. Nuclear Energy Office.

    Radiation is a natural energy force that has been a part of the environment since the Earth was formed. It takes various forms, none of which can be smelled, tasted, seen, heard, or felt. Nevertheless, scientists know what it is, where it comes from, how to measure and detect it, and how it affects people. Cosmic radiation from outer space and…

  5. Radiation Therapy

    MedlinePlus

    ... Tumors In Children Pediatric Brain Tumor Diagnosis Family Impact Late Effects After Treatment Returning to School Pediatric ... Una publicación de ABTA en español. Radiation Imaging Technology Information on Radiation and Imaging Technology Home Donor and ...

  6. Radiation Therapy

    MedlinePlus

    ... them from spreading. About half of all cancer patients receive it. The radiation may be external, from special machines, or internal, from radioactive substances that a doctor places inside your body. The type of radiation therapy you receive depends on many factors, including The ...

  7. Radiation Exposure

    MedlinePlus

    ... particles. It occurs naturally in sunlight. Man-made radiation is used in X-rays, nuclear weapons, nuclear power plants and cancer treatment. If you are exposed to small amounts of radiation over a long time, it raises your risk ...

  8. A Search for the Rare Decay B0 → γγ

    SciTech Connect

    Ruland, Andrew Michael

    2010-05-01

    This thesis describes a search for the rare radiative decay B0 → γγ, where the charged congugate mode is implied throughout. These decays are highly suppressed in the Standard Model where the branching fraction is expected to be of order 10-8. In some new physics scenarios this could be enhanced by up to an order of magnitude to 10-7. Therefore an observation of a significant signal above the Standard Model prediction could be a sign of new physics.

  9. Estimation of heat generation by radioactive decay of some phosphate rocks in Egypt.

    PubMed

    Din, Khaled Salahel

    2009-11-01

    Radiogenic heat production data for phosphate rocks outcropping on the three main areas Eastern Desert, Western Desert and Nile Valley are presented. They were derived from uranium, thorium and potassium concentration measurements of gamma radiation originating from the decay of (214)Bi ((238)U series), (208)Tl ((232)Th series) and the primary decay of (40)K. A low radioactive heat production rate (0.32+/-0.1 microWm(-3)) was found for Wadi Hegaza, whereas the highest value (19+/-4.1 microWm(-3)) was found for Gabel Anz, Eastern Desert of Egypt.

  10. Fluorescence decay rate statistics of a single molecule in a disordered cluster of nanoparticles

    SciTech Connect

    Froufe-Perez, L. S.; Carminati, R.; Saenz, J. J.

    2007-07-15

    The statistical properties of the fluorescence lifetime of single emitters in disordered systems are discussed. The contribution of radiative and nonradiative processes to the spontaneous decay rate is analyzed using a simple analytical model, in full agreement with exact numerical simulations. The relative fluctuations of the decay rate are shown to exhibit two well-defined regimes dominated either by near-field scattering or by absorption processes. In both regimes, the averaged apparent quantum yield remains high enough to permit practical measurements. Lifetime fluctuations could thus be used a probe of the local environment in complex systems at the nanometer scale.

  11. Search for the rare decay D0→γ γ at Belle

    NASA Astrophysics Data System (ADS)

    Nisar, N. K.; Mohanty, G. B.; Trabelsi, K.; Aziz, T.; Abdesselam, A.; Adachi, I.; Aihara, H.; Asner, D. M.; Aulchenko, V.; Aushev, T.; Ayad, R.; Babu, V.; Badhrees, I.; Bahinipati, S.; Barberio, E.; Behera, P.; Bhardwaj, V.; Biswal, J.; Bobrov, A.; Bozek, A.; Bračko, M.; Breibeck, F.; Browder, T. E.; Červenkov, D.; Chekelian, V.; Chen, A.; Cheon, B. G.; Chistov, R.; Cho, K.; Chobanova, V.; Choi, Y.; Cinabro, D.; Dalseno, J.; Dash, N.; Doležal, Z.; Drásal, Z.; Drutskoy, A.; Dutta, D.; Eidelman, S.; Farhat, H.; Fast, J. E.; Fulsom, B. G.; Gaur, V.; Garmash, A.; Gillard, R.; Goh, Y. M.; Goldenzweig, P.; Golob, B.; Greenwald, D.; Grzymkowska, O.; Haba, J.; Hara, T.; Hayasaka, K.; Hayashii, H.; He, X. H.; Hou, W.-S.; Inami, K.; Ishikawa, A.; Iwasaki, Y.; Jacobs, W. W.; Jaegle, I.; Jeon, H. B.; Joffe, D.; Joo, K. K.; Julius, T.; Kang, K. H.; Kato, E.; Kawasaki, T.; Kiesling, C.; Kim, D. Y.; Kim, H. J.; Kim, K. T.; Kim, M. J.; Kim, S. H.; Kinoshita, K.; Kodyš, P.; Korpar, S.; Križan, P.; Krokovny, P.; Kuhr, T.; Kumar, R.; Kumita, T.; Kuzmin, A.; Kwon, Y.-J.; Lee, I. S.; Lange, J. S.; Li, H.; Li, L.; Li Gioi, L.; Libby, J.; Liventsev, D.; Lukin, P.; Masuda, M.; Matvienko, D.; Miyabayashi, K.; Miyata, H.; Mizuk, R.; Mohanty, S.; Moll, A.; Moon, H. K.; Mori, T.; Mussa, R.; Nakano, E.; Nakao, M.; Nanut, T.; Natkaniec, Z.; Nayak, M.; Niiyama, M.; Nishida, S.; Ogawa, S.; Okuno, S.; Pakhlov, P.; Pakhlova, G.; Pal, B.; Park, C. W.; Park, H.; Paul, S.; Pedlar, T. K.; Pesántez, L.; Pestotnik, R.; Petrič, M.; Piilonen, L. E.; Prasanth, K.; Pulvermacher, C.; Rauch, J.; Ribežl, E.; Ritter, M.; Rostomyan, A.; Ryu, S.; Sahoo, H.; Sakai, Y.; Sandilya, S.; Sanuki, T.; Sato, Y.; Savinov, V.; Schlüter, T.; Schneider, O.; Schnell, G.; Schwanda, C.; Schwartz, A. J.; Seino, Y.; Senyo, K.; Seon, O.; Seong, I. S.; Shebalin, V.; Shibata, T.-A.; Shiu, J.-G.; Shwartz, B.; Simon, F.; Singh, J. B.; Sohn, Y.-S.; Solovieva, E.; Stanič, S.; Starič, M.; Stypula, J.; Sumihama, M.; Sumiyoshi, T.; Tamponi, U.; Teramoto, Y.; Uchida, M.; Uglov, T.; Uno, S.; Urquijo, P.; Van Hulse, C.; Vanhoefer, P.; Varner, G.; Varvell, K. E.; Vinokurova, A.; Vossen, A.; Wagner, M. N.; Wang, C. H.; Wang, M.-Z.; Wang, X. L.; Watanabe, M.; Watanabe, Y.; Williams, K. M.; Won, E.; Yelton, J.; Yuan, C. Z.; Yusa, Y.; Zhang, Z. P.; Zhilich, V.; Zhulanov, V.; Zupanc, A.; Belle Collaboration

    2016-03-01

    We search for the rare radiative decay D0→γ γ using a data sample with an integrated luminosity of 832 fb-1 recorded by the Belle detector at the KEKB e+e- asymmetric-energy collider. We find no statistically significant signal and set an upper limit on the branching fraction of B (D0→γ γ )<8.5 ×1 0-7 at 90% confidence level. This is the most restrictive limit on the decay channel to date.

  12. Inclusive gamma-ray spectra from psi/3095/ and psi-prime/3684/ decays

    NASA Technical Reports Server (NTRS)

    Biddick, C. J.; Burnett, T. H.; Masek, G. E.; Miller, E. S.; Smith, J. G.; Stronski, J. P.; Sullivan, M. K.; Vernon, W.; Badtke, D. H.; Barnett, B. A.

    1977-01-01

    Inclusive gamma-ray experiments were carried out in a e(+)e(-) colliding-beam apparatus with NaI(Tl) arrays as detectors. The inclusive gamma-ray spectra, after cosmic-ray background subtraction, are shown as histograms for the decays of the psi(3095) and psi-prime(3684). The psi spectrum has no significant narrow structure, while the psi-prime spectrum shows at least four peaks. Three major radiative decays of the psi-prime(3684) are found, and their respective branching fractions are computed.

  13. Radiation detector

    DOEpatents

    Fultz, B.T.

    1980-12-05

    Apparatus is provided for detecting radiation such as gamma rays and x-rays generated in backscatter Moessbauer effect spectroscopy and x-ray spectrometry, which has a large window for detecting radiation emanating over a wide solid angle from a specimen and which generates substantially the same output pulse height for monoenergetic radiation that passes through any portion of the detection chamber. The apparatus includes a substantially toroidal chamber with conductive walls forming a cathode, and a wire anode extending in a circle within the chamber with the anode lying closer to the inner side of the toroid which has the least diameter than to the outer side. The placement of the anode produces an electric field, in a region close to the anode, which has substantially the same gradient in all directions extending radially from the anode, so that the number of avalanche electrons generated by ionizing radiation is independent of the path of the radiation through the chamber.

  14. Radiation detector

    DOEpatents

    Fultz, Brent T.

    1983-01-01

    Apparatus is provided for detecting radiation such as gamma rays and X-rays generated in backscatter Mossbauer effect spectroscopy and X-ray spectrometry, which has a large "window" for detecting radiation emanating over a wide solid angle from a specimen and which generates substantially the same output pulse height for monoenergetic radiation that passes through any portion of the detection chamber. The apparatus includes a substantially toroidal chamber with conductive walls forming a cathode, and a wire anode extending in a circle within the chamber with the anode lying closer to the inner side of the toroid which has the least diameter than to the outer side. The placement of the anode produces an electric field, in a region close to the anode, which has substantially the same gradient in all directions extending radially from the anode, so that the number of avalanche electrons generated by ionizing radiation is independent of the path of the radiation through the chamber.

  15. Radiation retinopathy.

    PubMed Central

    Zamber, R W; Kinyoun, J L

    1992-01-01

    Radiation therapy is effective against many cancerous and noncancerous disease processes. As with other therapeutics, side effects must be anticipated, recognized, and managed appropriately. Radiation retinopathy is a vision-threatening complication of ocular, orbital, periorbital, facial, nasopharyngeal, and cranial irradiation. Factors that appear important in the pathogenesis of radiation retinopathy include total radiation dosage, fraction size, concomitant chemotherapy, and preexisting vascular disorders. Clinical manifestations of the disorder include macular edema and nonproliferative and proliferative retinopathy, similar to changes seen in diabetic retinopathy. Argon laser photocoagulation has proved efficacious for managing macular edema and fibrovascular proliferation in some of these patients. Ongoing basic laboratory and clinical research efforts have led to a better understanding of the pathogenesis, natural history, and treatment response of radiation retinopathy. The ultimate goal of this knowledge is to improve the prevention, recognition, and management of this vision-threatening complication. Images PMID:1441494

  16. Diffuse radiation

    NASA Technical Reports Server (NTRS)

    1981-01-01

    A diffuse celestial radiation which is isotropic at least on a course scale were measured from the soft X-ray region to about 150 MeV, at which energy the intensity falls below that of the galactic emission for most galactic latitudes. The spectral shape, the intensity, and the established degree of isotropy of this diffuse radiation already place severe constraints on the possible explanations for this radiation. Among the extragalactic theories, the more promising explanations of the isotropic diffuse emission appear to be radiation from exceptional galaxies from matter antimatter annihilation at the boundaries of superclusters of galaxies of matter and antimatter in baryon symmetric big bang models. Other possible sources for extragalactic diffuse gamma radiation are discussed and include normal galaxies, clusters of galaxies, primordial cosmic rays interacting with intergalactic matter, primordial black holes, and cosmic ray leakage from galaxies.

  17. Localized surface plasmon-influenced fluorescence decay in dye-doped metallo-dielectric opals

    NASA Astrophysics Data System (ADS)

    Rout, Dipak; Vijaya, R.

    2016-01-01

    Well-ordered opaline photonic crystals are grown by inward growing self-assembly method from Rhodamine B dye-doped polystyrene colloids. Subsequent to self-assembly, the crystals are infiltrated with gold nanoparticles of 40 nm diameter. Measurements of the stopband features and photoluminescence intensity from these crystals are supplemented by fluorescence decay time analysis. The fluorescence decay times from the dye-doped photonic crystals before and after the infiltration are dramatically different from each other. A lowered fluorescence decay time was observed for the case of gold infiltrated crystal along with an enhanced emission intensity. Double-exponential decay nature of the fluorescence from the dye-doped crystal gets converted into single-exponential decay upon the infiltration of gold nanoparticles due to the resonant radiative process resulting from the overlap of the surface plasmon resonance with the emission spectrum. The influence of localized surface plasmon due to gold nanoparticles on the increase in emission intensity and decrease in decay time of the emitters is established.

  18. Decaying radiolabelled lymphocytes and method of using same background of the invention

    SciTech Connect

    Chambers, G.P.

    1994-12-30

    Decaying radiolabelled lymphocytes and a method of using same are disclosed. A radiolabelled T-cell lymphocyte including a T-cell containing a Beta-emitting isotope which decays to an alpha-emitting isotope is provided. Alternatively, the T-cell may contain a Beta-emitting isotope which decays one of an x-ray and gamma-emitting isotope. A therapeutic radioisotope treatment method includes the steps of removing a cancerous nodule containing T-cells from a mammal, introducing into the T-cells a Beta-emitting isotope which decays to an alpha-emitting isotope and infusing the T-cells containing the Beta-emitting isotope which decays to an alpha-emitting isotope into the mammal. As an alternative, the treatment method may introduce into the T-cells a Beta-emitting isotope which decays to an x-ray or gamma-emitting isotope. Then, according to the alternative method, after the radioactive T- cells are infused into the mammal, the patient is monitored with a radiation detector to determine the location of T-cells containing the isotopes.

  19. Characteristic Time of the Magnetospheric Ring Current Decay FROM EXPIREMENT AND THEORY

    NASA Astrophysics Data System (ADS)

    Biktash(Sizova), L. Z.; Korotova, G. I.

    2006-12-01

    The magnetospheric ring current particles are the most dynamic part of the Earth's radiation belts especially during geomagnetic storms. The processes of the magnetospheric ring current decay are studied as a function of the solar wind electric field. It is shown that the ring current dissipation rate is different during the main and recovery phase of geomagnetic storms. The characteristic time of the ring current decay in the main phase is independent of storm intensity and equals 4 hours. The characteristic time of the ring current decay in a recovery phase increases with storm intensity. We examine the ring current ion lifetimes for the possible mechanisms of its decay. Coulomb scattering, charge exchange and plasma instability mechanisms are used for estimation of lifetime of electrons, protons, helium, and oxygen ions. The values of the characteristic lifetime of ring current dissipation obtained from experiment and theory are compared. It is shown that during main and recovery phase of magnetic storm the different mechanisms can play main role in dissipation of the ring current. Very short characteristic decay time during main phase of geomagnetic storms is associated with plasma instabilities. The available ion composition data of the ring current make possible to assume that the ring current decay is accounted for by ion composition variations with changing the intensity (and hence position) of the ring current and/or by a rise of energetic ion fraction on low L-shells.

  20. Sunset decay of the convective turbulence with Large-Eddy Simulation under realistic conditions

    NASA Astrophysics Data System (ADS)

    Rizza, U.; Miglietta, M. M.; Degrazia, G. A.; Acevedo, O. C.; Marques Filho, E. P.

    2013-10-01

    Large-Eddy Simulation is performed for a single day from the Cooperative Atmosphere-Surface Exchange Study (CASES-99) field program. This study investigates an observed case of evening transition boundary layer over land. Parameters of the ambient atmosphere in the LES-decay studies conducted so far were typically prescribed in an idealized form. To provide suitable data under the wide range of the PBL weather conditions, the LES should be able to adequately reproduce the PBL turbulence dynamics including-if possible-baroclinicity, radiation, large scale advection and not only be related to a decreasing surface heating. In addition LES-decay studies usually assume that the sensible heat flux decreases instantaneously or with a very short time scale. The main purpose of this investigation is to study the decay of boundary-layer average turbulent kinetic energy at sunset with Large-Eddy Simulation that is forced with realistic environment conditions. This allows investigating the Turbulent Kinetic Energy decay over the realistic time scale that is observed in the atmosphere. During the intermediate and last stage of decay of the boundary-layer average Turbulent Kinetic Energy the exponents of the decay power law t go from 2 to 6, as evidenced by experimental results and recent analytical modeling in the surface layer.

  1. Localized surface plasmon-influenced fluorescence decay in dye-doped metallo-dielectric opals

    SciTech Connect

    Rout, Dipak; Vijaya, R.

    2016-01-14

    Well-ordered opaline photonic crystals are grown by inward growing self-assembly method from Rhodamine B dye-doped polystyrene colloids. Subsequent to self-assembly, the crystals are infiltrated with gold nanoparticles of 40 nm diameter. Measurements of the stopband features and photoluminescence intensity from these crystals are supplemented by fluorescence decay time analysis. The fluorescence decay times from the dye-doped photonic crystals before and after the infiltration are dramatically different from each other. A lowered fluorescence decay time was observed for the case of gold infiltrated crystal along with an enhanced emission intensity. Double-exponential decay nature of the fluorescence from the dye-doped crystal gets converted into single-exponential decay upon the infiltration of gold nanoparticles due to the resonant radiative process resulting from the overlap of the surface plasmon resonance with the emission spectrum. The influence of localized surface plasmon due to gold nanoparticles on the increase in emission intensity and decrease in decay time of the emitters is established.

  2. ISOLDE decay station for decay studies of interest in astrophysics and exotic nuclei

    NASA Astrophysics Data System (ADS)

    Fynbo, Hans; Kirseboom, Oliver S.; Tengblad, Olof

    2017-04-01

    We report on studies of the beta-decays of 31Ar, {}{20,21}Mg, and 16N performed at the ISOLDE decay station (IDS) at CERN. These studies illustrate how beta-decays measured with the IDS can be used to extract information of astrophysical interest, or to study the structure and decay mechanism of exotic nuclei. We discuss the specific implementation of the IDS designed for this type of studies including detector setups and data acquisition.

  3. Capture and decay of electroweak WIMPonium

    NASA Astrophysics Data System (ADS)

    Asadi, Pouya; Baumgart, Matthew; Fitzpatrick, Patrick J.; Krupczak, Emmett; Slatyer, Tracy R.

    2017-02-01

    The spectrum of Weakly-Interacting-Massive-Particle (WIMP) dark matter generically possesses bound states when the WIMP mass becomes sufficiently large relative to the mass of the electroweak gauge bosons. The presence of these bound states enhances the annihilation rate via resonances in the Sommerfeld enhancement, but they can also be produced directly with the emission of a low-energy photon. In this work we compute the rate for SU(2) triplet dark matter (the wino) to bind into WIMPonium—which is possible via single-photon emission for wino masses above 5 TeV for relative velocity v < O(10‑2) —and study the subsequent decays of these bound states. We present results with applications beyond the wino case, e.g. for dark matter inhabiting a nonabelian dark sector; these include analytic capture and transition rates for general dark sectors in the limit of vanishing force carrier mass, efficient numerical routines for calculating positive and negative-energy eigenstates of a Hamiltonian containing interactions with both massive and massless force carriers, and a study of the scaling of bound state formation in the short-range Hulth&apos{e}n potential. In the specific case of the wino, we find that the rate for bound state formation is suppressed relative to direct annihilation, and so provides only a small correction to the overall annihilation rate. The soft photons radiated by the capture process and by bound state transitions could permit measurement of the dark matter's quantum numbers; for wino-like dark matter, such photons are rare, but might be observable by a future ground-based gamma-ray telescope combining large effective area and a low energy threshold.

  4. A review on natural background radiation

    PubMed Central

    Shahbazi-Gahrouei, Daryoush; Gholami, Mehrdad; Setayandeh, Samaneh

    2013-01-01

    The world is naturally radioactive and approximately 82% of human-absorbed radiation doses, which are out of control, arise from natural sources such as cosmic, terrestrial, and exposure from inhalation or intake radiation sources. In recent years, several international studies have been carried out, which have reported different values regarding the effect of background radiation on human health. Gamma radiation emitted from natural sources (background radiation) is largely due to primordial radionuclides, mainly 232Th and 238U series, and their decay products, as well as 40K, which exist at trace levels in the earth's crust. Their concentrations in soil, sands, and rocks depend on the local geology of each region in the world. Naturally occurring radioactive materials generally contain terrestrial-origin radionuclides, left over since the creation of the earth. In addition, the existence of some springs and quarries increases the dose rate of background radiation in some regions that are known as high level background radiation regions. The type of building materials used in houses can also affect the dose rate of background radiations. The present review article was carried out to consider all of the natural radiations, including cosmic, terrestrial, and food radiation. PMID:24223380

  5. Entropy shaping by shock decay

    NASA Astrophysics Data System (ADS)

    Piriz, A. R.; Sun, Y. B.; Tahir, N. A.

    2016-11-01

    A previous model [Piriz et al., Phys. Plasmas 23, 032704 (2016)] developed for describing the evolution of a shock wave driven by an arbitrary pressure pulse, is shown to be suitable for calculating the entropy shaping induced by a shock of decaying intensity. It is also shown that by allowing a causal connection between the shock and the piston, the model results to be complementary to the well-known self-similar solution for the impulsive loading problem, which is valid in the asymptotic regime when both fronts become decoupled. As a consequence, the entropy distribution depends on the details of the driving pressure pulse. A comparison with the available numerical simulations is presented.

  6. Decaying neutrinos in galaxy clusters

    NASA Technical Reports Server (NTRS)

    Melott, Adrian L.; Splinter, Randall J.; Persic, Massimo; Salucci, Paolo

    1993-01-01

    The DM profile in clusters of galaxies was studied and simulated using the Harrison-Zel'dovich spectrum of density fluctuations, and an amplitude previously derived from numerical simulations and in agreement with microwave background fluctuations. Neutrino DM densities, with this amplitude normalization cluster, are comparable to observed cluster DM values. It was concluded that given this normalization, the cluster DM should be al least largely composed of neutrinos. The constraint of Davidson et al., who argued that the failure to detect uv photons from the dark matter (DM) in cluster A665 excludes the decaying neutrino hypothesis, could be somewhat weakened by the presence of baryonic DM; but it cannot be eliminated given our assumptions.

  7. Decaying neutrinos in galaxy clusters

    NASA Technical Reports Server (NTRS)

    Melott, Adrian L.; Splinter, Randall J.; Persic, Massimo; Salucci, Paolo

    1994-01-01

    Davidsen et al. (1991) have argued that the failure to detect UV photons from the dark matter (DM) in cluster A665 excludes the decaying neutrino hypothesis. Sciama et al. (1993) argued that because of high central concentration the DM in that cluster must be baryonic. We study the DM profile in clusters of galaxies simulated using the Harrison-Zel'dovich spectrum of density fluctuations, and an amplitude previously derived from numerical simulations (Melott 1984b; Anninos et al. 1991) and in agreement with microwave background fluctuations (Smoot et al. 1992). We find that with this amplitude normalization cluster neutrino DM densities are comparable to observed cluster DM values. We conclude that given this normalization, the cluster DM should be at least largely composed of neutrinos. The constraint of Davidsen et al. can be somewhat weakened by the presence of baryonic DM; but it cannot be eliminated given our assumptions.

  8. Properties of a Decaying Sunspot

    NASA Astrophysics Data System (ADS)

    Balthasar, H.; Beck, C.; Gömöry, P.; Muglach, K.; Puschmann, K. G.; Shimizu, T.; Verma, M.

    A small decaying sunspot was observed with the Vacuum Tower Telescope (VTT) on Tenerife and the Japanese Hinode satellite. We obtained full Stokes scans in several wavelengths covering different heights in the solar atmosphere. Imaging time series from Hinode and the Solar Dynamics Observatory (SDO) complete our data sets. The spot is surrounded by a moat flow, which persists also on that side of the spot where the penumbra already had disappeared. Close to the spot, we find a chromospheric location with downflows of more than 10 km s^{-1} without photospheric counterpart. The height dependence of the vertical component of the magnetic field strength is determined in two different ways that yielded different results in previous investigations. Such a difference still exists in our present data, but it is not as pronounced as in the past.

  9. Pion Production from Proton Synchrotron Radiation in Strong Magnetic Fields

    NASA Astrophysics Data System (ADS)

    Maruyama, Tomoyuki; Cheoun, Myung-Ki; Kajino, Toshitaka; Mathews, Grant J.

    We study pion production by proton synchrotron radiation in the presence of a strong magnetic field. In this study we find that the decay width satisfies a robust scaling relation. This scaling implies that one can infer the decay width in more realistic magnetic fields of 1015 G, where ni,f ˜ 1012-1013, from the results for ni,f ˜ 104-105. Then, we present the resultant pion intensity and angular distributions for realistic magnetic field strengths.

  10. [Radiation carcinogenesis].

    PubMed

    Hosoi, Yoshio

    2013-11-01

    Misrepair of DNA damage induced by ionizing radiation is a potential cause of carcinogenesis following exposure to radiation. Radiation exposure increases the incidence of the same types of mutations that occur spontaneously in a given population. A high incidence of DNA double-strand breaks is characteristic of damage by ionizing radiation compared with those induced by other environmental mutagens. In China, residents living in areas with high level background radiation(6mSv/y) had a significantly higher frequency of dicentric and ring chromosomes compared to that for the residents living in the control areas(2mSv/y). Radiation-associated increases in risk were seen for most sites. Gender-averaged excess absolute risk rates estimated at age 70, after exposure at age 30, differ in the sites, and the risks of gastric cancer, breast cancer, colon cancer, and lung cancer were highly increased, in that order. Latent periods for the development of leukemia and thyroid cancer after radiation exposure at ages younger than 18 were shorter compared to those for other solid cancers.

  11. Spectroscopy and decays of charm and bottom

    SciTech Connect

    Butler, J.N.

    1997-10-01

    After a brief review of the quark model, we discuss our present knowledge of the spectroscopy of charm and bottom mesons and baryons. We go on to review the lifetimes, semileptonic, and purely leptonic decays of these particles. We conclude with a brief discussion B and D mixing and rare decays.

  12. Dark Matter Density from Heavy Neutrino Decays

    NASA Astrophysics Data System (ADS)

    Saadat, Hassan; Rostampour, Malihe

    2012-10-01

    As we know the heavy neutrino decays is a successful model for describing dark matter and also is origin of the universe entropy. In this paper we use heavy neutrino decays to calculate time-dependent dark matter density. In that case we use observational data to fixing our solutions.

  13. Decay studies of heavy and superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Clark, Roderick M.

    2016-12-01

    In this contribution I discuss recent results on the decay of excited states, via electromagnetic transitions (γ-ray and conversion electrons), α decay, and fission, and discuss what these studies reveal in terms of the stability of the heaviest elements.

  14. beta. -decay asymmetry of the free neutron

    SciTech Connect

    Bopp, P.; Dubbers, D.; Klemt, E.; Last, J.; Schuetze, H.; Weibler, W.; Freedman, S.J.; Schaerpf, O.

    1983-01-01

    The ..beta..-decay of polarized neutrons has been studied with the new superconducting spectrometer PERKEO at the ILL. The energy dependence of the ..beta..-decay asymmetry has been measured for the first time. From the measured ..beta..-asymmetry parameter we obtain a new value for the ratio of weak coupling constants g/sub A//g/sub V/. 11 references.

  15. 'Stutter timing' for charge decay time measurement

    NASA Astrophysics Data System (ADS)

    Chubb, John; Harbour, John; Pavey, Ian

    2011-06-01

    The paper describes the approach of 'stutter timing' that has been developed to improve the accuracy of measuring charge decay times in the presence of noise in compact and portable charge decay test instrumentation. The approach involves starting and stopping the timing clock as the noisy signal rises above and falls below the target threshold voltage level.

  16. QCD in heavy quark production and decay

    SciTech Connect

    Wiss, J.

    1997-06-01

    The author discusses how QCD is used to understand the physics of heavy quark production and decay dynamics. His discussion of production dynamics primarily concentrates on charm photoproduction data which are compared to perturbative QCD calculations which incorporate fragmentation effects. He begins his discussion of heavy quark decay by reviewing data on charm and beauty lifetimes. Present data on fully leptonic and semileptonic charm decay are then reviewed. Measurements of the hadronic weak current form factors are compared to the nonperturbative QCD-based predictions of Lattice Gauge Theories. He next discusses polarization phenomena present in charmed baryon decay. Heavy Quark Effective Theory predicts that the daughter baryon will recoil from the charmed parent with nearly 100% left-handed polarization, which is in excellent agreement with present data. He concludes by discussing nonleptonic charm decay which is traditionally analyzed in a factorization framework applicable to two-body and quasi-two-body nonleptonic decays. This discussion emphasizes the important role of final state interactions in influencing both the observed decay width of various two-body final states as well as modifying the interference between interfering resonance channels which contribute to specific multibody decays. 50 refs., 77 figs.

  17. Addressing Tooth Decay in Head Start Children

    ERIC Educational Resources Information Center

    Knowlden, Adam P.; Hill, Lawrence F.; Alles-White, Monica L.; Cottrell, Randall R.

    2012-01-01

    Tooth decay is the most prevalent chronic disease of childhood. Oral health education and dental services are crucial to reducing the number of children afflicted with dental cavities. Due to limited access to preventative care, Head Start children are particularly vulnerable to tooth decay. This article outlines practical implications of a…

  18. Effects of tensor interactions in τ decays

    NASA Astrophysics Data System (ADS)

    López Castro, G.; Godina Nava, J. J.

    1996-02-01

    Recent claims for the observation of antisymmetric weak tensor currents in π and K decays are considered for the case of τ→Kπν transitions. Assuming the existence of symmetric tensor currents, a mechanism for the direct production of the K2*(1430) spin-2 meson in τ decays is proposed.

  19. Radiation and Thermal Ageing of Nuclear Waste Glass

    SciTech Connect

    Weber, William J

    2014-01-01

    The radioactive decay of fission products and actinides incorporated into nuclear waste glass leads to self-heating and self-radiation effects that may affect the stability, structure and performance of the glass in a closed system. Short-lived fission products cause significant self-heating for the first 600 years. Alpha decay of the actinides leads to self-radiation damage that can be significant after a few hundred years, and over the long time periods of geologic disposal, the accumulation of helium and radiation damage from alpha decay may lead to swelling, microstructural evolution and changes in mechanical properties. Four decades of research on the behavior of nuclear waste glass are reviewed.

  20. Radiation dosimeter

    DOEpatents

    Fox, R.J.

    1981-09-01

    A radiation detector readout circuit is provided which produces a radiation dose-rate readout from a detector even through the detector output may be highly energy dependent. A linear charge amplifier including an output charge pump circuit amplifies the charge signal pulses from the detector and pumps the charge into a charge storage capacitor. The discharge rate of the capacitor through a resistor is controlled to provide a time-dependent voltage which when integrated provides an output proportional to the dose-rate of radiation detected by the detector. This output may be converted to digital form for readout on a digital display.

  1. Radiation dosimeter

    DOEpatents

    Fox, Richard J.

    1983-01-01

    A radiation detector readout circuit is provided which produces a radiation dose-rate readout from a detector even though the detector output may be highly energy dependent. A linear charge amplifier including an output charge pump circuit amplifies the charge signal pulses from the detector and pumps the charge into a charge storage capacitor. The discharge rate of the capacitor through a resistor is controlled to provide a time-dependent voltage which when integrated provides an output proportional to the dose-rate of radiation detected by the detector. This output may be converted to digital form for readout on a digital display.

  2. Search for CP violation in hyperon decays.

    SciTech Connect

    Zyla, Piotr; Chan, A.; Chen, Y.C.; Ho, C.; Teng, P.K.; Choong, W.S.; Gidal, G.; Fu, Y.; Gu, P.; Jones, T.D.; Luk, K.B.; Turko, B.; James, C.; Volk, J.; Felix, J.; Burnstein, R.A.; Chakrovorty, A.; Kaplan, D.M.; Lederman, L.M.; Luebke, W.; Rajaram, D.; Rubin, H.A.; Solomey, N.; Torun, Y.; White, C.G.; White, S.L.; Leros, N.; Perroud, J.P.; Gustafson, H.R.; Longo, M.J.; Lopez, F.; Park H.K.; Clark, K.; Jenkins, M.; Dukes, E.C.; Durandet, C.; Holmstrom, T.; Huang, M.; Lu, L.; Nelson, K.S.

    2002-10-25

    Direct CP violation in nonleptonic hyperon decays can be established by comparing the decays of hyperons and anti-hyperons. For {Xi} decay to {Lambda} {pi} followed by {Lambda} to p{pi}, the proton distribution in the rest frame of Lambda is governed by the product of the decay parameters {alpha}{sub {Xi}} {alpha}{sub {Lambda}}. The asymmetry A{sub {Xi}{Lambda}}, proportional to the difference of {alpha}{sub {Xi}}{alpha}{sub {Lambda}} of the hyperon and anti-hyperon decays, vanishes if CP is conserved. We report on an analysis of a fraction of 1997 and 1999 data collected by the Hyper CP (E871) collaboration during the fixed-target runs at Fermilab. The preliminary measurement of the asymmetry is {Alpha}{sub {Xi}{Lambda}} = [-7 {+-} 12(stat) {+-} 6.2(sys)] x 10{sup -4}, an order of magnitude better than the present limit.

  3. Magnetic field decay in model SSC dipoles

    SciTech Connect

    Gilbert, W.S.; Althaus, R.F.; Barale, P.J.; Benjegerdes, R.W.; Green, M.A.; Green, M.I.; Scanlan, R.M.

    1988-08-01

    We have observed that some of our model SSC dipoles have long time constant decays of the magnetic field harmonics with amplitudes large enough to result in significant beam loss, if they are not corrected. The magnets were run at constant current at the SSC injection field level of 0.3 tesla for one to three hours and changes in the magnetic field were observed. One explanation for the observed field decay is time dependent superconductor magnetization. Another explanation involves flux creep or flux flow. Data are presented on how the decay changes with previous flux history. Similar magnets with different Nb-Ti filament spacings and matrix materials have different long time field decay. A theoretical model using proximity coupling and flux creep for the observed field decay is discussed. 10 refs., 5 figs., 2 tabs.

  4. Searching for displaced Higgs boson decays

    NASA Astrophysics Data System (ADS)

    Csáki, Csaba; Kuflik, Eric; Lombardo, Salvator; Slone, Oren

    2015-10-01

    We study a simplified model of the Standard Model (SM) Higgs boson decaying to a degenerate pair of scalars which travel a macroscopic distance before decaying to SM particles. This is the leading signal for many well-motivated solutions to the hierarchy problem that do not propose additional light colored particles. Bounds for displaced Higgs boson decays below 10 cm are found by recasting existing tracker searches from Run I. New tracker search strategies, sensitive to the characteristics of these models and similar decays, are proposed with sensitivities projected for Run II at √{s }=13 TeV . With 20 fb-1 of data, we find that Higgs branching ratios down to 2 ×1 0-4 can be probed for centimeter decay lengths.

  5. Stick slip, charge separation and decay

    USGS Publications Warehouse

    Lockner, D.A.; Byerlee, J.D.; Kuksenko, V.S.; Ponomarev, A.V.

    1986-01-01

    Measurements of charge separation in rock during stable and unstable deformation give unexpectedly large decay times of 50 sec. Time-domain induced polarization experiments on wet and dry rocks give similar decay times and suggest that the same decay mechanisms operate in the induced polarization response as in the relaxation of charge generated by mechanical deformation. These large decay times are attributed to electrochemical processes in the rocks, and they require low-frequency relative permittivity to be very large, in excess of 105. One consequence of large permittivity, and therefore long decay times, is that a significant portion of any electrical charge generated during an earthquake can persist for tens or hundreds of seconds. As a result, electrical disturbances associated with earthquakes should be observable for these lengths of time rather than for the milliseconds previously suggested. ?? 1986 Birka??user Verlag.

  6. Radiation Hydrodynamics

    SciTech Connect

    Castor, J I

    2003-10-16

    The discipline of radiation hydrodynamics is the branch of hydrodynamics in which the moving fluid absorbs and emits electromagnetic radiation, and in so doing modifies its dynamical behavior. That is, the net gain or loss of energy by parcels of the fluid material through absorption or emission of radiation are sufficient to change the pressure of the material, and therefore change its motion; alternatively, the net momentum exchange between radiation and matter may alter the motion of the matter directly. Ignoring the radiation contributions to energy and momentum will give a wrong prediction of the hydrodynamic motion when the correct description is radiation hydrodynamics. Of course, there are circumstances when a large quantity of radiation is present, yet can be ignored without causing the model to be in error. This happens when radiation from an exterior source streams through the problem, but the latter is so transparent that the energy and momentum coupling is negligible. Everything we say about radiation hydrodynamics applies equally well to neutrinos and photons (apart from the Einstein relations, specific to bosons), but in almost every area of astrophysics neutrino hydrodynamics is ignored, simply because the systems are exceedingly transparent to neutrinos, even though the energy flux in neutrinos may be substantial. Another place where we can do ''radiation hydrodynamics'' without using any sophisticated theory is deep within stars or other bodies, where the material is so opaque to the radiation that the mean free path of photons is entirely negligible compared with the size of the system, the distance over which any fluid quantity varies, and so on. In this case we can suppose that the radiation is in equilibrium with the matter locally, and its energy, pressure and momentum can be lumped in with those of the rest of the fluid. That is, it is no more necessary to distinguish photons from atoms, nuclei and electrons, than it is to distinguish

  7. Leptonic and semileptonic decays of B mesons

    NASA Astrophysics Data System (ADS)

    Dingfelder, Jochen; Mannel, Thomas

    2016-07-01

    Semileptonic decays are ideally suited to study the weak interaction as well as strong interaction effects in B -meson decays. In the last decade, precision studies of semileptonic B decays have been made possible by the large samples of B mesons collected at the B factories KEKB in Japan and PEP-II in the USA. Measurements of the charged-current semileptonic transitions b →q ℓν (q =u , c ) allow for a determination of the magnitude of the Cabibbo-Kobayashi-Maskawa matrix elements Vc b and Vu b and the masses of the b and c quarks, which are fundamental parameters of the standard model of particle physics. The values of |Vc b| and |Vu b| are determined from measurements of inclusive B decays in combination with calculations of partial decay rates or from exclusive decays combined with theoretical predictions of hadronic form factors. Purely leptonic B decays B →ℓν (ℓ=e , μ , τ ) also provide access to |Vu b|. They are theoretically simpler, but the available signal samples are still small. Decays involving a τ lepton, B →τ ν and B →D(*)τ ν , are sensitive to new physics, in particular, to charged Higgs bosons in models with an extended Higgs sector, and provide a window to the physics of the third generation. In this article, the measurements and theoretical descriptions of charged-current leptonic and semileptonic B decays and the status of |Vc b| and |Vu b| determinations are reviewed. An overview of the theoretical approaches and the experimental techniques used in the study of these decays is also provided.

  8. The cancer epidemiology of radiation.

    PubMed

    Wakeford, Richard

    2004-08-23

    Ionizing radiation has been the subject of intense epidemiological investigation. Studies have demonstrated that exposure to moderate-to-high levels can cause most forms of cancer, leukaemia and cancers of the breast, lung and thyroid being particularly sensitive to induction by radiation, especially at young ages at exposure. Predominant among these studies is the Life Span Study of the cohort of survivors of the atomic bombings of Japan in 1945, but substantial evidence is derived from groups exposed for medical reasons, occupationally or environmentally. Notable among these other groups are underground hard rock miners who inhaled radioactive radon gas and its decay products, large numbers of patients irradiated therapeutically and workers who received high doses in the nuclear weapons programme of the former USSR. The degree of carcinogenic risk arising from low levels of exposure is more contentious, but the available evidence points to an increased risk that is approximately proportional to the dose received. Epidemiological investigations of nonionizing radiation have established ultraviolet radiation as a cause of skin cancer. However, the evidence for a carcinogenic effect of other forms of nonionizing radiation, such as those associated with mobile telephones or electricity transmission lines, is not convincing, although the possibility of a link between childhood leukaemia and extremely low-frequency electromagnetic fields cannot be dismissed entirely.

  9. Radiation therapy

    MedlinePlus

    ... Intensity-modulated radiotherapy (IMRT) Image-guided radiotherapy (IGRT) Proton therapy is another kind of radiation used to ... than using x-rays to destroy cancer cells, proton therapy uses a beam of special particles called ...

  10. RADIATION DETECTOR

    DOEpatents

    Wilson, H.N.; Glass, F.M.

    1960-05-10

    A radiation detector of the type is described wherein a condenser is directly connected to the electrodes for the purpose of performing the dual function of a guard ring and to provide capacitance coupling for resetting the detector system.

  11. Radiation Basics

    MedlinePlus

    ... of the heaviest radioactive elements, such as uranium , radium and polonium. Even though alpha particles are very ... is roughly the activity of one gram of Radium-226. Curies are not used to measure radiation ...

  12. Radiation Transport

    SciTech Connect

    Urbatsch, Todd James

    2015-06-15

    We present an overview of radiation transport, covering terminology, blackbody raditation, opacities, Boltzmann transport theory, approximations to the transport equation. Next we introduce several transport methods. We present a section on Caseology, observing transport boundary layers. We briefly broach topics of software development, including verification and validation, and we close with a section on high energy-density experiments that highlight and support radiation transport.

  13. Radiation and radiation reaction in continuous focusing channels

    SciTech Connect

    Huang, Zhirong; Chen, Pisin; Ruth, R.D.

    1994-12-31

    We show that the radiation damping rate of the transverse action of a particle in a straight, continuous focusing system is independent of the particle energy, and that no quantum excitation is induced. This absolute damping effect leads to the existence of a transverse ground state which the particle inevitably decays to, and yields the minimum beam emittance that one can ever attain, {gamma}{epsilon}{sub min} = {Dirac_h}/2mc, limited only by the uncertainty principle. Due to adiabatic invariance, the particle can be accelerated along the focusing channel in its ground state without any radiation energy loss. These findings may apply to bent systems provided that the focusing field dominates over the bending field.

  14. Radiation and radiation reaction in continuous focusing channels

    NASA Astrophysics Data System (ADS)

    Huang, Zhirong; Chen, Pisin; Ruth, Ronald D.

    1995-06-01

    We show that the radiation damping rate of the transverse action of a particle in a straight, continuous focusing system is independent of the particle energy, and that no quantum excitation is induced. This absolute damping effect leads to the existence of a transverse ground state which the particle inevitably decays to, and yields the minimum beam emittance that one can ever attain, γɛmin=ℏ/2mc, limited only by the uncertainty principle. Due to adiabatic invariance, the particle can be accelerated along the focusing channel in its ground state without any radiation energy loss. These findings may apply to bent systems provided that the focusing field dominates over the bending field.

  15. B, D and K Decays

    SciTech Connect

    Artuso, M.; Asner, D.M.; Ball, P.; Baracchini, E.; Bell, G.; Beneke, M.; Berryhill, J.; Bevan, A.; Bigi, I.I.; Blanke, M.; Bobeth, Ch.; Bona, M.; Borzumati, F.; Browder, T.; Buanes, T.; Buchalla, G.; Buchmuller, O.; Buras, A.J.; Burdin, S.; Cassel, D.G.; Cavanaugh, R.; /Syracuse U. /Carleton U. /Durham U., IPPP /Rome U. /INFN, Rome /Karlsruhe U. /RWTH Aachen U. /Fermilab /Queen Mary, U. of London /Notre Dame U. /Munich, Tech. U. /Munich, Max Planck Inst. /Dortmund U. /Annecy, LAPP /ICTP, Trieste /Taiwan, Natl. Central U. /Hawaii U. /Bergen U. /Munich U. /CERN /Liverpool U.

    2008-03-07

    The present report documents the results of Working Group 2: B, D and K decays, of the workshop on Flavor in the Era of the LHC, held at CERN from November 2005 through March 2007. With the advent of the LHC, we will be able to probe New Physics (NP) up to energy scales almost one order of magnitude larger than it has been possible with present accelerator facilities. While direct detection of new particles will be the main avenue to establish the presence of NP at the LHC, indirect searches will provide precious complementary information, since most probably it will not be possible to measure the full spectrum of new particles and their couplings through direct production. In particular, precision measurements and computations in the realm of flavor physics are expected to play a key role in constraining the unknown parameters of the Lagrangian of any NP model emerging from direct searches at the LHC. The aim of Working Group 2 was twofold: on one hand, to provide a coherent, up-to-date picture of the status of flavor physics before the start of the LHC; on the other hand, to initiate activities on the path towards integrating information on NP from high-p{sub T} and flavor data. This report is organized as follows. In Sec. 1, we give an overview of NP models, focusing on a few examples that have been discussed in some detail during the workshop, with a short description of the available computational tools for flavor observables in NP models. Sec. 2 contains a concise discussion of the main theoretical problem in flavor physics: the evaluation of the relevant hadronic matrix elements for weak decays. Sec. 3 contains a detailed discussion of NP effects in a set of flavor observables that we identified as 'benchmark channels' for NP searches. The experimental prospects for flavor physics at future facilities are discussed in Sec. 4. Finally, Sec. 5 contains some assessments on the work done at the workshop and the prospects for future developments.

  16. Radiation enteritis.

    PubMed

    Harb, Ali H; Abou Fadel, Carla; Sharara, Ala I

    2014-01-01

    Radiation enteritis continues to be a major health concern in recipients of radiation therapy. The incidence of radiation enteritis is expected to continue to rise during the coming years paralleling the unprecedented use of radiotherapy in pelvic cancers. Radiation enteritis can present as either an acute or chronic syndrome. The acute form presents within hours to days of radiation exposure and typically resolves within few weeks. The chronic form may present as early as 2 months or as long as 30 years after exposure. Risk factors can be divided into patient and treatment-related factors. Chronic radiation enteritis is characterized by progressive obliterative endarteritis with exaggerated submucosal fibrosis and can manifest by stricturing, formation of fistulae, local abscesses, perforation, and bleeding. In the right clinical context, diagnosis can be confirmed by cross-sectional imaging, flexible or video capsule endoscopy. Present treatment strategies are directed primarily towards symptom relief and management of emerging complications. Recently, however, there has been a shift towards rational drug design based on improved understanding of the molecular basis of disease in an effort to limit the fibrotic process and prevent organ damage.

  17. Nudat: Nuclear Structure and Decay Data from the National Nuclear Data Center (NNDC)

    DOE Data Explorer

    NuDat allows users to search and plot nuclear structure and decay data interactively. NuDat was developed by the National Nuclear Data Center (NNDC)but utilizes contributions from physicists around the world. It provides an interface between web users and several databases containing nuclear structure, nuclear decay and some neutron-induced nuclear reaction information. Users can search for nuclear level properties (energy, half-life, spinparity), gamma-ray information (energy, intensity, multipolarity, coincidences), radiation information following nuclear decay (energy, intensity, dose), and neutron-induced reaction data from the BNL-325 book (thermal cross section and resonance integral). The information provided by NuDat 2 can be viewed in tables, level schemes and an interactive chart of nuclides.

  18. Relativistic resonance and decay phenomena

    NASA Astrophysics Data System (ADS)

    Bui, Hai V.

    2015-04-01

    The exact relation τ = ℏ/Γ between the width Γ of a resonance and the lifetime τ for the decay of this resonance could not be obtained in standard quantum theory based on the Hilbert space or Schwartz space axiom in non-relativistic physics as well as in the relativistic regime. In order to obtain the exact relation, one has to modify the Hilbert space axiom or the Schwartz space axiom and choose new boundary conditions based on the Hardy space axioms in which the space of the states and the space of the observables are described by two different Hardy spaces. As consequences of the new Hardy space axioms, one obtains, instead of the symmetric time evolution for the states and the observables, asymmetrical time evolutions for the states and observables which are described by two semi-groups. A relativistic resonance obeying the exponential time evolution can be described by a relativistic Gamow vector, which is defined as superposition of the exact out-plane wave states with a Breit-Wigner energy distribution of the width Γ.

  19. Tau Decays at BaBar

    SciTech Connect

    Hast, Carsten; /SLAC

    2009-01-22

    Recent results of tau lepton decay studies based on luminosities between 350 fb{sup -1} and 469 fb{sup -1} collected with the BABAR detector at the PEP-II e{sup +}e{sup -} collider at the SLAC National Accelerator Laboratory are presented. The analyses reported here are Charged Current Lepton Universality and measurements of |V{sub us}| using {tau}{sup -} {yields} e{sup -}{bar {nu}}{sub e}{nu}{sub {tau}}, {mu}{sup -}{bar {nu}}{sub {mu}}{nu}{sub {tau}}, {pi}{sup -} {nu}{sub {tau}}, and K{sup -}{nu}{sub {tau}} decays, as well as searches for Second Class Currents in {tau}{sup -} {yields} {omega}{pi}{sup -}{nu}{sub {tau}} decays, studies of Lepton Flavor Violations, and a tau mass measurement and CPT-Test. If not explicitly mentioned, charge conjugate decay modes are also implied. decays, as well as searches for Second Class Currents in {tau}{sup -} {yields} {omega}{pi}{sup -}{nu}{sub {tau}} decays, studies of Lepton Flavor Violations, and a tau mass measurement and CPT-Test. If not explicitly mentioned, charge conjugate decay modes are also implied.

  20. Ring current proton decay by charge exchange

    NASA Technical Reports Server (NTRS)

    Smith, P. H.; Hoffman, R. A.; Fritz, T.

    1975-01-01

    Explorer 45 measurements during the recovery phase of a moderate magnetic storm have confirmed that the charge exchange decay mechanism can account for the decay of the storm-time proton ring current. Data from the moderate magnetic storm of 24 February 1972 was selected for study since a symmetrical ring current had developed and effects due to asymmetric ring current losses could be eliminated. It was found that after the initial rapid decay of the proton flux, the equatorially mirroring protons in the energy range 5 to 30 keV decayed throughout the L-value range of 3.5 to 5.0 at the charge exchange decay rate calculated by Liemohn. After several days of decay, the proton fluxes reached a lower limit where an apparent equilibrium was maintained, between weak particle source mechanisms and the loss mechanisms, until fresh protons were injected into the ring current region during substorms. While other proton loss mechanisms may also be operating, the results indicate that charge exchange can entirely account for the storm-time proton ring current decay, and that this mechanism must be considered in all studies involving the loss of proton ring current particles.

  1. Effects of radiation on carbapenems

    NASA Astrophysics Data System (ADS)

    Tepe, Semra; Polat, Mustafa; Korkmaz, Mustafa

    In the present work, effects of gamma radiation on solid meropenem trihydrate (MPT), which is the active ingredient of carbapenem antibiotics, were investigated by electron spin resonance (ESR) spectroscopy. Irradiated MPT presents an ESR spectrum consisting of many resonance peaks. Heights measured with respect to the spectrum baseline of these resonance peaks were used to explore the evolutions of the radicalic species responsible for the experimental spectrum under different conditions. Variations of the denoted 11 peak heights with microwave power, sample temperature and applied radiation doses and decay of the involved radicalic species at room and at high temperatures were studied. On the basis of the results derived from these studies, a molecular model consisting of the presence of four different radicalic species was proposed, and spectroscopic parameters of these species were calculated through spectrum simulation calculations. The dosimetric potential of MPT was also explored and it was concluded that MPT presents the characteristics of normal and accidental dosimetric materials.

  2. Radiating dipoles in photonic crystals

    PubMed

    Busch; Vats; John; Sanders

    2000-09-01

    The radiation dynamics of a dipole antenna embedded in a photonic crystal are modeled by an initially excited harmonic oscillator coupled to a non-Markovian bath of harmonic oscillators representing the colored electromagnetic vacuum within the crystal. Realistic coupling constants based on the natural modes of the photonic crystal, i.e., Bloch waves and their associated dispersion relation, are derived. For simple model systems, well-known results such as decay times and emission spectra are reproduced. This approach enables direct incorporation of realistic band structure computations into studies of radiative emission from atoms and molecules within photonic crystals. We therefore provide a predictive and interpretative tool for experiments in both the microwave and optical regimes.

  3. The Gas-Cooled Fast Reactor: Report on Safety System Design for Decay Heat Removal

    SciTech Connect

    K. D. Weaver; T. Marshall; T. Y. C. Wei; E. E. Feldman; M. J. Driscoll; H. Ludewig

    2003-09-01

    The gas-cooled fast reactor (GFR) was chosen as one of the Generation IV nuclear reactor systems to be developed based on its excellent potential for sustainability through reduction of the volume and radiotoxicity of both its own fuel and other spent nuclear fuel, and for extending/utilizing uranium resources orders of magnitude beyond what the current open fuel cycle can realize. In addition, energy conversion at high thermal efficiency is possible with the current designs being considered, thus increasing the economic benefit of the GFR. However, research and development challenges include the ability to use passive decay heat removal systems during accident conditions, survivability of fuels and in-core materials under extreme temperatures and radiation, and economical and efficient fuel cycle processes. This report addresses/discusses the decay heat removal options available to the GFR, and the current solutions. While it is possible to design a GFR with complete passive safety (i.e., reliance solely on conductive and radiative heat transfer for decay heat removal), it has been shown that the low power density results in unacceptable fuel cycle costs for the GFR. However, increasing power density results in higher decay heat rates, and the attendant temperature increase in the fuel and core. Use of active movers, or blowers/fans, is possible during accident conditions, which only requires 3% of nominal flow to remove the decay heat. Unfortunately, this requires reliance on active systems. In order to incorporate passive systems, innovative designs have been studied, and a mix of passive and active systems appears to meet the requirements for decay heat removal during accident conditions.

  4. Synchrotron radiation with radiation reaction

    NASA Astrophysics Data System (ADS)

    Nelson, Robert W.; Wasserman, Ira

    1991-04-01

    A rigorous discussion is presented of the classical motion of a relativistic electron in a magnetic field and the resulting electromagnetic radiation when radiation reaction is important. In particular, for an electron injected with initial energy gamma(0), a systematic perturbative solution to the Lorentz-Dirac equation of motion is developed for field strengths satisfying gamma(0) B much less than 6 x 10 to the 15th G. A particularly accurate solution to the electron orbital motion in this regime is found and it is demonstrated how lowest-order corrections can be calculated. It is shown that the total energy-loss rate corresponds to what would be found using the exact Larmor power formula without including radiation reaction. Provided that the particle energy and field strength satisfy the same contraint, it is explicitly demonstrated that the intuitive prescription for calculating the time-integrated radiation spectrum described above is correct.

  5. Particle physics: CP violation in hyperon decays

    SciTech Connect

    Longo, Michael J.

    2000-10-31

    The primary research activities under this grant were in E871 (HyperCP) at Fermilab, a search for CP violation in hyperon decays which completed data taking in January, 2000. HyperCP is an experiment designed to perform a sensitive search for direct CP violation in the decays of cascade ({Xi}) and {Lambda} hyperons by looking for an asymmetry between particle and antiparticle decay parameters. The experiment is expected to achieve a sensitivity {approx}10{sup -4} in the decay parameters. Standard model predictions for this CP-violating asymmetry range from 0.3 to 5 x 10{sup -4}. A difference between the decay parameters for particle and antiparticle is direct evidence that CP symmetry is violated. A non-zero asymmetry would be the first evidence for CP violation outside of the K{sup o} system. Recent results from KTeV indicate a direct CP violation in K{sup o} decays, which suggests that CP violation will appear in other decays. In addition, we will look at a number of rare hyperon decays involving muons. These probe important new physics topics such as Majorana neutrinos and lepton number violating processes. The latter are of great current interest because new evidence for neutrino oscillations indicate lepton flavor violation does occur. Our data will lead to an improvement in the limits on branching ratios for these processes typically by three to four orders-of-magnitude. The muon detector construction and data resulting from it have been the responsibility of the Michigan group. We are now leading the analysis of the rare muon-related decay modes, and were responsible for the muon system and beam monitor upgrades for the 1999 run.

  6. Brain radiation - discharge

    MedlinePlus

    Radiation - brain - discharge; Cancer-brain radiation; Lymphoma - brain radiation; Leukemia - brain radiation ... Decadron) while you are getting radiation to the brain. It may make you hungrier, cause leg swelling ...

  7. β -decay study of 94Kr

    NASA Astrophysics Data System (ADS)

    Miernik, K.; Rykaczewski, K. P.; Grzywacz, R.; Gross, C. J.; Madurga, M.; Miller, D.; Stracener, D. W.; Batchelder, J. C.; Brewer, N. T.; Cartegni, L.; Fijałkowska, A.; Karny, M.; Korgul, A.; Królas, W.; Mazzocchi, C.; Mendez, A. J., II; Padgett, S. W.; Paulauskas, S. V.; Winger, J. A.; Wolińska-Cichocka, M.; Zganjar, E. F.

    2016-08-01

    β decay of neutron-rich nuclide 94Kr was reinvestigated by means of a high resolution on-line mass separator and β -γ spectroscopy. In total 22 γ -ray transitions were assigned to the decay of 94Kr, and a new isomeric state was identified. The new information allows us to build detailed levels systematics in a chain of odd-odd rubidium isotopes and draw conclusions on nuclear structure for some of the observed states. The discussed level structure affects the evolution of β -decay half-lives for neutron-rich selenium, krypton, and strontium isotopes.

  8. An interactive database for decay data

    NASA Astrophysics Data System (ADS)

    Bé, M. M.; Duchemin, B.; Lamé, J.

    1996-02-01

    The Table de Radionucléides is maintained by the LPRI and offers easy access to nuclear decay data for all users. Only radionuclides of special interest for metrology or practical applications are included. Primary recommended decay data comprise half-lives, decay modes, X-rays, gamma-rays, alpha- and beta-particle transitions and emissions, and their uncertainties. The specific features and facilities of this database are outlined. The database has been developed by using Microsoft-Access software and is available for use on PCs.

  9. Spectroscopy of element 115 decay chains.

    PubMed

    Rudolph, D; Forsberg, U; Golubev, P; Sarmiento, L G; Yakushev, A; Andersson, L-L; Di Nitto, A; Düllmann, Ch E; Gates, J M; Gregorich, K E; Gross, C J; Heßberger, F P; Herzberg, R-D; Khuyagbaatar, J; Kratz, J V; Rykaczewski, K; Schädel, M; Åberg, S; Ackermann, D; Block, M; Brand, H; Carlsson, B G; Cox, D; Derkx, X; Eberhardt, K; Even, J; Fahlander, C; Gerl, J; Jäger, E; Kindler, B; Krier, J; Kojouharov, I; Kurz, N; Lommel, B; Mistry, A; Mokry, C; Nitsche, H; Omtvedt, J P; Papadakis, P; Ragnarsson, I; Runke, J; Schaffner, H; Schausten, B; Thörle-Pospiech, P; Torres, T; Traut, T; Trautmann, N; Türler, A; Ward, A; Ward, D E; Wiehl, N

    2013-09-13

    A high-resolution α, x-ray, and γ-ray coincidence spectroscopy experiment was conducted at the GSI Helmholtzzentrum für Schwerionenforschung. Thirty correlated α-decay chains were detected following the fusion-evaporation reaction 48Ca + 243Am. The observations are consistent with previous assignments of similar decay chains to originate from element Z=115. For the first time, precise spectroscopy allows the derivation of excitation schemes of isotopes along the decay chains starting with elements Z>112. Comprehensive Monte Carlo simulations accompany the data analysis. Nuclear structure models provide a first level interpretation.

  10. Positronium decay into a photon and neutrinos

    NASA Astrophysics Data System (ADS)

    Pokraka, Andrzej; Czarnecki, Andrzej

    2016-12-01

    We determine the rates and energy and angular distributions of the positronium decays into a photon and a neutrino-antineutrino pair, Ps →γ νℓν¯ℓ. We find that both positronium spin states have access to this decay channel, contrary to a previously published result. The low-energy tails of the spectra are shown to be sensitive to the binding effects and agree with Low's theorem. Additionally, we find a connection between the behavior of the soft photon spectrum in both o -Ps →γ νℓν¯ ℓ and o -Ps →3 γ decays, and the Stark effect.

  11. Suppressed $B_s$ decays at CDF

    SciTech Connect

    Dorigo, Mirco

    2011-05-01

    We review three recent results of the CDF collaboration on B{sub s}{sup 0} suppressed decays: the first search for CP-violation in the B{sub s}{sup 0} {yields} {phi}{phi} decay, where two CP-violating asymmetries expected to be zero in the Standard Model are measured, and the observation and the branching ratio measurements of B{sub s}{sup 0} {yields} J/{Psi} f{sub 0}(980) and B{sub s}{sup 0} {yields} J/{Psi} K{sup (*)} decays.

  12. String splitting and strong coupling meson decay.

    PubMed

    Cotrone, A L; Martucci, L; Troost, W

    2006-04-14

    We study the decay of high spin mesons using the gauge-string theory correspondence. The rate of the process is calculated by studying the splitting of a macroscopic string intersecting a D-brane. The result is applied to the decay of mesons in N=4 super Yang-Mills theory with a small number of flavors and in a gravity dual of large N QCD. In QCD the decay of high spin mesons is found to be heavily suppressed in the regime of validity of the supergravity description.

  13. Charmless and Penguin Decays at CDF

    SciTech Connect

    Dorigo, Mirco; Collaboration, for the CDF

    2010-12-01

    Penguin transitions play a key role in the search of New Physics hints in the heavy flavor sector. During the last decade CDF has been exploring this opportunity with a rich study of two-body charmless decays of neutral B mesons into charged final-state particles. After briefly introducing the aspects of this physics peculiar to the hadron collision environment, I report on two interesting results: the first polarization measurement of the B{sub s}{sup 0} {yields} {phi}{phi} decay and the update of the B{sub (s)}{sup 0} {yields} h{sup +}h{prime}{sup -} decays analysis.

  14. Top-down holographic glueball decay rates

    SciTech Connect

    Brünner, F.; Parganlija, D.; Rebhan, A.

    2016-01-22

    We present new results on the decay patterns of scalar and tensor glueballs in the top-down holographic Witten-Sakai-Sugimoto model. This model, which has only one free dimensionless parameter, gives semi-quantitative predictions for the vector meson spectrum, their decay widths, and also a gluon condensate in agreement with SVZ sum rules. The holographic predictions for scalar glueball decay rates are compared with experimental data for the widely discussed gluon candidates f{sub 0}(1500) and f{sub 0}(1710)

  15. Localized defects in radiation-damaged zircon

    PubMed

    Rios; Malcherek; Salje; Domeneghetti

    2000-12-01

    The crystal structure of a radiation-damaged natural zircon, ZrSiO(4) (alpha-decay radiation dose is ca 1.8 x 10(18) alpha-decay events g(-1)), has been determined. The anisotropic unit-cell swelling observed in the early stages of the amorphization process (0.17% along the a axis and 0.62% along the c axis compared with the undamaged material) is a consequence of the anisotropy of the expansion of ZrO(8) polyhedra. Larger anisotropic displacement parameters were found for Zr and O atoms, indicating that the distortion produced by alpha particle-induced localized defects mainly affects the ZrO(8) unit. The overall shape of SiO(4) tetrahedra remains essentially undistorted, while Si-O bonds are found to lengthen by 0.43%.

  16. Tachyonic Cherenkov radiation from supernova remnants

    NASA Astrophysics Data System (ADS)

    Tomaschitz, Roman

    2015-12-01

    The subexponential decay observed in the γ-ray spectral maps of supernova remnants is explained in terms of tachyonic Cherenkov emission from a relativistic electron population. The tachyonic radiation densities of an electronic spinor current are derived, the total density as well as the transversal and longitudinal polarization components, taking account of electron recoil. Tachyonic flux quantization subject to dispersive and dissipative permeabilities is discussed, the matrix elements of the transversal and longitudinal Poynting vectors of the Maxwell-Proca field are obtained, Cherenkov emission angles and radiation conditions are derived. The spectral energy flux of an ultra-relativistic electron plasma is calculated, a tachyonic Cherenkov fit to the high-energy (1 GeV to 30 TeV) γ-ray spectrum of the Crab Nebula is performed, and estimates of the linear polarization degree are given. The spectral tail shows subexponential Weibull decay, which can be modeled with a frequency-dependent tachyon mass in the dispersion relations. Tachyonic flux densities interpolate between exponential and power-law spectral decay, which is further illustrated by Cherenkov fits to the γ-ray spectra of the supernova remnants IC 443 and W44. Subexponential spectral decay is manifested in double-logarithmic spectral maps as curved Weibull or straight power-law slope.

  17. Impact of the new nuclear decay data of ICRP publication 107 on inhalation dose coefficients for workers.

    PubMed

    Manabe, K; Endo, A; Eckerman, K F

    2010-03-01

    The impact a revision of nuclear decay data had on dose coefficients was studied using data newly published in ICRP Publication 107 (ICRP 107) and existing data from ICRP Publication 38 (ICRP 38). Committed effective dose coefficients for occupational inhalation of radionuclides were calculated using two sets of decay data with the dose and risk calculation software DCAL for 90 elements, 774 nuclides and 1572 cases. The dose coefficients based on ICRP 107 increased by over 10 % compared with those based on ICRP 38 in 98 cases, and decreased by over 10 % in 54 cases. It was found that the differences in dose coefficients mainly originated from changes in the radiation energy emitted per nuclear transformation. In addition, revisions of the half-lives, radiation types and decay modes also resulted in changes in the dose coefficients.

  18. The impact of exospheric neutral dynamics on ring current decay

    NASA Astrophysics Data System (ADS)

    Ilie, R.; Liemohn, M. W.; Skoug, R. M.; Funsten, H. O.; Gruntman, M.; Bailey, J. J.; Toth, G.

    2015-12-01

    The geocorona plays an important role in the energy budget of the Earth's inner magnetosphere since charge exchange of energetic ions with exospheric neutrals makes the exosphere act as an energy sink for ring current particles. Long-term ring current decay following a magnetic storm is mainly due to these electron transfer reactions, leading to the formation energetic neutral atoms (ENAs) that leave the ring current system on ballistic trajectories. The number of ENAs emitted from a given region of space depends on several factors, such as the energy and species of the energetic ion population in that region and the density of the neutral gas with which the ions undergo charge exchange. However, the density and structure of the exosphere are strongly dependent on changes in atmospheric temperature and density as well as charge exchange with the ions of plasmaspheric origin, which depletes the geocorona (by having a neutral removed from the system). Moreover, the radiation pressure exerted by solar far-ultraviolet photons pushes the geocoronal hydrogen away from the Earth in an anti-sunward direction to form a tail of neutral hydrogen. TWINS ENA images provide a direct measurement of these ENA losses and therefore insight into the dynamics of the ring current decay through interactions with the geocorona. We assess the influence of geocoronal neutrals on ring current formation and decay by analysis of the predicted ENA emissions using 6 different geocoronal models and simulations from the HEIDI ring current model during storm time. Comparison with TWINS ENA images shows that the location of the peak ENA enhancements is highly dependent on the distribution of geocoronal hydrogen density. We show that the neutral dynamics has a strong influence on the time evolution of the ring current populations as well as on the formation of energetic neutral atoms.

  19. {mu}{yields}e{gamma} and {tau}{yields}l{gamma} decays in the fermion triplet seesaw model

    SciTech Connect

    Abada, A.; Bonnet, F.; Biggio, C.; Gavela, M. B.

    2008-08-01

    In the framework of the seesaw models with triplets of fermions, we evaluate the decay rates of {mu}{yields}e{gamma} and {tau}{yields}l{gamma} transitions. We show that although, due to neutrino mass constraints, those rates are in general expected to be well under the present experimental limits, this is not necessarily always the case. Interestingly enough, the observation of one of those decays in planned experiments would nevertheless contradict bounds stemming from present experimental limits on the {mu}{yields}eee and {tau}{yields}3l decay rates, as well as from {mu} to e conversion in atomic nuclei. Such detection of radiative decays would therefore imply that there exist sources of lepton flavor violation not associated to triplet fermions.

  20. Thermionic power-law decay of excited aluminum-cluster anions and its dependence on storage-device temperature

    SciTech Connect

    Froese, M. W.; Blaum, K.; Fellenberger, F.; Grieser, M.; Lange, M.; Laux, F.; Menk, S.; Orlov, D. A.; Repnow, R.; Sieber, T.; Hahn, R. von; Wolf, A.; Toker, Y.

    2011-02-15

    The decay of excited aluminum-cluster anions (Al{sub n}{sup -}, n=4 and 5) has been investigated in a cryogenic linear ion-beam trap. A power-law is found to accurately reproduce the time dependence of the observed decay rates at early storage times, although the exponents are significantly larger than the typically observed 1/t decay. It is shown that the power-law exponent is, at most, weakly dependent on the cluster electron affinity and heat capacity. A previous power-law exponent model for small clusters is also shown to be in disagreement with both investigated species. The attribution of a drop in the decay rate at later times to radiative cooling as observed in larger molecules also does not appear justified in our case. A strong dependence of the power-law exponent on the ambient temperature was observed.