Science.gov

Sample records for longitudinally polarized hadroproduction

  1. Impact of η(c) hadroproduction data on charmonium production and polarization within the nonrelativistic QCD framework.

    PubMed

    Zhang, Hong-Fei; Sun, Zhan; Sang, Wen-Long; Li, Rong

    2015-03-01

    With the recent LHCb data on η_{c} production and based on heavy quark spin symmetry, we obtain the long-distance matrix elements for both η_{c} and J/ψ productions, among which, the color-singlet one for η_{c} is obtained directly by the fit of experiment for the first time. Using our long-distance matrix elements, we can provide good description of the η_{c} and J/ψ hadroproduction measurements. Our predictions on J/ψ polarization are in good agreement with the LHCb data, explain most of the CMS data, and pass through the two sets of CDF measurements in the medium p_{t} region. Considering all the possible uncertainties carefully, we obtained quite narrow bands of the J/ψ polarization curves. PMID:25793807

  2. RHIC OPERATION WITH LONGITUDINALLY POLARIZED PROTONS.

    SciTech Connect

    HUANG,H.BAI,M.BEEBE-WANG,J.ET AL.

    2004-07-05

    Polarized proton beams have been accelerated, stored and collided at 100GeV per beam in the Relativistic Heavy Ion Collider (RHIC) with longitudinal polarization. The essential equipment includes four Siberian snakes, eight spin rotators and fast relative polarimeters in each of the two RHIC rings as well as local polarimeters at the STAR and PHENIX detectors. This paper summarizes the performance of RHIC as a polarized proton collider in the FY03 run with emphasis on polarization issues. Preliminary data from the FY04 run is also shown.

  3. Longitudinal Polarization of 12B in Muon Capture Reaction

    NASA Astrophysics Data System (ADS)

    Ami, H.; Kobayashi, M.; Ohtsubo, H.; Morita, M.

    1981-02-01

    A general formula is given for the longitudinal polarization of the recoil nucleus in polarized muon capture in a spin zero nucleus. The longitudinal polarization of the recoil 12B is studied numerically in the reaction 12C+μ^-to12B+ν_μ. Contributions from excited states play an important role in determining the induced pseudoscalar and induced tensor form factors. Existing experimental data on the longitudinal polarization and average polarization are consistent with the assumption of time reversal invariance.

  4. On relevance of triple-gluon fusion in hadroproduction

    NASA Astrophysics Data System (ADS)

    Motyka, Leszek; Sadzikowski, Mariusz

    2015-05-01

    A contribution to hadroproduction is analyzed in which the meson production is mediated by three-gluon partonic state, with two gluons coming from the target and one gluon from the projectile. This mechanism involves double gluon density in one of the protons, hence this contribution enters at a non-leading twist. It is, however, relevant due to an enhancement factor coming from large double gluon density at small . We calculate the three-gluon contribution to hadroproduction within perturbative QCD in the -factorization framework. Results are obtained for differential -dependent cross sections for all polarizations and for the sum over the polarization components. The rescattering contribution is found to provide a significant correction to the standard leading twist cross section at the energies of the Tevatron or the LHC at moderate . We suggest production in proton-nucleus collision as a possible probe of the triple-gluon mechanism.

  5. Nanofocusing of longitudinally polarized light using absorbance modulation

    SciTech Connect

    Li, Qiang; Zhao, Xing Zhang, Bo; Zheng, Yi; Zhou, Liqiu; Fang, Zhiliang; Wang, Lingjie; Wu, Yanxiong

    2014-02-10

    Recently, many methods based on amplitude or phase modulation to reduce the focal spot and enhance the longitudinal field component of a tight-focused radially polarized light beam have been suggested. But they all suffer from spot size limit 0.36λ/NA and large side lobes strength in longitudinal component. Here, we report a method of generating a tighter focused spot by focusing radially polarized and azimuthally polarized beams of different wavelengths on a thin photochromic film through a high-numerical-aperture lens simultaneously. In this method, by suppressing the radial component and compressing the longitudinal component of radially polarized beam, absorbance modulation makes the ultimate spot size break the size limit of 0.36λ/NA with side-lobe intensity of longitudinal component below 1% of central-peak intensity. The theoretical analysis and simulation demonstrate that the focal spot size could be smaller than 0.1λ with nearly all radial component blocked at high intensity ratio of the two illuminating beams.

  6. FDCHQHP: A Fortran package for heavy quarkonium hadroproduction

    NASA Astrophysics Data System (ADS)

    Wan, Lu-Ping; Wang, Jian-Xiong

    2014-11-01

    FDCHQHP is a Fortran package to calculate the transverse momentum (pt) distribution of yield and polarization for heavy quarkonium hadroproduction at next-to-leading-order (NLO) based on non-relativistic QCD(NRQCD) framework. It contains the complete color-singlet and color-octet intermediate states in present theoretical level, and is available to calculate different polarization parameters in different frames. As the LHC running now and in the future, it supplies a very useful tool to obtain theoretical prediction on the heavy quarkonium hadroproduction. Catalogue identifier: AETT_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AETT_v1_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 12020165 No. of bytes in distributed program, including test data, etc.: 103178384 Distribution format: tar.gz Programming language: Fortran 77. Computer: Any computer with Linux operating system, Intel Fortran Compiler and MPI library. Operating system: Linux. Has the code been vectorized or parallelized?: Parallelized with MPI. Classification: 11.1. External routines: MPI Library Nature of problem: This package is for the calculation of the heavy quarkonium hadroproduction at NRQCD NLO. Solution method: The Fortran codes of this package are generated by the FDC system [1] automatically. Additional comments: It is better to run the package on supercomputers or multi-core computers. !!!!! The distribution file for this program is over 100 MB and therefore is not delivered directly when download or Email is requested. Instead a html file giving details of how the program can be obtained is sent. !!!!! Running time: For an independent sub-process, it may take several seconds to several hours depending on the number of sample points if one CPU core is used. For a complete prompt

  7. Polarization-independent longitudinal multi-focusing metalens.

    PubMed

    Wang, Wei; Guo, Zhongyi; Zhou, Keya; Sun, Yongxuan; Shen, Fei; Li, Yan; Qu, Shiliang; Liu, Shutian

    2015-11-16

    A novel multi-focusing metalens in the longitudinal direction has been proposed and investigated based on the equal optical path principle, which is independent on the incident polarizations and can be suitable for both of the linear and circular polarization incidences simultaneously. Here, three novel designing principles: partitioned mode, radial alternating mode and angular alternating mode, have been proposed firstly for constructing different types of the longitudinal multi-focusing metalenses. The performances of the designed metalenses based on the different designed methods have also been analyzed and investigated in detail, and the intensity ratio of the focusing spots can be tuned easily by modulating the numbers of the relative type of nanoantennas, which is significant for the micro-manipulating optics and the multi-imaging technology in the integrated optics. PMID:26698469

  8. Lowest order QED radiative corrections to longitudinally polarized Moeller scattering

    SciTech Connect

    Ilyichev, A.; Zykunov, V.

    2005-08-01

    The total lowest-order electromagnetic radiative corrections to the observables in Moeller scattering of longitudinally polarized electrons have been calculated. The final expressions obtained by the covariant method for the infrared divergency cancellation are free from any unphysical cut-off parameters. Since the calculation is carried out within the ultrarelativistic approximation our result has a compact form that is convenient for computing. Basing on these expressions the FORTRAN code MERA has been developed. Using this code the detailed numerical analysis performed under SLAC (E-158) and JLab kinematic conditions has shown that the radiative corrections are significant and rather sensitive to the value of the missing mass (inelasticity) cuts.

  9. Longitudinal Polarization of {lambda} and {lambda}-bar Hyperons in Deep-Inelastic Scattering at COMPASS

    SciTech Connect

    Sapozhnikov, M. G.

    2007-06-13

    The longitudinal polarization of {lambda} and {lambda}-bar hyperons produced in deep-inelastic scattering of 160 GeV/c polarized positive muons is studied in the COMPASS (CERN NA58) experiment. Preliminary results on the longitudinal polarization of {lambda} and {lambda}-bar from data collected during the 2003 run are presented.

  10. Transverse and Longitudinal Lambda Polarization in Lepton Scattering by Unpolarized Nucleons at HERMES

    NASA Astrophysics Data System (ADS)

    Karyan, G.

    2016-02-01

    Transverse and longitudinal polarization of Λ hyperons has been studied. The transfere of polarization from high-energy positron to Λ0 hyperon has been measured. The longitudinal spin transverse coefficient is found to be DLL‧Λ = 0.11 ± 0.10(stat) ± 0.03(sys). The transverse polarization of Λ and Λ¯ hyperons has been measured in inclusive quasireal photoproduction process for various target nuclei. The polarization observed is positive for light target nuclei and compartaible with zero for heavy target nuclei.

  11. Longitudinally polarized electric and magnetic optical nano-needles of ultra high lengths

    NASA Astrophysics Data System (ADS)

    Grosjean, T.; Gauthier, I.

    2013-05-01

    We demonstrate a method to generate longitudinally polarized electric and magnetic light spots over ultra-long distances. The method proposed here relies on the generation of radially and azimuthally polarized Bessel beams at the limit between propagating and evanescent regimes, by projecting radially and azimuthally polarized doughnut beams onto an axicon-based system of numerical aperture (NA) equal to 1. Tight electric and magnetic light spots (0.36λ) can be produced over distances reaching 50λ and with longitudinal intensities about 3.5×104 times above the transverse intensities. Same confinement abilities over distances larger than 335 λ is also predicted with longitudinal intensities 883 fold above the transverse ones. Experimental characterization of these tiny optical needles with polarization-resolved heterodyne SNOM reveals electric and magnetic light spots smaller than 0.4 λ whose longitudinal intensities are about 200-fold larger than the transverse ones.

  12. Heavy flavor production at fixed target photo- and hadroproduction

    SciTech Connect

    Kwan, S.

    1993-11-01

    Recent results on photo- and hadroproduction of heavy flavor particles from fixed target experiments at CERN and Fermilab are presented. These include results on production characteristics, cross-section and pair correlation for both charm and beauty mesons.

  13. Longitudinally polarized single-cycle terahertz pulses generated with high electric field strengths

    NASA Astrophysics Data System (ADS)

    Cliffe, M. J.; Graham, D. M.; Jamison, S. P.

    2016-05-01

    We demonstrate the generation of single-cycle longitudinally polarized terahertz pulses with field amplitudes in excess of 11 kV/cm using the interferometric recombination of two linearly polarized terahertz beams. High field strength transversely polarized pulses were generated by optical rectification in a matched pair of magnesium-oxide doped stoichiometric lithium niobate (MgO:SLN) crystals with a reversal in the χ333 ( 2 ) orientation. The discontinuity in χ333 ( 2 ) produces a polarity flip in the transverse field; the longitudinal field produced as a consequence of the transverse field discontinuity was measured in the far-field. Both the spatial and temporal profiles of the measured longitudinally polarized terahertz radiation were consistent with the propagation of the transverse discontinuity.

  14. Longitudinal versus polar wrinkling of core-shell fibers with anisotropic size mismatches

    NASA Astrophysics Data System (ADS)

    Patrício, P.; Teixeira, P. I. C.; Trindade, A. C.; Godinho, M. H.

    2014-01-01

    We consider a fiber made of a soft elastic material, encased in a stiff elastic shell (core-shell geometry). If the core and shell dimensions are mismatched, e.g., because the core shrinks while the shell does not, but the two remain attached, then an elastic instability is triggered whereby wrinkles may appear on the shell. The wrinkle orientation may be longitudinal (along the fiber axis), polar (along the fiber perimeter), or a mixture of both, depending on the fiber's geometrical and material parameters. Here we investigate under what conditions longitudinal or polar wrinkling will occur.

  15. Longitudinal field characterization of converging terahertz vortices with linear and circular polarizations.

    PubMed

    Wang, Xinke; Shi, Jing; Sun, Wenfeng; Feng, Shengfei; Han, Peng; Ye, Jiasheng; Zhang, Yan

    2016-04-01

    Linearly and circularly polarized terahertz (THz) vortex beams are generated by adopting a THz quarter wave plate and spiral phase plates with topological charges 1 and 2. Taking advantage of a THz digital holographic imaging system, longitudinal components of THz vortices with different polarizations and topological charges are coherently measured and systemically analyzed in a focusing condition. The application potential of circularly polarized THz vortex beams in microscopy is experimentally demonstrated and the transformation between the spin angular momentums and orbital angular momentums of THz waves is also checked. Modified Richards-Wolf vector diffraction integration equations are applied to successfully simulate experimental phenomena. PMID:27137010

  16. Generation of longitudinally polarized terahertz pulses with field amplitudes exceeding 2 kV/cm

    SciTech Connect

    Cliffe, M. J. Rodak, A.; Graham, D. M.; Jamison, S. P.

    2014-11-10

    We demonstrate the generation of near-single cycle longitudinally polarized terahertz radiation using a large-area radially biased photoconductive antenna with a longitudinal field amplitude in excess of 2 kV/cm. The 76 mm diameter antenna was photo-excited by a 0.5 mJ amplified near-infrared femtosecond laser system and biased with a voltage of up to 100 kV applied over concentric electrodes. Amplitudes for both the transverse and longitudinal field components of the source were measured using a calibrated electro-optic detection scheme. By tightly focusing the radiation emitted from the photoconductive antenna, we obtained a maximum longitudinal field amplitude of 2.22 kV/cm with an applied bias field of 38.5 kV/cm.

  17. Twist-3 effect from the longitudinally polarized proton for ALT in hadron production from pp collisions

    NASA Astrophysics Data System (ADS)

    Koike, Yuji; Pitonyak, Daniel; Yoshida, Shinsuke

    2016-08-01

    We compute the contribution from the longitudinally polarized proton to the twist-3 double-spin asymmetry ALT in inclusive (light) hadron production from proton-proton collisions, i.e., p↑ p → → h X. We show that using the relevant QCD equation-of-motion relation and Lorentz invariance relation allows one to eliminate the twist-3 quark-gluon correlator (associated with the longitudinally polarized proton) in favor of one-variable twist-3 quark distributions and the (twist-2) transversity parton density. Including this result with the twist-3 pieces associated with the transversely polarized proton and unpolarized final-state hadron (which have already been calculated in the literature), we now have the complete leading-order cross section for this process.

  18. Results on charm hadroproduction from CERN experiment WA82

    SciTech Connect

    Antinori, F.; Barberis, D.; Beusch, W.; Davenport, M.; Dufey, J.P.; French, B.R.; Harrison, K.; Jacholkowski, A.; Kirk, A.; Lamanna, E.; Lassalle, J.C.; Muller, F.; Redaelli, N.; Roda, C.; Weymann, M. ); Forino, A.; Gessaroli, R.; Mazzanti, P.; Quareni, A.; Viaggi, F. ); Anselmi, R.; Casanova, V.; Dameri, M.; Hurst, R.; Novelli, P.; Osculati, B.; Rossi, L.; Tomasini, G. ); Buys, A.; Grard, F.; Legros, P. ); Adamovich, M.; Alexandrov, Y.; Kharlamov, S.; Nechaeva, P.; Zavertyaev, M. )

    1992-02-01

    Experiment WA82 has collected data from 1987 to 1989 with the [Omega][prime] spectrometer at the CERN SPS. The aim of WA82 was a high statistics study of charm hadroproduction, using a silicon microstrip vertex detector and an impact parameter trigger. Latest results on the nuclear dependence of charm production and on the [ital x][sub [ital F

  19. Fragmentation contributions to hadroproduction of prompt J /ψ , χc J, and ψ (2 S ) states

    NASA Astrophysics Data System (ADS)

    Bodwin, Geoffrey T.; Chao, Kuang-Ta; Chung, Hee Sok; Kim, U.-Rae; Lee, Jungil; Ma, Yan-Qing

    2016-02-01

    We compute fragmentation corrections to hadroproduction of the quarkonium states J /ψ , χc J, and ψ (2 S ) at leading power in mc2/pT2 , where mc is the charm-quark mass and pT is the quarkonium transverse momentum. The computation is carried out in the framework of nonrelativistic QCD. We include corrections to the parton-production cross sections through next-to-leading order in the strong coupling αs and corrections to the fragmentation functions through second order in αs. We also sum leading logarithms of pT2/mc2 to all orders in perturbation theory. We find that, when we combine these leading-power fragmentation corrections with fixed-order calculations through next-to-leading order in αs, we are able to obtain good fits for pT≥10 GeV to hadroproduction cross sections that were measured at the Tevatron and the LHC. Using values for the nonperturbative long-distance matrix elements that we extract from the cross-section fits, we make predictions for the polarizations of the quarkonium states. We obtain good agreement with measurements of the polarizations, with the exception of the CDF Run II measurement of the prompt J /ψ polarization, for which the agreement is only fair. In the predictions for the prompt-J /ψ cross sections and polarizations, we take into account feeddown from the χc J and ψ (2 S ) states.

  20. Deeply virtual Compton scattering on longitudinally polarized protons and neutrons at CLAS

    SciTech Connect

    Silvia Niccolai

    2012-04-01

    This paper focuses on a measurement of deeply virtual Compton scattering (DVCS) performed at Jefferson Lab using a nearly-6-GeV polarized electron beam, two longitudinally polarized (via DNP) solid targets of protons (NH{sub 3}) and deuterons (ND{sub 3}) and the CEBAF Large Acceptance Spectrometer. Here, preliminary results for target-spin asymmetries and double (beam-target) asymmetries for proton DVCS, as well as a very preliminary extraction of beam-spin asymmetry for neutron DVCS, are presented and linked to Generalized Parton Distributions.

  1. Measurement of Single and Double Spin Asymmetries in Deep Inelastic Pion Electroproduction with a Longitudinally Polarized Target

    SciTech Connect

    Avakian, H; Bosted, P; Elouadrhiri, L; Adhikari, K P; Aghasyan, M; Amaryan, M; Anghinolfi, M; Baghdasaryan, H; Ball, J; Battaglieri, M; Bedlinskiy, I; Biselli, A S; Branford, D; Briscoe, W J; Brooks, W; Carman, D S; Casey, L; Cole, P L; Collins, P; Crabb, D; Crede, V; D'Angelo, A; Daniel, A; Dashyan, N; DeVita, R; DeSanctis, E; Deur, A; Dey, B; Dhamija, S; Dickson, R; Djalali, C; Dodge, G; Doughty, D; Dupre, R; El Alaoui, A; Eugenio, P; Fegan, S; Fersch, M; Guler, N; Guo, L; Hafidi, K; Hakobyan, H; Hanretty, C; Hassall, N; Heddle, D; Hicks, K; Holtrop, M; Ilieva, Y; Ireland, D G; Isupov, E L; Jawalkar, S S; Jo, H S; Joo, K; Keller, D; Khandaker, M; Khetarpal,; Kim, W; Klein, A; Klein, F J; Konczykowski, P; Kubarovsky, V; Kuhn, S E; Kuleshov, S V; Kuznetsov, V; Livingston, K; Lu, H Y; Markov, N; Mayer, M; McAndrew, J; McCracken, M E; McKInnon, B; Meyer, C A; Mineeva, T; Mirazita, M; Mokeev, V; Moreno, B; Moriya, K; Morrison, B; Moutarde, H; Munevar, E; Nadel-Turonski, P; Nasseripour, R; Niccolai, S; Niculescu, G; Niculescu, I; Niroula, M R; Osipenko, M; Ostrovidov, A I; Paremuzyan, R; Park, K; Park, S; Pasyuk, E; Anefalos Pereira, S; Perrin, Y; Pisano, S; Pogorelko, O; Price, J W; Procureur, S; Prok, Protopopescu; Raue, B A; Ricco, G; Ripani, M; Rosner, G; Rossi, P; Sabatie, F; Saini, M S; Salamanca, J; Salgado, C; Schumacher, R A; Seder, E; Seraydaryan, H; Sharabian, Y G; Sober, D I; Sokhan, D; Stapanyan, S S; Stepanyan, S; Stoler, P; Strauch, S; Suleiman, R; Taiuti, M; Tedeschi, D J; Tkachenko, S; Ungaro, M; Vernarsky, B; Vineyard, M F; Voutier, E; Watts, D P; Weinstein, L B; Weygand, D P; Wood, M H; Zhang, J; Zhao, B; Zhao, Z W

    2010-12-01

    We report the first measurement of the transverse momentum dependence of double spin asymmetries in semi-inclusive production of pions in deep inelastic scattering off the longitudinally polarized proton. Data have been obtained using a polarized electron beam of 5.7 GeV with the CLAS detector at the Thomas Jefferson National Accelerator Facility (JLab). A significant non-zero $\\sin2\\phi$ single spin asymmetry was also observed for the first time indicating strong spin-orbit correlations for transversely polarized quarks in the longitudinally polarized proton. The azimuthal modulations of single spin asymmetries have been measured over a wide kinematic range.

  2. Recent Fermilab results on hadroproduction of heavy flavors

    SciTech Connect

    Garbincius, P.H.

    1993-08-01

    Recent results from various Fermilab experiments on the hadroproduction of states containing charm, bottom, and top quarks are discussed. These include observation of the spectra, lifetime, and production characteristics of charmonium, open charm states, and bottom particle production with both high energy fixed target and {bar p}-p collider facilities. The status of the search for the top quark by the Fermilab collider experiments is updated.

  3. Strangeonia and kin; new results from kaon hadroproduction with LASS

    SciTech Connect

    Aston, D.; Bienz, T.; Bird, F.; Dunwoodie, W.; Johnson, W.B.; Kunz, P.; Kwon, Y.; Leith, D.W.G.S.; Levinson, L.; Ratcliff, B.N.; Rensing, P.; Schultz, D.; Shapiro, S.; Sinervo, P.K.; Tarnopolsky, G.; Toge, N.; Waite, A.; Williams, S. ); Awaji, N.; Fujii, K.; Hayashii, H.; Iwata, S.; Kajikawa, R.; Matsui, T.; Miyamoto, A.; Ozaki, H.; Pak, C.O.; Shimomura, T.; Sugiyama,

    1989-12-01

    Recent results from a high statistics study of strangeonium mesons produced in LASS by an 11 GeV/c K{sup -} beam are reviewed and compared with the quark model. New data from a variety of final states (K*{ovr K*}, {phi}{phi}, {phi}{pi}{sup 0}) produced by hypercharge exchange are described, and compared with results from other hadroproduction modes and from J/{psi} decay. 17 refs., 12 figs.

  4. On the Mechanisms of Heavy-Quarkonium Hadroproduction

    SciTech Connect

    Lansberg, J.P.

    2008-12-01

    We discuss the various mechanisms potentially at work in hadroproduction of heavy quarkonia in the light of computations of higher-order QCD corrections both in the Colour-Singlet (CS) and Colour-Octet (CO) channels and the inclusion of the contribution arising from the s-channel cut in the CS channel. We also discuss new observables meant to better discriminate between these different mechanisms.

  5. Design of Spin Polarization Analyzer using Transverse-Longitudinal Correlation in Resistivities Induced by Spin-Orbit Interaction

    NASA Astrophysics Data System (ADS)

    Sakai, Masamichi; Kakizaki, Koichi; Hasegawa, Shigehiko; Kitajima, Akira; Oshima, Akihiro; Awano, Hiroyuki

    2013-01-01

    We have theoretically studied a methodology for the measurement of the degree of spin polarization (P) in metals as well as semiconductors. Our principle is based on the correlation existing between transverse resistivity (ρyx) and longitudinal resistivity (ρxx), both influenced by transverse scattering due to a spin-orbit interaction (SOI) as well as longitudinal scattering due to usual mechanisms. Our spin polarization analyzer employs an unknown polarization conductor as a source electrode from which spin-polarized electrons are injected into a nonmagnetic (NM) channel region. The channel length is set to be much smaller than its spin diffusion length so that ρyx and ρxx in the NM region, both complementarily influenced by carrier spin polarization, would be measured to obtain the P value. Also, application to OR and XOR logic gates are discussed on the basis of our spin polarization analyzer.

  6. Lowest order QED radiative corrections to longitudinally polarized Møller scattering

    NASA Astrophysics Data System (ADS)

    Ilyichev, A.; Zykunov, V.

    2005-08-01

    The total lowest-order electromagnetic radiative corrections to the observables in Møller scattering of longitudinally polarized electrons have been calculated. The final expressions obtained by the covariant method for the infrared divergency cancellation are free from any unphysical cut-off parameters. Since the calculation is carried out within the ultrarelativistic approximation our result has a compact form that is convenient for computing. Basing on these expressions the FORTRAN code MERA has been developed. Using this code the detailed numerical analysis performed under SLAC (E-158) and JLab kinematic conditions has shown that the radiative corrections are significant and rather sensitive to the value of the missing mass (inelasticity) cuts.

  7. Longitudinal polarization of hyperon and antihyperon in semi-inclusive deep-inelastic scattering

    SciTech Connect

    Zhou Shanshan; Chen Ye; Liang Zuotang; Xu Qinghua

    2009-05-01

    We make a detailed study of the longitudinal polarization of hyperons and antihyperons in semi-inclusive deep-inelastic lepton-nucleon scattering. We present the numerical results for spin transfer in quark fragmentation processes, and analyze the possible origins for a difference between the polarization for hyperon and that for the corresponding antihyperon. We present the results obtained in the case that there is no asymmetry between sea and antisea distribution in the nucleon as well as those obtained when such an asymmetry is taken into account. We compare the results with the available data such as those from COMPASS and make predictions for future experiments including those at even higher energies such as at eRHIC.

  8. Extracting W Single Spin Asymmetry in Longitudinally Polarized pp Collisions at PHENIX forward arms

    NASA Astrophysics Data System (ADS)

    Meles, Abraham

    2014-09-01

    The parity-violating longitudinal single spin asymmetry AL in the production of W bosons in p + p collisions at √{ s} = 510 GeV is sensitive to the polarization of light quarks and anti-quarks in the proton. However, identifying the muons from the decay of the W is challenging due to a great background of hadronic processes and other muon producing processes. In the forward and backward hemispheres of PHENIX at RHIC, the muon spectrometers have been recently upgraded in order to provide additional trigger and tracking information to suppress those backgrounds. One of those upgrades is the Forward Vertex (FVTX) detector, a silicon-strip tracker. In 2013, PHENIX collected approximately 240 pb-1 of polarized p + p collisions at √{ s} = 510 GeV with a beam polarization of 56 %. The ability of the FVTX to improve the W signal will be reviewed, over view of the analysis techniques used to extract the signal from the data in RHIC 2013 run will be discussed. The parity-violating longitudinal single spin asymmetry AL in the production of W bosons in p + p collisions at √{ s} = 510 GeV is sensitive to the polarization of light quarks and anti-quarks in the proton. However, identifying the muons from the decay of the W is challenging due to a great background of hadronic processes and other muon producing processes. In the forward and backward hemispheres of PHENIX at RHIC, the muon spectrometers have been recently upgraded in order to provide additional trigger and tracking information to suppress those backgrounds. One of those upgrades is the Forward Vertex (FVTX) detector, a silicon-strip tracker. In 2013, PHENIX collected approximately 240 pb-1 of polarized p + p collisions at √{ s} = 510 GeV with a beam polarization of 56 %. The ability of the FVTX to improve the W signal will be reviewed, over view of the analysis techniques used to extract the signal from the data in RHIC 2013 run will be discussed. Support from US Department of Energy.

  9. Measurement of Longitudinal Spin Asymmetries for Weak Boson Production in Polarized Proton-Proton Collisions at RHIC

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Balewski, J.; Banerjee, A.; Beavis, D. R.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chwastowski, J.; Codrington, M. J. M.; Contin, G.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; Dhamija, S.; di Ruzza, B.; Didenko, L.; Dilks, C.; Ding, F.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Engle, K. S.; Eppley, G.; Eun, L.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Gliske, S.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Kosarzewski, L. K.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; LeVine, M. J.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Madagodagettige Don, D. M. M. D.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Olvitt, D. L.; Pachr, M.; Page, B. S.; Pal, S. K.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Peryt, W.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Pujahari, P. R.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Singaraju, R. N.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Sun, X.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szelezniak, M. A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Vossen, A.; Wada, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yan, W.; Yang, C.; Yang, Y.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zawisza, Y.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, J. L.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2014-08-01

    We report measurements of single- and double-spin asymmetries for W± and Z/γ* boson production in longitudinally polarized p+p collisions at √s =510 GeV by the STAR experiment at RHIC. The asymmetries for W± were measured as a function of the decay lepton pseudorapidity, which provides a theoretically clean probe of the proton's polarized quark distributions at the scale of the W mass. The results are compared to theoretical predictions, constrained by polarized deep inelastic scattering measurements, and show a preference for a sizable, positive up antiquark polarization in the range 0.05

  10. Measurement of single- and double-spin asymmetries in deep inelastic pion electroproduction with a longitudinally polarized target.

    PubMed

    Avakian, H; Bosted, P; Burkert, V D; Elouadrhiri, L; Adhikari, K P; Aghasyan, M; Amaryan, M; Anghinolfi, M; Baghdasaryan, H; Ball, J; Battaglieri, M; Bedlinskiy, I; Biselli, A S; Branford, D; Briscoe, W J; Brooks, W; Carman, D S; Casey, L; Cole, P L; Collins, P; Crabb, D; Crede, V; D'Angelo, A; Daniel, A; Dashyan, N; De Vita, R; De Sanctis, E; Deur, A; Dey, B; Dhamija, S; Dickson, R; Djalali, C; Dodge, G; Doughty, D; Dupre, R; El Alaoui, A; Eugenio, P; Fegan, S; Fersch, R; Forest, T A; Fradi, A; Gabrielyan, M Y; Gavalian, G; Gevorgyan, N; Gilfoyle, G P; Giovanetti, K L; Girod, F X; Gohn, W; Gothe, R W; Griffioen, K A; Guidal, M; Guler, N; Guo, L; Hafidi, K; Hakobyan, H; Hanretty, C; Hassall, N; Heddle, D; Hicks, K; Holtrop, M; Ilieva, Y; Ireland, D G; Isupov, E L; Jawalkar, S S; Jo, H S; Joo, K; Keller, D; Khandaker, M; Khetarpal, P; Kim, W; Klein, A; Klein, F J; Konczykowski, P; Kubarovsky, V; Kuhn, S E; Kuleshov, S V; Kuznetsov, V; Livingston, K; Lu, H Y; Markov, N; Mayer, M; Martinez, D; McAndrew, J; McCracken, M E; McKinnon, B; Meyer, C A; Mineeva, T; Mirazita, M; Mokeev, V; Moreno, B; Moriya, K; Morrison, B; Moutarde, H; Munevar, E; Nadel-Turonski, P; Nasseripour, R; Niccolai, S; Niculescu, G; Niculescu, I; Niroula, M R; Osipenko, M; Ostrovidov, A I; Paremuzyan, R; Park, K; Park, S; Pasyuk, E; Pereira, S Anefalos; Perrin, Y; Pisano, S; Pogorelko, O; Price, J W; Procureur, S; Prok, Y; Protopopescu, D; Raue, B A; Ricco, G; Ripani, M; Rosner, G; Rossi, P; Sabatié, F; Saini, M S; Salamanca, J; Salgado, C; Schumacher, R A; Seder, E; Seraydaryan, H; Sharabian, Y G; Sober, D I; Sokhan, D; Stepanyan, S S; Stepanyan, S; Stoler, P; Strauch, S; Suleiman, R; Taiuti, M; Tedeschi, D J; Tkachenko, S; Ungaro, M; Vernarsky, B; Vineyard, M F; Voutier, E; Watts, D P; Weinstein, L B; Weygand, D P; Wood, M H; Zhang, J; Zhao, B; Zhao, Z W

    2010-12-31

    We report the first measurement of the transverse momentum dependence of double-spin asymmetries in semi-inclusive production of pions in deep-inelastic scattering off the longitudinally polarized proton. Data have been obtained using a polarized electron beam of 5.7 GeV with the CLAS detector at the Jefferson Lab (JLab). Modulations of single spin asymmetries over the azimuthal angle between lepton scattering and hadron production planes ϕ have been measured over a wide kinematic range in Bjorken x and virtual photon squared four-momentum Q2. A significant nonzero sin2ϕ single spin asymmetry was observed for the first time indicating strong spin-orbit correlations for transversely polarized quarks in the longitudinally polarized proton. PMID:21231647

  11. Measurement of Single- and Double-Spin Asymmetries in Deep Inelastic Pion Electroproduction with a Longitudinally Polarized Target

    SciTech Connect

    Avakian, H.; Bosted, P.; Burkert, V. D.; Elouadrhiri, L.; Brooks, W.; Carman, D. S.; Deur, A.; Guo, L.; Kubarovsky, V.; Nadel-Turonski, P.; Weygand, D. P.; Adhikari, K. P.; Amaryan, M.; Dodge, G.; Gavalian, G.; Guler, N.; Klein, A.; Kuhn, S. E.; Niroula, M. R.; Seraydaryan, H.

    2010-12-31

    We report the first measurement of the transverse momentum dependence of double-spin asymmetries in semi-inclusive production of pions in deep-inelastic scattering off the longitudinally polarized proton. Data have been obtained using a polarized electron beam of 5.7 GeV with the CLAS detector at the Jefferson Lab (JLab). Modulations of single spin asymmetries over the azimuthal angle between lepton scattering and hadron production planes {phi} have been measured over a wide kinematic range in Bjorken x and virtual photon squared four-momentum Q{sup 2}. A significant nonzero sin2{phi} single spin asymmetry was observed for the first time indicating strong spin-orbit correlations for transversely polarized quarks in the longitudinally polarized proton.

  12. Chimera distribution amplitudes for the pion and the longitudinally polarized ρ-meson

    NASA Astrophysics Data System (ADS)

    Stefanis, N. G.; Pimikov, A. V.

    2016-01-01

    Using QCD sum rules with nonlocal condensates, we show that the distribution amplitude of the longitudinally polarized ρ-meson may have a shorttailed platykurtic profile in close analogy to our recently proposed platykurtic distribution amplitude for the pion. Such a chimera distribution de facto amalgamates the broad unimodal profile of the distribution amplitude, obtained with a Dyson-Schwinger equations-based computational scheme, with the suppressed tails characterizing the bimodal distribution amplitudes derived from QCD sum rules with nonlocal condensates. We argue that pattern formation, emerging from the collective synchronization of coupled oscillators, can provide a single theoretical scaffolding to study unimodal and bimodal distribution amplitudes of light mesons without recourse to particular computational schemes and the reasons for them.

  13. On effects of multiple gluons in J/ψ hadroproduction

    SciTech Connect

    Motyka, Leszek; Sadzikowski, Mariusz

    2015-04-10

    The three-gluon contribution to J/ψ hadroproduction is calculated within perturbative QCD in the k{sub T}-factorization framework. This mechanism involves double gluon density and enters at a non-leading twist, but it is enhanced at large energies due to large double gluon density at small x. We obtain results for differential p{sub T}-dependent cross-sections for all J/ψ polarisations. The rescattering contribution is found to provide a significant correction to the standard leading twist cross-section at the energies of the Tevatron or the LHC at moderate p{sub T}. We also discuss a possible contribution of the rescattering correction to the anti-shadowing effect for J/ψ production in proton - nucleus collisions.

  14. Longitudinal diffusion of a polar tracer in the outer segments of rod photoreceptors from different species.

    PubMed

    Wu, Qingqing; Chen, Chunhe; Koutalos, Yiannis

    2006-01-01

    Vertebrate rod photoreceptors are the ultimate light sensors, as they can detect a single photon. In darkness, rods maintain a high concentration of the intracellular messenger cyclic guanosine monophosphate (cGMP), which binds to and keeps open cationic channels on the plasma membrane of the outer segment. Absorption of a photon by the visual pigment of the rod, rhodopsin, initiates a biochemical amplification cascade that leads to a reduction in the concentration of cGMP and closure of the channels, thereby converting the incoming light to an electrical signal. Because the absorption of a photon and the ensuing reactions are localized events, the magnitude of the response of the rod to a single photon depends on the spread of the decrease in the cGMP concentration along the length of the outer segment. The longitudinal diffusion of cGMP depends on the structural parameters of the rod outer segment, specifically the area and the volume available for diffusion. To characterize the effect of rod outer segment cytoarchitecture on diffusion, we have used fluorescence recovery after photobleaching (FRAP) and examined the mobility of a fluorescent polar tracer, calcein, in the rod outer segments from three species with different outer segment structures: frog (Rana pipiens), mouse (Mus musculus domesticus) and gecko (Gekko gekko). We found that the diffusion coefficient is similar for all three species, in the order of 8-17 microm(2) s(-1), in broad agreement with the predictions by Holcman and Korenbrot (Biophys. J. 2004:86;2566-2582) based on the known cytoarchitecture of rod outer segments. Consequently, the results also support their prediction that the longitudinal spread of light excitation in rods is similar across species. PMID:16906792

  15. Tau longitudinal polarization in B{yields}D{tau}{nu} and its role in the search for the charged Higgs boson

    SciTech Connect

    Tanaka, Minoru; Watanabe, Ryoutaro

    2010-08-01

    We study the longitudinal polarization of the tau lepton in B{yields}D{tau}{nu} decay. After discussing possible sensitivities of {tau} decay modes to the {tau} polarization, we examine the effect of charged Higgs boson on the {tau} polarization in B{yields}D{tau}{nu}. We find a relation between the decay rate and the {tau} polarization, and clarify the role of the {tau} polarization measurement in the search for the charged Higgs boson.

  16. NMR longitudinal relaxation enhancement in metal halides by heteronuclear polarization exchange during magic-angle spinning.

    PubMed

    Shmyreva, Anna A; Safdari, Majid; Furó, István; Dvinskikh, Sergey V

    2016-06-14

    Orders of magnitude decrease of (207)Pb and (199)Hg NMR longitudinal relaxation times T1 upon magic-angle-spinning (MAS) are observed and systematically investigated in solid lead and mercury halides MeX2 (Me = Pb, Hg and X = Cl, Br, I). In lead(ii) halides, the most dramatic decrease of T1 relative to that in a static sample is in PbI2, while it is smaller but still significant in PbBr2, and not detectable in PbCl2. The effect is magnetic-field dependent but independent of the spinning speed in the range 200-15 000 Hz. The observed relaxation enhancement is explained by laboratory-frame heteronuclear polarization exchange due to crossing between energy levels of spin-1/2 metal nuclei and adjacent quadrupolar-spin halogen nuclei. The enhancement effect is also present in lead-containing organometal halide perovskites. Our results demonstrate that in affected samples, it is the relaxation data recorded under non-spinning conditions that characterize the local properties at the metal sites. A practical advantage of fast relaxation at slow MAS is that spectral shapes with orientational chemical shift anisotropy information well retained can be acquired within a shorter experimental time. PMID:27306000

  17. NMR longitudinal relaxation enhancement in metal halides by heteronuclear polarization exchange during magic-angle spinning

    NASA Astrophysics Data System (ADS)

    Shmyreva, Anna A.; Safdari, Majid; Furó, István; Dvinskikh, Sergey V.

    2016-06-01

    Orders of magnitude decrease of 207Pb and 199Hg NMR longitudinal relaxation times T1 upon magic-angle-spinning (MAS) are observed and systematically investigated in solid lead and mercury halides MeX2 (Me = Pb, Hg and X = Cl, Br, I). In lead(ii) halides, the most dramatic decrease of T1 relative to that in a static sample is in PbI2, while it is smaller but still significant in PbBr2, and not detectable in PbCl2. The effect is magnetic-field dependent but independent of the spinning speed in the range 200-15 000 Hz. The observed relaxation enhancement is explained by laboratory-frame heteronuclear polarization exchange due to crossing between energy levels of spin-1/2 metal nuclei and adjacent quadrupolar-spin halogen nuclei. The enhancement effect is also present in lead-containing organometal halide perovskites. Our results demonstrate that in affected samples, it is the relaxation data recorded under non-spinning conditions that characterize the local properties at the metal sites. A practical advantage of fast relaxation at slow MAS is that spectral shapes with orientational chemical shift anisotropy information well retained can be acquired within a shorter experimental time.

  18. Measurement of longitudinal spin asymmetries for weak boson production in polarized proton-proton collisions at RHIC.

    PubMed

    Adamczyk, L; Adkins, J K; Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alekseev, I; Alford, J; Anson, C D; Aparin, A; Arkhipkin, D; Aschenauer, E C; Averichev, G S; Balewski, J; Banerjee, A; Beavis, D R; Bellwied, R; Bhasin, A; Bhati, A K; Bhattarai, P; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Borowski, W; Bouchet, J; Brandin, A V; Brovko, S G; Bültmann, S; Bunzarov, I; Burton, T P; Butterworth, J; Caines, H; Calderón de la Barca Sánchez, M; Campbell, J M; Cebra, D; Cendejas, R; Cervantes, M C; Chaloupka, P; Chang, Z; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, L; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Chwastowski, J; Codrington, M J M; Contin, G; Cramer, J G; Crawford, H J; Cui, X; Das, S; Davila Leyva, A; De Silva, L C; Debbe, R R; Dedovich, T G; Deng, J; Derevschikov, A A; Derradi de Souza, R; Dhamija, S; di Ruzza, B; Didenko, L; Dilks, C; Ding, F; Djawotho, P; Dong, X; Drachenberg, J L; Draper, J E; Du, C M; Dunkelberger, L E; Dunlop, J C; Efimov, L G; Engelage, J; Engle, K S; Eppley, G; Eun, L; Evdokimov, O; Eyser, O; Fatemi, R; Fazio, S; Fedorisin, J; Filip, P; Finch, E; Fisyak, Y; Flores, C E; Gagliardi, C A; Gangadharan, D R; Garand, D; Geurts, F; Gibson, A; Girard, M; Gliske, S; Greiner, L; Grosnick, D; Gunarathne, D S; Guo, Y; Gupta, A; Gupta, S; Guryn, W; Haag, B; Hamed, A; Han, L-X; Haque, R; Harris, J W; Heppelmann, S; Hirsch, A; Hoffmann, G W; Hofman, D J; Horvat, S; Huang, B; Huang, H Z; Huang, X; Huck, P; Humanic, T J; Igo, G; Jacobs, W W; Jang, H; Judd, E G; Kabana, S; Kalinkin, D; Kang, K; Kauder, K; Ke, H W; Keane, D; Kechechyan, A; Kesich, A; Khan, Z H; Kikola, D P; Kisel, I; Kisiel, A; Koetke, D D; Kollegger, T; Konzer, J; Koralt, I; Kosarzewski, L K; Kotchenda, L; Kraishan, A F; Kravtsov, P; Krueger, K; Kulakov, I; Kumar, L; Kycia, R A; Lamont, M A C; Landgraf, J M; Landry, K D; Lauret, J; Lebedev, A; Lednicky, R; Lee, J H; LeVine, M J; Li, C; Li, W; Li, X; Li, X; Li, Y; Li, Z M; Lisa, M A; Liu, F; Ljubicic, T; Llope, W J; Lomnitz, M; Longacre, R S; Luo, X; Ma, G L; Ma, Y G; Madagodagettige Don, D M M D; Mahapatra, D P; Majka, R; Margetis, S; Markert, C; Masui, H; Matis, H S; McDonald, D; McShane, T S; Minaev, N G; Mioduszewski, S; Mohanty, B; Mondal, M M; Morozov, D A; Mustafa, M K; Nandi, B K; Nasim, Md; Nayak, T K; Nelson, J M; Nigmatkulov, G; Nogach, L V; Noh, S Y; Novak, J; Nurushev, S B; Odyniec, G; Ogawa, A; Oh, K; Ohlson, A; Okorokov, V; Oldag, E W; Olvitt, D L; Pachr, M; Page, B S; Pal, S K; Pan, Y X; Pandit, Y; Panebratsev, Y; Pawlak, T; Pawlik, B; Pei, H; Perkins, C; Peryt, W; Pile, P; Planinic, M; Pluta, J; Poljak, N; Poniatowska, K; Porter, J; Poskanzer, A M; Pruthi, N K; Przybycien, M; Pujahari, P R; Putschke, J; Qiu, H; Quintero, A; Ramachandran, S; Raniwala, R; Raniwala, S; Ray, R L; Riley, C K; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Ross, J F; Roy, A; Ruan, L; Rusnak, J; Rusnakova, O; Sahoo, N R; Sahu, P K; Sakrejda, I; Salur, S; Sandweiss, J; Sangaline, E; Sarkar, A; Schambach, J; Scharenberg, R P; Schmah, A M; Schmidke, W B; Schmitz, N; Seger, J; Seyboth, P; Shah, N; Shahaliev, E; Shanmuganathan, P V; Shao, M; Sharma, B; Shen, W Q; Shi, S S; Shou, Q Y; Sichtermann, E P; Singaraju, R N; Skoby, M J; Smirnov, D; Smirnov, N; Solanki, D; Sorensen, P; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stevens, J R; Stock, R; Strikhanov, M; Stringfellow, B; Sumbera, M; Sun, X; Sun, X M; Sun, Y; Sun, Z; Surrow, B; Svirida, D N; Symons, T J M; Szelezniak, M A; Takahashi, J; Tang, A H; Tang, Z; Tarnowsky, T; Thomas, J H; Timmins, A R; Tlusty, D; Tokarev, M; Trentalange, S; Tribble, R E; Tribedy, P; Trzeciak, B A; Tsai, O D; Turnau, J; Ullrich, T; Underwood, D G; Van Buren, G; van Nieuwenhuizen, G; Vandenbroucke, M; Vanfossen, J A; Varma, R; Vasconcelos, G M S; Vasiliev, A N; Vertesi, R; Videbæk, F; Viyogi, Y P; Vokal, S; Vossen, A; Wada, M; Wang, F; Wang, G; Wang, H; Wang, J S; Wang, X L; Wang, Y; Wang, Y; Webb, G; Webb, J C; Westfall, G D; Wieman, H; Wissink, S W; Witt, R; Wu, Y F; Xiao, Z; Xie, W; Xin, K; Xu, H; Xu, J; Xu, N; Xu, Q H; Xu, Y; Xu, Z; Yan, W; Yang, C; Yang, Y; Yang, Y; Ye, Z; Yepes, P; Yi, L; Yip, K; Yoo, I-K; Yu, N; Zawisza, Y; Zbroszczyk, H; Zha, W; Zhang, J B; Zhang, J L; Zhang, S; Zhang, X P; Zhang, Y; Zhang, Z P; Zhao, F; Zhao, J; Zhong, C; Zhu, X; Zhu, Y H; Zoulkarneeva, Y; Zyzak, M

    2014-08-15

    We report measurements of single- and double-spin asymmetries for W^{±} and Z/γ^{*} boson production in longitudinally polarized p+p collisions at sqrt[s]=510  GeV by the STAR experiment at RHIC. The asymmetries for W^{±} were measured as a function of the decay lepton pseudorapidity, which provides a theoretically clean probe of the proton's polarized quark distributions at the scale of the W mass. The results are compared to theoretical predictions, constrained by polarized deep inelastic scattering measurements, and show a preference for a sizable, positive up antiquark polarization in the range 0.05

  19. Longitudinal monitoring of demineralization peripheral to orthodontic brackets using cross polarization optical coherence tomography

    PubMed Central

    Nee, Alexander; Chan, Kenneth; Kang, Hobin; Staninec, Michal; Darling, Cynthia L.; Fried, Daniel

    2014-01-01

    Objectives The aim of this study was to test the hypothesis that cross-polarization optical coherence tomography (CP-OCT) can be used to longitudinally monitor demineralization peripheral to orthodontic brackets in an extended clinical study. Methods A high-speed CP-OCT system was used to acquire 3D volumetric images of the area at the base of orthodontic brackets over a period of 12-months after placement. The reflectivity was measured at 3-month intervals for 12-months to determine if there was increased demineralization. Two teeth were monitored on twenty test subjects and the brackets were bonded using two types of adhesives This was a randomized controlled clinical study with a split mouth design such that each subject served as his or her own control. On one side, the control premolar was bonded with a bonding agent (Adper Scotchbond from 3M ESPE, St. Paul, MN) and composite (Transbond XT from 3M Unitek, Monrovia, CA) that lacked fluoride. On the other side, the experimental premolar was bonded with a fluoride releasing glass ionomer cement (GC Fuji Ortho LC from GC America, Alsip, IL). Results There was a small but significant increase in the calculated lesion depth and integrated reflectivity over that depth (Δ R) for both adhesive types (p<0.0001) indicating increasing demineralization with time. There was no significant difference in the lesion depth (p=0.22) and Δ R (p=0.91) between the groups with the fluoride releasing glass ionomer cement and the conventional composite. Conclusions CP-OCT was able to measure a significant increase in demineralization (P<0.0001) at the base of orthodontic brackets over a period of 12-months. PMID:24561340

  20. Longitudinal polarization periodicity of unpolarized light passing through a double wedge depolarizer.

    PubMed

    de Sande, Juan Carlos G; Santarsiero, Massimo; Piquero, Gemma; Gori, Franco

    2012-12-01

    The polarization characteristics of unpolarized light passing through a double wedge depolarizer are studied. It is found that the degree of polarization of the radiation propagating after the depolarizer is uniform across transverse planes after the depolarizer, but it changes from one plane to another in a periodic way giving, at different distances, unpolarized, partially polarized, or even perfectly polarized light. An experiment is performed to confirm this result. Measured values of the Stokes parameters and of the degree of polarization are in complete agreement with the theoretical predictions. PMID:23262685

  1. Dominance of the Breit interaction in the cross section and circular polarization of x-ray radiation following longitudinally-polarized-electron-impact excitation of highly charged ions

    NASA Astrophysics Data System (ADS)

    Chen, Zhan-Bin; Dong, Chen-Zhong; Jiang, Jun

    2014-08-01

    Longitudinally-polarized-electron-impact excitation cross sections from the ground state to the individual magnetic sublevels of the excited state 1s2s22p3/2(J = 2) of highly charged Be-like ions are calculated using a fully relativistic distorted-wave method. The contributions of the Breit interaction to the cross sections and circular polarizations of the 1s2s22p3/2(J = 2)→1s22s2(J = 0) magnetic quadrupole (M2) line for selected Be-like Ag43+, Ho63+, and Bi79+ ions are investigated systematically. It is found that the Breit interaction has a large effect and makes the cross sections increase, especially to the mf = -1 and -2 sublevels, the Breit interaction can modify the cross sections by several orders of magnitude. These dramatic influences also lead to a remarkable decrease in the circular polarization of subsequent x-ray radiation, the character of which becomes more and more evident with increasing incident energy and atomic number. And all these characteristics are very different from the conclusions for the linear polarization of radiation following the electron-impact process [S. Fritzsche, A. Surzhykov, and T. Stöhlker, Phys. Rev. Lett. 103, 113001 (2009), 10.1103/PhysRevLett.103.113001; Z. W. Wu, J. Jiang, and C. Z. Dong, Phys. Rev. A 84, 032713 (2011), 10.1103/PhysRevA.84.032713].

  2. Measurement of parity-violating spin asymmetries in W± production at midrapidity in longitudinally polarized p +p collisions

    NASA Astrophysics Data System (ADS)

    Adare, A.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Akimoto, R.; Alexander, J.; Alfred, M.; Aoki, K.; Apadula, N.; Aramaki, Y.; Asano, H.; Aschenauer, E. C.; Atomssa, E. T.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Bai, M.; Bai, X.; Bandara, N. S.; Bannier, B.; Barish, K. N.; Bassalleck, B.; Bathe, S.; Baublis, V.; Baumann, C.; Baumgart, S.; Bazilevsky, A.; Beaumier, M.; Beckman, S.; Belmont, R.; Berdnikov, A.; Berdnikov, Y.; Black, D.; Blau, D. S.; Bok, J. S.; Boyle, K.; Brooks, M. L.; Bryslawskyj, J.; Buesching, H.; Bumazhnov, V.; Butsyk, S.; Campbell, S.; Chen, C.-H.; Chi, C. Y.; Chiu, M.; Choi, I. J.; Choi, J. B.; Choi, S.; Choudhury, R. K.; Christiansen, P.; Chujo, T.; Chvala, O.; Cianciolo, V.; Citron, Z.; Cole, B. A.; Connors, M.; Cronin, N.; Crossette, N.; Csanád, M.; Csörgő, T.; Dairaku, S.; Danley, T. W.; Datta, A.; Daugherity, M. S.; David, G.; Deblasio, K.; Dehmelt, K.; Denisov, A.; Deshpande, A.; Desmond, E. J.; Dietzsch, O.; Ding, L.; Dion, A.; Diss, P. B.; Do, J. H.; Donadelli, M.; D'Orazio, L.; Drapier, O.; Drees, A.; Drees, K. A.; Durham, J. M.; Durum, A.; Edwards, S.; Efremenko, Y. V.; Engelmore, T.; Enokizono, A.; En'yo, H.; Esumi, S.; Eyser, K. O.; Fadem, B.; Feege, N.; Fields, D. E.; Finger, M.; Finger, M.; Fleuret, F.; Fokin, S. L.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fukao, Y.; Fusayasu, T.; Gainey, K.; Gal, C.; Gallus, P.; Garg, P.; Garishvili, A.; Garishvili, I.; Ge, H.; Giordano, F.; Glenn, A.; Gong, X.; Gonin, M.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grosse Perdekamp, M.; Gu, Y.; Gunji, T.; Guragain, H.; Hachiya, T.; Haggerty, J. S.; Hahn, K. I.; Hamagaki, H.; Hamilton, H. F.; Han, S. Y.; Hanks, J.; Hasegawa, S.; Haseler, T. O. S.; Hashimoto, K.; Hayano, R.; Hayashi, S.; He, X.; Hemmick, T. K.; Hester, T.; Hill, J. C.; Hollis, R. S.; Homma, K.; Hong, B.; Horaguchi, T.; Hoshino, T.; Hotvedt, N.; Huang, J.; Huang, S.; Ichihara, T.; Iinuma, H.; Ikeda, Y.; Imai, K.; Imazu, Y.; Imrek, J.; Inaba, M.; Iordanova, A.; Isenhower, D.; Isinhue, A.; Ivanishchev, D.; Jacak, B. V.; Javani, M.; Jeon, S. J.; Jezghani, M.; Jia, J.; Jiang, X.; Johnson, B. M.; Joo, E.; Joo, K. S.; Jouan, D.; Jumper, D. S.; Kamin, J.; Kanda, S.; Kang, B. H.; Kang, J. H.; Kang, J. S.; Kapustinsky, J.; Karatsu, K.; Kawall, D.; Kazantsev, A. V.; Kempel, T.; Key, J. A.; Khachatryan, V.; Khandai, P. K.; Khanzadeev, A.; Kihara, K.; Kijima, K. M.; Kim, B. I.; Kim, C.; Kim, D. H.; Kim, D. J.; Kim, E.-J.; Kim, G. W.; Kim, H.-J.; Kim, M.; Kim, Y.-J.; Kim, Y. K.; Kimelman, B.; Kinney, E.; Kistenev, E.; Kitamura, R.; Klatsky, J.; Kleinjan, D.; Kline, P.; Koblesky, T.; Kofarago, M.; Komkov, B.; Koster, J.; Kotchetkov, D.; Kotov, D.; Krizek, F.; Kurita, K.; Kurosawa, M.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Lebedev, A.; Lee, D. M.; Lee, G. H.; Lee, J.; Lee, K. B.; Lee, K. S.; Lee, S.; Lee, S. H.; Lee, S. R.; Leitch, M. J.; Leite, M. A. L.; Leitgab, M.; Lewis, B.; Li, X.; Lim, S. H.; Linden Levy, L. A.; Liu, M. X.; Lynch, D.; Maguire, C. F.; Makdisi, Y. I.; Makek, M.; Manion, A.; Manko, V. I.; Mannel, E.; Maruyama, T.; McCumber, M.; McGaughey, P. L.; McGlinchey, D.; McKinney, C.; Meles, A.; Mendoza, M.; Meredith, B.; Miake, Y.; Mibe, T.; Midori, J.; Mignerey, A. C.; Miller, A. J.; Milov, A.; Mishra, D. K.; Mitchell, J. T.; Miyasaka, S.; Mizuno, S.; Mohanty, A. K.; Mohapatra, S.; Montuenga, P.; Moon, H. J.; Moon, T.; Morrison, D. P.; Moskowitz, M.; Moukhanova, T. V.; Murakami, T.; Murata, J.; Mwai, A.; Nagae, T.; Nagamiya, S.; Nagashima, K.; Nagle, J. L.; Nagy, M. I.; Nakagawa, I.; Nakagomi, H.; Nakamiya, Y.; Nakamura, K. R.; Nakamura, T.; Nakano, K.; Nattrass, C.; Netrakanti, P. K.; Nihashi, M.; Niida, T.; Nishimura, S.; Nouicer, R.; Novák, T.; Novitzky, N.; Nukariya, A.; Nyanin, A. S.; Obayashi, H.; O'Brien, E.; Ogilvie, C. A.; Oide, H.; Okada, K.; Orjuela Koop, J. D.; Osborn, J. D.; Oskarsson, A.; Ozaki, H.; Ozawa, K.; Pak, R.; Pantuev, V.; Papavassiliou, V.; Park, I. H.; Park, J. S.; Park, S.; Park, S. K.; Pate, S. F.; Patel, L.; Patel, M.; Pei, H.; Peng, J.-C.; Perepelitsa, D. V.; Perera, G. D. N.; Peressounko, D. Yu.; Perry, J.; Petti, R.; Pinkenburg, C.; Pinson, R.; Pisani, R. P.; Purschke, M. L.; Qu, H.; Rak, J.; Ramson, B. J.; Ravinovich, I.; Read, K. F.; Reynolds, D.; Riabov, V.; Riabov, Y.; Richardson, E.; Rinn, T.; Riveli, N.; Roach, D.; Roche, G.; Rolnick, S. D.; Rosati, M.; Rowan, Z.; Rubin, J. G.; Ryu, M. S.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sako, H.; Samsonov, V.; Sarsour, M.; Sato, S.; Sawada, S.; Schaefer, B.; Schmoll, B. K.; Sedgwick, K.; Seele, J.; Seidl, R.; Sekiguchi, Y.; Sen, A.; Seto, R.; Sett, P.; Sexton, A.; Sharma, D.; Shaver, A.; Shein, I.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shoji, K.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Sim, K. S.; Singh, B. K.; Singh, C. P.; Singh, V.; Skolnik, M.; Slunečka, M.; Snowball, M.; Solano, S.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Stankus, P. W.; Steinberg, P.; Stenlund, E.; Stepanov, M.; Ster, A.; Stoll, S. P.; Stone, M. R.; Sugitate, T.; Sukhanov, A.; Sumita, T.; Sun, J.; Sziklai, J.; Takagui, E. M.; Takahara, A.; Taketani, A.; Tanaka, Y.; Taneja, S.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tennant, E.; Tieulent, R.; Timilsina, A.; Todoroki, T.; Tomášek, M.; Torii, H.; Towell, C. L.; Towell, M.; Towell, R.; Towell, R. S.; Tserruya, I.; Tsuchimoto, Y.; Vale, C.; van Hecke, H. W.; Vargyas, M.; Vazquez-Zambrano, E.; Veicht, A.; Velkovska, J.; Vértesi, R.; Virius, M.; Voas, B.; Vrba, V.; Vznuzdaev, E.; Wang, X. R.; Watanabe, D.; Watanabe, K.; Watanabe, Y.; Watanabe, Y. S.; Wei, F.; Whitaker, S.; White, A. S.; White, S. N.; Winter, D.; Wolin, S.; Woody, C. L.; Wysocki, M.; Xia, B.; Xue, L.; Yalcin, S.; Yamaguchi, Y. L.; Yanovich, A.; Ying, J.; Yokkaichi, S.; Yoo, J. H.; Yoon, I.; You, Z.; Younus, I.; Yu, H.; Yushmanov, I. E.; Zajc, W. A.; Zelenski, A.; Zhou, S.; Zou, L.; Phenix Collaboration

    2016-03-01

    We present midrapidity measurements from the PHENIX experiment of large parity-violating single-spin asymmetries of high transverse momentum electrons and positrons from W±/Z decays, produced in longitudinally polarized p +p collisions at center of mass energies of √{s }=500 and 510 GeV. These asymmetries allow direct access to the antiquark polarized parton distribution functions due to the parity-violating nature of the W -boson coupling to quarks and antiquarks. The results presented are based on data collected in 2011, 2012, and 2013 with an integrated luminosity of 240 pb-1 , which exceeds previous PHENIX published results by a factor of more than 27. These high Q2 data probe the parton structure of the proton at W mass scale and provide an important addition to our understanding of the antiquark parton helicity distribution functions at an intermediate Bjorken x value of roughly MW/√{s }=0.16 .

  3. Single and double spin asymmetries for deeply virtual Compton scattering measured with CLAS and a longitudinally polarized proton target

    SciTech Connect

    Pisano, S.; Biselli, A.; Niccolai, S.; Seder, E.; Guidal, M.; Mirazita, M.; Adhikari, K. P.; Adikaram, D.; Amaryan, M. J.; Anderson, M. D.; Anefalos Pereira, S.; Avakian, H.; Ball, J.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Bosted, P.; Briscoe, B.; Brock, J.; Brooks, W. K.; Burkert, V. D.; Carlin, C.; Carman, D. S.; Celentano, A.; Chandavar, S.; Charles, G.; Colaneri, L.; Cole, P. L.; Compton, N.; Contalbrigo, M.; Cortes, O.; Crabb, D. G.; Crede, V.; D' Angelo, A.; De Vita, R.; De Sanctis, E.; Deur, A.; Djalali, C.; Dupre, R.; Egiyan, H.; El Alaoui, A.; El Fassi, L.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Fegan, S.; Fersch, R.; Filippi, A.; Fleming, J. A.; Fradi, A.; Garillon, B.; Garcon, M.; Ghandilyan, Y.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Goetz, J. T.; Gohn, W.; Golovatch, E.; Gothe, R. W.; Griffioen, K. A.; Guo, L.; Hafidi, K.; Hanretty, C.; Hattawy, M.; Hicks, K.; Holtrop, M.; Hughes, S. M.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Jenkins, D.; Jiang, X.; Jo, H. S.; Joo, K.; Joosten, S.; Keith, C. D.; Keller, D.; Kim, A.; Kim, W.; Klein, F. J.; Kubarovsky, V.; Kuhn, S. E.; Lenisa, P.; Livingston, K.; Lu, H. Y.; MacCormick, M.; MacGregor, Ian J. D.; Mayer, M.; McKinnon, B.; Meekins, D. G.; Meyer, C. A.; Mokeev, V.; Montgomery, R. A.; Moody, C. I.; Munoz Camacho, C.; Nadel-Turonski, P.; Osipenko, M.; Ostrovidov, A. I.; Park, K.; Phelps, W.; Phillips, J. J.; Pogorelko, O.; Price, J. W.; Procureur, S.; Prok, Y.; Puckett, A. J. R.; Ripani, M.; Rizzo, A.; Rosner, G.; Rossi, P.; Roy, P.; Sabatie, F.; Salgado, C.; Schott, D.; Schumacher, R. A.; Skorodumina, I.; Smith, G. D.; Sober, D. I.; Sokhan, D.; Sparveris, N.; Stepanyan, S.; Stoler, P.; Strauch, S.; Sytnik, V.; Tian, Ye; Tkachenko, S.; Turisini, M.; Ungaro, M.; Voutier, E.; Walford, N. K.; Watts, D. P.; Wei, X.; Weinstein, L. B.; Wood, M. H.; Zachariou, N.; Zana, L.; Zhang, J.; Zhao, Z. W.; Zonta, I.

    2015-03-19

    Single-beam, single-target, and double-spin asymmetries for hard exclusive photon production on the proton e→p→e'p'γ are presented. The data were taken at Jefferson Lab using the CLAS detector and a longitudinally polarized 14NH3 target. The three asymmetries were measured in 165 4-dimensional kinematic bins, covering the widest kinematic range ever explored simultaneously for beam and target-polarization observables in the valence quark region. The kinematic dependences of the obtained asymmetries are discussed and compared to the predictions of models of Generalized Parton Distributions. As a result, the measurement of three DVCS spin observables at the same kinematic points allows a quasi-model-independent extraction of the imaginary parts of the H and H~ Compton Form Factors, which give insight into the electric and axial charge distributions of valence quarks in the proton.

  4. Polarization observables in the longitudinal basis for pseudo-scalar meson photoproduction using a density matrix approach

    SciTech Connect

    Biplab Dey, Michael E. McCracken, David G. Ireland, Curtis A. Meyer

    2011-05-01

    The complete expression for the intensity in pseudo-scalar meson photoproduction with a polarized beam, target, and recoil baryon is derived using a density matrix approach that offers great economy of notation. A Cartesian basis with spins for all particles quantized along a single direction, the longitudinal beam direction, is used for consistency and clarity in interpretation. A single spin-quantization axis for all particles enables the amplitudes to be written in a manifestly covariant fashion with simple relations to those of the well-known CGLN formalism. Possible sign discrepancies between theoretical amplitude-level expressions and experimentally measurable intensity profiles are dealt with carefully. Our motivation is to provide a coherent framework for coupled-channel partial-wave analysis of several meson photoproduction reactions, incorporating recently published and forthcoming polarization data from Jefferson Lab.

  5. Longitudinal Spin Transfer of LAMBDA and LAMBDA-bar Hyperons in Polarized Proton-Proton Collisions at sq root(s) = 200 GeV

    SciTech Connect

    Sichtermann, Ernst

    2009-08-04

    The longitudinal spin transfer D{sub LL} of LAMBDA and LAMBDA-bar hyperons produced with large transverse momenta P{sub T} in polarized proton-proton collisions is sensitive to the helicity distribution functions of strange quarks and anti-quarks, and to polarized fragmentation functions. This contribution reports a measurement of the longitudinal spin transfer D{sub LL} in the inclusive production of LAMBDA and LAMBDA-bar hyperons at central rapidities in polarized proton-proton collisions at a center of mass energy of sq root(s) = 200 GeV. The data were collected with the STAR experiment at RHIC and correspond to a approx =3 pb{sup -1} luminosity and a approx =50% beam polarization.

  6. Present theoretical uncertainties on charm hadroproduction in QCD and prompt neutrino fluxes

    NASA Astrophysics Data System (ADS)

    Garzelli, M. V.; Moch, S.; Sigl, G.

    2016-04-01

    Prompt neutrino fluxes are basic backgrounds in the search of high-energy neutrinos of astrophysical origin, performed by means of full-size neutrino telescopes located at Earth, under ice or under water. Predictions for these fluxes are provided on the basis of up-to-date theoretical results for charm hadroproduction in perturbative QCD, together with a comprehensive discussion of the various sources of theoretical uncertainty affecting their computation, and a quantitative estimate of each uncertainty contribution.

  7. Longitudinal fecal hormone analysis for monitoring reproductive activity in the female polar bear (Ursus maritimus).

    PubMed

    Stoops, M A; MacKinnon, K M; Roth, T L

    2012-12-01

    The objective was to identify suitable enzyme immunoassays to monitor gonadal and placental function in the female polar bear. Immunoreactive progesterone, progesterone metabolite (PdG), estrogen, and androgen metabolite (T) concentrations were measured in fecal samples collected over 24 mo from captive female bears (N = 20). Whereas fecal extracts produced displacement curves parallel to the standard curve for each respective steroid, T and PdG more accurately reflected reproductive events. Concentrations of fecal T increased (P < 0.05) during the breeding season, and brief spikes were associated with estrus and mating. A postovulatory increase in PdG was not always detected, but sustained baseline T after mating appeared consistent with ovulation. Parturient bears excreted higher PdG concentrations (P < 0.05) during expected time of embryo implantation in Fall, and a late gestational rise in fecal T occurred 30 days prepartum. Many nonparturient bears also had a PdG rise in the Fall, suggesting they experienced either pregnancy loss or a pseudopregnancy. Differentiating pregnant and pseudopregnant states was not achieved using fecal PdG alone, but when combined with fecal T, comprehensive diagnoses could be made. Nonparturient bears demonstrated elevated (P < 0.05) fecal T during summer months, whereas parturient bears did not. In summary, noninvasive hormone monitoring techniques were established for the female polar bear. Although this study was directed at facilitating management and breeding efforts of captive polar bears, the methods could be applied to studies of reproductive function in wild populations. PMID:23040062

  8. Extracting W Single Spin Asymmetry in Longitudinally Polarized pp Collisions at PHENIX forward arms

    NASA Astrophysics Data System (ADS)

    Meles, Abraham

    2014-03-01

    The parity-violating asymmetry AL in the production of W bosons in p + p collisions at √{ s} = 510 GeV is sensitive to the polarization of light quarks and anti-quarks in the proton. However, identifying the lepton from the decay of the W is challenging due to a great background of hadronic processes. In the forward and backward hemispheres of PHENIX at RHIC, the muon spectrometers have been recently upgraded in order to provide additional trigger and tracking information to suppress those backgrounds. One of those upgrades is the Forward Vertex (FVTX) detector, a silicon-strip tracker. In 2013, PHENIX collected approximately 240 pb-1 of polarized p + p collisions at √{ s} = 510 GeV with a beam polarization of 52 %. The ability of the FVTX to improve the W signal will be reviewed, and progress on analysis of real data in the RHIC 2013 run will be discussed. Supported by the US DOE, Office of Science.

  9. Azimuthal asymmetries of hadrons produced in muon SIDIS off longitudinally polarized deuterons

    NASA Astrophysics Data System (ADS)

    Savin, I. A.

    2016-02-01

    The azimuthal asymmetries in the cross sections of charged-hadron production in the muon SIDIS reactions off the longitudinally polarised deuterons are determined using the COMPASS data of 2006 and combined data of 2002-2006. The asymmetries are presented as functions of the hadron azimuthal angle ϕ in two ways: first, for hadrons integrated over the kinematic variables and, second, as a function of one of the kinematic variables x, z or phT while integrating over two other. In each case asymmetries were fitted by functions included the ϕ-independent terms and terms amplitude of which are modulated with ø as predicted by the theory: sin ϕ, sin 2ϕ, sin 3ϕ and cos ϕ. Results for amplitudes are presented and discussed.

  10. Longitudinal Double-Spin Asymmetry and Cross Section for Inclusive Jet Production in Polarized Proton Collisions at s=200GeV

    NASA Astrophysics Data System (ADS)

    Abelev, B. I.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D.; Anderson, M.; Arkhipkin, D.; Averichev, G. S.; Bai, Y.; Balewski, J.; Barannikova, O.; Barnby, L. S.; Baudot, J.; Bekele, S.; Belaga, V. V.; Bellingeri-Laurikainen, A.; Bellwied, R.; Benedosso, F.; Bhardwaj, S.; Bhasin, A.; Bhati, A. K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Blyth, S.-L.; Bonner, B. E.; Botje, M.; Bouchet, J.; Brandin, A. V.; Bravar, A.; Burton, T. P.; Bystersky, M.; Cadman, R. V.; Cai, X. Z.; Caines, H.; Sánchez, M. Calderón De La Barca; Castillo, J.; Catu, O.; Cebra, D.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Coffin, J. P.; Cormier, T. M.; Cosentino, M. R.; Cramer, J. G.; Crawford, H. J.; Das, D.; Das, S.; Dash, S.; Daugherity, M.; de Moura, M. M.; Dedovich, T. G.; Dephillips, M.; Derevschikov, A. A.; Didenko, L.; Dietel, T.; Djawotho, P.; Dogra, S. M.; Dong, W. J.; Dong, X.; Draper, J. E.; Du, F.; Dunin, V. B.; Dunlop, J. C.; Mazumdar, M. R. Dutta; Eckardt, V.; Edwards, W. R.; Efimov, L. G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Filip, P.; Finch, E.; Fine, V.; Fisyak, Y.; Fu, J.; Gagliardi, C. A.; Gaillard, L.; Ganti, M. S.; Ghazikhanian, V.; Ghosh, P.; Gonzalez, J. E.; Gorbunov, Y. G.; Gos, H.; Grebenyuk, O.; Grosnick, D.; Guertin, S. M.; Guimaraes, K. S. F. F.; Gupta, N.; Gutierrez, T. D.; Haag, B.; Hallman, T. J.; Hamed, A.; Harris, J. W.; He, W.; Heinz, M.; Henry, T. W.; Hepplemann, S.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffman, A. M.; Hoffmann, G. W.; Horner, M. J.; Huang, H. Z.; Huang, S. L.; Hughes, E. W.; Humanic, T. J.; Igo, G.; Jacobs, P.; Jacobs, W. W.; Jakl, P.; Jia, F.; Jiang, H.; Jones, P. G.; Judd, E. G.; Kabana, S.; Kang, K.; Kapitan, J.; Kaplan, M.; Keane, D.; Kechechyan, A.; Khodyrev, V. Yu.; Kim, B. C.; Kiryluk, J.; Kisiel, A.; Kislov, E. M.; Klein, S. R.; Kocoloski, A.; Koetke, D. D.; Kollegger, T.; Kopytine, M.; Kotchenda, L.; Kouchpil, V.; Kowalik, K. L.; Kramer, M.; Kravtsov, P.; Kravtsov, V. I.; Krueger, K.; Kuhn, C.; Kulikov, A. I.; Kumar, A.; Kuznetsov, A. A.; Lamont, M. A. C.; Landgraf, J. M.; Lange, S.; Lapointe, S.; Laue, F.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, C.-H.; Lehocka, S.; Levine, M. J.; Li, C.; Li, Q.; Li, Y.; Lin, G.; Lin, X.; Lindenbaum, S. J.; Lisa, M. A.; Liu, F.; Liu, H.; Liu, J.; Liu, L.; Liu, Z.; Ljubicic, T.; Llope, W. J.; Long, H.; Longacre, R. S.; Love, W. A.; Lu, Y.; Ludlam, T.; Lynn, D.; Ma, G. L.; Ma, J. G.; Ma, Y. G.; Magestro, D.; Mahapatra, D. P.; Majka, R.; Mangotra, L. K.; Manweiler, R.; Margetis, S.; Markert, C.; Martin, L.; Matis, H. S.; Matulenko, Yu. A.; McClain, C. J.; McShane, T. S.; Melnick, Yu.; Meschanin, A.; Millane, J.; Miller, M. L.; Minaev, N. G.; Mioduszewski, S.; Mironov, C.; Mischke, A.; Mishra, D. K.; Mitchell, J.; Mohanty, B.; Molnar, L.; Moore, C. F.; Morozov, D. A.; Munhoz, M. G.; Nandi, B. K.; Nattrass, C.; Nayak, T. K.; Nelson, J. M.; Netrakanti, P. K.; Nogach, L. V.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Okorokov, V.; Oldenburg, M.; Olson, D.; Pachr, M.; Pal, S. K.; Panebratsev, Y.; Panitkin, S. Y.; Pavlinov, A. I.; Pawlak, T.; Peitzmann, T.; Perevoztchikov, V.; Perkins, C.; Peryt, W.; Phatak, S. C.; Picha, R.; Planinic, M.; Pluta, J.; Poljak, N.; Porile, N.; Porter, J.; Poskanzer, A. M.; Potekhin, M.; Potrebenikova, E.; Potukuchi, B. V. K. S.; Prindle, D.; Pruneau, C.; Putschke, J.; Rakness, G.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Razin, S. V.; Reinnarth, J.; Relyea, D.; Ridiger, A.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Rose, A.; Roy, C.; Ruan, L.; Russcher, M. J.; Sahoo, R.; Sakuma, T.; Salur, S.; Sandweiss, J.; Sarsour, M.; Sazhin, P. S.; Schambach, J.; Scharenberg, R. P.; Schmitz, N.; Seger, J.; Selyuzhenkov, I.; Seyboth, P.; Shabetai, A.; Shahaliev, E.; Shao, M.; Sharma, M.; Shen, W. Q.; Shimanskiy, S. S.; Sichtermann, E. P.; Simon, F.; Singaraju, R. N.; Smirnov, N.; Snellings, R.; Sood, G.; Sorensen, P.; Sowinski, J.; Speltz, J.; Spinka, H. M.; Srivastava, B.; Stadnik, A.; Stanislaus, T. D. S.; Stock, R.; Stolpovsky, A.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Sugarbaker, E.; Sumbera, M.; Sun, Z.; Surrow, B.; Swanger, M.; Symons, T. J. M.; de Toledo, A. Szanto; Tai, A.; Takahashi, J.; Tang, A. H.; Tarnowsky, T.; Thein, D.; Thomas, J. H.; Timmins, A. R.; Timoshenko, S.; Tokarev, M.; Trainor, T. A.; Trentalange, S.; Tribble, R. E.; Tsai, O. D.; Ulery, J.; Ullrich, T.; Underwood, D. G.; Buren, G. Van; van der Kolk, N.; van Leeuwen, M.; Molen, A. M. Vander; Varma, R.; Vasilevski, I. M.; Vasiliev, A. N.; Vernet, R.; Vigdor, S. E.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Waggoner, W. T.; Wang, F.; Wang, G.; Wang, J. S.; Wang, X. L.; Wang, Y.; Watson, J. W.; Webb, J. C.; Westfall, G. D.; Wetzler, A.; Whitten, C., Jr.; Wieman, H.; Wissink, S. W.; Witt, R.; Wood, J.; Wu, J.; Xu, N.; Xu, Q. H.; Xu, Z.; Yepes, P.; Yoo, I.-K.; Yurevich, V. I.; Zhan, W.; Zhang, H.; Zhang, W. M.; Zhang, Y.; Zhang, Z. P.; Zhao, Y.; Zhong, C.; Zoulkarneev, R.; Zoulkarneeva, Y.; Zubarev, A. N.; Zuo, J. X.

    2006-12-01

    We report a measurement of the longitudinal double-spin asymmetry ALL and the differential cross section for inclusive midrapidity jet production in polarized proton collisions at s=200GeV. The cross section data cover transverse momenta 5polarization in the polarized nucleon.

  11. Precision measurement of the longitudinal double-spin asymmetry for inclusive jet production in polarized proton collisions at √s = 200 GeV

    DOE PAGESBeta

    Adamczyk, L.

    2015-08-26

    We report a new measurement of the midrapidity inclusive jet longitudinal double-spin asymmetry, ALL, in polarized pp collisions at center-of-mass energy √s = 200 GeV. The STAR data place stringent constraints on polarized parton distribution functions extracted at next-to-leading order from global analyses of inclusive deep-inelastic scattering (DIS), semi-inclusive DIS, and RHIC pp data. Lastly, the measured asymmetries provide evidence at the 3σ level for positive gluon polarization in the Bjorken-x region x > 0.05 .

  12. Precision measurement of the longitudinal double-spin asymmetry for inclusive jet production in polarized proton collisions at √s = 200 GeV

    SciTech Connect

    Adamczyk, L.

    2015-08-26

    We report a new measurement of the midrapidity inclusive jet longitudinal double-spin asymmetry, ALL, in polarized pp collisions at center-of-mass energy √s = 200 GeV. The STAR data place stringent constraints on polarized parton distribution functions extracted at next-to-leading order from global analyses of inclusive deep-inelastic scattering (DIS), semi-inclusive DIS, and RHIC pp data. Lastly, the measured asymmetries provide evidence at the 3σ level for positive gluon polarization in the Bjorken-x region x > 0.05 .

  13. Precision Measurement of the Longitudinal Double-Spin Asymmetry for Inclusive Jet Production in Polarized Proton Collisions at √{s }=200 GeV

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Beavis, D. R.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chwastowski, J.; Codrington, M. J. M.; Contin, G.; Cramer, J. G.; Crawford, H. J.; Cudd, A. B.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; Dhamija, S.; di Ruzza, B.; Didenko, L.; Dilks, C.; Ding, F.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Engle, K. S.; Eppley, G.; Eun, L.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Gliske, S.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Kosarzewski, L. K.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; LeVine, M. J.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Madagodagettige Don, D. M. M. D.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Olvitt, D. L.; Pachr, M.; Page, B. S.; Pal, S. K.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Peryt, W.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Pujahari, P. R.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Singaraju, R. N.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Sun, X.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szelezniak, M. A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Vossen, A.; Wada, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yan, W.; Yang, C.; Yang, Y.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zawisza, Y.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, J. L.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2015-08-01

    We report a new measurement of the midrapidity inclusive jet longitudinal double-spin asymmetry, AL L, in polarized p p collisions at center-of-mass energy √{s }=200 GeV . The STAR data place stringent constraints on polarized parton distribution functions extracted at next-to-leading order from global analyses of inclusive deep-inelastic scattering (DIS), semi-inclusive DIS, and RHIC p p data. The measured asymmetries provide evidence at the 3 σ level for positive gluon polarization in the Bjorken-x region x >0.05 .

  14. Precision Measurement of the Longitudinal Double-Spin Asymmetry for Inclusive Jet Production in Polarized Proton Collisions at sqrt[s]=200  GeV.

    PubMed

    Adamczyk, L; Adkins, J K; Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alekseev, I; Alford, J; Anson, C D; Aparin, A; Arkhipkin, D; Aschenauer, E C; Averichev, G S; Banerjee, A; Beavis, D R; Bellwied, R; Bhasin, A; Bhati, A K; Bhattarai, P; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Borowski, W; Bouchet, J; Brandin, A V; Brovko, S G; Bültmann, S; Bunzarov, I; Burton, T P; Butterworth, J; Caines, H; Calderón de la Barca Sánchez, M; Campbell, J M; Cebra, D; Cendejas, R; Cervantes, M C; Chaloupka, P; Chang, Z; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, L; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Chwastowski, J; Codrington, M J M; Contin, G; Cramer, J G; Crawford, H J; Cudd, A B; Cui, X; Das, S; Davila Leyva, A; De Silva, L C; Debbe, R R; Dedovich, T G; Deng, J; Derevschikov, A A; Derradi de Souza, R; Dhamija, S; di Ruzza, B; Didenko, L; Dilks, C; Ding, F; Djawotho, P; Dong, X; Drachenberg, J L; Draper, J E; Du, C M; Dunkelberger, L E; Dunlop, J C; Efimov, L G; Engelage, J; Engle, K S; Eppley, G; Eun, L; Evdokimov, O; Eyser, O; Fatemi, R; Fazio, S; Fedorisin, J; Filip, P; Finch, E; Fisyak, Y; Flores, C E; Gagliardi, C A; Gangadharan, D R; Garand, D; Geurts, F; Gibson, A; Girard, M; Gliske, S; Greiner, L; Grosnick, D; Gunarathne, D S; Guo, Y; Gupta, A; Gupta, S; Guryn, W; Haag, B; Hamed, A; Han, L-X; Haque, R; Harris, J W; Heppelmann, S; Hirsch, A; Hoffmann, G W; Hofman, D J; Horvat, S; Huang, B; Huang, H Z; Huang, X; Huck, P; Humanic, T J; Igo, G; Jacobs, W W; Jang, H; Judd, E G; Kabana, S; Kalinkin, D; Kang, K; Kauder, K; Ke, H W; Keane, D; Kechechyan, A; Kesich, A; Khan, Z H; Kikola, D P; Kisel, I; Kisiel, A; Koetke, D D; Kollegger, T; Konzer, J; Koralt, I; Kosarzewski, L K; Kotchenda, L; Kraishan, A F; Kravtsov, P; Krueger, K; Kulakov, I; Kumar, L; Kycia, R A; Lamont, M A C; Landgraf, J M; Landry, K D; Lauret, J; Lebedev, A; Lednicky, R; Lee, J H; LeVine, M J; Li, C; Li, W; Li, X; Li, X; Li, Y; Li, Z M; Lisa, M A; Liu, F; Ljubicic, T; Llope, W J; Lomnitz, M; Longacre, R S; Luo, X; Ma, G L; Ma, Y G; Madagodagettige Don, D M M D; Mahapatra, D P; Majka, R; Margetis, S; Markert, C; Masui, H; Matis, H S; McDonald, D; McShane, T S; Minaev, N G; Mioduszewski, S; Mohanty, B; Mondal, M M; Morozov, D A; Mustafa, M K; Nandi, B K; Nasim, Md; Nayak, T K; Nelson, J M; Nigmatkulov, G; Nogach, L V; Noh, S Y; Novak, J; Nurushev, S B; Odyniec, G; Ogawa, A; Oh, K; Ohlson, A; Okorokov, V; Oldag, E W; Olvitt, D L; Pachr, M; Page, B S; Pal, S K; Pan, Y X; Pandit, Y; Panebratsev, Y; Pawlak, T; Pawlik, B; Pei, H; Perkins, C; Peryt, W; Pile, P; Planinic, M; Pluta, J; Poljak, N; Poniatowska, K; Porter, J; Poskanzer, A M; Pruthi, N K; Przybycien, M; Pujahari, P R; Putschke, J; Qiu, H; Quintero, A; Ramachandran, S; Raniwala, R; Raniwala, S; Ray, R L; Riley, C K; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Ross, J F; Roy, A; Ruan, L; Rusnak, J; Rusnakova, O; Sahoo, N R; Sahu, P K; Sakrejda, I; Salur, S; Sandweiss, J; Sangaline, E; Sarkar, A; Schambach, J; Scharenberg, R P; Schmah, A M; Schmidke, W B; Schmitz, N; Seger, J; Seyboth, P; Shah, N; Shahaliev, E; Shanmuganathan, P V; Shao, M; Sharma, B; Shen, W Q; Shi, S S; Shou, Q Y; Sichtermann, E P; Singaraju, R N; Skoby, M J; Smirnov, D; Smirnov, N; Solanki, D; Sorensen, P; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stevens, J R; Stock, R; Strikhanov, M; Stringfellow, B; Sumbera, M; Sun, X; Sun, X M; Sun, Y; Sun, Z; Surrow, B; Svirida, D N; Symons, T J M; Szelezniak, M A; Takahashi, J; Tang, A H; Tang, Z; Tarnowsky, T; Thomas, J H; Timmins, A R; Tlusty, D; Tokarev, M; Trentalange, S; Tribble, R E; Tribedy, P; Trzeciak, B A; Tsai, O D; Turnau, J; Ullrich, T; Underwood, D G; Van Buren, G; van Nieuwenhuizen, G; Vandenbroucke, M; Vanfossen, J A; Varma, R; Vasconcelos, G M S; Vasiliev, A N; Vertesi, R; Videbæk, F; Viyogi, Y P; Vokal, S; Vossen, A; Wada, M; Wang, F; Wang, G; Wang, H; Wang, J S; Wang, X L; Wang, Y; Wang, Y; Webb, G; Webb, J C; Westfall, G D; Wieman, H; Wissink, S W; Witt, R; Wu, Y F; Xiao, Z; Xie, W; Xin, K; Xu, H; Xu, J; Xu, N; Xu, Q H; Xu, Y; Xu, Z; Yan, W; Yang, C; Yang, Y; Yang, Y; Ye, Z; Yepes, P; Yi, L; Yip, K; Yoo, I-K; Yu, N; Zawisza, Y; Zbroszczyk, H; Zha, W; Zhang, J B; Zhang, J L; Zhang, S; Zhang, X P; Zhang, Y; Zhang, Z P; Zhao, F; Zhao, J; Zhong, C; Zhu, X; Zhu, Y H; Zoulkarneeva, Y; Zyzak, M

    2015-08-28

    We report a new measurement of the midrapidity inclusive jet longitudinal double-spin asymmetry, A_{LL}, in polarized pp collisions at center-of-mass energy sqrt[s]=200  GeV. The STAR data place stringent constraints on polarized parton distribution functions extracted at next-to-leading order from global analyses of inclusive deep-inelastic scattering (DIS), semi-inclusive DIS, and RHIC pp data. The measured asymmetries provide evidence at the 3σ level for positive gluon polarization in the Bjorken-x region x>0.05. PMID:26371644

  15. Longitudinal Double-Spin Asymmetry and Cross Section for Inclusive Jet Production in Polarized Proton Collisions at {radical}(s)=200 GeV

    SciTech Connect

    Abelev, B. I.; Bielcik, J.; Bielcikova, J.; Caines, H.; Catu, O.; Chikanian, A.; Du, F.; Finch, E.; Harris, J. W.; Heinz, M.; Lamont, M. A. C.; Lin, G.; Majka, R.; Nattrass, C.; Salur, S.; Sandweiss, J.; Smirnov, N.; Witt, R.; Aggarwal, M. M.; Bhati, A. K.

    2006-12-22

    We report a measurement of the longitudinal double-spin asymmetry A{sub LL} and the differential cross section for inclusive midrapidity jet production in polarized proton collisions at {radical}(s)=200 GeV. The cross section data cover transverse momenta 5polarization in the polarized nucleon.

  16. Longitudinal, 3D Imaging of Collagen Remodeling in Murine Hypertrophic Scars In Vivo Using Polarization-Sensitive Optical Frequency Domain Imaging.

    PubMed

    Lo, William C Y; Villiger, Martin; Golberg, Alexander; Broelsch, G Felix; Khan, Saiqa; Lian, Christine G; Austen, William G; Yarmush, Martin; Bouma, Brett E

    2016-01-01

    Hypertrophic scars (HTS), frequently seen after traumatic injuries and surgery, remain a major clinical challenge because of the limited success of existing therapies. A significant obstacle to understanding HTS etiology is the lack of tools to monitor scar remodeling longitudinally and noninvasively. We present an in vivo, label-free technique using polarization-sensitive optical frequency domain imaging for the 3D, longitudinal assessment of collagen remodeling in murine HTS. In this study, HTS was induced with a mechanical tension device for 4-10 days on incisional wounds and imaged up to 1 month after device removal; an excisional HTS model was also imaged at 6 months after injury to investigate deeper and more mature scars. We showed that local retardation and degree of polarization provide a robust signature for HTS. Compared with normal skin with heterogeneous local retardation and low degree of polarization, HTS was characterized by an initially low local retardation, which increased as collagen fibers remodeled, and a persistently high degree of polarization. This study demonstrates that polarization-sensitive optical frequency domain imaging offers a powerful tool to gain significant biological insights into HTS remodeling by enabling longitudinal assessment of collagen in vivo, which is critical to elucidating HTS etiology and developing more effective HTS therapies. PMID:26763427

  17. A Spin-Light Polarimeter for Multi-GeV Longitudinally Polarized Electron Beams

    SciTech Connect

    Mohanmurthy, Prajwal; Dutta, Dipangkar

    2014-02-01

    The physics program at the upgraded Jefferson Lab (JLab) and the physics program envisioned for the proposed electron-ion collider (EIC) include large efforts to search for interactions beyond the Standard Model (SM) using parity violation in electroweak interactions. These experiments require precision electron polarimetry with an uncertainty of < 0.5 %. The spin dependent Synchrotron radiation, called "spin-light," can be used to monitor the electron beam polarization. In this article we develop a conceptual design for a "spin-light" polarimeter that can be used at a high intensity, multi-GeV electron accelerator. We have also built a Geant4 based simulation for a prototype device and report some of the results from these simulations.

  18. Large-scale Observations of a Subauroral Polarization Stream by Midlatitude SuperDARN Radars: Instantaneous Longitudinal Velocity Variations

    NASA Technical Reports Server (NTRS)

    Clausen, L. B. N.; Baker, J. B. H.; Sazykin, S.; Ruohoniemi, J. M.; Greenwald, R. A.; Thomas, E. J.; Shepherd, S. G.; Talaat, E. R.; Bristow, W. A.; Zheng, Y.; Coster, A. J.

    2012-01-01

    We present simultaneous measurements of flow velocities inside a subauroral polarization stream (SAPS) made by six midlatitude high-frequency SuperDARN radars. The instantaneous observations cover three hours of universal time and six hours of magnetic local time (MLT). From velocity variations across the field-of-view of the radars we infer the local 2D flow direction at three different longitudes. We find that the local flow direction inside the SAPS channel is remarkably constant over the course of the event. The flow speed, however, shows significant temporal and spatial variations. After correcting for the radar look direction we are able to accurately determine the dependence of the SAPS velocity on magnetic local time. We find that the SAPS velocity variation with magnetic local time is best described by an exponential function. The average velocity at 00 MLT was 1.2 km/s and it decreased with a spatial e-folding scale of two hours of MLT toward the dawn sector. We speculate that the longitudinal distribution of pressure gradients in the ring current is responsible for this dependence and find these observations in good agreement with results from ring current models. Using TEC measurements we find that the high westward velocities of the SAPS are - as expected - located in a region of low TEC values, indicating low ionospheric conductivities.

  19. Switchable single-longitudinal-mode dual-wavelength erbium-doped fiber laser based on one polarization-maintaining fiber Bragg grating incorporating saturable absorber

    NASA Astrophysics Data System (ADS)

    Feng, Suchun; Xu, Ou; Lu, Shaohua; Chen, Ming; Jian, Shuisheng

    2009-08-01

    Switchable single-longitudinal-mode (SLM) dual-wavelength erbium-doped fiber laser at room temperature is demonstrated. One fiber Bragg grating (FBG) directly written in a polarization-maintaining and photosensitive erbiumdoped fiber (PMPEDF) as the wavelength-selective component is used in a linear laser cavity. Due to the polarization hole burning (PHB) enhanced by the polarization-maintaining fiber Bragg grating (PMFBG), the laser can be designed to operate in stable dual-wavelength or wavelength-switching modes with a wavelength spacing of 0.202 nm by adjusting a polarization controller (PC). The stable SLM operation is guaranteed by a saturable absorber (SA). The optical signal-tonoise ratio (OSNR) of the laser is over 40 dB. The amplitude variation in nearly one and half an hour is less than 0.5 dB for both wavelengths.

  20. Leading and next-to-leading order gluon polarization in the nucleon and longitudinal double spin asymmetries from open charm muoproduction

    NASA Astrophysics Data System (ADS)

    Adolph, C.; Alekseev, M. G.; Alexakhin, V. Yu.; Alexandrov, Yu.; Alexeev, G. D.; Amoroso, A.; Antonov, A. A.; Austregesilo, A.; Badełek, B.; Balestra, F.; Barth, J.; Baum, G.; Bedfer, Y.; Berlin, A.; Bernhard, J.; Bertini, R.; Bettinelli, M.; Bicker, K.; Bieling, J.; Birsa, R.; Bisplinghoff, J.; Bordalo, P.; Bradamante, F.; Braun, C.; Bravar, A.; Bressan, A.; Büchele, M.; Burtin, E.; Capozza, L.; Chiosso, M.; Chung, S. U.; Cicuttin, A.; Crespo, M. L.; Dalla Torre, S.; Das, S.; Dasgupta, S. S.; Dasgupta, S.; Denisov, O. Yu.; Dhara, L.; Donskov, S. V.; Doshita, N.; Duic, V.; Dünnweber, W.; Dziewiecki, M.; Efremov, A.; Elia, C.; Eversheim, P. D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Filin, A.; Finger, M.; Finger, M., Jr.; Fischer, H.; Franco, C.; du Fresne von Hohenesche, N.; Friedrich, J. M.; Frolov, V.; Garfagnini, R.; Gautheron, F.; Gavrichtchouk, O. P.; Gerassimov, S.; Geyer, R.; Giorgi, M.; Gnesi, I.; Gobbo, B.; Goertz, S.; Grabmüller, S.; Grasso, A.; Grube, B.; Gushterski, R.; Guskov, A.; Guthörl, T.; Haas, F.; von Harrach, D.; Heinsius, F. H.; Herrmann, F.; Heß, C.; Hinterberger, F.; Horikawa, N.; Höppner, Ch.; d'Hose, N.; Huber, S.; Ishimoto, S.; Ivanov, O.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jary, V.; Jasinski, P.; Joosten, R.; Kabuß, E.; Kang, D.; Ketzer, B.; Khaustov, G. V.; Khokhlov, Yu. A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koblitz, S.; Koivuniemi, J. H.; Kolosov, V. N.; Kondo, K.; Königsmann, K.; Konorov, I.; Konstantinov, V. F.; Korzenev, A.; Kotzinian, A. M.; Kouznetsov, O.; Krämer, M.; Kroumchtein, Z. V.; Kunne, F.; Kurek, K.; Lauser, L.; Lednev, A. A.; Lehmann, A.; Levorato, S.; Lichtenstadt, J.; Liska, T.; Maggiora, A.; Magnon, A.; Makke, N.; Mallot, G. K.; Mann, A.; Marchand, C.; Martin, A.; Marzec, J.; Matsuda, T.; Meshcheryakov, G.; Meyer, W.; Michigami, T.; Mikhailov, Yu. V.; Morreale, A.; Mutter, A.; Nagaytsev, A.; Nagel, T.; Nerling, F.; Neubert, S.; Neyret, D.; Nikolaenko, V. I.; Nowak, W.-D.; Nunes, A. S.; Olshevsky, A. G.; Ostrick, M.; Padee, A.; Panknin, R.; Panzieri, D.; Parsamyan, B.; Paul, S.; Perevalova, E.; Pesaro, G.; Peshekhonov, D. V.; Piragino, G.; Platchkov, S.; Pochodzalla, J.; Polak, J.; Polyakov, V. A.; Pretz, J.; Quaresma, M.; Quintans, C.; Rajotte, J.-F.; Ramos, S.; Rapatsky, V.; Reicherz, G.; Rocco, E.; Rondio, E.; Rossiyskaya, N. S.; Ryabchikov, D. I.; Samoylenko, V. D.; Sandacz, A.; Sapozhnikov, M. G.; Sarkar, S.; Savin, I. A.; Sbrizzai, G.; Schiavon, P.; Schill, C.; Schlüter, T.; Schmidt, A.; Schmidt, K.; Schmitt, L.; Schmïden, H.; Schönning, K.; Schopferer, S.; Schott, M.; Shevchenko, O. Yu.; Silva, L.; Sinha, L.; Sissakian, A. N.; Slunecka, M.; Smirnov, G. I.; Sosio, S.; Sozzi, F.; Srnka, A.; Steiger, L.; Stolarski, M.; Sulc, M.; Sulej, R.; Suzuki, H.; Sznajder, P.; Takekawa, S.; Ter Wolbeek, J.; Tessaro, S.; Tessarotto, F.; Tkatchev, L. G.; Uhl, S.; Uman, I.; Vandenbroucke, M.; Virius, M.; Vlassov, N. V.; Wang, L.; Weisrock, T.; Wilfert, M.; Windmolders, R.; Wiślicki, W.; Wollny, H.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zhuravlev, N.; Zvyagin, A.

    2013-03-01

    The gluon polarization in the nucleon was measured using open charm production by scattering 160GeV/c polarized muons off longitudinally polarized protons or deuterons. The data were taken by the COMPASS Collaboration between 2002 and 2007. A detailed account is given of the analysis method that includes the application of neural networks. Several decay channels of D0 mesons are investigated. Longitudinal spin asymmetries of the D meson production cross sections are extracted in bins of D0 transverse momentum and energy. At leading order QCD accuracy, the average gluon polarization is determined as ⟨Δg/g⟩LO=-0.06±0.21(stat.)±0.08(syst.) at the scale ⟨μ2⟩≈13(GeV/c)2 and an average gluon momentum fraction ⟨x⟩≈0.11. The average gluon polarization is also obtained at next-to-leading order QCD accuracy as ⟨Δg/g⟩ NLO=-0.13±0.15(stat.)±0.15(syst.) at the scale ⟨μ2⟩≈13(GeV/c)2 and ⟨x⟩≈0.20.

  1. Longitudinal double-spin asymmetry and cross section for inclusivejet production in polarized proton collisions at sqrt(s) = 200 GeV

    SciTech Connect

    Abelev, B.I.; Adams, J.; Aggarwal, M.M.; Ahammed, Z.; Amonett,J.; Anderson, B.D.; Anderson, M.; Arkhipkin, D.; Averichev, G.S.; Bai,Y.; Balewski, J.; Barannikova, O.; Barnby, L.S.; Baudot, J.; Bekele, S.; Belaga, V.V.; Bellingeri-Laurikainen, A.; Bellwied, R.; Benedosso, F.; Bhardwaj, S.; Bhasin, A.; Bhati, A.K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L.C.; Blyth, S.-L.; Bonner, B.E.; Botje, M.; Bouchet, J.; Brandin, A.V.; Bravar, A.; Bystersky, M.; Cadman, R.V.; Cai,X.Z.; Caines, H.; Calderon de la Barca Sanchez, M.; Castillo, J.; Catu,O.; Cebra, D.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen,H.F.; Chen, J.H.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Coffin, J.P.; Cormier, T.M.; Cosentino, M.R.; Cramer, J.G.; Crawford,H.J.; Das, D.; Das, S.; Daugherity, M.; de Moura, M.M.; Dedovich, T.G.; DePhillips, M.; Derevschikov, A.A.; Didenko, L.; Dietel, T.; Djawotho,P.; Dogra, S.M.; Dong, W.J.; Dong, X.; Draper, J.E.; Du, F.; Dunin, V.B.; Dunlop, J.C.; Dutta Mazumdar, M.R.; Eckardt, V.; Edwards, W.R.; Efimov,L.G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Filimonov, K.; Filip, P.; Finch,E.; Fine, V.; Fisyak, Y.; Fu, J.; Gagliardi, C.A.; Gaillard, L.; Ganti,M.S.; Ghazikhanian, V.; Ghosh, P.; Gonzalez, J.S.; Gorbunov, Y.G.; Gos,H.; Grebenyuk, O.; Grosnick, D.; Guertin, S.M.; Guimaraes, K.S.F.F.; Guo,Y.; Gupta, N.; Gutierrez, T.D.; Haag, B.; Hallman, T.J.; Hamed, A.; Harris, J.W.; He, W.; Heinz, M.; Henry, T.W.; Hepplemann, S.; Hippolyte,B.; Hirsch, A.; Hjort, E.; Hoffman, A.M.; Hoffmann, G.W.; Horner, M.J.; Huang, H.Z.; Huang, S.L.; Hughes, E.W.; Humanic, T.J.; Igo, G.; Jacobs,P.; Jacobs, W.W.; Jakl, P.; Jia, F.; Jiang, H.; Jones, P.G.; Judd, E.G.; Kabana, S.; Kang, K.; Kapitan, J.; Kaplan, M.; Keane, D.; Kechechyan, A.; Khodyrev, V.Yu.; Kim, B.C.; Kiryluk, J.; Kisiel, A.; Kislov, E.M.; Klein,S.R.; Kocoloski, A.; Koetke, D.D.; et al.

    2006-08-10

    We report a measurement of the longitudinal double-spinasymmetry A_LL and the differential cross section for inclusivemidrapidity jet production in polarized proton collisions at sqrt(s)=200GeV. The cross section data cover transverse momenta 5polarization in the polarizednucleon.

  2. High-aperture binary axicons for the formation of the longitudinal electric field component on the optical axis for linear and circular polarizations of the illuminating beam

    SciTech Connect

    Khonina, S. N. Savelyev, D. A.

    2013-10-15

    Diffraction of uniformly polarized laser beams with vortex phase singularity is theoretically analyzed using the plane wave expansion. It is shown that for a high numerical aperture, an intense longitudinal electric field component is formed on the optical axis in this case. It is numerically demonstrated that an analogous effect is ensured for diffraction of a conventional Gaussian beam from asymmetric binary axicons. The field intensity on the optical axis can be varied either by rotating the optical element or by changing the direction of polarization of radiation.

  3. Longitudinal Double Spin Asymmetries in Heavy Flavor Production in Polarized p+p Collisions at {radical}(s) = 200 GeV

    SciTech Connect

    Wang, Xiaorong

    2009-08-04

    One of the main goals of the RHIC spin program is to determine the contribution of gluons to the proton spin. At RHIC energies, heavy quark (charm and beauty) production is expected to be dominated by gluon-gluon interactions, so a measurement of the double longitudinal spin asymmetry A{sub LL} in heavy quark production in polarized p+p collisions directly probes the polarized gluon distribution inside the proton. We present the latest results on an A{sub LL} measurement for J/{psi} and open charm production measured by the PHENIX detector.

  4. Longitudinal double-spin asymmetry and cross section for inclusive neutral pion production at midrapidity in polarized proton collisions at s=200GeV

    NASA Astrophysics Data System (ADS)

    Abelev, B. I.; Aggarwal, M. M.; Ahammed, Z.; Alakhverdyants, A. V.; Anderson, B. D.; Arkhipkin, D.; Averichev, G. S.; Balewski, J.; Barannikova, O.; Barnby, L. S.; Baumgart, S.; Beavis, D. R.; Bellwied, R.; Benedosso, F.; Betancourt, M. J.; Betts, R. R.; Bhasin, A.; Bhati, A. K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Biritz, B.; Bland, L. C.; Bonner, B. E.; Bouchet, J.; Braidot, E.; Brandin, A. V.; Bridgeman, A.; Bruna, E.; Bueltmann, S.; Bunzarov, I.; Burton, T. P.; Cai, X. Z.; Caines, H.; Sánchez, M. Calderón De La Barca; Catu, O.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, J. Y.; Cheng, J.; Cherney, M.; Chikanian, A.; Choi, K. E.; Christie, W.; Chung, P.; Clarke, R. F.; Codrington, M. J. M.; Corliss, R.; Cramer, J. G.; Crawford, H. J.; Das, D.; Dash, S.; Leyva, A. Davila; Silva, L. C. De; Debbe, R. R.; Dedovich, T. G.; Dephillips, M.; Derevschikov, A. A.; de Souza, R. Derradi; Didenko, L.; Djawotho, P.; Dogra, S. M.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Dunlop, J. C.; Mazumdar, M. R. Dutta; Efimov, L. G.; Elhalhuli, E.; Elnimr, M.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Eun, L.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Fersch, R. G.; Filip, P.; Finch, E.; Fine, V.; Fisyak, Y.; Gagliardi, C. A.; Gangadharan, D. R.; Ganti, M. S.; Garcia-Solis, E. J.; Geromitsos, A.; Geurts, F.; Ghazikhanian, V.; Ghosh, P.; Gorbunov, Y. N.; Gordon, A.; Grebenyuk, O.; Grosnick, D.; Grube, B.; Guertin, S. M.; Gupta, A.; Gupta, N.; Guryn, W.; Haag, B.; Hallman, T. J.; Hamed, A.; Han, L.-X.; Harris, J. W.; Hays-Wehle, J. P.; Heinz, M.; Heppelmann, S.; Hirsch, A.; Hjort, E.; Hoffman, A. M.; Hoffmann, G. W.; Hofman, D. J.; Hollis, R. S.; Huang, H. Z.; Humanic, T. J.; Huo, L.; Igo, G.; Iordanova, A.; Jacobs, P.; Jacobs, W. W.; Jakl, P.; Jena, C.; Jin, F.; Jones, C. L.; Jones, P. G.; Joseph, J.; Judd, E. G.; Kabana, S.; Kajimoto, K.; Kang, K.; Kapitan, J.; Kauder, K.; Keane, D.; Kechechyan, A.; Kettler, D.; Kikola, D. P.; Kiryluk, J.; Kisiel, A.; Klein, S. R.; Knospe, A. G.; Kocoloski, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Kopytine, M.; Koralt, I.; Korsch, W.; Kotchenda, L.; Kouchpil, V.; Kravtsov, P.; Krueger, K.; Krus, M.; Kumar, L.; Kurnadi, P.; Lamont, M. A. C.; Landgraf, J. M.; Lapointe, S.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, C.-H.; Lee, J. H.; Leight, W.; Levine, M. J.; Li, C.; Li, L.; Li, N.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z.; Lin, G.; Lindenbaum, S. J.; Lisa, M. A.; Liu, F.; Liu, H.; Liu, J.; Ljubicic, T.; Llope, W. J.; Longacre, R. S.; Love, W. A.; Lu, Y.; Ma, G. L.; Ma, Y. G.; Mahapatra, D. P.; Majka, R.; Mall, O. I.; Mangotra, L. K.; Manweiler, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; Matulenko, Yu. A.; McDonald, D.; McShane, T. S.; Meschanin, A.; Milner, R.; Minaev, N. G.; Mioduszewski, S.; Mischke, A.; Mitrovski, M. K.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Munhoz, M. G.; Nandi, B. K.; Nattrass, C.; Nayak, T. K.; Nelson, J. M.; Netrakanti, P. K.; Ng, M. J.; Nogach, L. V.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Okada, H.; Okorokov, V.; Olson, D.; Pachr, M.; Page, B. S.; Pal, S. K.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Peitzmann, T.; Perevoztchikov, V.; Perkins, C.; Peryt, W.; Phatak, S. C.; Pile, P.; Planinic, M.; Ploskon, M. A.; Pluta, J.; Plyku, D.; Poljak, N.; Poskanzer, A. M.; Potukuchi, B. V. K. S.; Powell, C. B.; Prindle, D.; Pruneau, C.; Pruthi, N. K.; Pujahari, P. R.; Putschke, J.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Redwine, R.; Reed, R.; Rehberg, J. M.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Rose, A.; Roy, C.; Ruan, L.; Russcher, M. J.; Sahoo, R.; Sakai, S.; Sakrejda, I.; Sakuma, T.; Salur, S.; Sandweiss, J.; Sangaline, E.; Schambach, J.; Scharenberg, R. P.; Schmitz, N.; Schuster, T. R.; Seele, J.; Seger, J.; Selyuzhenkov, I.; Seyboth, P.; Shahaliev, E.; Shao, M.; Sharma, M.; Shi, S. S.; Sichtermann, E. P.; Simon, F.; Singaraju, R. N.; Skoby, M. J.; Smirnov, N.; Sorensen, P.; Sowinski, J.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Staszak, D.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Suarez, M. C.; Subba, N. L.; Sumbera, M.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Symons, T. J. M.; de Toledo, A. Szanto; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarini, L. H.; Tarnowsky, T.; Thein, D.; Thomas, J. H.; Tian, J.; Timmins, A. R.; Timoshenko, S.; Tlusty, D.; Tokarev, M.; Trainor, T. A.; Tram, V. N.; Trentalange, S.; Tribble, R. E.; Tsai, O. D.; Ulery, J.; Ullrich, T.; Underwood, D. G.; van Buren, G.; van Nieuwenhuizen, G.; Vanfossen, J. A., Jr.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Videbaek, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Wada, M.; Walker, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, Q.; Wang, X.; Wang, X. L.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Whitten, C., Jr.; Wieman, H.; Wingfield, E.; Wissink, S. W.; Witt, R.; Wu, Y.; Xie, W.; Xu, N.; Xu, Q. H.; Xu, W.; Xu, Y.; Xu, Z.; Xue, L.; Yang, Y.; Yepes, P.; Yip, K.; Yoo, I.-K.; Yue, Q.; Zawisza, M.; Zbroszczyk, H.; Zhan, W.; Zhang, S.; Zhang, W. M.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, J.; Zhong, C.; Zhou, J.; Zhou, W.; Zhu, X.; Zhu, Y. H.; Zoulkarneev, R.; Zoulkarneeva, Y.

    2009-12-01

    We report a measurement of the longitudinal double-spin asymmetry ALL and the differential cross section for inclusive π0 production at midrapidity in polarized proton collisions at s=200GeV. The cross section was measured over a transverse momentum range of 1longitudinal double-spin asymmetry was measured in the range of 3.7polarization in the proton. The mean transverse momentum fraction of π0’s in their parent jets was found to be around 0.7 for electromagnetically triggered events.

  5. Diffractive hadroproduction of W{sup {+-}} and Z{sup 0} bosons at high energies

    SciTech Connect

    Ducati, M. B. Gay; Machado, M. M.; Machado, M. V. T.

    2008-10-13

    An analysis of W{sup {+-}} and Z{sup 0} hard diffractive hadroproduction at high energies is presented obtained using the simple assumption of Regge factorization and considering the recent diffractive parton density functions extracted by the H1 Collaboration at DESY-HERA. The corresponding multiple Pomeron exchange corrections to the single Pomeron one is considered by taking into account by a gap survival probability factor. It is shown that the ratio of diffractive to nondiffractive boson production is in good agreement with the Tevatron data. Estimations which are relevant for the incoming measurements at the LHC are discussed.

  6. Diffractive hadroproduction of W{sup {+-}} and Z{sup 0} bosons at high energies

    SciTech Connect

    Gay Ducati, M. B.; Machado, M. M.; Machado, M. V. T.

    2007-06-01

    Results from a phenomenological analysis of W and Z hard diffractive hadroproduction at high energies are reported. Using the Regge factorization approach, we consider the recent diffractive parton density functions extracted by the H1 Collaboration at DESY-HERA. In addition, we take into account multiple Pomeron exchange corrections considering a gap survival probability factor. It is found that the ratio of diffractive to nondiffractive boson production is in good agreement with the CDF and D0 data. We make predictions which could be compared to future measurements at the LHC.

  7. Hadron spectroscopy in photo- and hadroproduction at COMPASS

    SciTech Connect

    Friedrich, J. M.

    2006-07-11

    COMPASS at CERN uses a 160 GeV/c muon beam on a polarized 6LiD target to measure spin-dependent nucleon structure functions. In addition, these high-statistics data on photoproduction offer information on hadron spectroscopy. We present results on the search for the {phi}(1860) pentaquark which had been observed by the NA49 experiment at CERN.COMPASS has also taken a first data sample using a pion beam, aiming to improve the pion polarisability measurement via scattering off a photon in the Coulomb field of a heavy nucleus, as well as meson spectroscopy in the diffractive scattering regime. First spectra of the ongoing analysis are presented.

  8. Longitudinal, 3D Imaging of Collagen Remodeling in Murine Hypertrophic Scars In Vivo using Polarization-sensitive Optical Frequency Domain Imaging

    PubMed Central

    Lo, William C. Y.; Villiger, Martin; Golberg, Alexander; Broelsch, G. Felix; Khan, Saiqa; Lian, Christine G.; Austen, William G.; Yarmush, Martin; Bouma, Brett E.

    2016-01-01

    Hypertrophic scars (HTS), frequently seen after traumatic injuries and surgery, remain a major clinical challenge due to the limited success of existing therapies. A significant obstacle to understanding HTS etiology is the lack of tools to monitor scar remodeling longitudinally and non-invasively. We present an in vivo, label-free technique using polarization-sensitive optical frequency domain imaging (PS-OFDI) for the 3D, longitudinal assessment of collagen remodeling in murine HTS. In this study, HTS was induced with a mechanical tension device for 4 to 10 days on incisional wounds and imaged up to one month after device removal; an excisional HTS model was also imaged at 6 months after injury to investigate deeper and more mature scars. We showed that local retardation (LR) and degree of polarization (DOP) provide a robust signature for HTS. Compared to normal skin with heterogeneous LR and low DOP, HTS was characterized by an initially low LR, which increased as collagen fibers remodeled, and a persistently high DOP. This study demonstrates that PS-OFDI offers a powerful tool to gain significant biological insights into HTS remodeling by enabling longitudinal assessment of collagen in vivo, which is critical to elucidating HTS etiology and developing more effective HTS therapies. PMID:26763427

  9. Longitudinal spin transfer to {lambda} and {lambda} hyperons in polarized proton-proton collisions at {radical}(s)=200 GeV

    SciTech Connect

    Abelev, B. I.; Barannikova, O.; Betts, R. R.; Garcia-Solis, E. J.; Hofman, D. J.; Hollis, R. S.; Iordanova, A.; Kauder, K.; Suarez, M. C.; Aggarwal, M. M.; Bhati, A. K.; Kumar, L.; Pruthi, N. K.; Ahammed, Z.; Chattopadhyay, S.; Dutta Mazumdar, M. R.; Ganti, M. S.; Ghosh, P.; Mohanty, B.; Nayak, T. K.

    2009-12-01

    The longitudinal spin transfer, D{sub LL}, from high energy polarized protons to {lambda} and {lambda} hyperons has been measured for the first time in proton-proton collisions at {radical}(s)=200 GeV with the STAR detector at the Relativistic Heavy Ion Collider. The measurements cover pseudorapidity, {eta}, in the range |{eta}|<1.2 and transverse momenta, p{sub T}, up to 4 GeV/c. The longitudinal spin transfer is found to be D{sub LL}=-0.03{+-}0.13(stat){+-}0.04(syst) for inclusive {lambda} and D{sub LL}=-0.12{+-}0.08(stat){+-}0.03(syst) for inclusive {lambda} hyperons with <{eta}>=0.5 and =3.7 GeV/c. The dependence on {eta} and p{sub T} is presented.

  10. Longitudinal Spin Transfer to Lambda and Lambda bar Hyperons in Polarized Proton-Proton Collisions at sqrt s = 200 GeV

    SciTech Connect

    STAR Collaboration; Abelev, Betty

    2010-07-05

    The longitudinal spin transfer, D{sub LL}, from high energy polarized protons to {Lambda} and {bar {Lambda}} hypersons has been measured for the first time in proton-proton collisions at {radical}s = 200 GeV with the STAR detector at RHIC. The measurements cover pseudorapidity, {eta}, in the range |{eta}| < 1.2 and transverse momenta, p{sub T}, up to 4 GeV/c. The longitudinal spin transfer is found to be D{sub LL} = -0.03{+-}0.13(stat){+-}0.04(syst) for inclusive {Lambda} and D{sub LL} = -0.12{+-}0.08(stat){+-}0.03(syst) for inclusive {bar {Lambda}} hyperons with <{eta}> = 0.5 and = 3.7 GeV/c. The dependence on {eta} and p{sub T} is presented.

  11. Longitudinal spin transfer to {Lambda} and {bar Lambda} hyperons in polarized proton-proton collisions at {radical}{ovr s} = 200 GeV.

    SciTech Connect

    Abelev, B. I.; Aggarwal, M. M.; Ahammed, Z.; Alakhverdyants, A. V.; Anderson, B. D.; Bridgeman, A.; Krueger, K.; Spinka, H. M.; Underwood, D. G.; STAR Collaboration

    2009-01-01

    The longitudinal spin transfer, D{sub LL}, from high energy polarized protons to {Lambda} and {bar {Lambda}} hyperons has been measured for the first time in proton-proton collisions at {radical}s = 200 GeV with the STAR detector at the Relativistic Heavy Ion Collider. The measurements cover pseudorapidity, {eta}, in the range |{eta}| < 1.2 and transverse momenta, p{sub T}, up to 4 GeV/c. The longitudinal spin transfer is found to be D{sub LL} = -0.03 {+-} 0.13(stat) {+-} 0.04(syst) for inclusive {Lambda} and D{sub LL} = -0.12 {+-} 0.08(stat) {+-} 0.03(syst) for inclusive {bar {Lambda}} hyperons with {eta} = 0.5 and p{sub T} =3.7 GeV/c. The dependence on {eta} and p{sub T} is presented.

  12. Hadroproduction of t-anti-t pair with two isolated photons with PowHel

    NASA Astrophysics Data System (ADS)

    Kardos, A.; Trócsányi, Z.

    2015-08-01

    We simulate the hadroproduction of a t t bar pair in association with two isolated hard photons at 13 TeV LHC using the PowHel package. We use the generated events, stored according to the Les-Houches event format, to make predictions for differential distributions formally at the next-to-leading order (NLO) accuracy. We present predictions at the hadron level employing the cone-type isolation of the photons used by experiments. We also compare the kinematic distributions to the same distributions obtained in the t t bar H final state when the Higgs-boson decays into a photon pair, to which the process discussed here is an irreducible background.

  13. Differentiating between and Synthesizing Quantitative, Qualitative, and Longitudinal Research on Polarized School Cultures: A Comment on Van Houtte (2006)

    ERIC Educational Resources Information Center

    Abraham, John

    2007-01-01

    Van Houtte provides a valuable large-sample quantitative analysis of differentiation and polarization processes between and within school cultures in Belgium. Such research across 34 secondary schools provides greater confidence that the findings in the ethnographic tradition for the differentiation-polarization theory are not due to…

  14. Double-helicity dependence of jet properties from dihadrons in longitudinally polarized p+p collisions at {radical}(s)=200 GeV

    SciTech Connect

    Adare, A.; Bickley, A. A.; Ellinghaus, F.; Glenn, A.; Kinney, E.; Kiriluk, K.; Nagle, J. L.; Seele, J.; Wysocki, M.; Afanasiev, S.; Isupov, A.; Litvinenko, A.; Malakhov, A.; Peresedov, V.; Rukoyatkin, P.; Zolin, L.; Aidala, C.; Ajitanand, N. N.; Alexander, J.; Chung, P.

    2010-01-01

    It has been postulated that partonic orbital angular momentum can lead to a significant double-helicity dependence in the net transverse momentum of Drell-Yan dileptons produced in longitudinally polarized p+p collisions. Analogous effects are also expected for dijet production. If confirmed by experiment, this hypothesis, which is based on semiclassical arguments, could lead to a new approach for studying the contributions of orbital angular momentum to the proton spin. We report the first measurement of the double-helicity dependence of the dijet transverse momentum in longitudinally polarized p+p collisions at {radical}(s)=200 GeV from data taken by the PHENIX experiment in 2005 and 2006. The analysis deduces the transverse momentum of the dijet from the widths of the near- and far-side peaks in the azimuthal correlation of the dihadrons. When averaged over the transverse momentum of the triggered particle, the difference of the root mean square of the dijet transverse momentum between like- and unlike-helicity collisions is found to be -37{+-}88{sup stat{+-}}14{sup syst} MeV/c.

  15. A comparison of the longitudinal distributions of polar stratospheric clouds and temperatures for the 1987 Antarctic spring

    SciTech Connect

    Watterson, I.G. ); Tuck, A.F. )

    1989-11-30

    The Stratospheric Aerosol Measurement (SAM) II stratospheric extinction coefficients have been analyzed to provide information on the geographical distribution of Antarctic stratospheric clouds in 1987. The peak extinction above 15 km was determined for each of the approximately 14 vertical profiles each day. A longitude by time graph of this extinction is presented, extending from early June to late October. Similar graphs for extinction at 17 km and for temperature at 17 km and 70 mbar geopotential height from the National Meteorological Center at the measurement locations are also shown. It is assumed that extinction is a measure of cloud density. Statistics of the fractional incidence of cloud and of temperature and pressure for five time periods and 24 longitudinal sectors are presented. Cloud incidences for latitudes which either cross or pass to the south of the Antarctic Peninsula are shown. In order to remove the effect of the latitudinal drift of the measurements the statistics are also shown for data binned by 70-mbar geopotential height relative to the minimum within the vortex. In general, there is a good correlation between enhanced extinctions and cold temperatures. Both exhibit a planetary wave structure which tends to move eastward. However, the distribution of dense clouds is highly zonally asymmetric and unlike that of temperature. These clouds are very rare over East Antarctica even when temperatures are low there. After July, clouds are also rare close to the center of the vortex, as determined by the 70-mbar geopotential height of the measurement locations. It is concluded that both cold temperature and the availability of condensable material are important in determining the location of cloud.

  16. On the cos ⁡ϕh asymmetry in electroproduction of pions in double longitudinally polarized process

    NASA Astrophysics Data System (ADS)

    Mao, Wenjuan; Wang, Xiaoyu; Du, Xiaozhen; Lu, Zhun; Ma, Bo-Qiang

    2016-01-01

    We study the cos ⁡ϕh azimuthal asymmetry in double polarized semi-inclusive pion production by considering the twist-3 effects directly from a quark-quark correlator. In particular, we evaluate the role of the transverse momentum dependent distributions eL (x, kT2) and gL⊥ (x, kT2) on the asymmetry. Using two different sets of spectator model results for these distributions, we predict the cos ⁡ϕh asymmetry of π+, π-, and π0 at the kinematic configuration available at CLAS, HERMES. Our estimate shows that the asymmetries for charged and neutral pions are sizable and could be accessed by CLAS and HERMES. We also calculate the asymmetries for charged hadrons at the kinematics of COMPASS and compare them with the experimental data. We find that the asymmetry at COMPASS in our model is small which is consistent with the COMPASS data. We also find that gL⊥ gives the dominant contribution to the cos ⁡ϕh asymmetry, while the contribution of eL is almost negligible.

  17. Beam flavor dependence in the hadroproduction of D{sup {+-}} and D{sub s}{sup {+-}} mesons

    SciTech Connect

    Fermilab E769 Collaboration

    1994-07-01

    Fermilab E769, a fixed-target experiment conducted during the 1987--88 running period, yielded large numbers of charm particles. Through collisions of 250 GeV {pi}{sup {+-}}, K{sup {+-}}, and p on a multifoil target, E769 allows for studies of beam flavor dependence in the hadroproduction of charm. Through the decay modes D{sup +} {yields} K{sup {minus}}{pi}{sup +}{pi}{sup +}, D{sub s}{sup +} {yields} {phi}{pi}{sup +}, and D{sub s}{sup +} {yields} {anti K}{sup *0} K{sup +} (and charge conjugates), the authors have extracted D{sup {+-}} and D{sub s}{sup {+-}} signals for all five beam types. They report preliminary measurements of the beam dependence of the absolute production cross-sections (For Feynman x > 0) of the D{sup {+-}} and D{sub s}{sup {+-}}.

  18. Measurement of Longitudinal Single Spin Asymmetry in the Production of Muons from W/Z Boson Decays in Polarized p+p Collisions at sqrt s = 510 GeV with the PHENIX Detector at RHIC

    NASA Astrophysics Data System (ADS)

    Meles, Abraham

    The contribution from the sea quarks to the proton spin have been poorly constrained mainly because of the limited knowledge we have on the fragmentation function in polarized Semi Inclusive Deep Inelastic Scattering (SIDIS) experiments. The parity-violating longitudinal single spin asymmetry AL in the production of W bosons in p + p collisions does not involve fragmentation function and is an alternative better way of exploring the polarization of sea quarks in the proton. The measurement will be useful especially in constraining u and d¯ in the very backward and forward rapidities respectively. However, identifying the muons from the decay of the W is challenging due to a great background of hadronic in flight decays and other muon producing processes such as heavy flavor decays. In the forward and backward hemispheres of PHENIX at RHIC, the muon spectrometers have been recently upgraded in order to provide additional trigger and tracking information to suppress those backgrounds. One of those upgrades is the Forward Vertex (FVTX) detector, a silicon-strip tracker. In 2013, PHENIX accumulated the largest amount of polarized p + p collision data ever collected in the world (˜ 240pb--1 ) at s = 510 GeV with a beam polarization of 56%. The analysis techniques used to extract the signal from the data and the longitudinal single spin asymmetries AL in RHIC 2013 run will be discussed.

  19. Measurement of the parity-violating longitudinal single-spin asymmetry for W± boson production in polarized proton-proton collisions at sqrt[s] = 500 GeV.

    PubMed

    Aggarwal, M M; Ahammed, Z; Alakhverdyants, A V; Alekseev, I; Alford, J; Anderson, B D; Anson, C D; Arkhipkin, D; Averichev, G S; Balewski, J; Beavis, D R; Bellwied, R; Betancourt, M J; Betts, R R; Bhasin, A; Bhati, A K; Bichsel, H; Bielcik, J; Bielcikova, J; Biritz, B; Bland, L C; Borowski, W; Bouchet, J; Braidot, E; Brandin, A V; Bridgeman, A; Brovko, S G; Bruna, E; Bueltmann, S; Bunzarov, I; Burton, T P; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Cebra, D; Cendejas, R; Cervantes, M C; Chajecki, Z; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, J Y; Cheng, J; Cherney, M; Chikanian, A; Choi, K E; Christie, W; Chung, P; Codrington, M J M; Corliss, R; Cramer, J G; Crawford, H J; Dash, S; Davila Leyva, A; De Silva, L C; Debbe, R R; Dedovich, T G; Derevschikov, A A; Derradi de Souza, R; Didenko, L; Djawotho, P; Dogra, S M; Dong, X; Drachenberg, J L; Draper, J E; Dunlop, J C; Dutta Mazumdar, M R; Efimov, L G; Elnimr, M; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Eun, L; Evdokimov, O; Fatemi, R; Fedorisin, J; Fersch, R G; Finch, E; Fine, V; Fisyak, Y; Gagliardi, C A; Gangadharan, D R; Ganti, M S; Geromitsos, A; Geurts, F; Ghosh, P; Gorbunov, Y N; Gordon, A; Grebenyuk, O; Grosnick, D; Guertin, S M; Gupta, A; Guryn, W; Haag, B; Hamed, A; Han, L-X; Harris, J W; Hays-Wehle, J P; Heinz, M; Heppelmann, S; Hirsch, A; Hjort, E; Hoffmann, G W; Hofman, D J; Huang, B; Huang, H Z; Humanic, T J; Huo, L; Igo, G; Jacobs, P; Jacobs, W W; Jena, C; Jin, F; Joseph, J; Judd, E G; Kabana, S; Kang, K; Kapitan, J; Kauder, K; Keane, D; Kechechyan, A; Kettler, D; Kikola, D P; Kiryluk, J; Kisiel, A; Kizka, V; Klein, S R; Knospe, A G; Kocoloski, A; Koetke, D D; Kollegger, T; Konzer, J; Koralt, I; Koroleva, L; Korsch, W; Kotchenda, L; Kouchpil, V; Kravtsov, P; Krueger, K; Krus, M; Kumar, L; Kurnadi, P; Lamont, M A C; Landgraf, J M; LaPointe, S; Lauret, J; Lebedev, A; Lednicky, R; Lee, C-H; Lee, J H; Leight, W; LeVine, M J; Li, C; Li, L; Li, N; Li, W; Li, X; Li, X; Li, Y; Li, Z M; Lisa, M A; Liu, F; Liu, H; Liu, J; Ljubicic, T; Llope, W J; Longacre, R S; Love, W A; Lu, Y; Lukashov, E V; Luo, X; Ma, G L; Ma, Y G; Mahapatra, D P; Majka, R; Mall, O I; Mangotra, L K; Manweiler, R; Margetis, S; Markert, C; Masui, H; Matis, H S; Matulenko, Yu A; McDonald, D; McShane, T S; Meschanin, A; Milner, R; Minaev, N G; Mioduszewski, S; Mischke, A; Mitrovski, M K; Mohanty, B; Mondal, M M; Morozov, B; Morozov, D A; Munhoz, M G; Naglis, M; Nandi, B K; Nayak, T K; Netrakanti, P K; Ng, M J; Nogach, L V; Nurushev, S B; Odyniec, G; Ogawa, A; Ohlson, A; Okorokov, V; Oldag, E W; Olson, D; Pachr, M; Page, B S; Pal, S K; Pandit, Y; Panebratsev, Y; Pawlak, T; Peitzmann, T; Perkins, C; Peryt, W; Phatak, S C; Pile, P; Planinic, M; Ploskon, M A; Pluta, J; Plyku, D; Poljak, N; Poskanzer, A M; Potukuchi, B V K S; Powell, C B; Prindle, D; Pruneau, C; Pruthi, N K; Pujahari, P R; Putschke, J; Qiu, H; Raniwala, R; Raniwala, S; Ray, R L; Redwine, R; Reed, R; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Rose, A; Ruan, L; Sakai, S; Sakrejda, I; Sakuma, T; Salur, S; Sandweiss, J; Sangaline, E; Schambach, J; Scharenberg, R P; Schmah, A M; Schmitz, N; Schuster, T R; Seele, J; Seger, J; Selyuzhenkov, I; Seyboth, P; Shahaliev, E; Shao, M; Sharma, M; Shi, S S; Sichtermann, E P; Simon, F; Singaraju, R N; Skoby, M J; Smirnov, N; Sorensen, P; Spinka, H M; Srivastava, B; Stanislaus, T D S; Staszak, D; Stevens, J R; Stock, R; Strikhanov, M; Stringfellow, B; Suaide, A A P; Suarez, M C; Subba, N L; Sumbera, M; Sun, X M; Sun, Y; Sun, Z; Surrow, B; Svirida, D N; Symons, T J M; Szanto de Toledo, A; Takahashi, J; Tang, A H; Tang, Z; Tarini, L H; Tarnowsky, T; Thein, D; Thomas, J H; Tian, J; Timmins, A R; Timoshenko, S; Tlusty, D; Tokarev, M; Trainor, T A; Tram, V N; Trentalange, S; Tribble, R E; Tsai, O D; Ullrich, T; Underwood, D G; Van Buren, G; van Leeuwen, M; van Nieuwenhuizen, G; Vanfossen, J A; Varma, R; Vasconcelos, G M S; Vasiliev, A N; Videbæk, F; Viyogi, Y P; Vokal, S; Voloshin, S A; Wada, M; Walker, M; Wang, F; Wang, G; Wang, H; Wang, J S; Wang, Q; Wang, X L; Wang, Y; Webb, G; Webb, J C; Westfall, G D; Whitten, C; Wieman, H; Wissink, S W; Witt, R; Wu, Y F; Xie, W; Xu, H; Xu, N; Xu, Q H; Xu, W; Xu, Y; Xu, Z; Xue, L; Yang, Y; Yepes, P; Yip, K; Yoo, I-K; Yue, Q; Zawisza, M; Zbroszczyk, H; Zhan, W; Zhang, J B; Zhang, S; Zhang, W M; Zhang, X P; Zhang, Y; Zhang, Z P; Zhao, J; Zhong, C; Zhou, W; Zhu, X; Zhu, Y H; Zoulkarneev, R; Zoulkarneeva, Y

    2011-02-11

    We report the first measurement of the parity-violating single-spin asymmetries for midrapidity decay positrons and electrons from W+ and W- boson production in longitudinally polarized proton-proton collisions at sqrt[s] = 500 GeV by the STAR experiment at RHIC. The measured asymmetries, A(L)(W+) = -0.27 ± 0.10(stat.) ± 0.02(syst.) ± 0.03(norm.) and A(L)(W-) = 0.14 ± 0.19(stat.) ± 0.02(syst.) ± 0.01(norm.), are consistent with theory predictions, which are large and of opposite sign. These predictions are based on polarized quark and antiquark distribution functions constrained by polarized deep-inelastic scattering measurements. PMID:21405460

  20. Switchable single-longitudinal-mode dual-wavelength erbium-doped fiber ring laser based on one polarization-maintaining fiber Bragg grating incorporating saturable absorber and feedback fiber loop

    NASA Astrophysics Data System (ADS)

    Feng, Suchun; Xu, Ou; Lu, Shaohua; Ning, Tigang; Jian, Shuisheng

    2009-06-01

    Switchable single-longitudinal-mode (SLM) dual-wavelength erbium-doped fiber ring laser based on one polarization-maintaining fiber Bragg grating (PMFBG) is demonstrated. Due to the enhancement of the polarization hole burning (PHB) by the PMFBG, the laser can be designed to operate in stable dual-wavelength or wavelength-switching modes with a wavelength spacing of 0.336 nm at room temperature by adjusting a polarization controller (PC). The stable SLM operation is guaranteed by a compound-ring cavity and a saturable absorber (SA). The optical signal-to-noise ratio (OSNR) is over 45 dB. The amplitude variation in nearly one and half an hour is less than 0.2 dB.

  1. Stimulated-Brillouin-scattering-suppressed high-power single-frequency polarization-maintaining Raman fiber amplifier with longitudinally varied strain for laser guide star.

    PubMed

    Zhang, Lei; Hu, Jinmeng; Wang, Jianhua; Feng, Yan

    2012-11-15

    An up to 44 W, 1 MHz linewidth, 1178 nm CW laser is obtained by Raman amplification of a distributed feedback diode laser in a variably strained polarization-maintaining fiber with a record-high optical efficiency of 52%, pumped by a linearly polarized 1120 nm fiber laser. A polarization extinction ratio of 30 dB is achieved due to the all-polarization-maintaining configuration and the polarization dependence of Raman gain. The strain distribution is designed according to the signal power evolution along the fiber. A 20 times reduction in the effective stimulated Brillouin scattering coefficient is achieved. A 24.3 W 589 nm laser is generated by an external resonant doubling cavity with an optical efficiency of 68.5%. The laser is locked to 589.1591 nm for a laser guide star. PMID:23164917

  2. Rich eight-branch spectrum of the oblique propagating longitudinal waves in partially spin-polarized electron-positron-ion plasmas

    NASA Astrophysics Data System (ADS)

    Andreev, Pavel A.; Iqbal, Z.

    2016-03-01

    We consider the separate spin evolution of electrons and positrons in electron-positron and electron-positron-ion plasmas. We consider the oblique propagating longitudinal waves in these systems. Working in a regime of high-density n0˜1027cm-3 and high-magnetic-field B0=1010 G, we report the presence of the spin-electron acoustic waves and their dispersion dependencies. In electron-positron plasmas, similarly to the electron-ion plasmas, we find one spin-electron acoustic wave (SEAW) at the propagation parallel or perpendicular to the external field and two spin-electron acoustic waves at the oblique propagation. At the parallel or perpendicular propagation of the longitudinal waves in electron-positron-ion plasmas, we find four branches: the Langmuir wave, the positron-acoustic wave, and a pair of waves having spin nature, they are the SEAW and the wave discovered in this paper, called the spin-electron-positron acoustic wave (SEPAW). At the oblique propagation we find eight longitudinal waves: the Langmuir wave, the Trivelpiece--Gould wave, a pair of positron-acoustic waves, a pair of SEAWs, and a pair of SEPAWs. Thus, for the first time, we report the existence of the second positron-acoustic wave existing at the oblique propagation and the existence of SEPAWs.

  3. Polarization phenomena in quantum chromodynamics

    SciTech Connect

    Brodsky, S.J.

    1994-03-01

    The author discusses a number of interrelated hadronic spin effects which test fundamental features of perturbative and non-perturbative QCD. For example, the anomalous magnetic moment of the proton and the axial coupling g{sub A} on the nucleon are shown to be related to each other for fixed proton radius, independent of the form of the underlying three-quark relativistic quark wavefunction. The renormalization scale and scheme ambiguities for the radiative corrections to the Bjorken sum rule for the polarized structure functions can be eliminated by using commensurate scale relations with other observables. Other examples include (a) new constraints on the shape and normalization of the polarized quark and gluon structure functions of the proton at large and small x{sub bj}; (b) consequences of the principle of hadron helicity retention in high x{sub F} inclusive reactions; (c) applications of hadron helicity conservation to high momentum transfer exclusive reactions; and (d) the dependence of nuclear structure functions and shadowing on virtual photon polarization. He also discusses the implications of a number of measurements which are in striking conflict with leading-twist perturbative QCD predictions, such as the extraordinarily large spin correlation A{sub NN} observed in large angle proton-proton scattering, the anomalously large {rho}{pi} branching ratio of the J/{psi}, and the rapidly changing polarization dependence of both J/{psi} and continuum lepton pair hadroproduction observed at large x{sub F}. The azimuthal angular dependence of the Drell-Yan process is shown to be highly sensitive to the projectile distribution amplitude, the fundamental valence light-cone wavefunction of the hadron.

  4. Transversely polarized source cladding for an optical fiber

    NASA Technical Reports Server (NTRS)

    Egalon, Claudio Oliveira (Inventor); Rogowski, Robert S. (Inventor)

    1994-01-01

    An optical fiber comprising a fiber core having a longitudinal symmetry axis is provided. An active cladding surrounds a portion of the fiber core and comprises light-producing sources which emit light in response to chemical or light excitation. The cladding sources are oriented transversely with respect to the longitudinal axis of the fiber core. This polarization results in a superior power efficiency compared to active cladding sources that are randomly polarized or longitudinally polarized parallel with the longitudinal symmetry axis.

  5. Polarization at the SLC

    SciTech Connect

    Moffeit, K.C.

    1988-10-01

    The Stanford Linear collider was designed to accommodate polarized electron beams. Longitudinally polarized electrons colliding with unpolarized positrons at a center of mass energy near the Z/sup 0/ mass can be used as novel and sensitive probes of the electroweak process. A gallium arsenide based photon emission source will provide a beam of longitudinally polarized electrons of about 45 percent polarization. A system of bend magnets and a superconducting solenoid will be used to rotate the spins so that the polarization is preserved while the 1.21 GeV electrons are stored in the damping ring. Another set of bend magnets and two superconducting solenoids orient the spin vectors so that longitudinal polarization of the electrons is achieved at the collision point with the unpolarized positrons. A system to monitor the polarization based on Moller and Compton scattering will be used. Nearly all major components have been fabricated and tested. Subsystems of the source and polarimeters have been installed, and studies are in progress. The installation and commissioning of the entire system will take place during available machine shutdown periods as the commissioning of SLC progresses. 8 refs., 16 figs., 1 tab.

  6. Gluon polarization in the proton: Constraints at low x from the measurement of the double longitudinal spin asymmetry for forward-rapidity hadrons with the PHENIX detector at RHIC

    NASA Astrophysics Data System (ADS)

    McKinney, Cameron Palmer

    In the 1980s, polarized deep inelastic lepton-nucleon scattering experiments revealed that only about a third of the proton's spin of ½ h is carried by the quarks and antiquarks, leaving physicists with the puzzle of how to account for the remaining spin. As gluons carry roughly 50% of the proton's momentum, it seemed most logical to look to the gluon spin as another significant contributor. However, lepton-nucleon scattering experiments only access the gluon helicity distribution, Delta g, through effects on the quark distributions via scaling violations. Constraining Deltag through scaling violations requires experiments that together cover a large range of Q 2. Such experiments had been carried out with unpolarized beams, leaving g(x) (the unpolarized gluon distribution) relatively well-known, but the polarized experiments have only thus far provided weak constraints on Deltag in a limited momentum fraction range. With the commissioning in 2000 of the Relativistic Heavy Ion Collider, the first polarized proton-proton (pp) collider, and the first polarized pp running in 2002, the gluon distributions could be accessed directly by studying quark-gluon and gluon-gluon interactions. In 2009, data from measurements of double longitudinal spin asymmetries, ALL, at the STAR and PHENIX experiments through 2006 were included in a QCD global analysis performed by Daniel de Florian, Rodolfo Sassot, Marco Stratmann, and Werner Vogelsang (DSSV), yielding the first direct constraints on the gluon helicity. The DSSV group found that the contribution of the gluon spin to the proton spin was consistent with zero, but the data provided by PHENIX and STAR was all at mid-rapidity, meaning Delta g was constrained by data only a range in x from 0.05 to 0.2, leaving out helicity contributions from the huge number of low- x gluons. A more recent analysis by DSSV from 2014 including RHIC data through 2009 for the first time points to significant gluon polarization at intermediate

  7. GUIDE FOR POLARIZED NEUTRONS

    DOEpatents

    Sailor, V.L.; Aichroth, R.W.

    1962-12-01

    The plane of polarization of a beam of polarized neutrons is changed by this invention, and the plane can be flipped back and forth quicitly in two directions in a trouble-free manner. The invention comprises a guide having a plurality of oppositely directed magnets forming a gap for the neutron beam and the gaps are spaced longitudinally in a spiral along the beam at small stepped angles. When it is desired to flip the plane of polarization the magnets are suitably rotated to change the direction of the spiral of the gaps. (AEC)

  8. Polarized proton beams in RHIC

    SciTech Connect

    Zelenski, A.

    2010-10-04

    The polarized beam for RHIC is produced in the optically-pumped polarized H{sup -} ion source and then accelerated in Linac to 200 MeV for strip-injection to Booster and further accelerated 24.3 GeV in AGS for injection in RHIC. In 2009 Run polarized protons was successfully accelerated to 250 GeV beam energy. The beam polarization of about 60% at 100 GeV beam energy and 36-42% at 250 GeV beam energy was measured with the H-jet and p-Carbon CNI polarimeters. The gluon contribution to the proton spin was studied in collisions of longitudinally polarized proton beams at 100 x 100 GeV. At 250 x 250 GeV an intermediate boson W production with the longitudinally polarized beams was studied for the first time.

  9. RHIC Polarized proton operation

    SciTech Connect

    Huang, H.; Ahrens, L.; Alekseev, I.G.; Aschenauer, E.; Atoian, G.; Bai, M.; Bazilevsky, A.; Blaskiewicz, M.; Brennan, J.M.; Brown, K.A.; Bruno, D.; Connolly, R.; Dion, A.; D'Ottavio, T.; Drees, K.A.; Fischer, W.; Gardner, C.; Glenn, J.W.; Gu, X.; Harvey, M.; Hayes, T.; Hoff, L.; Hulsart, R.L.; Laster, J.; Liu, C.; Luo, Y.; MacKay, W.W.; Makdisi, Y.; Marr, G.J.; Marusic, A.; Meot, F.; Mernick, K.; Michnoff, R,; Minty, M.; Montag, C.; Morris, J.; Nemesure, S.; Poblaguev, A.; Ptitsyn, V.; Ranjibar, V.; Robert-Demolaize, G.; Roser, T.; J.; Severino, F.; Schmidke, B.; Schoefer, V.; Severino, F.; Smirnov, D.; Smith, K.; Steski, D.; Svirida, D.; Tepikian, S.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J. Wang, G.; Wilinski, M.; Yip, K.; Zaltsman, A.; Zelenski, A.; Zeno, K.; Zhang, S.Y.

    2011-03-28

    The Relativistic Heavy Ion Collider (RHIC) operation as the polarized proton collider presents unique challenges since both luminosity(L) and spin polarization(P) are important. With longitudinally polarized beams at the experiments, the figure of merit is LP{sup 4}. A lot of upgrades and modifications have been made since last polarized proton operation. A 9 MHz rf system is installed to improve longitudinal match at injection and to increase luminosity. The beam dump was upgraded to increase bunch intensity. A vertical survey of RHIC was performed before the run to get better magnet alignment. The orbit control is also improved this year. Additional efforts are put in to improve source polarization and AGS polarization transfer efficiency. To preserve polarization on the ramp, a new working point is chosen such that the vertical tune is near a third order resonance. The overview of the changes and the operation results are presented in this paper. Siberian snakes are essential tools to preserve polarization when accelerating polarized beams to higher energy. At the same time, the higher order resonances still can cause polarization loss. As seen in RHIC, the betatron tune has to be carefully set and maintained on the ramp and during the store to avoid polarization loss. In addition, the orbit control is also critical to preserve polarization. The higher polarization during this run comes from several improvements over last run. First we have a much better orbit on the ramp. The orbit feedback brings down the vertical rms orbit error to 0.1mm, much better than the 0.5mm last run. With correct BPM offset and vertical realignment, this rms orbit error is indeed small. Second, the jump quads in the AGS improved input polarization for RHIC. Third, the vertical tune was pushed further away from 7/10 snake resonance. The tune feedback maintained the tune at the desired value through the ramp. To calibrate the analyzing power of RHIC polarimeters at any energy above

  10. HERMES measurements of {lambda} polarization

    SciTech Connect

    Rith, Klaus

    2007-06-13

    The HERMES experiment at DESY has measured the transfer of polarization from longitudinally polarized 27.6 GeV positrons to {lambda} hyperons produced in semi-inclusive deep-inelastic scattering from unpolarized gas targets internal to the electron/positron ring of the HERA collider. The longitudinal spin transfer coefficient is found to be D{sub LL'}{sup {lambda}} = 0.11 {+-} 0.10 (stat) {+-} 0.03 (syst) at an average fractional energy carried by the {lambda} hyperon = 0.45.

  11. PEPPo: Using a Polarized Electron Beam to Produce Polarized Positrons

    SciTech Connect

    Adeyemi, Adeleke H.

    2015-09-01

    Polarized positron beams have been identified as either an essential or a significant ingredient for the experimental program of both the present and next generation of lepton accelerators (JLab, Super KEK B, ILC, CLIC). An experiment demonstrating a new method for producing polarized positrons has been performed at the Continuous Electron Beam Accelerator Facility at Jefferson Lab. The PEPPo (Polarized Electrons for Polarized Positrons) concept relies on the production of polarized e⁻/e⁺ pairs from the bremsstrahlung radiation of a longitudinally polarized electron beam interacting within a high-Z conversion target. PEPPo demonstrated the effective transfer of spin-polarization of an 8.2 MeV/c polarized (P~85%) electron beam to positrons produced in varying thickness tungsten production targets, and collected and measured in the range of 3.1 to 6.2 MeV/c. In comparison to other methods this technique reveals a new pathway for producing either high-energy or thermal polarized positron beams using a relatively low polarized electron beam energy (~10MeV) .This presentation will describe the PEPPo concept, the motivations of the experiment and high positron polarization achieved.

  12. Longitudinal spin fluctuations in nickel

    SciTech Connect

    Boeni, P. , Villigen ); Martinez, J.L. ); Tranquada, J.M. )

    1989-10-10

    The longitudinal and transverse spin fluctuations in Ni have been measured below {Tc} by means of polarized neutron scattering in the momentum range 0.06 < q < 0.18 {angstrom}{sup -1}. In transverse scans spin wave peaks at E{sub q} = Dq{sup 2} appear as expected from early measurements performed with unpolarized neutrons. The longitudinal magnetic scattering {sub {chi}L}(q, E), on the other hand, is quasielastic without any signature of inelastic peaks near E{sub q}. The q and T dependences of {sub {chi}L}(q, E) resemble the paramagnetic scattering above {Tc}, i.e., the linewidth is roughly proportional to q{sup 2.5} and the integrated intensity I(q) is proportional to (q{sup 2} + {kappa}{sub z}{sup 2}){sup -1}. 8 refs., 3 figs.

  13. Recoil-Proton Polarization in High-Energy Deuteron Photodisintegration with Circularly Polarized Photons

    SciTech Connect

    Jiang, X.; Benmokhtar, F.; Glashauser, C.; McCormick, K.; Ransome, R. D.; Arrington, J.; Holt, R. J.; Reimer, P. E.; Schulte, E. C.; Wijesooriya, K.; Camsonne, A.

    2007-05-04

    We measured the angular dependence of the three recoil-proton polarization components in two-body photodisintegration of the deuteron at a photon energy of 2 GeV. These new data provide a benchmark for calculations based on quantum chromodynamics. Two of the five existing models have made predictions of polarization observables. Both explain the longitudinal polarization transfer satisfactorily. Transverse polarizations are not well described, but suggest isovector dominance.

  14. Recoil-Proton Polarization in High-Energy Deuteron Photodisintegration with Circularly Polarized Photons

    SciTech Connect

    X. Jiang; J. Arrington; F. Benmokhtar; A. Camsonne; J. P. Chen; S. Choi; E. Chudakov; F. Cusanno; A. Deur; D. Dutta; F. Garibaldi; D. Gaskell; O. Gayou; R. Gilman; C. Glashauser; D. Hamilton; O. Hansen; D. W. Higinbotham; R. J. Holt; C. W. de Jager; M. K. Jones; L. J. Kaufman; E. R. Kinney; K. Kramer; L. Lagamba; R. de Leo; J. Lerose; D. Lhuillier; R. Lindgren; N. Liyanage; K. McCormick; Z.-E. Meziani; R. Michaels; B. Moffit; P. Monaghan; S. Nanda; K. D. Paschke; C. F. Perdrisat; V. Punjabi; I. A. Qattan; R. D. Ransome; P. E. Reimer; B. Reitz; A. Saha; E. C. Schulte; R. Sheyor; K. Slifer; P. Solvignon; V. Sulkosky; G. M. Urciuoli; E. Voutier; K. Wang; K. Wijesooriya; B. Wojtsekhowski; and L. Zhu

    2007-05-01

    We measured the angular dependence of the three recoil-proton polarization components in two-body photodisintegration of the deuteron at a photon energy of 2 GeV. These new data provide a benchmark for calculations based on quantum chromodynamics. Two of the five existing models have made predictions of polarization observables. Both explain the longitudinal polarization transfer satisfactorily. Transverse polarizations are not well described, but suggest isovector dominance.

  15. Ion polarization in the MEIC figure-8 ion collider ring

    SciTech Connect

    V.S. Morozov, Ya.S. Derbenev, Y. Zhang, P. Chevtsov, A.M. Kondratenko, M.A. Kondratenko, Yu.N. Filatov

    2012-07-01

    The nuclear physics program envisaged at the Medium-energy Electron-Ion Collider (MEIC) currently being developed at the Jefferson Lab calls for collisions of 3-11 GeV/c longitudinally polarized electrons and 20-100 GeV/c, in equivalent proton momentum, longitudinally/ transversely polarized protons/ deuterons/ light ions. We present a scheme that provides the required ion polarization arrangement in the MEIC's ion collider ring.

  16. Baryon Spectroscopy with Polarization Observables from CLAS

    NASA Astrophysics Data System (ADS)

    Strauch, Steffen

    2016-06-01

    The spectrum of nucleon excitations is dominated by broad and overlapping resonances. Polarization observables in photoproduction reactions are key in the study of these excitations. They give indispensable constraints to partial-wave analyses and help clarify the spectrum. A series of polarized photoproduction experiments have been performed at the Thomas Jefferson National Accelerator Facility with the CEBAF Large Acceptance Spectrometer. These measurements include data with linearly and circularly polarized tagged-photon beams, longitudinally and transversely polarized proton and deuterium targets, and recoil polarizations through the observation of the weak decay of hyperons. An overview of these studies and recent results will be given.

  17. Primary aberrations in focused radially polarized vortex beams

    NASA Astrophysics Data System (ADS)

    Biss, David P.; Brown, T. G.

    2004-02-01

    We study the effect of primary aberrations on the 3-D polarization of the electric field in a focused lowest order radially polarized beam. A full vector diffraction treatment of the focused beams is used. Attention is given to the effects of primary spherical, astigmatic, and comatic aberrations on the local polarization, Strehl ratio, and aberration induced degradation of the longitudinal field at focus

  18. LAMBDA Polarization with a Transversely Polarized Proton Target at the COMPASS Experiment

    SciTech Connect

    Negrini, Teresa

    2009-08-04

    The transverse polarization of LAMBDA and LAMBDA-bar hyperons is investigated at the COMPASS experiment at CERN. In 2007 a 160 GeV/c longitudinally polarized muon beam and a transversely polarized NH{sub 3} target were employed to study events in semi-inclusive deep-inelastic scattering. Preliminary results for the LAMBDA and LAMBDA-bar polarizations extracted from this new data set are presented as a function of x{sub Bj} and z. The polarizations of LAMBDA and LAMBDA-bar are compatible with zero within their error bars and no dependence on x{sub Bj} or z is observed.

  19. Measurement of transverse {lambda} and {lambda}-bar polarization at COMPASS

    SciTech Connect

    Ferrero, A.

    2007-06-13

    New data on hyperon polarization in semi-inclusive deep inelastic scattering have been collected by the COMPASS collaboration at CERN during the years 2002-2004, using a beam of longitudinally polarized muons of 160 GeV/c and a 6LiD target that can be polarized both longitudinally and transversely. The various combinations of beam and target polarizations allow for the study of a wide variety of hyperon polarization effects. Here we present preliminary results on the transverse polarization of {lambda} and {lambda}-bar produced both with unpolarized and transversely polarized deuteron targets.

  20. Restoration of longitudinal images.

    PubMed

    Hu, Y; Frieden, B R

    1988-01-15

    In this paper, a method of restoring longitudinal images is developed. By using the transfer function for longitudinal objects, and inverse filtering, a longitudinal image may be restored. The Fourier theory and sampling theorems for transverse images cannot be used directly in the longitudinal case. A modification and reasonable approximation are introduced. We have numerically established a necessary relationship between just-resolved longitudinal separation (after inverse filtering), noise level, and the taking conditions of object distance and lens diameter. An empirical formula is also found to well-fit the computed results. This formula may be of use for designing optical systems which are to image longitudinal details, such as in robotics or microscopy. PMID:20523607

  1. Polarization developments

    SciTech Connect

    Prescott, C.Y.

    1993-07-01

    Recent developments in laser-driven photoemission sources of polarized electrons have made prospects for highly polarized electron beams in a future linear collider very promising. This talk discusses the experiences with the SLC polarized electron source, the recent progress with research into gallium arsenide and strained gallium arsenide as a photocathode material, and the suitability of these cathode materials for a future linear collider based on the parameters of the several linear collider designs that exist.

  2. Neuronal polarization.

    PubMed

    Takano, Tetsuya; Xu, Chundi; Funahashi, Yasuhiro; Namba, Takashi; Kaibuchi, Kozo

    2015-06-15

    Neurons are highly polarized cells with structurally and functionally distinct processes called axons and dendrites. This polarization underlies the directional flow of information in the central nervous system, so the establishment and maintenance of neuronal polarization is crucial for correct development and function. Great progress in our understanding of how neurons establish their polarity has been made through the use of cultured hippocampal neurons, while recent technological advances have enabled in vivo analysis of axon specification and elongation. This short review and accompanying poster highlight recent advances in this fascinating field, with an emphasis on the signaling mechanisms underlying axon and dendrite specification in vitro and in vivo. PMID:26081570

  3. Polarization Aberrations

    NASA Technical Reports Server (NTRS)

    Mcguire, James P., Jr.; Chipman, Russell A.

    1990-01-01

    The analysis of the polarization characteristics displayed by optical systems can be divided into two categories: geometrical and physical. Geometrical analysis calculates the change in polarization of a wavefront between pupils in an optical instrument. Physical analysis propagates the polarized fields wherever the geometrical analysis is not valid, i.e., near the edges of stops, near images, in anisotropic media, etc. Polarization aberration theory provides a starting point for geometrical design and facilitates subsequent optimization. The polarization aberrations described arise from differences in the transmitted (or reflected) amplitudes and phases at interfaces. The polarization aberration matrix (PAM) is calculated for isotropic rotationally symmetric systems through fourth order and includes the interface phase, amplitude, linear diattenuation, and linear retardance aberrations. The exponential form of Jones matrices used are discussed. The PAM in Jones matrix is introduced. The exact calculation of polarization aberrations through polarization ray tracing is described. The report is divided into three sections: I. Rotationally Symmetric Optical Systems; II. Tilted and Decentered Optical Systems; and Polarization Analysis of LIDARs.

  4. Opportunities with polarized beam & target

    NASA Astrophysics Data System (ADS)

    Miyachi, Yoshiyuki

    2014-09-01

    Single spin asymmetries in Drell-Yan (DY) scattering, which are going to be measured in the present and planned polarized DY experiments, gain further insight into the internal structure of the nucleon. For the novel Sivers distribution function, the possible sign change in DY and Semi-Inclusive Deep-Inelastic-Scattering (SIDIS) may be confirmed for the first time, which is a critical test of the transverse momentum dependent (TMD) factorization in QCD, and precise information on the sea quarks, which are less sensitive in DIS, will be obtained. Since DY is one of the cleanest hard scattering processes, where no hadron fragmentation involved, it does not require information on hadron fragmentation functions (FF) to extract TMD PDF from the observed azimuthal amplitudes, where TMD PDF appears along with a corresponding FF in the case of SIDIS. Various azimuthal amplitudes of un-polarized cross section and singly-polarized or doubly-polarized cross section asymmetries in SIDIS have been measured. Double spin asymmetry in DY where beam and target are polarized is another unique tool to study TMD PDFs directly and it is a complementary measurement to SIDIS toward the complete description of the nucleon. Single spin asymmetries of the W-production cross section in the polarized proton-proton collision, recently measured at the RHIC/spin program, indicate the possible quark flavor symmetry violation in the polarized light-sea. Similar flavor asymmetry in the un-polarized light-sea, known as violation of the Gottfried sum rule, is currently studied at the on-going DY experiment SeaQuest at Fermilab. The observed flavor asymmetries can be a key to understand non-perturbative structure of the nucleon. With double spin asymmetry measurements in longitudinally polarized DY the flavor asymmetry in the polarized sea can be confirmed. In the presentation, physics cases which can be studied in doubly polarized DY and related topics will be discussed.

  5. Longitudinal Double Spin Asymmetry and Cross Section for Direct Photon Production Measured at Mid-rapidity in Polarized {radical}(s) = 200 GeV pp Collisions at PHENIX

    SciTech Connect

    Bennett, Robert

    2009-08-04

    Direct photon production in pp collisions at RHIC is one of the important channels PHENIX will employ to determine the polarized gluon distribution {delta}G. The direct photon A{sub LL} is linear in {delta}G, therefore sensitive to its sign and magnitude. To establish the applicability of perturbative Quantum Chromodynamics (pQCD) to this process, we present a comparison of the direct photon unpolarized cross section, with next-to-leading order pQCD calculations. We then evaluate the double helicity spin asymmetries, A{sub LL}, from these data and compare with theoretical models. We present results and the current status the analysis of 2005 and 2006 data sets.

  6. Determination of the Linear Polarization of the Hall-B Tagged Photon Beam at Jefferson Lab

    SciTech Connect

    Sabintsev, A. A.; Livingston, K.

    2011-10-24

    The JLab CLAS g9a/FROST experiments are double polarization measurements that have accumulated photo-production data using linearly polarized, tagged photons incident on a longitudinally polarized, frozen spin butanol target. The analysis of the resulting coherent peaks was used to determine the photon polarization, which is in agreement with phenomenological calculations.

  7. Determination of the linear polarization of the Hall-B tagged photon beam at Jefferson Lab

    SciTech Connect

    A.A. Sabintsev, K. Livingston

    2011-10-01

    The JLab CLAS g9a/FROST experiments are double polarization measurements that have accumulated photo-production data using linearly polarized, tagged photons incident on a longitudinally polarized, frozen spin butanol target. The analysis of the resulting coherent peaks was used to determine the photon polarization, which is in agreement with phenomenological calculations.

  8. Polar Bear

    USGS Publications Warehouse

    Amstrup, S.D.; DeMaster

    1988-01-01

    Polar bears are long-lived, late-maturing carnivores that have relatively low rates of reproduction and natural mortality. Their populations are susceptible to disturbance from human activities, such as the exploration and development of mineral resources or hunting. Polar bear populations have been an important renewable resource available to coastal communities throughout the Arctic for thousands of years.

  9. Polarized rainbow.

    PubMed

    Können, G P; de Boer, J H

    1979-06-15

    The Airy theory of the rainbow is extended to polarized light. For both polarization directions a simple analytic expression is obtained for the intensity distribution as a function of the scattering angle in terms of the Airy function and its derivative. This approach is valid at least down to droplet diameters of 0.3 mm in visible light. The degree of polarization of the rainbow is less than expected from geometrical optics; it increases with droplet size. For a droplet diameter >1 mm the locations of the supernumerary rainbows are equal for both polarization directions, but for a diameter <1 mm the supernumerary rainbows of the weaker polarization component are located between those in the strong component. PMID:20212586

  10. Longitudinal impedance of RHIC

    SciTech Connect

    Blaskiewicz, M.; Brennan, J. M.; Mernick, K.

    2015-05-03

    The longitudinal impedance of the two RHIC rings has been measured using the effect of potential well distortion on longitudinal Schottky measurements. For the blue RHIC ring Im(Z/n) = 1.5±0.2Ω. For the yellow ring Im(Z/n) = 5.4±1Ω.

  11. Longitudinal Multistage Testing

    ERIC Educational Resources Information Center

    Pohl, Steffi

    2013-01-01

    This article introduces longitudinal multistage testing (lMST), a special form of multistage testing (MST), as a method for adaptive testing in longitudinal large-scale studies. In lMST designs, test forms of different difficulty levels are used, whereas the values on a pretest determine the routing to these test forms. Since lMST allows for…

  12. BCVEGPY2.0: An upgraded version of the generator BCVEGPY with the addition of hadroproduction of the P-wave B states

    NASA Astrophysics Data System (ADS)

    Chang, Chao-Hsi; Wang, Jian-Xiong; Wu, Xing-Gang

    2006-02-01

    The generator BCVEGPY is upgraded by improving some of its features and by adding the hadroproduction of the P-wave excited B states (denoted by BcJ,L=1∗ or by hB_c and χB_c). In order to make the generator more efficient, we manipulate the amplitude as compact as possible with special effort. The correctness of the program is tested by various checks. We denote it as BCVEGPY2.0. As for the added part of the P-wave production, only the dominant gluon-gluon fusion mechanism ( gg→BcJ,L=1∗+c¯+b) is taken into account. Moreover, in the program, not only the ability to compute the contributions from the color-singlet components ( to the P-wave production but also the ability to compute the contributions from the color-octet components ( are available. With BCVEGPY2.0 the contributions from the two 'color components' to the production of each of the P-wave states may be computed separately by an option, furthermore, besides individually the event samples of the S-wave and P-wave ( cb¯)-heavy-quarkonium in various correct (realistic) mixtures can be generated by relevant options too. Program summaryTitle of program: BCVEGPY Version: 2.0 (December, 2004) Catalogue identifier: ADWQ Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADWQ Program obtained from: CPC Program Library, Queen's University of Belfast, N. Ireland Reference to original program: ADTJ (BCVEGPY1.0) Reference in CPC: Comput. Phys. Comm. 159 (2004) 192 Does the new version supersede the old program: yes Computer: Any computer with FORTRAN 77 or 90 compiler. The program has been tested on HP-SC45 Sigma-X parallel computer, Linux PCs and Windows PCs with Visual Fortran Operating systems: UNIX, Linux and Windows Programming language used: FORTRAN 77/90 Memory required to execute with typical data: About 2.0 MB No. of lines in distributed program, including test data, etc.: 124 297 No. of bytes in distributed program, including test data, etc.: 1 137 177 Distribution format: tar.g2 Nature of

  13. Polarization methods for diode laser excitation of solid state lasers

    DOEpatents

    Holtom, Gary R.

    2008-11-25

    A mode-locked laser employs a coupled-polarization scheme for efficient longitudinal pumping by reshaped laser diode bars. One or more dielectric polarizers are configured to reflect a pumping wavelength having a first polarization and to reflect a lasing wavelength having a second polarization. A Yb-doped gain medium can be used that absorbs light having a first polarization and emits light having a second polarization. Using such pumping with laser cavity dispersion control, pulse durations of less than 100 fs can be achieved.

  14. Polar Glaciology

    NASA Technical Reports Server (NTRS)

    Robin, G. D.

    1984-01-01

    Two fields of research on polar ice sheets are likely to be of dominant interest during the 1990s. These are: the role of polar ice sheets in the hydrological cycle ocean-atmosphere-ice sheets-oceans, especially in relation to climate change; and the study and interpretation of material in deep ice cores to provide improved knowledge of past climates and of the varying levels of atmospheric constituents such as CO2, NOx, SO2, aerosols, etc., over the past 200,000 years. Both topics require a better knowledge of ice dynamics. Many of the studies that should be undertaken in polar regions by Earth Observing System require similar instruments and techniques to those used elsewhere over oceans and inland surfaces. However to study polar regions two special requirements need to be met: Earth Observing System satellite(s) need to be in a sufficiently high inclination orbit to cover most of the polar regions. Instruments must also be adapted, often by relatively limited changes, to give satisfactory data over polar ice. The observational requirements for polar ice sheets in the 1990s are summarized.

  15. Geomagnetic polarity transitions

    NASA Astrophysics Data System (ADS)

    Merrill, Ronald T.; McFadden, Phillip L.

    1999-05-01

    reasonable to draw the following conclusions with varying degrees of confidence. There appears to be a substantial decrease in the mean intensity of the dipole field during a transition to ˜25% of its usual value. The duration of an average geomagnetic polarity transition is not well known but probably lies between 1000 and 8000 years. Values outside these bounds have been reported, but we give reasons as to why such outliers are likely to be artifacts. The reversal process is probably longer than the manifestation of the reversal at Earth's surface as recorded in paleomagnetic directional data. Convection hiatus during a geomagnetic polarity transition seems unlikely, and free-decay models for reversals appear to be generally incompatible with the data. This implies that certain theorems in dynamo theory, such as Cowling's theorem, should not be invoked to explain the origin of reversals. Unfortunately, the detailed description of directional changes during transitions remains controversial. Contrary to common belief, certain low-degree nondipole fields can produce significant longitudinal confinement of virtual geomagnetic poles (VGP) during a transition. The data are currently inadequate to refute or verify claims of longitudinal dipole confinement, VGP clustering, or other systematics during polarity transitions.

  16. Polarizing cues.

    PubMed

    Nicholson, Stephen P

    2012-01-01

    People categorize themselves and others, creating ingroup and outgroup distinctions. In American politics, parties constitute the in- and outgroups, and party leaders hold sway in articulating party positions. A party leader's endorsement of a policy can be persuasive, inducing co-partisans to take the same position. In contrast, a party leader's endorsement may polarize opinion, inducing out-party identifiers to take a contrary position. Using survey experiments from the 2008 presidential election, I examine whether in- and out-party candidate cues—John McCain and Barack Obama—affected partisan opinion. The results indicate that in-party leader cues do not persuade but that out-party leader cues polarize. This finding holds in an experiment featuring President Bush in which his endorsement did not persuade Republicans but it polarized Democrats. Lastly, I compare the effect of party leader cues to party label cues. The results suggest that politicians, not parties, function as polarizing cues. PMID:22400143

  17. Polar motion

    NASA Technical Reports Server (NTRS)

    Kolenkiewicz, R.

    1973-01-01

    Tracking of the Beacon Explorer-C satellite by a precision laser system was used to measure the polar motion and solid earth tide. The tidal perturbation of satellite latitude is plotted as variation in maximum latitude in seconds of arc on earth's surface as a function of the date, and polar motion is shown by plotting the variation in latitude of the laser in seconds of arc along the earth's surface as a function of date

  18. Recent Results from the Jet Longitudinal Spin Program at STAR

    SciTech Connect

    Igo, G.

    2009-03-23

    We report STAR's preliminary measurement of the inclusive jet longitudinal spin asymmetry A{sub LL} using data from the RHIC 2006 run. The 2006 data set was taken with 200 GeV polarized proton-proton collisions and represents 4.7 pb{sup -1} of data. Typical beam polarizations were {approx}55-60%. The data are compared with theoretical calculations of A{sub LL} based on various models of the polarized parton distribution functions in the nucleon. STAR inclusive jet A{sub LL} measurements from the RHIC 2005 run are also discussed.

  19. Measurement of Λ polarization from Z decays

    NASA Astrophysics Data System (ADS)

    Buskulic, D.; de Bonis, I.; Decamp, D.; Ghez, P.; Goy, C.; Lees, J.-P.; Lucotte, A.; Minard, M.-N.; Odier, P.; Pietrzyk, B.; Chmeissani, M.; Crespo, J. M.; Delfino, M.; Efthymiopoulos, I.; Fernandez, E.; Fernandez-Bosman, M.; Garrido, Ll.; Juste, A.; Martinez, M.; Orteu, S.; Pacheco, A.; Padilla, C.; Palla, F.; Pascual, A.; Perlas, J. A.; Riu, I.; Sanchez, F.; Teubert, F.; Colaleo, A.; Creanza, D.; de Palma, M.; Farilla, A.; Gelao, G.; Girone, M.; Iaselli, G.; Maggi, G.; Maggi, M.; Marinelli, N.; Natali, S.; Nuzzo, S.; Ranieri, A.; Raso, G.; Romano, F.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Huang, X.; Lin, J.; Ouyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Alemany, R.; Bazarko, A. O.; Bonvicini, G.; Cattaneo, M.; Comas, P.; Coyle, P.; Drevermann, H.; Forty, R. W.; Frank, M.; Hagelberg, R.; Harvey, J.; Jacobsen, R.; Janot, P.; Jost, B.; Kneringer, E.; Knobloch, J.; Lehraus, I.; Martin, E. B.; Mato, P.; Minten, A.; Miquel, R.; Mir, Ll. M.; Moneta, L.; Oest, T.; Palazzi, P.; Pater, J. R.; Pusztaszeri, J.-F.; Ranjard, F.; Rensing, P.; Rolandi, L.; Schlatter, D.; Schmelling, M.; Schneider, O.; Tejessy, W.; Tomalin, I. R.; Venturi, A.; Wachsmuth, H.; Wagner, A.; Wildish, T.; Witzeling, W.; Wotschack, J.; Ajlatouni, Z.; Barrès, A.; Boyer, C.; Falvard, A.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Monteil, S.; Montret, J.-C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Rossignol, J.-M.; Fearnley, T.; Hansen, J. B.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Nilsson, B. S.; Wäänänen, A.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Siotis, I.; Vayaki, A.; Zachariadou, K.; Blondel, A.; Bonneaud, G.; Brient, J. C.; Bourdon, P.; Rougé, A.; Rumpf, M.; Tanaka, R.; Valassi, A.; Verderi, M.; Videau, H.; Candlin, D. J.; Parsons, M. I.; Focardi, E.; Parrini, G.; Corden, M.; Georgiopoulos, C.; Jaffe, D. E.; Antonelli, A.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Casper, D.; Chiarella, V.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Passalacqua, L.; Pepe-Altarelli, M.; Curtis, L.; Dorris, S. J.; Halley, A. W.; Knowles, I. G.; Lynch, J. G.; O'Shea, V.; Raine, C.; Reeves, P.; Scarr, J. M.; Smith, K.; Thompson, A. S.; Thomson, F.; Thorn, S.; Turnbull, R. M.; Becker, U.; Geweniger, C.; Graefe, G.; Hanke, P.; Hansper, G.; Hepp, V.; Kluge, E. E.; Putzer, A.; Rensch, B.; Schmidt, M.; Sommer, J.; Stenzel, H.; Tittel, K.; Werner, S.; Wunsch, M.; Abbaneo, D.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Dornan, P. J.; Dornan, P. J.; Moutoussi, A.; Nash, J.; Sedgbeer, J. K.; Stacey, A. M.; Williams, M. D.; Dissertori, G.; Girtler, P.; Kuhn, D.; Rudolph, G.; Bowdery, C. K.; Brodbeck, T. J.; Colrain, P.; Crawford, G.; Finch, A. J.; Foster, F.; Hughes, G.; Sloan, T.; Whelan, E. P.; Williams, M. I.; Galla, A.; Greene, A. M.; Kleinknecht, K.; Quast, G.; Renk, B.; Rohne, E.; Sander, H.-G.; van Gemmeren, P.; Zeitnitz, C.; Aubert, J. J.; Bencheikh, A. M.; Benchouk, C.; Bonissent, A.; Bujosa, G.; Calvet, D.; Carr, J.; Diaconu, C.; Etienne, F.; Konstantinidis, N.; Nicod, D.; Payre, P.; Rousseau, D.; Talby, M.; Sadouki, A.; Thulasidas, M.; Trabelsi, K.; Abt, I.; Assmann, R.; Bauer, C.; Blum, W.; Dietl, H.; Dydak, F.; Ganis, G.; Gotzhein, C.; Jakobs, K.; Kroha, H.; Lütjens, G.; Lutz, G.; Männer, W.; Moser, H.-G.; Richter, R.; Rosado-Schlosser, A.; Schael, S.; Settles, R.; Seywerd, H.; Denis, R. St.; Wiedenmann, W.; Wolf, G.; Boucrot, J.; Callot, O.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, Ph.; Jacquet, M.; Kim, D. W.; Le Diberder, F.; Lefrançois, J.; Lutz, A.-M.; Nikolic, I.; Park, H. J.; Park, I. C.; Schune, M.-H.; Simion, S.; Veillet, J.-J.; Videau, I.; Azzurri, P.; Bagliesi, G.; Batignani, G.; Bettarini, S.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M. A.; Ciulli, V.; Dell'Orso, R.; Fantechi, R.; Ferrante, I.; Foà, L.; Forti, F.; Giassi, A.; Giorgi, M. A.; Gregorio, A.; Ligabue, F.; Lusiani, A.; Marrocchesi, P. S.; Messineo, A.; Rizzo, G.; Sanguinetti, G.; Sciabà, A.; Spagnolo, P.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Vannini, C.; Verdini, P. G.; Walsh, J.; Betteridge, A. P.; Blair, G. A.; Bryant, L. M.; Cerutti, F.; Chambers, J. T.; Gao, Y.; Green, M. G.; Johnson, D. L.; Medcalf, T.; Perrodo, P.; Strong, J. A.; von Wimmersperg-Toeller, J. H.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Haywood, S.; Maley, P.; Norton, P. R.; Thompson, J. C.; Wright, A. E.; Bloch-Devaux, B.; Colas, P.; Emery, S.; Kozanecki, W.; Lançon, E.; Lemaire, M. C.; Locci, E.; Marx, B.; Perez, P.; Rander, J.; Renardy, J.-F.; Roussarie, A.; Schuller, J.-P.; Schwindling, J.; Trabelsi, A.; Vallage, B.; Johnson, R. P.; Kim, H. Y.; Litke, A. M.; McNeil, M. A.; Taylor, G.; Beddall, A.; Booth, C. N.; Boswell, R.; Brew, C. A. J.; Cartwright, S.; Combley, F.; Koksal, A.; Letho, M.; Newton, W. M.; Rankin, C.; Reeve, J.; Thompson, L. F.; Böhrer, A.; Brandt, S.; Büscher, V.; Cowan, G.; Grupen, C.; Lutters, G.; Minguet-Rodriguez, J.; Rivera, F.; Saraiva, P.; Smolik, L.; Stephan, F.; Aleppo, M.; Apollonio, M.; Bosisio, L.; Della Marina, R.; Giannini, G.; Gobbo, B.; Musolino, G.; Ragusa, F.; Rothberg, J.; Wasserbaech, S.; Armstrong, S. R.; Bellantoni, L.; Elmer, P.; Feng, Z.; Ferguson, D. P. S.; Gao, Y. S.; González, S.; Grahl, J.; Greening, T. C.; Harton, J. L.; Hayes, O. J.; Hu, H.; McNamara, P. A.; Nachtman, J. M.; Orejudos, W.; Pan, Y. B.; Saadi, Y.; Schmitt, M.; Scott, I. J.; Sharma, V.; Turk, J. D.; Walsh, A. M.; Wu, Sau Lan; Wu, X.; Yamartino, J. M.; Zheng, M.; Zobernig, G.; Aleph Collaboration

    1996-02-01

    The polarization of Λ baryons from Z decays is studied with the ALEPH apparatus. Evidence of longitudinal polarization of s quarks from Z decay is observed for the first time. The measured longitudinal Λ polarization is PLΛ = -0.32 ± 0.07 for z = {p}/{p beam} > 0.3 . This agrees with the prediction of -0.39 ± 0.08 from the standard model and the constituent quark model, where the error is due to uncertainties in the mechanism for Λ production. The observed Λ polarization is diluted with respect to the primary s quark polarization by Λ baryons without a primary s quark. Measurements of the Λ forward-backward asymmetry and of the correlation between back-to-back Λ overlineΛ pairs are used to check this dilution. In addition the transverse Λ polarization is measured. An indication of transverse polarization, more than two standard deviations away from zero, is found along the normal to the plane defined by the thrust axis and the Λ direction.

  20. Numerical calculation of the ion polarization in MEIC

    SciTech Connect

    Derbenev, Yaroslav; Lin, Fanglei; Morozov, Vasiliy; Zhang, Yuhong; Kondratenko, Anatoliy M.; Kondratenko, M. A.; Filatov, Yury N.

    2015-09-01

    Ion polarization in the Medium-energy Electron-Ion Collider (MEIC) is controlled by means of universal 3D spin rotators designed on the basis of "weak" solenoids. We use numerical calculations to demonstrate that the 3D rotators have negligible effect on the orbital properties of the ring. We present calculations of the polarization dynamics along the collider's orbit for both longitudinal and transverse polarization directions at a beam interaction point. We calculate the degree of depolarization due to the longitudinal and transverse beam emittances in case when the zero-integer spin resonance is compensated.

  1. Polar Stratigraphy

    NASA Technical Reports Server (NTRS)

    1999-01-01

    These three images were taken on three different orbits over the north polar cap in April 1999. Each shows a different part of the same ice-free trough. The left and right images are separated by a distance of more than 100 kilometers (62 miles). Note the similar layers in each image.

  2. Political polarization

    PubMed Central

    Dixit, Avinash K.; Weibull, Jörgen W.

    2007-01-01

    Failures of government policies often provoke opposite reactions from citizens; some call for a reversal of the policy, whereas others favor its continuation in stronger form. We offer an explanation of such polarization, based on a natural bimodality of preferences in political and economic contexts and consistent with Bayesian rationality. PMID:17452633

  3. Longitudinal Lisfranc injury.

    PubMed

    Oak, Nikhil R; Manoli, Arthur; Holmes, James R

    2014-01-01

    Most Lisfranc or tarsometatarsal (TMT) joint injuries result from a horizontally directed force in which the metatarsals are displaced relative to the midfoot. The injury pattern that is described in this article is one of a longitudinal force through the first ray and cuneiform. A reliable measure to recognize the longitudinal Lisfranc variant injury has been the height difference between the distal articular surfaces of the first and second cuneiform bones in an anteroposterior (AP) weight-bearing radiograph. This measure helps identify subtle injuries in which there is a proximal and medial subluxation of the first cuneiform-metatarsal complex. Delayed diagnosis and treatment have been associated with poorer results and significant functional consequences. This article describes a simple radiographic measurement to recognize the longitudinal injury pattern and to aid in determining whether operative intervention is required. PMID:25785475

  4. Idiopathic Polydactylous Longitudinal Erythronychia

    PubMed Central

    2011-01-01

    Objective: To describe the clinical features of idiopathic polydactylous longitudinal erythronychia. Introduction: Longitudinal erythronychia presents as a linear red band on the nail plate. Idiopathic polydactylous longitudinal erythronychia is a rarely described manifestation of longitudinal erythronychia in which one or more linear red bands present on the nails of multiple digits without any associated subungual malignant tumor, dermatological condition, or systemic disease. Methods: As part of a total body skin examination, the fingernails and toenails were evaluated for linear red bands. Results: One or more asymptomatic linear red bands (longitudinal erythronychia) was observed on multiple digits of the hands in one percent (3 men of 134 men and 112 women) of patients examined during a period of 75 days. The author also noted similar changes of his own nails. Between 3 to 10 digits were affected. Multiple linear red bands per nail were usually narrow (less than 1mm wide), whereas a single band on a nail often ranged from 4 to 6mm wide. The intensity of an individual wider linear red band was position-dependent in three individuals in whom the distal portion appeared less prominent when the affected digit was held upward above the level of the patient's heart—pseudolongitudinal erythronychia. Other nail changes in these patients included distal subungual hyperkeratosis, fissuring at the free end of the nail, leukonychia, red lunula, and splinter hemorrhages. Discussion: Idiopathic polydactylous longitudinal erythronychia is a benign, usually asymptomatic, condition of undetermined etiology characterized by one or more linear red bands originating at the proximal nail fold or distal lunula and extending to the free edge of the nail. It appears to be more prevalent in men over 50 years of age and its incidence was noted to be one percent of adults attending a dermatology clinic. Patients are either unaware of the nail changes or seek medical attention because

  5. Cell polarity

    PubMed Central

    Romereim, Sarah M

    2011-01-01

    Despite extensive genetic analysis of the dynamic multi-phase process that transforms a small population of lateral plate mesoderm into the mature limb skeleton, the mechanisms by which signaling pathways regulate cellular behaviors to generate morphogenetic forces are not known. Recently, a series of papers have offered the intriguing possibility that regulated cell polarity fine-tunes the morphogenetic process via orienting cell axes, division planes and cell movements. Wnt5a-mediated non-canonical signaling, which may include planar cell polarity, has emerged as a common thread in the otherwise distinct signaling networks that regulate morphogenesis in each phase of limb development. These findings position the limb as a key model to elucidate how global tissue patterning pathways direct local differences in cell behavior that, in turn, generate growth and form. PMID:22064549

  6. Longitudinal discharge laser baffles

    DOEpatents

    Warner, B.E.; Ault, E.R.

    1994-06-07

    The IR baffles placed between the window and the electrode of a longitudinal discharge laser improve laser performance by intercepting off-axis IR radiation from the laser and in doing so reduce window heating and subsequent optical distortion of the laser beam. 1 fig.

  7. Longitudinal discharge laser baffles

    DOEpatents

    Warner, Bruce E.; Ault, Earl R.

    1994-01-01

    The IR baffles placed between the window and the electrode of a longitudinal discharge laser improve laser performance by intercepting off-axis IR radiation from the laser and in doing so reduce window heating and subsequent optical distortion of the laser beam.

  8. Longitudinal discharge laser electrodes

    DOEpatents

    Warner, B.E.; Miller, J.L.; Ault, E.R.

    1994-08-23

    The improved longitudinal discharge laser electrode with IR baffle includes an electrode made up of washers spaced along the laser axis in order to form inter-washer spaces for hollow cathode discharge to take place and for IR radiation to be trapped. Additional IR baffles can be placed between the electrode ann the window. 2 figs.

  9. Longitudinal discharge laser electrodes

    DOEpatents

    Warner, Bruce E.; Miller, John L.; Ault, Earl R.

    1994-01-01

    The improved longitudinal discharge laser electrode with IR baffle includes an electrode made up of washers spaced along the laser axis in order to form inter-washer spaces for hollow cathode discharge to take place and for IR radiation to be trapped. Additional IR baffles can be placed between the electrode ann the window.

  10. WISCONSIN LONGITUDINAL STUDY (WLS)

    EPA Science Inventory

    The Wisconsin Longitudinal Study (WLS) is a long-term study of a random sample of 10,317 men and women who graduated from Wisconsin high schools in 1957. The WLS provides an opportunity to study of the life course, intergenerational transfers and relationships, family functioning...

  11. Polar Textures

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Context image for PIA03646 Polar Textures

    This VIS image shows part of the south polar region. The ejecta from the relatively young crater covers the rougher textured polar surface.

    Image information: VIS instrument. Latitude 81S, Longitude 54.5E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  12. Heavy Quarkonium Production and Polarization

    NASA Astrophysics Data System (ADS)

    Kang, Zhong-Bo; Qiu, Jian-Wei; Sterman, George

    2012-03-01

    We present a perturbative QCD factorization formalism for the production of heavy quarkonia of large transverse momentum pT at collider energies, which includes both the leading-power (LP) and next-to-leading-power (NLP) contributions to the cross section in the mQ2/pT2 expansion for heavy quark mass mQ. We estimate fragmentation functions in the nonrelativistic QCD formalism and reproduce the bulk of the large enhancement found in explicit next-to-leading-order calculations in the color-singlet model. Heavy quarkonia produced from NLP channels prefer longitudinal polarization.

  13. Build a circularly polarized waveguide slot antenna

    NASA Astrophysics Data System (ADS)

    Kisliuk, M.; Axelrod, A.

    1987-06-01

    The development and design of a circularly polarized waveguide slot antenna are described. Consideration is given to the resonance frequency, radiation efficiencies, excitement, and resonant conductance of the transverse and longitudinal slots. The transverse and longitudinal slots in a rectangular guide are analyzed. The voltage distribution across the slot is calculated from the solution of a standard transmission line equation; and using the Poynting theorem the fields scattered by the slot in an arbitrary frequency range are determined. The proposed antenna is examined using an equivalent circuit; a diagram of the circuit is given. The radiation, slot, and antenna efficiencies are measured.

  14. Experimental Demonstration of Longitudinal Magnification

    ERIC Educational Resources Information Center

    Razpet, Nada; Susman, Katarina; Cepic, Mojca

    2009-01-01

    We describe an experiment which enables the observation of longitudinal magnification for the real image of a three-dimensional (3D) object formed by a converging lens. The experiment also shows the absence of longitudinal inversion. Possible reasons for misconceptions with respect to real images and longitudinal inversions are discussed and a…

  15. Nucleon Spin Structure: Longitudinal and Transverse

    SciTech Connect

    Jian-Ping Chen

    2011-02-01

    Inclusive Deep-Inelastic Scattering (DIS) experiments have provided us with the most extensive information on the unpolarized and longitudinal polarized parton (quark and gluon) distributions in the nucleon. It has becoming clear that transverse spin and transverse momentum dependent distributions (TMDs) study are crucial for a more complete understanding of the nucleon structure and the dynamics of the strong interaction. The transverse spin structure and the TMDs are the subject of increasingly intense theoretical and experimental study recently. With a high luminosity electron beam facility, JLab has played a major role in the worldwide effort to study both the longitudinal and transverse spin structure. Highlights of recent results will be presented. With 12-GeV energy upgrade, JLab will provide the most precise measurements in the valence quark region to close a chapter in longitudinal spin study. JLab will also perform a multi-dimensional mapping of the transverse spin structure and TMDs in the valence quark region through Semi-Inclusive DIS (SIDIS) experiments, providing a 3-d partonic picture of the nucleon in momentum space and extracting the u and d quark tensor charges of the nucleon. The precision mapping of TMDs will also allow a detailed study of the quark orbital motion and its dynamics.

  16. Polar Landforms

    NASA Technical Reports Server (NTRS)

    2005-01-01

    10 August 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows eroded remnants of carbon dioxide ice in the south polar residual cap of Mars. The scarps that outline each small mesa have retreated about 3 meters (10 feet) per Mars year since MGS began orbiting the red planet in 1997.

    Location near: 87.0oS, 31.9oW Image width: width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Spring

  17. Longitudinal epiphyseal bracket.

    PubMed

    Nguyen, Jimmy Q; Gatewood, Jason B; Beall, Douglas; Herndon, William; Puffinberger, William R; Ly, Justin; Fish, Jon R

    2007-10-01

    A longitudinal epiphyseal bracket (LEB) is a defect of the tubular bones and has been primarily described in the hands and feet, especially the proximal phalanges, metacarpals, and metatarsals. The LEB results from a defective C-shaped secondary ossification center that brackets the diaphysis and metaphysis, causing restricted longitudinal growth in these bones with resultant shortening and angular deformities. Deformities associated with metatarsal epiphyseal bracket include a short, broad metatarsal and medial deviation of the metatarsophalangeal joint (hallux varus deformity). Excision of the cartilaginous LEB has been proposed to prevent future soft tissue contractures and osseous deformities. The LEB has been associated with numerous syndromes including Rubinstein-Taybi syndrome, Cenani-Lenz syndactyly, isolated oligosyndactyly, and Nievergelt syndrome. We describe a two-month-old patient in whom plain film and MR imaging demonstrated bilateral bracketed first metatarsals with associated hallux varus deformities. Bilateral bracket excision was performed with excellent clinical results. PMID:18085094

  18. Polar ozone

    NASA Technical Reports Server (NTRS)

    Solomon, S.; Grose, W. L.; Jones, R. L.; Mccormick, M. P.; Molina, Mario J.; Oneill, A.; Poole, L. R.; Shine, K. P.; Plumb, R. A.; Pope, V.

    1990-01-01

    The observation and interpretation of a large, unexpected ozone depletion over Antarctica has changed the international scientific view of stratospheric chemistry. The observations which show the veracity, seasonal nature, and vertical structure of the Antarctic ozone hole are presented. Evidence for Arctic and midlatitude ozone loss is also discussed. The chemical theory for Antarctic ozone depletion centers around the occurrence of polar stratospheric clouds (PSCs) in Antarctic winter and spring; the climatology and radiative properties of these clouds are presented. Lab studies of the physical properties of PSCs and the chemical processes that subsequently influence ozone depletion are discussed. Observations and interpretation of the chemical composition of the Antarctic stratosphere are described. It is shown that the observed, greatly enhanced abundances of chlorine monoxide in the lower stratosphere are sufficient to explain much if not all of the ozone decrease. The dynamic meteorology of both polar regions is given, interannual and interhemispheric variations in dynamical processes are outlined, and their likely roles in ozone loss are discussed.

  19. Polar Markings

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA02155 Polar Markings

    These bright and dark markings occurred near the end of summer in the south polar region. The dark material is likely dust that has been freed of frost cover.

    Image information: VIS instrument. Latitude -76.3N, Longitude 84.9E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  20. Polar Layers

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA02153 Polar Layers

    This image of the south polar region shows layered material. It is not known if the layers are formed yearly or if they form over the period of 10s to 100s of years or more.

    Image information: VIS instrument. Latitude -80.3N, Longitude 296.2E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  1. Polar Ridges

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA03662 Polar Ridges

    This ridge system is located in the south polar region.

    Image information: VIS instrument. Latitude -81.7N, Longitude 296.5E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  2. Polar Textures

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Context image for PIA03638 Polar Textures

    This image illustrates the variety of textures that appear in the south polar region during late summer.

    Image information: VIS instrument. Latitude 80.5S, Longitude 57.9E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  3. Polar Terrains

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Context image for PIA03577 Polar Terrains

    The region surrounding the South Polar Cap contains many different terrain types. This image shows both etched terrain and a region of 'mounds'.

    Image information: VIS instrument. Latitude 75S, Longitude 286.5E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  4. Polarimetry for Stored Polarized Hadron Beams

    NASA Astrophysics Data System (ADS)

    Stephenson, E. J.

    2016-02-01

    Feasibility studies using 0.97-GeV/c polarized deuterons to determine the suitability of storage rings in the search for intrinsic electric dipole moments have led to new developments in storage ring polarimeters. Efficiency has increased with the use of thick carbon targets. The calibration of the effects of geometric and rate-dependent errors has made possible the subtraction of these systematic errors, resulting in sensitivities at or below 10‑5 to polarization changes during the time of the store. Tagging polarimeter events with the clock time had made available the turn number for each event, making possible longitudinal profile and horizontal polarization measurements. These have been used to explore the correction of second-order contributions to decoherence using sextupole fields, yielding horizontal polarization lifetimes as long as 20 minutes. Such studies may be extended to protons and 3He.

  5. Gluon Polarization and Jet Production at STAR

    SciTech Connect

    Djawotho, Pibero

    2009-12-17

    I will discuss the most recent measurements of the inclusive jet longitudinal spin asymmetry A{sub LL} in polarized proton-proton collisions. STAR collected its largest data sample thus far, 4.7 pb{sup -1} of integrated luminosity at an average beam polarization of {approx}57%, during the 2006 run at a center-of-mass energy of 200 GeV. I will also present previous STAR inclusive jet A{sub LL} and cross section measurements. The results are compared with theoretical calculations of A{sub LL} based on polarized distribution functions in the nucleon with a range of different contributions from the gluon polarization, {delta}G. The STAR data place significant constraints on {delta}G for 0.02

  6. Proton Form Factor Measurements Using Polarization Method: Beyond Born Approximation

    SciTech Connect

    Pentchev, Lubomir

    2008-10-13

    Significant theoretical and experimental efforts have been made over the past 7 years aiming to explain the discrepancy between the proton form factor ratio data obtained at JLab using the polarization method and the previous Rosenbluth measurements. Preliminary results from the first high precision polarization experiment dedicated to study effects beyond Born approximation will be presented. The ratio of the transferred polarization components and, separately, the longitudinal polarization in ep elastic scattering have been measured at a fixed Q{sup 2} of 2.5 GeV{sup 2} over a wide kinematic range. The two quantities impose constraints on the real part of the ep elastic amplitudes.

  7. Polar Barchans

    NASA Technical Reports Server (NTRS)

    2004-01-01

    20 July 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows dark, barchan sand dunes of the north polar region of Mars. Barchan dunes are simple, rounded forms with two horns that extend downwind. Inequalities in local wind patterns may result in one horn being extended farther than the other, as is the case for several dunes in this image. The image also shows several barchans may merge to form a long dune ridge. The horns and attendant slip faces on these dunes indicate wind transport of sand from the upper left toward the lower right. The image is located near 77.6oN, 103.6oW. The picture covers an area about 3 km (1.9 mi) wide; sunlight illuminates the scene from the lower left.

  8. Polar Polygons

    NASA Technical Reports Server (NTRS)

    2004-01-01

    26 December 2003 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) picture displays polygons outlined by cracks in the martian south polar region. This southern summer view was acquired in October 2003 and is located near 86.9oS, 170.6oW. Polygons similar in size and shape to these are common in the arctic and antarctic regions of Earth. On Earth, they indicate the presence (or the past presence) of ground ice and the freeze-thaw cycles that accompany this ice. On Mars, whether ground ice was responsible for these landforms is uncertain, but their presence is suggestive that ground ice may exist or may once have existed in this region. The picture covers an area 3 km (1.9 mi) wide. Sunlight illuminates the scene from the upper left.

  9. Recoil-proton polarization in high-energy deuteron photodisintegration with circularly plarized photons.

    SciTech Connect

    Jiang, X.; Arrington, J.; Benmokhtar, F.; Camsonne, A.; Chen, J. P.; Holt, R. J.; Qattan, I. A.; Reimer, P. E.; Schulte, E. C.; Wijesooriya, K.; Physics; Rutgers Univ.; Univ. Blaise Pascal; Thomas Jefferson National Accelerator Facility

    2007-05-01

    We measured the angular dependence of the three recoil-proton polarization components in two-body photodisintegration of the deuteron at a photon energy of 2 GeV. These new data provide a benchmark for calculations based on quantum chromodynamics. Two of the five existing models have made predictions of polarization observables. Both explain the longitudinal polarization transfer satisfactorily. Transverse polarizations are not well described, but suggest isovector dominance.

  10. Angular dependence of recoil proton polarization in high-energy \\gamma d \\to p n

    SciTech Connect

    X. Jiang; J. Arrington; F. Benmokhtar; A. Camsonne; J.P. Chen; S. Choi; E. Chudakov; F. Cusanno; A. Deur; D. Dutta; F. Garibaldi; D. Gaskell; O. Gayou; R. Gilman; C. Glashauser; D. Hamilton; O. Hansen; D.W. Higinbotham; R.J. Holt; C.W. de Jager; M.K. Jones; L.J. Kaufman; E.R. Kinney; K. Kramer; L. Lagamba; R. de Leo; J. Lerose; D. Lhuillier; R. Lindgren; N. Liyanage; K. McCormick; Z.-E. Meziani; R. Michaels; B. Moffit; P. Monaghan; S. Nanda; K.D. Paschke; C.F. Perdrisat; V. Punjabi; I.A. Qattan; R.D. Ransome; P.E. Reimer; B. Reitz; A. Saha; E.C. Schulte; R. Sheyor; K. Slifer; P. Solvignon; V. Sulkosky; G.M. Urciuoli; E. Voutier; K. Wang; K. Wijesooriya; B. Wojtsekhowski; L. Zhu

    2007-02-26

    We measured the angular dependence of the three recoil proton polarization components in two-body photodisintegration of the deuteron at a photon energy of 2 GeV. These new data provide a benchmark for calculations based on quantum chromodynamics. Two of the five existing models have made predictions of polarization observables. Both explain the longitudinal polarization transfer satisfactorily.. Transverse polarizations are not well described, but suggest isovector dominance.

  11. Measurement of the correlation between electron spin and photon linear polarization in atomic-field bremsstrahlung.

    PubMed

    Tashenov, S; Bäck, T; Barday, R; Cederwall, B; Enders, J; Khaplanov, A; Poltoratska, Yu; Schässburger, K-U; Surzhykov, A

    2011-10-21

    Atomic-field bremsstrahlung has been studied with a longitudinally polarized electron beam. The correlation between the initial orientation of the electron spin and the angle of photon polarization has been measured at the photon high energy tip region. In the time reversal this corresponds to a so-far unobserved phenomenon of production of longitudinally polarized electrons by photoionization of unpolarized atoms with linearly polarized photons. The results confirm the fully relativistic calculations for radiative recombination and suggest a new method for electron beam polarimetry. PMID:22107514

  12. Cross-polarized excitons in carbon nanotubes.

    PubMed

    Kilina, Svetlana; Tretiak, Sergei; Doorn, Stephen K; Luo, Zhengtang; Papadimitrakopoulos, Fotios; Piryatinski, Andrei; Saxena, Avadh; Bishop, Alan R

    2008-05-13

    Polarization of low-lying excitonic bands in finite-size semiconducting single-walled carbon nanotubes (SWNTs) is studied by using quantum-chemical methodologies. Our calculations elucidate properties of cross-polarized excitons, which lead to the transverse optical absorption of nanotubes and presumably couple to intermediate-frequency modes recently observed in resonance Raman excitation spectroscopy. We identify up to 12 distinct excitonic transitions below the second fundamental band associated with the E(22) van Hove singularity. Calculations for several chiral SWNTs distinguish the optically active "bright" excitonic band polarized parallel to the tube axis and several optically "weak" cross-polarized excitons. The rest are optically (near) forbidden "dark" transitions. An analysis of the transition density matrices related to excitonic bands provides detailed information about delocalization of excitonic wavefunction along the tube. Utilization of the natural helical coordinate system accounting for the tube chirality allows one to disentangle longitudinal and circumferential components. The distribution of the transition density matrix along a tube axis is similar for all excitons. However, four parallel-polarized excitons associated with the E(11) transition are more localized along the circumference of a tube, compared with others related to the E(12) and E(21) cross-polarized transitions. Calculated splitting between optically active parallel- and cross-polarized transitions increases with tube diameter, which compares well with experimental spectroscopic data. PMID:18463293

  13. Cross-polarized excitons in carbon nanotubes

    PubMed Central

    Kilina, Svetlana; Tretiak, Sergei; Doorn, Stephen K.; Luo, Zhengtang; Papadimitrakopoulos, Fotios; Piryatinski, Andrei; Saxena, Avadh; Bishop, Alan R.

    2008-01-01

    Polarization of low-lying excitonic bands in finite-size semiconducting single-walled carbon nanotubes (SWNTs) is studied by using quantum-chemical methodologies. Our calculations elucidate properties of cross-polarized excitons, which lead to the transverse optical absorption of nanotubes and presumably couple to intermediate-frequency modes recently observed in resonance Raman excitation spectroscopy. We identify up to 12 distinct excitonic transitions below the second fundamental band associated with the E22 van Hove singularity. Calculations for several chiral SWNTs distinguish the optically active “bright” excitonic band polarized parallel to the tube axis and several optically “weak” cross-polarized excitons. The rest are optically (near) forbidden “dark” transitions. An analysis of the transition density matrices related to excitonic bands provides detailed information about delocalization of excitonic wavefunction along the tube. Utilization of the natural helical coordinate system accounting for the tube chirality allows one to disentangle longitudinal and circumferential components. The distribution of the transition density matrix along a tube axis is similar for all excitons. However, four parallel-polarized excitons associated with the E11 transition are more localized along the circumference of a tube, compared with others related to the E12 and E21 cross-polarized transitions. Calculated splitting between optically active parallel- and cross-polarized transitions increases with tube diameter, which compares well with experimental spectroscopic data. PMID:18463293

  14. Optical transmission through a polarization preserving single mode optical fiber at two Ar(+) laser wavelengths

    NASA Technical Reports Server (NTRS)

    Tedjojuwono, Ken K.; Hunter, William W., Jr.

    1989-01-01

    The transmission characteristics of two Ar(+) laser wavelengths through a twenty meter Panda type Polarization Preserving Single Mode Optical Fiber (PPSMOF) were measured. The measurements were done with both single and multi-longitudinal mode radiation. In the single longitudinal mode case, a degrading Stimulated Brillouin Scattering (SBS) is observed as a backward scattering loss. By choosing an optimum coupling system and manipulating the input polarization, the threshold of the SBS onset can be raised and the transmission efficiency can be increased.

  15. Internal spin structure of the proton from high energy polarized e-p scattering

    SciTech Connect

    Hughes, V.W.; Baum, G.; Bergstroem, M.R.

    1981-02-01

    A review is given of experimental knowledge of the spin dependent structure functions of the proton, which is based on inclusive high energy scattering of longitudinal polarized electrons by longitudinally polarized protons in both the deep inelastic and resonance regions, and includes preliminary results from our most recent SLAC experiment. Implications for scaling, sum rules, models of proton structure, and the hyperfine structure interval in hydrogen are given. Possible future directions of research are indicated.

  16. Visualization of Longitudinal and Transverse Components of Strongly Focused Optical Field by means of Photo-Reactive Azopolymers

    NASA Astrophysics Data System (ADS)

    Kharitonov, A. V.; Kharintsev, S. S.

    2015-09-01

    Most important problems in modern photonics are fabrication, visualization and characterization of nanomaterials at optical frequencies. A number of optical techniques uses tightly focused laser beams to access longitudinal electromagnetic fields, which are directed towards the wave vector. In this Letter, the distribution of transverse and longitudinal optical fields in tightly focused laser beams, polarized in a new fashion, is investigated. Polarization dependent fingerprints of transverse and longitudinal optical fields are experimentally captured by means of photoinduced surface deformations in azobenzene polymer thin films.

  17. Polarized internal target apparatus

    DOEpatents

    Holt, R.J.

    1984-10-10

    A polarized internal target apparatus with a polarized gas target of improved polarization and density (achieved by mixing target gas atoms with a small amount of alkali metal gas atoms, and passing a high intensity polarized light source into the mixture to cause the alkali metal gas atoms to become polarized which interact in spin exchange collisions with target gas atoms yielding polarized target gas atoms) is described.

  18. Polarized internal target apparatus

    DOEpatents

    Holt, Roy J.

    1986-01-01

    A polarized internal target apparatus with a polarized gas target of improved polarization and density achieved by mixing target gas atoms with a small amount of alkali metal gas atoms, and passing a high intensity polarized light source into the mixture to cause the alkali metal gas atoms to become polarized which interact in spin exchange collisions with target gas atoms yielding polarized target gas atoms.

  19. Perceiving polarization with the naked eye: characterization of human polarization sensitivity.

    PubMed

    Temple, Shelby E; McGregor, Juliette E; Miles, Camilla; Graham, Laura; Miller, Josie; Buck, Jordan; Scott-Samuel, Nicholas E; Roberts, Nicholas W

    2015-07-22

    Like many animals, humans are sensitive to the polarization of light. We can detect the angle of polarization using an entoptic phenomenon called Haidinger's brushes, which is mediated by dichroic carotenoids in the macula lutea. While previous studies have characterized the spectral sensitivity of Haidinger's brushes, other aspects remain unexplored. We developed a novel methodology for presenting gratings in polarization-only contrast at varying degrees of polarization in order to measure the lower limits of human polarized light detection. Participants were, on average, able to perform the task down to a threshold of 56%, with some able to go as low as 23%. This makes humans the most sensitive vertebrate tested to date. Additionally, we quantified a nonlinear relationship between presented and perceived polarization angle when an observer is presented with a rotatable polarized light field. This result confirms a previous theoretical prediction of how uniaxial corneal birefringence impacts the perception of Haidinger's brushes. The rotational dynamics of Haidinger's brushes were then used to calculate corneal retardance.We suggest that psychophysical experiments, based upon the perception of polarized light, are amenable to the production of affordable technologies for self-assessment and longitudinal monitoring of visual dysfunctions such as age-related macular degeneration. PMID:26136441

  20. Perceiving polarization with the naked eye: characterization of human polarization sensitivity

    PubMed Central

    Temple, Shelby E.; McGregor, Juliette E.; Miles, Camilla; Graham, Laura; Miller, Josie; Buck, Jordan; Scott-Samuel, Nicholas E.; Roberts, Nicholas W.

    2015-01-01

    Like many animals, humans are sensitive to the polarization of light. We can detect the angle of polarization using an entoptic phenomenon called Haidinger's brushes, which is mediated by dichroic carotenoids in the macula lutea. While previous studies have characterized the spectral sensitivity of Haidinger's brushes, other aspects remain unexplored. We developed a novel methodology for presenting gratings in polarization-only contrast at varying degrees of polarization in order to measure the lower limits of human polarized light detection. Participants were, on average, able to perform the task down to a threshold of 56%, with some able to go as low as 23%. This makes humans the most sensitive vertebrate tested to date. Additionally, we quantified a nonlinear relationship between presented and perceived polarization angle when an observer is presented with a rotatable polarized light field. This result confirms a previous theoretical prediction of how uniaxial corneal birefringence impacts the perception of Haidinger's brushes. The rotational dynamics of Haidinger's brushes were then used to calculate corneal retardance. We suggest that psychophysical experiments, based upon the perception of polarized light, are amenable to the production of affordable technologies for self-assessment and longitudinal monitoring of visual dysfunctions such as age-related macular degeneration. PMID:26136441

  1. Cup waveguide antenna with integrated polarizer and OMT

    NASA Technical Reports Server (NTRS)

    Acosta, Roberto J. (Inventor); Kory, Carol (Inventor); Lambert, Kevin M. (Inventor)

    2011-01-01

    A cup waveguide antenna with integrated polarizer and OMT for simultaneously communicating left and right hand circularly polarized electromagnetic waves is adjustable to obtain efficient propagation and reception of electromagnetic waves. The antenna includes a circular waveguide having an orthomode transducer utilizing first and second pins longitudinally spaced apart and oriented orthogonally with respect to each other. Six radially-oriented adjustable polarizer screws extend from the exterior to the interior of the waveguide. A septum intermediate the first and second pins is aligned with the first pin. Adjustment of the polarizer screws enables maximized propagation of and/or response to left hand circularly polarized electromagnetic waves by the first pin while simultaneously enabling maximized propagation of and/or response to right hand circularly polarized electromagnetic waves by the second pin.

  2. Longitudinal Stern-Gerlach

    NASA Astrophysics Data System (ADS)

    Higinbotham, Douglas

    2006-11-01

    In 1922 Otto Stern and Walther Gerlach split a beam of silver atoms using a transverse gradient field. This experiment, which lead to the understanding that electrons have intrinsic spin, oddly enough does not work for free electrons due to the interplay between the Lorentz force and Heisenberg uncertainly principle. Recent calculations, Phys. Rev. Lett. 79 (1997) 4517 and Phys. Rev. Lett. 86 (2001) 4508, have shown that a dismissed idea of L. Brillouin from 1928 to use a longitudinal gradient field to minimize the effect of the Lorentz force may in fact be possible. The history of the Stern-Gerlach device will be presented along with the revived ideas for separating a beam of free electrons into its two spin states.

  3. Digital Longitudinal Tomosynthesis

    NASA Astrophysics Data System (ADS)

    Rimkus, Daniel Steven

    1985-12-01

    The purpose of this dissertation was to investigate the clinical utility of digital longitudinal tomosynthesis in radiology. By acquiring a finite group of digital images during a longitudinal tomographic exposure, and processing these images, tomographic planes, other than the fulcrum plane, can be reconstructed. This process is now termed "tomosynthesis". A prototype system utilizing this technique was developed. Both phantom and patient studies were done with this system. The phantom studies were evaluated by subjective, visual criterion and by quantitative analysis of edge sharpness and noise in the reconstructions. Two groups of patients and one volunteer were studied. The first patient group consisted of 8 patients undergoing intravenous urography (IVU). These patients had digital tomography and film tomography of the abdomen. The second patient group consisted of 4 patients with lung cancer admitted to the hospital for laser resection of endobronchial tumor. These patients had mediastinal digital tomograms to evaluate the trachea and mainstem bronchi. The knee of one volunteer was imaged by film tomography and digital tomography. The results of the phantom studies showed that the digital reconstructions accurately produced images of the desired planes. The edge sharpness of the reconstructions approached that of the acquired images. Adequate reconstructions were achieved with as few as 5 images acquired during the exposure, with the quality of the reconstructions improving as the number of images acquired increased. The IVU patients' digital studies had less contrast and spatial resolution than the film tomograms. The single renal lesion visible on the film tomograms was also visible in the digital images. The digital mediastinal studies were felt by several radiologists to be superior to a standard chest xray in evaluating the airways. The digital images of the volunteer's knee showed many of the same anatomic features as the film tomogram, but the digital

  4. Polar Color

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released 3 May 2004 This nighttime visible color image was collected on January 1, 2003 during the Northern Summer season near the North Polar Troughs.

    This daytime visible color image was collected on September 4, 2002 during the Northern Spring season in Vastitas Borealis. The THEMIS VIS camera is capable of capturing color images of the martian surface using its five different color filters. In this mode of operation, the spatial resolution and coverage of the image must be reduced to accommodate the additional data volume produced from the use of multiple filters. To make a color image, three of the five filter images (each in grayscale) are selected. Each is contrast enhanced and then converted to a red, green, or blue intensity image. These three images are then combined to produce a full color, single image. Because the THEMIS color filters don't span the full range of colors seen by the human eye, a color THEMIS image does not represent true color. Also, because each single-filter image is contrast enhanced before inclusion in the three-color image, the apparent color variation of the scene is exaggerated. Nevertheless, the color variation that does appear is representative of some change in color, however subtle, in the actual scene. Note that the long edges of THEMIS color images typically contain color artifacts that do not represent surface variation.

    Image information: VIS instrument. Latitude 79, Longitude 346 East (14 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with

  5. Penta prism laser polarizer.

    PubMed

    Lotem, H; Rabinovitch, K

    1993-04-20

    A novel type of laser prism polarizer is proposed. The polarizer is characterized by a high transmission efficiency, a high optical damage threshold, and a high extinction ratio. The polarizer is shaped like a regular penta prism and, thus, it is a constant deviation angle device. Polarization effects occur upon the two internal cascade reflections in the prism. Anisotropic and Isotropic types of the polarizer are discussed. The isotropic polarizer is a prism made of a high refractive-index glass coated by multilayer polarization-type dielectric coatings. Efficient s-state polarization is obtained because of p-state leakage upon the two internal cascade reflections. The anisotropic polarizer is made of a birefringent crystal in which angular polarization splitting is obtained by the bireflectance (double-reflection) effect. Fanning of a laser beam into up to eight polarized beams is possible in a prism made of a biaxial crystal. PMID:20820335

  6. Generation of longitudinal vibrations in piano strings: From physics to sound synthesis

    NASA Astrophysics Data System (ADS)

    Bank, Balázs; Sujbert, László

    2005-04-01

    Longitudinal vibration of piano strings greatly contributes to the distinctive character of low piano notes. In this paper a simplified modal model is developed, which describes the generation of phantom partials and longitudinal free modes jointly. The model is based on the simplification that the coupling from the transverse vibration to the longitudinal polarization is unidirectional. The modal formulation makes it possible to predict the prominent components of longitudinal vibration as a function of transverse modal frequencies. This provides a qualitative insight into the generation of longitudinal vibration, while the model is still capable of explaining the empirical results of earlier works. The semi-quantitative agreement with measurement results implies that the main source of phantom partials is the transverse to longitudinal coupling, while the string termination and the longitudinal to transverse coupling have only small influence. The results suggest that the longitudinal component of the tone can be treated as a quasi-harmonic spectrum with formantlike peaks at the longitudinal modal frequencies. The model is further simplified and applied for the real-time synthesis of piano sound with convincing sonic results. .

  7. Generation of longitudinal vibrations in piano strings: from physics to sound synthesis.

    PubMed

    Bank, Balázs; Sujbert, László

    2005-04-01

    Longitudinal vibration of piano strings greatly contributes to the distinctive character of low piano notes. In this paper a simplified modal model is developed, which describes the generation of phantom partials and longitudinal free modes jointly. The model is based on the simplification that the coupling from the transverse vibration to the longitudinal polarization is unidirectional. The modal formulation makes it possible to predict the prominent components of longitudinal vibration as a function of transverse modal frequencies. This provides a qualitative insight into the generation of longitudinal vibration, while the model is still capable of explaining the empirical results of earlier works. The semi-quantitative agreement with measurement results implies that the main source of phantom partials is the transverse to longitudinal coupling, while the string termination and the longitudinal to transverse coupling have only small influence. The results suggest that the longitudinal component of the tone can be treated as a quasi-harmonic spectrum with formantlike peaks at the longitudinal modal frequencies. The model is further simplified and applied for the real-time synthesis of piano sound with convincing sonic results. PMID:15898667

  8. Focal spot analysis of radially polarized femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Sun, Wenchao; Hu, Wenhua; Qi, Junli; Wang, Weiming; Liao, Jiali; Yi, Wenjun; Jia, Hui; Li, Xiujian

    2014-09-01

    When radially polarized light beams focus through high numerical-aperture lens, there will be a very strong longitudinal component of the light field near the focus. And, under the condition of certain system parameters, they can shape a spot which is over the focusing spot of the diffraction limit, which are the superiorities that linearly polarized light and circularly polarized light do not have. Besides, what we have found in the experiment is that radially polarized femtosecond laser pulses own the same superiorities, which provides the basis for using the focusing characteristics of radially polarized light beams under the condition of shorter and more powerful laser pulses. So far, although people have studied a lot on radially polarized light beams, this kind of light beams' focusing characters are rarely researched. What is worse, most research of its focusing characters still stays in the stage of theoretical simulation,and it seems that none of people have really studied it by the way of experiments. This article is precisely based on this. On the basis of predecessors' a lot of theoretical research, the article pays more attention on analyzing radially polarized light beams' focusing character through experiments. What's more, the article, based on femtosecond laser pulses, compares the differences of the focusing nature among linearly polarized light, circularly polarized light and radially polarized light. And it gets the conclusion that radially polarized femtosecond laser pulses have better focusing character in longitudinal light field, confirming the feasibility that radially polarized light beams can be used in the fields of pulling, catching, and accelerating particles, metal cutting and high-density storage.

  9. Faraday polarization fluctuations of satellite beacon signals

    NASA Technical Reports Server (NTRS)

    Lee, M. C.; Klobuchar, J. A.

    1988-01-01

    The anisotropic effects of random density irregularities in causing Faraday polarization fluctuations of VHF radio signals are examined, taking both rod-like and sheet-like irregularities into consideration. It is found that the variance of Faraday polarization fluctuations depends on the ratio of perpendicular to parallel correlation lengths. The anisotropic effect of rod-like ionospheric irregularities are shown to be most appreciable for longitudinal propagation. The anisotropic effect of sheet-like ionospheric irregularities, however, is not strongly dependent on the radio propagation angle. During transionospheric propagation at large angles with respect to the geomagnetic field, sheet-like irregularities may cause greater Faraday polarization fluctuations than rod-like irregularities.

  10. Study on the Langevin piezoelectric ceramic ultrasonic transducer of longitudinal-flexural composite vibrational mode.

    PubMed

    Lin, Shuyu

    2006-01-01

    In this paper, the Langevin longitudinal-flexural composite mode piezoelectric ultrasonic transducer is studied. This type of transducers consists of slender metal rods and longitudinally polarized piezoelectric ceramic rings. The resonance frequency equations for the longitudinal and flexural vibrations in the transducer are derived. By correcting the length of the metal slender rods, the simultaneous resonance of the longitudinal and flexural vibrations in the transducer is acquired. The experimental results show that the measured resonance frequencies of the transducers are in good agreement with the computed ones, and the measured resonance frequencies of the longitudinal and the flexural vibrations in the composite transducers are also in good agreement with each other. PMID:16289195

  11. Polarized Light in Astronomy.

    ERIC Educational Resources Information Center

    King, D. J.

    1983-01-01

    The application of very sensitive electronic detecting devices during the last decade has revolutionized and revitalized the study of polarization in celestial objects. The nature of polarization, how polaroids work, interstellar polarization, dichroic filters, polarization by scattering, and modern polarimetry are among the topics discussed. (JN)

  12. Linearly polarized fiber amplifier

    DOEpatents

    Kliner, Dahv A.; Koplow, Jeffery P.

    2004-11-30

    Optically pumped rare-earth-doped polarizing fibers exhibit significantly higher gain for one linear polarization state than for the orthogonal state. Such a fiber can be used to construct a single-polarization fiber laser, amplifier, or amplified-spontaneous-emission (ASE) source without the need for additional optical components to obtain stable, linearly polarized operation.

  13. Nondiffracting transversally polarized beam.

    PubMed

    Yuan, G H; Wei, S B; Yuan, X-C

    2011-09-01

    Generation of a nondiffracting transversally polarized beam by means of transmitting an azimuthally polarized beam through a multibelt spiral phase hologram and then highly focusing by a high-NA lens is presented. A relatively long depth of focus (∼4.84λ) of the electric field with only radial and azimuthal components is achieved. The polarization of the wavefront near the focal plane is analyzed in detail by calculating the Stokes polarization parameters. It is found that the polarization is spatially varying and entirely transversally polarized, and the polarization singularity disappears at the beam center, which makes the central bright channel possible. PMID:21886250

  14. Crossed elliptical polarization undulator

    SciTech Connect

    Sasaki, Shigemi

    1997-05-01

    The first switching of polarization direction is possible by installing two identical helical undulators in series in a same straight section in a storage ring. By setting each undulator in a circular polarization mode in opposite handedness, one can obtain linearly polarized radiation with any required polarization direction depending on the modulator setting between two undulators. This scheme can be used without any major degradation of polarization degree in any low energy low emittance storage ring.

  15. Polarization-balanced beamsplitter

    DOEpatents

    Decker, D.E.

    1998-02-17

    A beamsplitter assembly is disclosed that includes several beamsplitter cubes arranged to define a plurality of polarization-balanced light paths. Each polarization-balanced light path contains one or more balanced pairs of light paths, where each balanced pair of light paths includes either two transmission light paths with orthogonal polarization effects or two reflection light paths with orthogonal polarization effects. The orthogonal pairing of said transmission and reflection light paths cancels polarization effects otherwise caused by beamsplitting. 10 figs.

  16. Polarization-balanced beamsplitter

    DOEpatents

    Decker, Derek E.

    1998-01-01

    A beamsplitter assembly that includes several beamsplitter cubes arranged to define a plurality of polarization-balanced light paths. Each polarization-balanced light path contains one or more balanced pairs of light paths, where each balanced pair of light paths includes either two transmission light paths with orthogonal polarization effects or two reflection light paths with orthogonal polarization effects. The orthogonal pairing of said transmission and reflection light paths cancels polarization effects otherwise caused by beamsplitting.

  17. Polarization Transfer in Proton Compton Scattering at High Momentum Transfer

    SciTech Connect

    Hamilton, D.J.; Annand, J.R.M.; Mamyan, V.H.; Aniol, K.A.; Margaziotis, D.J.; Bertin, P.Y.; Camsonne, A.; Laveissiere, G.; Bosted, P.; Paschke, K.; Calarco, J.R.; Chang, G.C.; Horn, T.; Savvinov, N.; Chang, T.-H.; Danagoulian, A.; Nathan, A.M.; Roedelbronn, M.; Chen, J.-P.

    2005-06-24

    Compton scattering from the proton was investigated at s=6.9 GeV{sup 2} and t=-4.0 GeV{sup 2} via polarization transfer from circularly polarized incident photons. The longitudinal and transverse components of the recoil proton polarization were measured. The results are in disagreement with a prediction of perturbative QCD based on a two-gluon exchange mechanism, but agree well with a prediction based on a reaction mechanism in which the photon interacts with a single quark carrying the spin of the proton.

  18. Polarization Transfer in Proton Compton Scattering at High Momentum Transfer

    SciTech Connect

    D.J. Hamilton; Vahe Mamyan

    2004-10-01

    Compton scattering from the proton was investigated at s = 6.9 GeV{sup 2} and t = -4.0 TeV{sup 2} via polarization transfer from circularly polarized incident photons. The longitudinal and transverse components of the recoil proton polarization were measured. The results are in excellent agreement with a prediction based on a reaction mechanism in which the photon interacts with a single quark carrying the spin of the proton and in disagreement with a prediction of pQCD based on a two-gluon exchange mechanism.

  19. Observation of Polarized Positrons from an Undulator-Based Source

    SciTech Connect

    Alexander, G; Barley, J.; Batygin, Y.; Berridge, S.; Bharadwaj, V.; Bower, G.; Bugg, W.; Decker, F.-J.; Dollan, R.; Efremenko, Y.; Gharibyan, V.; Hast, C.; Iverson, R.; Kolanoski, H.; Kovermann, J.; Laihem, K.; Lohse, T.; McDonald, K.T.; Mikhailichenko, A.A.; Moortgat-Pick, G.A.; Pahl, P.; /Tel Aviv U. /Cornell U., Phys. Dept. /SLAC /Tennessee U. /Humboldt U., Berlin /DESY /Yerevan Phys. Inst. /Aachen, Tech. Hochsch. /DESY, Zeuthen /Princeton U. /Durham U. /Daresbury

    2008-03-06

    An experiment (E166) at the Stanford Linear Accelerator Center (SLAC) has demonstrated a scheme in which a multi-GeV electron beam passed through a helical undulator to generate multi-MeV, circularly polarized photons which were then converted in a thin target to produce positrons (and electrons) with longitudinal polarization above 80% at 6 MeV. The results are in agreement with Geant4 simulations that include the dominant polarization-dependent interactions of electrons, positrons and photons in matter.

  20. Neutron polarizers based on polarized ^3He

    NASA Astrophysics Data System (ADS)

    Gentile, T. R.; Jones, G. L.; Thompson, A. K.; Fei, X.; Keith, C. D.; Rich, D.; Snow, W. M.; Penttila, S.

    1997-10-01

    Research is underway at NIST, Indiana Univ., and LANL to develop neutron polarizers and analyzers based on polarized ^3He. Such devices, which rely on the strong spin dependence of the neutron capture cross section by polarized ^3He, have applications in weak interaction physics and materials science. In addition, the technology for polarized ^3He production is directly applicable to polarized gas MRI of lungs, and polarized targets. Our program, which includes both the spin-exchange and metastability-exchange optical pumping methods, will be reviewed. Spin-exchange has been used to analyze a polarized cold neutron beam at NIST, and also for lung imaging in collaboration with the Univ. of Pennsylvania. In the metastable method, the ^3He is polarized at low pressure, and must be substantially compressed. A piston compressor has been designed for this goal at Indiana Univ. and is under construction. At NIST we have compressed polarized gas using an apparatus that is based on a modified commercial diaphragm pump.

  1. Linear Polarization Measurements of Chromospheric Emission Lines

    NASA Technical Reports Server (NTRS)

    Sheeley, N. R., Jr.; Keller, C. U.

    2003-01-01

    We have used the Zurich Imaging Stokes Polarimeter (ZIMPOL I) with the McMath-Pierce 1.5 m main telescope on Kitt Peak to obtain linear polarization measurements of the off-limb chromosphere with a sensitivity better than 1 x 10(exp -5). We found that the off-disk observations require a combination of good seeing (to show the emission lines) and a clean heliostat (to avoid contamination by scattered light from the Sun's disk). When these conditions were met, we obtained the following principal results: 1. Sometimes self-reversed emission lines of neutral and singly ionized metals showed linear polarization caused by the transverse Zeeman effect or by instrumental cross talk from the longitudinal Zeeman effect in chromospheric magnetic fields. Otherwise, these lines tended to depolarize the scattered continuum radiation by amounts that ranged up to 0.2%. 2. Lines previously known to show scattering polarization just inside the limb (such as the Na I lambda5889 D2 and the He I lambda5876 D3 lines) showed even more polarization above the Sun's limb, with values approaching 0.7%. 3. The O I triplet at lambda7772, lambda7774, and lambda7775 showed a range of polarizations. The lambda7775 line, whose maximum intrinsic polarizability, P(sub max), is less than 1%, revealed mainly Zeeman contributions from chromospheric magnetic fields. However, the more sensitive lambda7772 (P(sub max) = 19%) and lambda7774 (P(sub max) = 29%) lines had relatively strong scattering polarizations of approximately 0.3% in addition to their Zeeman polarizations. At times of good seeing, the polarization spectra resolve into fine structures that seem to be chromospheric spicules.

  2. Helical Dipole Magnets for Polarized Protons in RHIC

    NASA Astrophysics Data System (ADS)

    Syphers, M.; Courant, E.; Fischer, W.; Luccio, A.; Mariam, F.; Peggs, S.; Pilat, F.; Roser, T.; Tepikian, S.; Tsoupas, N.; Willen, E.; Katayama, T.; Hatanaka, K.; Kawaguchi, T.; Okamura, M.; Tominaka, T.; Wu, H.; Ptitsin, V.; Shatunov, Y.

    1997-05-01

    The Brookhaven Relativistic Heavy Ion Collider (RHIC) will be able to support experiments using polarized proton beams. Siberian Snakes are used to maintain polarization in this high energy superconducting collider. To make efficient use of available space while taking advantage of high field superconducting magnets, 4 Tesla helical dipole magnets will be used. These magnets generate a central dipole field in which the field direction rotates through 360^circ about the longitudinal axis over the length of the device. An arrangement of four such magnets can produce the desired change in the spin direction while keeping the proton orbit outside of the ``Snake'' unaltered. Similar magnet arrangements will be used to produce longitudinal polarization at the two major interaction points in RHIC. The basic requirements and layout of these magnets are described, as well as tolerances on field quality and integrated field strengths. First results of tests of prototype helical magnets will be discussed.

  3. Polarization Effects in Lambda and Anti-Lambda Production at HERMES

    SciTech Connect

    Belostotski, S. L.

    2009-08-04

    Study of the LAMBDA and LAMBDA hyperon production in the HERMES experiment is discussed. The data were collected using a 27.6 GeV longitudinally polarized positron (or electron) beam of the HERA accelerator and a polarized or unpolarized target. The transverse polarizations (perpendicular to the production plane) of the LAMBDA and LAMBDA hyperons have been measured. The spin transfer K{sub LL} from the longitudinally polarized target has been found for inclusively detected LAMBDA and LAMBDA events. Longitudinal spin transfer D{sub LL} from the beam to the LAMBDA hyperon in the deep inelastic scattering regime has been analyzed. The D{sub LL} for LAMBDA has been measured for the first time.

  4. Polarization effects in double open-charm production at LHCb

    NASA Astrophysics Data System (ADS)

    Echevarría, Miguel G.; Kasemets, Tomas; Mulders, Piet J.; Pisano, Cristian

    2015-04-01

    Double open-charm production is one of the most promising channels to disentangle single from double parton scattering (DPS) and study different properties of DPS. Several studies of the DPS contributions have been made. A missing ingredient so far has been the study of polarization effects, arising from spin correlations between the two partons inside an unpolarized proton. We investigate the impact polarization has on the double open-charm cross section. We show that the longitudinally polarized gluons can give significant contributions to the cross section, but for most of the considered kinematic region only have a moderate effect on the shape. We compare our findings to the LHCb data in the D 0 D 0 final state, identify observables where polarization does have an impact on the distribution of the final state particles, and suggest measurements which could lead to first experimental indications of, or limits on, polarization in DPS.

  5. Milliarcsecond polarization structure of the superluminal quasar 3C 273

    NASA Astrophysics Data System (ADS)

    Roberts, David H.; Kollgaard, Ronald I.; Brown, Leslie F.; Gabuzda, Denise C.; Wardle, John F. C.

    1990-09-01

    A 2 x 10 marcsec-resolution determination is presented for the total intensity and linear polarization structures of the superluminal quasar 3C 273 at 5 GHz. Substantial polarized flux was detected from several superluminal components of the jet, whose fractional polarization increased symmetrically with distance from the core; the most distant component is highly polarized and exhibits a highly ordered magnetic field. Within a few marcsec of the core, the inferred magnetic field orientation varies rapidly with position along the jet. The primarily longitudinal magnetic field orientation is concluded to become established within 20 marcsec of the core. A highly disorganized magnetic field is the most plausible explanation for the low degree of polarization in the innermost regions of the jet.

  6. Charm hadroproduction results from Fermilab E-400

    SciTech Connect

    Coteus, P.; Binkley, M.; Bossi, F.; Butler, J.; Cumalat, J.P.; DiCorato, M.; Diesburg, M.; Enagonio, J.; Filaseta, J.; Frabetti, P.L.

    1987-09-01

    Results are presented from Fermilab E-400 on the production of charmed baryons and mesons at a mean energy of 640 GeV. We show evidence for the charm-strange baryon, ..xi../sub c//sup +/, and present our measurements of its mass, width, lifetime, cross section and relative branching fractions, and the A, x/sub f/, p/sub t/, and particle/antiparticle dependence of the state. We show evidence for both the ..sigma../sub c//sup 2 +/ and ..sigma../sub c//sup 0/, and present measurements of three mass differences, ..sigma../sub c//sup 2 +/ - ..sigma../sub c//sup 0/, ..sigma../sub c//sup 0/ - ..lambda../sub c//sup +/, and ..sigma../sub c//sup 2 +/ - ..lambda../sub c//sup +/. Measurements of the A dependence and particle/antiparticle ratios for ..sigma../sub c/ production are also presented. We show preliminary results on the ratio of two decay modes of the D/sup 0/, D/sup 0/ ..-->.. K/sup +/K/sup -/ and D/sup 0/ ..-->.. K/sub 0/anti K/sub 0/. The latter mode has not been previously observed. 8 refs., 10 figs.

  7. Hadroproduction of heavy quarkonia at the LHC

    SciTech Connect

    Berezhnoy, A. V.; Likhoded, A. K.; Luchinsky, A. V. Poslavsky, S. V.

    2015-05-15

    The production of heavy quarkonia at the LHC is considered. It is shown that, in the case of the inclusive production of χ{sub cJ}P-wave charmonia, existing experimental data can be described upon taking into account next-to-leading corrections, a dominant contribution coming from color-singlet states. For the case of B{sub c}-meson production, it is shown that, at experimentally accessible values of the transverse momentum, power-law corrections to the cross section make a significant contribution, with the result that the cross-section ratio σ(B{sub c})/σ(B) develops a p{sub T} dependence not observed in the fragmentation regime. The case of double vector-charmonium production is also considered.

  8. Undulator-Based Production of Polarized Photons

    SciTech Connect

    Professor Kirk McDonald

    2008-05-29

    "Project Title: Undulator-Based Production of Polarized Photons" DOE Contract Number: FG02-04ER41355 Principal Investigator: Prof. Kirk McDonald Period of Performance: 09/10/2004 thru 08/31/2006 This award was to fund Princeton's activity on SLAC experiment E166, "Undulator-Based Production of Polarized Positrons" which was performed at SLAC during June and September 2005. Princeton U. fabricated a magnetic spectrometer for this experiment, and participated in the commissioning, operation, and analysis of the experiment, for which Prof. McDonald was a co-spokesperson. The experiment demonstrated that an intense positron beam with 80% longitudinal polarization could be generated by conversion of MeVenergy circularly polarized photons in a thin target, which photons were generated by passage of high-energy electrons through a helical undulator. This technique has since been adopted as the baseline for the polarized positron source of the proposed International Linear Collider. Results of the experiment have been published in Physical Review Letters, vol 100, p 210801 (2008) [see attached .pdf file], and a longer paper is in preparation.

  9. Polarized Light Corridor Demonstrations.

    ERIC Educational Resources Information Center

    Davies, G. R.

    1990-01-01

    Eleven demonstrations of light polarization are presented. Each includes a brief description of the apparatus and the effect demonstrated. Illustrated are strain patterns, reflection, scattering, the Faraday Effect, interference, double refraction, the polarizing microscope, and optical activity. (CW)

  10. Polarization at SLAC

    SciTech Connect

    Woods, M.

    1995-01-01

    A highly polarized electron beam is a key feature. for the Current physics program at SLAC. An electron beam polarization of 80% can now be routinely achieved for typically 5000 hours of machine operation per year. Two main Physics programs utilize the polarized beam. Fixed target experiments in End Station A study the collision of polarized electrons with polarized nuclear targets to elucidate the spin structure of the nucleon and to provide an important test of QCD. Using the SLAC Linear Collider, collisions of polarized electrons with unpolarized positrons allow precise measurements of parity violation in the Z-fermion couplings and provide a very precise measurement of tile weak mixing angle. This paper discusses polarized beam operation at SLAC, and gives an overview of the polarized physics program.

  11. A Translational Polarization Rotator

    NASA Technical Reports Server (NTRS)

    Chuss, David T.; Wollack, Edward J.; Pisano, Giampaolo; Ackiss, Sheridan; U-Yen, Kongpop; Ng, Ming wah

    2012-01-01

    We explore a free-space polarization modulator in which a variable phase introduction between right- and left-handed circular polarization components is used to rotate the linear polarization of the outgoing beam relative to that of the incoming beam. In this device, the polarization states are separated by a circular polarizer that consists of a quarter-wave plate in combination with a wire grid. A movable mirror is positioned behind and parallel to the circular polarizer. As the polarizer-mirror distance is separated, an incident liear polarization will be rotated through an angle that is proportional to the introduced phase delay. We demonstrate a prototype device that modulates Stokes Q and U over a 20% bandwidth.

  12. Longitudinal spin transfer to the {lambda} hyperon in semiinclusive deep-inelastic scattering

    SciTech Connect

    Airapetian, A.; Deconinck, W.; Lorenzon, W.; Akopov, N.; Akopov, Z.; Avakian, R.; Avetissian, A.; Elbakian, G.; Gharibyan, V.; Marukyan, H.; Rostomyan, A.; Taroian, S.; Amarian, M.; Andrus, A.; Bailey, P.; Bouwhuis, M.; Chiang, H. C.; Linden-Levy, L. A.; Makins, N. C. R.; Rubin, J.

    2006-10-01

    The transfer of polarization from a high-energy positron to a {lambda}{sup 0} hyperon produced in semiinclusive deep-inelastic scattering has been measured. The data have been obtained by the HERMES experiment at DESY using the 27.6 GeV longitudinally polarized positron beam of the HERA collider and unpolarized gas targets internal to the positron (electron) storage ring. The longitudinal spin-transfer coefficient is found to be D{sub LL{sup '}}{sup {lambda}}=0.11{+-}0.10(stat){+-}0.03(syst) at an average fractional energy carried by the {lambda}{sup 0} hyperon =0.45. The dependence of D{sub LL{sup '}}{sup {lambda}} on both the fractional energy z and the fractional longitudinal momentum x{sub F} is presented.

  13. Spin polarization transfer in exclusive phi electroproduction

    NASA Astrophysics Data System (ADS)

    Rakness, Gregory Leif

    The helicity structure of the diffractive reaction γ* + A --> f + A was studied with f mesons produced by longitudinally polarized positrons scattering from nuclear targets. By moment analysis of the distributions of data in the azimuthal production angle and two f --> K+K -decay angles, values for the elements of the spin-density matrix of the f meson were measured. As the helicity structure of the photon is known from the theory of Quantum Electrodynamics, the target contribution to the helicity of the f meson can be inferred. The data indicate that the f meson preserves the helicity of the photon in the kinematic range of this experiment, with the magnitude of the helicity preserving amplitude measured to be |T11| = 1.28 +/- 0.05 and the magnitude of the largest helicity changing amplitude measured to be | T1-1| = 0.36 +/- 0.14. The predictions of a 2g exchange model based on perturbative Quantum Chromodynamics are compared to the data, and found not to agree with the observed matrix elements. With the observation that the helicity of the photon is preserved by the f , the ratio of the longitudinal to transverse polarized photoproduction cross sections for the f meson, Rf = σL /σT, can be computed from the measured longitudinal polarization of the f . The data are combined with previous published data, and fit to the parameterization Rf = (0.38 +/- 0.04) (Q2/ M2f )0.87+/-012, in approximate agreement with the Vector Meson Dominance model of the photon. The results are compared with the results for the ρ0 vector meson.

  14. Polar Ozone Workshop. Abstracts

    NASA Technical Reports Server (NTRS)

    Aikin, Arthur C.

    1988-01-01

    Results of the proceedings of the Polar Ozone Workshop held in Snowmass, CO, on May 9 to 13, 1988 are given. Topics covered include ozone depletion, ozonometry, polar meteorology, polar stratospheric clouds, remote sensing of trace gases, atmospheric chemistry and dynamical simulations.

  15. Hybrid polarization control

    NASA Astrophysics Data System (ADS)

    Gray, George R.; Ibragimov, Edem; Sluz, Joseph; Sova, Raymond

    2005-05-01

    We demonstrate a novel method of polarization control that combines rotatable waveplates (angle control) and variable retarders (retardance control). Such a "hybrid" polarization controller performs far better than conventional controllers, allowing nearly perfect arbitrary-to-arbitrary polarization transformations. We show theoretically that the two control parameters augment one another because they tend to result in orthogonal movements on the Poincaré sphere.

  16. Graphing Polar Curves

    ERIC Educational Resources Information Center

    Lawes, Jonathan F.

    2013-01-01

    Graphing polar curves typically involves a combination of three traditional techniques, all of which can be time-consuming and tedious. However, an alternative method--graphing the polar function on a rectangular plane--simplifies graphing, increases student understanding of the polar coordinate system, and reinforces graphing techniques learned…

  17. Playing with Polarizers.

    ERIC Educational Resources Information Center

    Hecht, Jeff

    1991-01-01

    Discussed is how polarized sunglasses block glare, help spot subtle differences in surfaces, and give a clearer view under water. Information on unpolarized and polarized light is provided. The reasons causing glare to occur and how polarizers decrease glare are discussed. (KR)

  18. Polarity at Many Levels

    ERIC Educational Resources Information Center

    Flannery, Maura C.

    2004-01-01

    An attempt is made to find how polarity arises and is maintained, which is a central issue in development. It is a fundamental attribute of living things and cellular polarity is also important in the development of multicellular organisms and controversial new work indicates that polarization in mammals may occur much earlier than previously…

  19. Physics with Polarized Nuclei.

    ERIC Educational Resources Information Center

    Thompson, William J.; Clegg, Thomas B.

    1979-01-01

    Discusses recent advances in polarization techniques, specifically those dealing with polarization of atomic nuclei, and how polarized beams and targets are produced. These techniques have greatly increased the scope of possible studies, and provided the tools for testing fundamental symmetries and the spin dependence of nuclear forces. (GA)

  20. Bumblebees Learn Polarization Patterns

    PubMed Central

    Foster, James J.; Sharkey, Camilla R.; Gaworska, Alicia V.A.; Roberts, Nicholas W.; Whitney, Heather M.; Partridge, Julian C.

    2014-01-01

    Summary Foraging insect pollinators such as bees must find and identify flowers in a complex visual environment. Bees use skylight polarization patterns for navigation [1–3], a capacity mediated by the polarization-sensitive dorsal rim area (DRA) of their eye [4, 5]. While other insects use polarization sensitivity to identify appropriate habitats [6], oviposition sites, and food sources [7], to date no nonnavigational functions of polarization vision have been identified in bees. Here we investigated the ability of bumblebees (Bombus terrestris) to learn polarization patterns on artificial “flowers” in order to obtain a food reward. We show that foraging bumblebees can learn to discriminate between two differently polarized targets, but only when the target artificial “flower” is viewed from below. A context for these results is provided by polarization imaging of bee-pollinated flowers, revealing the potential for polarization patterns in real flowers. Bees may therefore have the ability to use polarization vision, possibly mediated by their polarization-sensitive DRA, both for navigation and to learn polarization patterns on flowers, the latter being the first nonnavigational function for bee polarization vision to be identified. PMID:24909321

  1. Polarization feedback laser stabilization

    DOEpatents

    Esherick, Peter; Owyoung, Adelbert

    1988-01-01

    A system for locking two Nd:YAG laser oscillators includes an optical path for feeding the output of one laser into the other with different polarizations. Elliptical polarization is incorporated into the optical path so that the change in polarization that occurs when the frequencies coincide may be detected to provide a feedback signal to control one laser relative to the other.

  2. Calculation of polarization effects

    SciTech Connect

    Chao, A.W.

    1983-09-01

    Basically there are two areas of accelerator applications that involve beam polarization. One is the acceleration of a polarized beam (most likely a proton beam) in a synchrotron. Another concerns polarized beams in an electron storage ring. In both areas, numerical techniques have been very useful.

  3. Three-dimensional orientation-unlimited polarization encryption by a single optically configured vectorial beam

    PubMed Central

    Li, Xiangping; Lan, Tzu-Hsiang; Tien, Chung-Hao; Gu, Min

    2012-01-01

    The interplay between light polarization and matter is the basis of many fundamental physical processes and applications. However, the electromagnetic wave nature of light in free space sets a fundamental limit on the three-dimensional polarization orientation of a light beam. Although a high numerical aperture objective can be used to bend the wavefront of a radially polarized beam to generate the longitudinal polarization state in the focal volume, the arbitrary three-dimensional polarization orientation of a beam has not been achieved yet. Here we present a novel technique for generating arbitrary three-dimensional polarization orientation by a single optically configured vectorial beam. As a consequence, by applying this technique to gold nanorods, orientation-unlimited polarization encryption with ultra-security is demonstrated. These results represent a new landmark of the orientation-unlimited three-dimensional polarization control of the light–matter interaction. PMID:22893122

  4. Polarization transfer in inelastic scattering and pionic models of the EMC effect

    SciTech Connect

    Carey, T.A.; Jones, K.W.; McClelland, J.B.; Moss, J.M.; Rees, L.B.; Tanaka, N.; Bacher, A.D.

    1985-01-01

    The aim of the experiment reported was to make a precise test of the enhanced pion field model in a medium-energy scattering experiment. The quantity probed is the spin-longitudinal response function, a measure of the nuclear pion density which is used explicitly in the pion-excess models of the EMC effect. The point of reference used is deuterium. The spin-dependent response functions for heavy targets and /sup 2/H are compared using identical experimental techniques. The technique of complete polarization transfer is used to separate the spin-longitudinal and spin-transverse response in the continuum. The experiment consisted of precise determinations of the polarization transfer coefficients for 500 MeV protons inelastically scattered from Pb, Ca, and /sup 2/H. The experiment utilized longitudinal, sideways, and normal polarized beams in conjunction with final polarization analysis from the focal-plane polarimeter of the high-resolution spectrometer. Quantities constructed from these data are the longitudinal and transverse spin-flip probabilities. Calculations were performed of the ratio of longitudinal to transverse response functions and of the EMC effect with the same model. No evidence was found for collectivity in the isovector spin-longitudinal response function. 10 refs. (LEW)

  5. Energetic electron-bunch generation in a phase-locked longitudinal laser electric field

    NASA Astrophysics Data System (ADS)

    Xiao, K. D.; Huang, T. W.; Ju, L. B.; Li, R.; Yang, S. L.; Yang, Y. C.; Wu, S. Z.; Zhang, H.; Qiao, B.; Ruan, S. C.; Zhou, C. T.; He, X. T.

    2016-04-01

    Energetic electron acceleration processes in a plasma hollow tube irradiated by an ultraintense laser pulse are investigated. It is found that the longitudinal component of the laser field is much enhanced when a linear polarized Gaussian laser pulse propagates through the plasma tube. This longitudinal field is of π /2 phase shift relative to the transverse electric field and has a π phase interval between its upper and lower parts. The electrons in the plasma tube are first pulled out by the transverse electric field and then trapped by the longitudinal electric field. The trapped electrons can further be accelerated to higher energy in the presence of the longitudinal electric field. This acceleration mechanism is clearly illustrated by both particle-in-cell simulations and single particle modelings.

  6. Composition law for polarizers

    NASA Astrophysics Data System (ADS)

    Lages, J.; Giust, R.; Vigoureux, J.-M.

    2008-09-01

    The polarization process when polarizers act on an optical field is studied. We give examples for two kinds of polarizers. The first kind presents an anisotropic absorption—as in a Polaroid film—and the second one is based on total reflection at the interface with a birefringent medium. Using the Stokes vector representation, we determine explicitly the trajectories of the wave light polarization during the polarization process. We find that such trajectories are not always geodesics of the Poincaré sphere as is usually thought. Using the analogy between light polarization and special relativity, we find that the action of successive polarizers on the light wave polarization is equivalent to the action of a single resulting polarizer followed by a rotation achieved, for example, by a device with optical activity. We find a composition law for polarizers similar to the composition law for noncollinear velocities in special relativity. We define an angle equivalent to the relativistic Wigner angle which can be used to quantify the quality of two composed polarizers.

  7. The Physics of Polarization

    NASA Astrophysics Data System (ADS)

    Degl'Innocenti, Egidio Landi

    2015-10-01

    The introductory lecture that has been delivered at this Symposium is a condensed version of an extended course held by the author at the XII Canary Island Winter School from November 13 to November 21, 2000. The full series of lectures can be found in Landi Degl'Innocenti (2002). The original reference is organized in 20 Sections that are here itemized: 1. Introduction, 2. Description of polarized radiation, 3. Polarization and optical devices: Jones calculus and Muller matrices, 4. The Fresnel equations, 5. Dichroism and anomalous dispersion, 6. Polarization in everyday life, 7. Polarization due to radiating charges, 8. The linear antenna, 9. Thomson scattering, 10. Rayleigh scattering, 11. A digression on Mie scattering, 12. Bremsstrahlung radiation, 13. Cyclotron radiation, 14. Synchrotron radiation, 15. Polarization in spectral lines, 16. Density matrix and atomic polarization, 17. Radiative transfer and statistical equilibrium equations, 18. The amplification condition in polarized radiative transfer, and 19. Coupling radiative transfer and statistical equilibrium equations.

  8. Polarization dependent, surface plasmon induced photoconductance in gold nanorod arrays

    NASA Astrophysics Data System (ADS)

    Diefenbach, S.; Erhard, N.; Schopka, J.; Martin, A.; Karnetzky, C.; Iacopino, D.; Holleitner, A. W.

    2014-03-01

    We report on the photoconductance in two-dimensional arrays of gold nanorods which is strongly enhanced at the frequency of the longitudinal surface plasmon of the nanorods. The arrays are formed by a combination of droplet deposition and stamping of gold nanorod solutions on SiO2 substrates. We find that the plasmon induced photoconductance is sensitive to the linear polarization of the exciting photons. We interpret the occurrence of the photoconductance as a bolometric enhancement of the arrays' conductance upon excitation of the longitudinal surface plasmon resonance of the nanorods.

  9. Longitudinal dynamics in storage rings

    SciTech Connect

    Colton, E.P.

    1986-01-01

    The single-particle equations of motion are derived for charged particles in a storage ring. Longitudinal space charge is included in the potential assuming an infinitely conducting circular beam pipe with a distributed inductance. The framework uses Hamilton's equations with the canonical variables phi and W. The Twiss parameters for longitudinal motion are also defined for the small amplitude synchrotron oscillations. The space-charge Hamiltonian is calculated for both parabolic bunches and ''matched'' bunches. A brief analysis including second-harmonic rf contributions is also given. The final sections supply calculations of dynamical quantities and particle simulations with the space-charge effects neglected.

  10. Longitudinal Double Spin Asymmetry in Inclusive Jet Production atSTAR

    SciTech Connect

    Kowalik, Katarzyna; STAR Collaboration

    2006-08-15

    This contribution reports on the first measurement of the longitudinal double-spin asymmetry A{sub LL} for the inclusive production of jets in polarized proton-proton collisions at {radical}s = 200 GeV. The data were collected with STAR at RHIC in the years 2003 and 2004, and correspond to a sampled integrated luminosity of 0.3 pb{sup -1} with beam polarizations up to 45%. The results on A{sub LL} cover jet transverse momenta 5 < p{sub T} < 17 GeV/c and agree with perturbative QCD evaluations based on deep-inelastic scattering parametrizations for the gluon polarization in the proton. The results disfavor large positive gluon polarization in the polarized proton.

  11. Evidence of Longitudinal Acoustic Phonon Generation in Si Doping Superlattices by Ge Prism-Coupled THz Laser Radiation

    NASA Astrophysics Data System (ADS)

    Wilson, T.; Kasper, E.; Oehme, M.; Schulze, J.; Korolev, K.

    2014-11-01

    We report on the direct excitation of 246 GHz longitudinal acoustic phonons in silicon doping superlattices by the resonant absorption of nanosecond-pulsed far-infrared laser radiation of the same frequency. A longitudinally polarized evanescent laser light field is coupled to the superlattice through a germanium prism providing total internal reflection at the superlattice interface. The ballistic phonon signal is detected by a superconducting aluminum bolometer. The sample is immersed in low-temperature liquid helium.

  12. Asymmetric chemical reactions by polarized quantum beams

    NASA Astrophysics Data System (ADS)

    Takahashi, Jun-Ichi; Kobayashi, Kensei

    One of the most attractive hypothesis for the origin of homochirality in terrestrial bio-organic compounds (L-amino acid and D-sugar dominant) is nominated as "Cosmic Scenario"; a chiral impulse from asymmetric excitation sources in space triggered asymmetric reactions on the surfaces of such space materials as meteorites or interstellar dusts prior to the existence of terrestrial life. 1) Effective asymmetric excitation sources in space are proposed as polarized quantum beams, such as circularly polarized light and spin polarized electrons. Circularly polarized light is emitted as synchrotron radiation from tightly captured electrons by intense magnetic field around neutron stars. In this case, either left-or right-handed polarized light can be observed depending on the direction of observation. On the other hand, spin polarized electrons is emitted as beta-ray in beta decay from radioactive nuclei or neutron fireballs in supernova explosion. 2) The spin of beta-ray electrons is longitudinally polarized due to parity non-conservation in the weak interaction. The helicity (the the projection of the spin onto the direction of kinetic momentum) of beta-ray electrons is universally negative (left-handed). For the purpose of verifying the asymmetric structure emergence in bio-organic compounds by polarized quantum beams, we are now carrying out laboratory simulations using circularly polarized light from synchrotron radiation facility or spin polarized electron beam from beta-ray radiation source. 3,4) The target samples are solid film or aqueous solution of racemic amino acids. 1) K.Kobayashi, K.Kaneko, J.Takahashi, Y.Takano, in Astrobiology: from simple molecules to primitive life; Ed. V.Basiuk; American Scientific Publisher: Valencia, 2008. 2) G.A.Gusev, T.Saito, V.A.Tsarev, A.V.Uryson, Origins Life Evol. Biosphere. 37, 259 (2007). 3) J.Takahashi, H.Shinojima, M.Seyama, Y.Ueno, T.Kaneko, K.Kobayashi, H.Mita, M.Adachi, M.Hosaka, M.Katoh, Int. J. Mol. Sci. 10, 3044

  13. Device For Viewing Polarized Light

    NASA Technical Reports Server (NTRS)

    Noever, David A.

    1995-01-01

    Technique for detection of polarized light based on observation of scene through two stacked polarizing disks. No need to rotate polarizers to create flicker indicative of polarization. Implemented by relatively simple, lightweight apparatus. Polarization seen as bow-tie rainbow pattern. Advantageous for detecting polarization in variety of meteorological, geological, astronomical, and related applications.

  14. Consecutive polarizers arrangement producing maximum polarized light intensity

    NASA Astrophysics Data System (ADS)

    Wirjawan, Johannes V. D.

    2016-03-01

    Polarizer mainly functions as a specific filter that blocks or transmits lights of certain polarization. Malus' law predicts the average intensity of polarized light passing a polarizer that transmits certain polarization direction will be proportional to the squared cosine of angle between the two polarization directions. Arranging several polarizers consecutively with various transmission directions will produce various final intensity as well as final polarized direction. Specific arrangement of an arbitrary number (N > 3) of polarizers producing maximum intensity of polarized light will be discussed in this paper. In addition, interesting pattern of maximum values of some trigonometric functions that are difficult to be solved analytically can be obtained from this discussion.

  15. Recent COMPASS results on the gluon polarization

    SciTech Connect

    Quintans, Catarina

    2009-03-23

    The spin structure of the nucleon is studied in the COMPASS experiment at CERN/SPS, from the collisions of 160 GeV polarized muon beam with a {sup 6}LiD target. The data collected from 2002 to 2006 provide an accurate measurement of longitudinal double spin cross-section asymmetries. The latest results on the gluon polarization, accessed from two independent analyses of photon-gluon fusion selected events, are presented. The study of the open-charm production allows to extract the gluon polarization (in LO QCD) from the measurement of the asymmetry, the value obtained being {delta}g/g -0.49{+-}0.27(stat){+-}0.11(syst), at an average x{sub g} 0.11{sub -0.05}{sup +0.11} and a scale <{mu}{sup 2}> = 13(GeV/c){sup 2}. An alternative and independent way to study the gluon polarization, by studying the high transverse momentum hadron pairs produced, leads to a value {delta}g/g 0.08{+-}0.10(stat){+-}0.05(syst), at x{sub g}{sup a{nu}} 0.082{sub -0.027}{sup +0.041} and <{mu}{sup 2}> = 3(GeV/c){sup 2}.

  16. LONGITUDINAL STUDY OF AGING (LSOA)

    EPA Science Inventory

    The Longitudinal Study of Aging (LSOA) is a collaborative effort of the National Center for Health Statistics (NCHS) and the National Institute on Aging (NIA). The Supplement on Aging (SOA), conducted in conjunction with the 1984 National Health Interview Survey (NHIS), served as...

  17. The National Longitudinal Surveys Handbook.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. Center for Human Resource Research.

    This volume discussed the research methodology used in the National Longitudinal Surveys of Labor Market Ecperience (NLS). The survey studied employment market conditions for four groups in the labor force: men, aged 45-59; women, aged 30-44; young men, aged 14-24; and young women, aged 14-24. Data were collected on 20,000 individuals over a five…

  18. Longitudinally-vibrating surgical microelectrode

    NASA Technical Reports Server (NTRS)

    Feldstein, C.; Crawford, D.; Kawabus, E. W.

    1977-01-01

    Microelectrode attached to cone of loudspeaker imparting longitudinal vibrations, penetrates relatively tough tissue of arterial walls easier and with more precise depth control because dimpling is eliminated. Vibrating microelectrode has been successfully used to make accurate oxygen-content measurements in arterial walls.

  19. Extracting the flavor dependence of the polarized sea quarks

    NASA Astrophysics Data System (ADS)

    Xu, Qinghua

    2015-10-01

    The measurement of single spin asymmetry AL of W bosons in longitudinally polarized pp collisions at RHIC provides an unique probe for the flavor separation of the nucleon spin structure, especially the polarization of sea quarks. The recent AL results of W bosons from RHIC via leptonic decay provided significant new constraints on the helicity distributions of light sea quarks in addition to constraints from the semi-inclusive deep inelastic scattering data, which also indicated a symmetry breaking between anti-u and anti-d quark polarization in the nucleon. In 2013 the RHIC/STAR experiment collected a proton-proton collision data sample about 3 times larger than the previous data sample. The newest results of AL analysis from RHIC W program and the impact on sea quark polarization will be discussed.

  20. Polarization-dependent SERS at differently oriented single gold nanorods.

    PubMed

    Jiao, Jiqing; Wang, Xiao; Wackenhut, Frank; Horneber, Anke; Chen, Liuping; Failla, Antonio Virgilio; Meixner, Alfred J; Zhang, Dai

    2012-03-01

    We investigated the influence of the orientation of individual gold nanorods on the polarization-dependent single-particle surface-enhanced Raman spectroscopy (SERS) of adenine. Higher-order laser beams (radial and azimuthal polarizations) have been used in combination with a parabolic mirror-assisted confocal optical microscope. Based on the photoluminescence (PL) patterns of the single gold nanorods and the simulated electric-field distribution in the focus, we distinguished between isolated gold rods and clusters as well as single nanorods with different orientations. We found that for single gold nanorods lying flat on the substrate, the longitudinal particle plasmon resonance (PPR) mode can be excited more efficiently with the in-plane field component in the focus of an azimuthally polarized laser beam, which enables the observation of stronger enhanced adenine Raman spectra from the single gold nanorods compared to the case of a radially polarized beam. PMID:22378600

  1. Automatic Bayesian polarity determination

    NASA Astrophysics Data System (ADS)

    Pugh, D. J.; White, R. S.; Christie, P. A. F.

    2016-07-01

    The polarity of the first motion of a seismic signal from an earthquake is an important constraint in earthquake source inversion. Microseismic events often have low signal-to-noise ratios, which may lead to difficulties estimating the correct first-motion polarities of the arrivals. This paper describes a probabilistic approach to polarity picking that can be both automated and combined with manual picking. This approach includes a quantitative estimate of the uncertainty of the polarity, improving calculation of the polarity probability density function for source inversion. It is sufficiently fast to be incorporated into an automatic processing workflow. When used in source inversion, the results are consistent with those from manual observations. In some cases, they produce a clearer constraint on the range of high-probability source mechanisms, and are better constrained than source mechanisms determined using a uniform probability of an incorrect polarity pick.

  2. Automatic Bayesian polarity determination

    NASA Astrophysics Data System (ADS)

    Pugh, D. J.; White, R. S.; Christie, P. A. F.

    2016-04-01

    The polarity of the first motion of a seismic signal from an earthquake is an important constraint in earthquake source inversion. Microseismic events often have low signal-to-noise ratios, which may lead to difficulties estimating the correct first-motion polarities of the arrivals. This paper describes a probabilistic approach to polarity picking that can be both automated and combined with manual picking. This approach includes a quantitative estimate of the uncertainty of the polarity, improving calculation of the polarity probability density function for source inversion. It is sufficiently fast to be incorporated into an automatic processing workflow. When used in source inversion, the results are consistent with those from manual observations. In some cases, they produce a clearer constraint on the range of high-probability source mechanims, and are better constrained than source mechanisms determined using a uniform probability of an incorrect polarity pick.

  3. A dual polarized antenna system using a meanderline polarizer

    NASA Technical Reports Server (NTRS)

    Burger, H. A.

    1978-01-01

    Certain applications of synthetic aperture radars require transmitting on one linear polarization and receiving on two orthogonal linear polarizations for adequate characterization of the surface. To meet the current need at minimum cost, it was desirable to use two identical horizontally polarized shaped beam antennas and to change the polarization of one of them by a polarization conversion plate. The plate was realized as a four-layer meanderline polarizer designed to convert horizontal polarization to vertical.

  4. Polarization feedback laser stabilization

    DOEpatents

    Esherick, P.; Owyoung, A.

    1987-09-28

    A system for locking two Nd:YAG laser oscillators includes an optical path for feeding the output of one laser into the other with different polarizations. Elliptical polarization is incorporated into the optical path so that the change in polarization that occurs when the frequencies coincide may be detected to provide a feedback signal to control one laser relative to the other. 4 figs.

  5. The polarization of continuum radiation in sunspots. I - Rayleigh and Thomson scattering

    NASA Technical Reports Server (NTRS)

    Finn, G. D.; Jefferies, J. T.

    1974-01-01

    Expressions are derived for the Stokes parameters of light scattered by a layer of free electrons and hydrogen atoms in a sunspot. A physically reasonable sunspot model was found so that the direction of the calculated linear polarization agrees reasonably with observations. The magnitude of the calculated values of the linear polarization agrees generally with values observed in the continuum at 5830 A. Circular polarization in the continuum also accompanies electron scattering in spot regions; however for commonly accepted values of the longitudinal magnetic field, the predicted circular polarization is much smaller than observed.

  6. Asymptotes in Polar Coordinates.

    ERIC Educational Resources Information Center

    Fay, Temple H.

    1986-01-01

    An old way to determine asymptotes for curves described in polar coordinates is presented. Practice in solving trigonometric equations, in differentiation, and in calculating limits is involved. (MNS)

  7. Polarization at SLC

    SciTech Connect

    Swartz, M.L.

    1988-07-01

    The SLAC Linear Collider has been designed to readily accommodate polarized electron beams. Considerable effort has been made to implement a polarized source, a spin rotation system, and a system to monitor the beam polarization. Nearly all major components have been fabricated. At the current time, several source and polarimeter components have been installed. The installation and commissioning of the entire system will take place during available machine shutdown periods as the commissioning of SLC progresses. It is expected that a beam polarization of 45% will be achieved with no loss in luminosity. 13 refs., 15 figs.

  8. Polarized negative ions

    SciTech Connect

    Haeberli, W.

    1981-04-01

    This paper presents a survey of methods, commonly in use or under development, to produce beams of polarized negative ions for injection into accelerators. A short summary recalls how the hyperfine interaction is used to obtain nuclear polarization in beams of atoms. Atomic-beam sources for light ions are discussed. If the best presently known techniques are incorporated in all stages of the source, polarized H/sup -/ and D/sup -/ beams in excess of 10 ..mu..A can probably be achieved. Production of polarized ions from fast (keV) beams of polarized atoms is treated separately for atoms in the H(25) excited state (Lamb-Shift source) and atoms in the H(1S) ground state. The negative ion beam from Lamb-Shift sources has reached a plateau just above 1 ..mu..A, but this beam current is adequate for many applications and the somewhat lower beam current is compensated by other desirable characteristics. Sources using fast polarized ground state atoms are in a stage of intense development. The next sections summarize production of polarized heavy ions by the atomic beam method, which is well established, and by optical pumping, which has recently been demonstrated to yield very large nuclear polarization. A short discussion of proposed ion sources for polarized /sup 3/He/sup -/ ions is followed by some concluding remarks.

  9. Polarization In Remote Sensing

    NASA Astrophysics Data System (ADS)

    Egan, Walter G.

    1988-06-01

    Various aspects of polarization in remote sensing are presented including mathematical treatments and selected experimental observations. The observations are of the percent polarization from Haleakala volcanic ash, basalt powder, rhyolytic oumice. rose quartz, niccolite, ilmenite, black oak leaves. dried red pine needles, a New Haven red pine stand, moist soil, the sky above Mauna Loa Observatory, the sky above Long Island in summer and winter, and cirrus clouds. Also, space based shuttle photographic observations of polarization are described. Instrumental polarization from a Cassegrainian telescope is described as well as the design of an imaging soectropolarimeter for remote sensing. A list is presented of twelve polarimetric properties associated with remote sensing.

  10. Three-dimensional polarization marked multiple-QR code encryption by optimizing a single vectorial beam

    NASA Astrophysics Data System (ADS)

    Lin, Chao; Shen, Xueju; Hua, Binbin; Wang, Zhisong

    2015-10-01

    We demonstrate the feasibility of three dimensional (3D) polarization multiplexing by optimizing a single vectorial beam using a multiple-signal window multiple-plane (MSW-MP) phase retrieval algorithm. Original messages represented with multiple quick response (QR) codes are first partitioned into a series of subblocks. Then, each subblock is marked with a specific polarization state and randomly distributed in 3D space with both longitudinal and transversal adjustable freedoms. A generalized 3D polarization mapping protocol is established to generate a 3D polarization key. Finally, multiple-QR code is encrypted into one phase only mask and one polarization only mask based on the modified Gerchberg-Saxton (GS) algorithm. We take the polarization mask as the cyphertext and the phase only mask as additional dimension of key. Only when both the phase key and 3D polarization key are correct, original messages can be recovered. We verify our proposal with both simulation and experiment evidences.

  11. Planetary Wave Influence on Wintertime OH Meinel Longitudinal Variation?

    NASA Astrophysics Data System (ADS)

    Winick, J. R.; Picard, R. H.; Wintersteiner, P. P.; Mlynczak, M. G.; Russell, J. M.; Gordley, L.

    2009-05-01

    We report on very unusual conditions in the upper mesosphere during the boreal winters of 2004 and 2006. Unusually bright OH volume emissions, as measured by TIMED/SABER, occurred in the region north of 60N. These emissions also occurred at unusually low altitudes, while at the same time very high temperatures characterized the upper mesosphere. These large perturbations allowed us to see more clearly longitudinal spatial and temporal variations that were present in the emissions. The affected areas varied in size and location on time scales of a few days and had a distinct planetary-wave wave-1 structure. We present data demonstrating the variability in the emissions and temperatures throughout the polar region and the correlations among them, and we contrast their behavior with that in normal years. The underlying cause of the correlations and longitudinal structure appears to be greatly enhanced downwelling in the upper mesosphere, which in turn was produced by unusual dynamical conditions in the lower atmosphere, consisting of stratospheric warmings and perturbations of wave structures within the polar vortex.

  12. Longitudinally slotted conical horn antenna with small flare angle

    NASA Astrophysics Data System (ADS)

    Scharten, T.; Nellen, J.; van den Bogaart, F.

    1981-06-01

    The radiation and cross polarization characteristics of a longitudinally slotted, conical horn antenna with small flare angle, excited in the modified TE(11) mode, are investigated. To this end the electromagnetic wave propagation in a longitudinally slotted circular waveguide is studied first, using a wall reactance model. Because of the need to introduce mode-dependent wall reactances in the present structure, conditions for orthogonality are given. Propagation characteristics and field line patterns are presented. It turns out that the modified TE(11) mode in this guide, used as an aperture antenna, produces a main radiation lobe which can be made nearly symmetrical around the axis over a wide frequency range by a proper choice of the slot depth. As a typical example, the maximum cross polarization level in the main lobe is lower than -30 to -45 dB, dependent on slot depth and frequency range. Experiments carried out with a slotted conical horn antenna with small flare angle confirm the theoretical results.

  13. Manipulating photoinduced voltage in metasurface with circularly polarized light.

    PubMed

    Bai, Qiang

    2015-02-23

    Recently, the concept of metasurface has provided one an unprecedented opportunity and ability to control the light in the deep subwavelength scale. However, so far most efforts are devoted to exploiting the novel scattering properties and applications of metasurface in optics. Here, I theoretically and numerically demonstrate that longitudinal and transverse photoinduced voltages can be simultaneously realized in the proposed metasurface utilizing the magnetic resonance under the normal incidence of circularly polarized light, which may extend the concept and functionality of metasurface into the electronics and may provide a potential scheme to realize a nanoscale tunable voltage source through a nanophotonic roadmap. The signs of longitudinal and transverse photoin-duced voltages can be manipulated by tuning the resonant frequency and the handedness of circularly polarized light, respectively. Analytical formulae of photoinduced voltage are presented based on the theory of symmetry of field. This work may bridge nanophotonics and electronics, expands the capability of metasurface and has many potential applications. PMID:25836566

  14. Recent results of gluon and sea quark polarization measurements in polarized proton-proton collisions at STAR

    NASA Astrophysics Data System (ADS)

    Li, Xuan; Star Collaboration

    2014-09-01

    The STAR experiment at RHIC is carrying out a comprehensive high-energy spin physics program to understand the internal structure and dynamics of the proton in polarized proton-proton collisions at = 200 GeV and = 500/510 GeV. STAR has the capability, with nearly full azimuthal coverage, to reconstruct leptons, hadrons and jets in the mid-rapidity region (|η| < 1). The results for inclusive jet longitudinal double spin asymmetries taken during the 2009 RHIC run indicate the first non-zero gluon contribution (Δg(x,Q2)/g(x,Q2)) to the proton spin for 0.05 < x < 1 (Bjorken-x: momentum fraction of partons). Recent longitudinal single-spin asymmetry measurements of W+/- bosons at = 500/510 GeV in polarized proton-proton collisions provide a direct probe of the polarized anti-u and anti-d quark distributions (Δū(x, Q2), Δbar d(x, Q2)). These results better constrain the polarized gluon and sea quark distributions of the proton in the RHIC sensitive kinematic region. Future measurements with continuing high energy polarized proton-proton run at RHIC and detector upgrade will explore the gluonic contribution to the proton spin in extended range.

  15. Preservation and control of the proton and deuteron polarizations in the proposed electron-ion collider at Jefferson Lab

    SciTech Connect

    Kondratenko, Anatoliy; Derbenev, Yaroslav S.; Filatov, Yury; Lin, Fanglei; Morozov, Vasiliy; Kondratenko, M. A.; Zhang, Yuhong

    2014-01-01

    We propose a scheme of preserving the proton and deuteron beam polarizations during acceleration and storage in the proposed electron-ion collider at Jefferson Lab. This scheme allows one to provide both the longitudinal and transverse polarization orientations of the proton and deuteron beams at the interaction points of the figure-8 ion collider ring. We discuss questions of matching the polarization direction at all stages of the beam transport including the pre-booster, large booster and ion collider ring.

  16. Measurements of spin observables in pseudo-scalar meson photo-production using polarized neutrons in solid HD

    SciTech Connect

    Kageya, Tsuneo

    2014-01-01

    A measurement of psuedo-scalar meson photo production from longitudinally polarized solid HD has been carried out with the CLAS at Thomas Jefferson National Accelerator Facility (Jlab) with circularly and linearly polarized photon beams. Its aim is to measure a complete set of spin observables for the neutron simultaneously from the same experiment. As a polarized neutron, deutron in HD was used. Preliminary asymmetries are shown for the {pi}{sup -} channel.

  17. Measurements of spin observables in pseudo-scalar meson photo-production using polarized neutrons in solid HD

    NASA Astrophysics Data System (ADS)

    Kageya, T.

    2014-01-01

    A measurement of psuedo-scalar meson photo production from longitudinally polarized solid HD has been carried out with the CLAS at Thomas Jefferson National Accelerator Facility (Jlab) with circularly and linearly polarized photon beams. Its aim is to measure a complete set of spin observables for the neutron simultaneously from the same experiment. As a polarized neutron, deutron in HD was used. Preliminary asymmetries are shown for the π- channel.

  18. Longitudinal modes along thin piezoelectric waveguides for liquid sensing applications.

    PubMed

    Caliendo, Cinzia

    2015-01-01

    The propagation of longitudinally polarized acoustic modes along thin piezoelectric plates (BN, ZnO, InN, AlN and GaN) is theoretically studied, aiming at the design of high frequency electroacoustic devices suitable for work in liquid environments. The investigation of the acoustic field profile across the plate revealed the presence of longitudinally polarized Lamb modes, travelling at velocities close to that of the longitudinal bulk acoustic wave propagating in the same direction. Such waves are suitable for the implementation of high-frequency, low-loss electroacoustic devices operating in liquid environments. The time-averaged power flow density, the phase velocity and the electroacoustic coupling coefficient K2 dispersion curves were studied, for the first (S0) and four higher order (S1, S2, S3, S4) symmetrical modes for different electrical boundary conditions. Two electroacoustic coupling configurations were investigated, based on interdigitated transducers, with or without a metal floating electrode at the opposite plate surface. Enhanced performances, such as a K2 as high as 8.5% and a phase velocity as high as 16,700 m/s, were demostrated for the ZnO- and BN-based waveguides, as an example. The relative velocity changes, and the inertial and viscous sensitivities of the first symmetric and anti-symmetric mode, S0 and A0, propagating along thin plates bordered by a viscous liquid were derived using the perturbation approach. The present study highlights the feasibility of the piezoelectric waveguides to the development of high-frequency, integrated-circuits compatible electroacoustic devices suitable for working in liquid environment. PMID:26043174

  19. Longitudinal Modes along Thin Piezoelectric Waveguides for Liquid Sensing Applications

    PubMed Central

    Caliendo, Cinzia

    2015-01-01

    The propagation of longitudinally polarized acoustic modes along thin piezoelectric plates (BN, ZnO, InN, AlN and GaN) is theoretically studied, aiming at the design of high frequency electroacoustic devices suitable for work in liquid environments. The investigation of the acoustic field profile across the plate revealed the presence of longitudinally polarized Lamb modes, travelling at velocities close to that of the longitudinal bulk acoustic wave propagating in the same direction. Such waves are suitable for the implementation of high-frequency, low-loss electroacoustic devices operating in liquid environments. The time-averaged power flow density, the phase velocity and the electroacoustic coupling coefficient K2 dispersion curves were studied, for the first (S0) and four higher order (S1, S2, S3, S4) symmetrical modes for different electrical boundary conditions. Two electroacoustic coupling configurations were investigated, based on interdigitated transducers, with or without a metal floating electrode at the opposite plate surface. Enhanced performances, such as a K2 as high as 8.5% and a phase velocity as high as 16,700 m/s, were demostrated for the ZnO- and BN-based waveguides, as an example. The relative velocity changes, and the inertial and viscous sensitivities of the first symmetric and anti-symmetric mode, S0 and A0, propagating along thin plates bordered by a viscous liquid were derived using the perturbation approach. The present study highlights the feasibility of the piezoelectric waveguides to the development of high-frequency, integrated-circuits compatible electroacoustic devices suitable for working in liquid environment. PMID:26043174

  20. The Polar Insulation Investigation

    ERIC Educational Resources Information Center

    Urban-Rich, Juanita

    2006-01-01

    In this article, the author developed an activity called "The Polar Insulation Investigation." This activity builds on students' natural interest in "things polar" and introduces them to animal adaptations in a unique way. The aim of the exploration is to determine the role of animal coverings (e.g., blubber, fur, and feathers) and to see which is…

  1. Our Polar Past

    ERIC Educational Resources Information Center

    Clary, Renee; Wandersee, James

    2009-01-01

    The study of polar exploration is fascinating and offers students insights into the history, culture, and politics that affect the developing sciences at the farthest ends of Earth. Therefore, the authors think there is value in incorporating polar exploration accounts within modern science classrooms, and so they conducted research to test their…

  2. Polar Science Is Cool!

    ERIC Educational Resources Information Center

    Weeks, Sophie

    2012-01-01

    Children are fascinated by the fact that polar scientists do research in extremely cold and dangerous places. In the Arctic they might be viewed as lunch by a polar bear. In the Antarctic, they could lose toes and fingers to frostbite and the wind is so fast it can rip skin off. They camp on ice in continuous daylight, weeks from any form of…

  3. Polarized Light: Three Demonstrations.

    ERIC Educational Resources Information Center

    Goehmann, Ruth; Welty, Scott

    1984-01-01

    Describes three demonstrations used in the Chicago Museum of Science and Industry polarized light show. The procedures employed are suitable for the classroom by using smaller polarizers and an overhead projector. Topic areas include properties of cellophane tape, nondisappearing arrows, and rope through a picket fence. (JN)

  4. Mechanism of lunar polarization.

    PubMed

    Hopfield, J J

    1966-03-18

    A theoretical model to explain the negative polarization of moonlight at small lunar phase angles is developed. The model is based on the polarization of light in the diffraction region bordering the geometric shadow of an opaque dielectric obstacle. PMID:17817298

  5. LONGITUDINAL LASER WIRE AT SNS

    SciTech Connect

    Aleksandrov, Alexander V; Liu, Yun; Zhukov, Alexander P

    2014-01-01

    This paper describes a longitudinal H- beam profile scanner that utilizes laser light to detach convoy electrons and an MCP to collect and measure these electrons. The scanner is located in MEBT with H- energy of 2.5MeV and an RF frequency 402.5MHz. The picosecond pulsed laser runs at 80.5MHz in sync with the accelerator RF. The laser beam is delivered to the beam line through a 30m optical fiber. The pulse width after the fiber transmission measures about 10ps. Scanning the laser phase effectively allows measurements to move along ion bunch longitudinal position. We are able to reliably measure production beam bunch length with this method. The biggest problem we have encountered is background signal from electrons being stripped by vacuum. Several techniques of signal detection are discussed.

  6. The Importance of Longitudinal Studies

    NASA Astrophysics Data System (ADS)

    Knezek, Patricia

    2014-01-01

    It has been eight years since the AAS Council unanimously endorsed the document, known as "Equity Now: The Pasadena Recommendations for Gender Equality in Astronomy," in January 2005. This document was the main product of the conference entitled “Women in Astronomy II: Ten Years After” (WIA II), held in June 2003 in Pasadena, CA. One of the key recommendations represented in that document was the need for a longitudinal study of astronomers. It was recognized that in order to understand our own field, how it is evolving, and the impact on individuals, we need to track people over time. I will discuss the fundamental questions that led to the recommendation, and set the stage for the current (ongoing) longitudinal study.

  7. Polarization and polarization fatigue in ferroelectrics

    NASA Astrophysics Data System (ADS)

    Du, Xiaofeng

    This thesis addresses some fundamental issues in ferroelectricity and its applications through a computational and experimental effort. It focuses on a variety of perovskite-type ferroelectric oxides and investigates the physical basis for spontaneous polarization, domain wall dynamics, and texture development in thin film applications. The dipole-dipole interactions between ionic species in perovskite-type materials have been calculated to determine the local field and the lattice instability. Different ferroelectric and anti-ferroelectric polarization transitions can be realized by taking into account the structure distortion of the parent perovskites. We find the local field is enhanced by short range disorder and its nature varies from disorder to disorder, causing polarization transitions in non-(100) directions. The molecular field theory has also been extended to layered perovskites, which favors in-plane polarization over c-polarization. These theoretical predictions are in agreement with the experimental observations of various perovskites and layered perovskites in both single crystal and thin film forms. Domain switching in PZT has been studied by probing the frequency dependency of polarization hysteresis. A picture of thermally activated domain wall movement is established from the frequency spectra of coercive field. The field dependence of domain wall bulging and the nature of the binding between pinning obstacles and the walls are inferred from such a study. Consistent with this picture, polarization fatigue can be defined as a process of increasing the resistance from pinning defects to domain wall motion. The chemical species that act as pinning defects have been identified through model experiments that control carrier injection, electrode interfaces, and film compositions. Based on these observations, a methodology is proposed to evaluate and predict the fatigue damage of both PZT and layered perovskite thin films. Processing of layered

  8. Parallel Polarization State Generation

    PubMed Central

    She, Alan; Capasso, Federico

    2016-01-01

    The control of polarization, an essential property of light, is of wide scientific and technological interest. The general problem of generating arbitrary time-varying states of polarization (SOP) has always been mathematically formulated by a series of linear transformations, i.e. a product of matrices, imposing a serial architecture. Here we show a parallel architecture described by a sum of matrices. The theory is experimentally demonstrated by modulating spatially-separated polarization components of a laser using a digital micromirror device that are subsequently beam combined. This method greatly expands the parameter space for engineering devices that control polarization. Consequently, performance characteristics, such as speed, stability, and spectral range, are entirely dictated by the technologies of optical intensity modulation, including absorption, reflection, emission, and scattering. This opens up important prospects for polarization state generation (PSG) with unique performance characteristics with applications in spectroscopic ellipsometry, spectropolarimetry, communications, imaging, and security. PMID:27184813

  9. Polarization of clouds

    NASA Astrophysics Data System (ADS)

    Goloub, Philippe; Herman, Maurice; Parol, Frederic

    1995-12-01

    This paper reports the main results concerning polarization by clouds derived from POLDER (polarization and directionality of earth's reflectances) airborne version. These results tend to confirm the high information content in the polarization (phase, altimetry). The preliminary results of EUCREX'94 (European Cloud Radiation Experiment) evidenced the drastically different polarized signatures for ice crystals and water droplets. Here we report systematic and statistically significative observations over the whole EUCREX data set. The results show that the cirrus exhibit their own signature. Preliminary observations performed during CLEOPATRA'91 (Cloud Experiment Ober Pfaffenhofen And Transport) and EUCREX'94 campaigns have shown the feasibility of cloud altimetry using spectral information (443 nm and 865 nm) of the polarized light over liquid water droplets clouds. Altimetry technique has been generalized on ASTEX-SOFIA'92 and EUCREX'94 data sets. All these results are presented and discussed in this paper.

  10. Precision Polarization of Neutrons

    NASA Astrophysics Data System (ADS)

    Martin, Elise; Barron-Palos, Libertad; Couture, Aaron; Crawford, Christopher; Chupp, Tim; Danagoulian, Areg; Estes, Mary; Hona, Binita; Jones, Gordon; Klein, Andi; Penttila, Seppo; Sharma, Monisha; Wilburn, Scott

    2009-05-01

    Determining polarization of a cold neutron beam to high precision is required for the next generation neutron decay correlation experiments at the SNS, such as the proposed abBA and PANDA experiments. Precision polarimetry measurements were conducted at Los Alamos National Laboratory with the goal of determining the beam polarization to the level of 10-3 or better. The cold neutrons from FP12 were polarized using optically polarized ^3He gas as a spin filter, which has a highly spin-dependent absorption cross section. A second ^ 3He spin filter was used to analyze the neutron polarization after passing through a resonant RF spin rotator. A discussion of the experiment and results will be given.

  11. Parallel Polarization State Generation

    NASA Astrophysics Data System (ADS)

    She, Alan; Capasso, Federico

    2016-05-01

    The control of polarization, an essential property of light, is of wide scientific and technological interest. The general problem of generating arbitrary time-varying states of polarization (SOP) has always been mathematically formulated by a series of linear transformations, i.e. a product of matrices, imposing a serial architecture. Here we show a parallel architecture described by a sum of matrices. The theory is experimentally demonstrated by modulating spatially-separated polarization components of a laser using a digital micromirror device that are subsequently beam combined. This method greatly expands the parameter space for engineering devices that control polarization. Consequently, performance characteristics, such as speed, stability, and spectral range, are entirely dictated by the technologies of optical intensity modulation, including absorption, reflection, emission, and scattering. This opens up important prospects for polarization state generation (PSG) with unique performance characteristics with applications in spectroscopic ellipsometry, spectropolarimetry, communications, imaging, and security.

  12. Parallel Polarization State Generation.

    PubMed

    She, Alan; Capasso, Federico

    2016-01-01

    The control of polarization, an essential property of light, is of wide scientific and technological interest. The general problem of generating arbitrary time-varying states of polarization (SOP) has always been mathematically formulated by a series of linear transformations, i.e. a product of matrices, imposing a serial architecture. Here we show a parallel architecture described by a sum of matrices. The theory is experimentally demonstrated by modulating spatially-separated polarization components of a laser using a digital micromirror device that are subsequently beam combined. This method greatly expands the parameter space for engineering devices that control polarization. Consequently, performance characteristics, such as speed, stability, and spectral range, are entirely dictated by the technologies of optical intensity modulation, including absorption, reflection, emission, and scattering. This opens up important prospects for polarization state generation (PSG) with unique performance characteristics with applications in spectroscopic ellipsometry, spectropolarimetry, communications, imaging, and security. PMID:27184813

  13. Cell polarity: mechanochemical patterning.

    PubMed

    Goehring, Nathan W; Grill, Stephan W

    2013-02-01

    Nearly every cell type exhibits some form of polarity, yet the molecular mechanisms vary widely. Here we examine what we term 'chemical systems' where cell polarization arises through biochemical interactions in signaling pathways, 'mechanical systems' where cells polarize due to forces, stresses and transport, and 'mechanochemical systems' where polarization results from interplay between mechanics and chemical signaling. To reveal potentially unifying principles, we discuss mathematical conceptualizations of several prototypical examples. We suggest that the concept of local activation and global inhibition - originally developed to explain spatial patterning in reaction-diffusion systems - provides a framework for understanding many cases of cell polarity. Importantly, we find that the core ingredients in this framework - symmetry breaking, self-amplifying feedback, and long-range inhibition - involve processes that can be chemical, mechanical, or even mechanochemical in nature. PMID:23182746

  14. Longitudinal bulk acoustic mass sensor

    SciTech Connect

    Hales, J. H.; Teva, J.; Boisen, A.; Davis, Z. J.

    2009-07-20

    A polycrystalline silicon longitudinal bulk acoustic cantilever is fabricated and operated in air at 51 MHz. A mass sensitivity of 100 Hz/fg (1 fg=10{sup -15} g) is obtained from the preliminary experiments where a minute mass is deposited on the device by means of focused ion beam. The total noise in the currently applied measurement system allows for a minimum detectable mass of 0.5 fg in air.

  15. QCD corrections to polarization of J/{psi} and {upsilon} at Fermilab Tevatron and CERN LHC

    SciTech Connect

    Gong Bin; Wang Jianxiong

    2008-10-01

    In this work, we present more details of the calculation on the next-to-leading-order (NLO) QCD corrections to polarization of direct J/{psi} production via color singlet at the Tevatron and LHC, together with the results for {upsilon} for the first time. Our results show that the J/{psi} polarization status drastically changes from transverse polarization dominant at leading order into longitudinal polarization dominant in the whole range of the transverse momentum p{sub t} of J/{psi} when the NLO corrections are counted. For {upsilon} production, the p{sub t} distribution of the polarization status behaves almost the same as that for J/{psi} except that the NLO result is transverse polarization at small p{sub t} range. Although the theoretical evaluation predicts a larger longitudinal polarization than the measured value at the Tevatron, it may provide a solution towards the previous large discrepancy for J/{psi} and {upsilon} polarization between theoretical prediction and experimental measurement, and suggests that the next important step is to calculate the NLO corrections to hadronproduction of color-octet state J/{psi}{sup (8)} and {upsilon}{sup (8)}. Our calculations are performed in two ways: namely, we do and do not analytically sum over the polarizations, and then check them with each other.

  16. Molecular content of polar-ring galaxies

    NASA Astrophysics Data System (ADS)

    Combes, F.; Moiseev, A.; Reshetnikov, V.

    2013-06-01

    We have searched for CO lines in a sample of 21 new morphologically determined polar-ring galaxies (of which nine are kinematically confirmed), obtained from a wide search in the Galaxy Zoo project by Moiseev and collaborators. Polar-ring galaxies (PRGs) are a unique class of objects, tracing special episodes in the galaxy mass assembly: they can be formed through galaxy interaction and merging, but also through accretion from cosmic filaments. Furthermore, they enable the study of dark matter haloes in three dimensions. The polar ring itself is a sub-system rich in gas, where molecular gas is expected, and new stars are formed. Among the sample of 21 PRGs, we have detected five CO-rich systems, that can now be followed up with higher spatial resolution. Their average molecular mass is 9.4 × 109M⊙, and their average gas fraction is 27% of their baryonic mass, with a range from 15 to 43%, implying that they have just accreted a large amount of gas. The position of the detected objects in the velocity-magnitude diagram is offset from the Tully-Fisher relation of normal spirals, as was already found for PRGs. This work is part of our multi-wavelength project to determine the detailed morphology and dynamics of PRGs, test through numerical models their formation scenario, and deduce their dark matter content and 3D-shape. Based on observations carried out with the IRAM 30 m telescope. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain).Spectra of detections are available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (ftp://130.79.128.5">130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/554/A11

  17. Generation of a beam of fast electrons by tightly focusing a radially polarized ultrashort laser pulse

    SciTech Connect

    Payeur, S.; Fourmaux, S.; Schmidt, B. E.; MacLean, J. P.; Tchervenkov, C.; Legare, F.; Kieffer, J. C.; Piche, M.

    2012-07-23

    The generation of an electron beam through longitudinal field acceleration from a tightly focused radially polarized (TM{sub 01}) laser mode is reported. The longitudinal field is generated by focusing a TM{sub 01} few-cycle laser pulse (1.8 {mu}m, 550 {mu}J, 15 fs) with a high numerical aperture parabola. The created longitudinal field in the focal region is intense enough to ionize atoms and accelerate electrons to 23 keV of energy from a low density oxygen gas. The characteristics of the electron beam are presented.

  18. Parameterized Linear Longitudinal Airship Model

    NASA Technical Reports Server (NTRS)

    Kulczycki, Eric; Elfes, Alberto; Bayard, David; Quadrelli, Marco; Johnson, Joseph

    2010-01-01

    A parameterized linear mathematical model of the longitudinal dynamics of an airship is undergoing development. This model is intended to be used in designing control systems for future airships that would operate in the atmospheres of Earth and remote planets. Heretofore, the development of linearized models of the longitudinal dynamics of airships has been costly in that it has been necessary to perform extensive flight testing and to use system-identification techniques to construct models that fit the flight-test data. The present model is a generic one that can be relatively easily specialized to approximate the dynamics of specific airships at specific operating points, without need for further system identification, and with significantly less flight testing. The approach taken in the present development is to merge the linearized dynamical equations of an airship with techniques for estimation of aircraft stability derivatives, and to thereby make it possible to construct a linearized dynamical model of the longitudinal dynamics of a specific airship from geometric and aerodynamic data pertaining to that airship. (It is also planned to develop a model of the lateral dynamics by use of the same methods.) All of the aerodynamic data needed to construct the model of a specific airship can be obtained from wind-tunnel testing and computational fluid dynamics

  19. Recent developments in stored polarized electron positron beams

    NASA Astrophysics Data System (ADS)

    Rossmanith, R.

    1992-01-01

    In nearly all electron or positron storage rings the beams are polarized vertically by the Sokolov-Ternov effect. The existence of polarized beams was established both in low energy rings such as ACO (the first storage ring in which the Sokolov-Ternov polarization effect was measured), BESSY, and VEPP2 and in high energy rings such as TRISTAN, HERA, and LEP. As a result beam polarization seems to be an inherent property of electron-positron rings. It should be noted that this free polarization was never used for high energy experiments except in those instances in which exact energy calibration measurements were performed. Proposals for using stored polarized beams for internal target experiments are fairly new. Experiments with polarized longitudinal beams in LEP are still in the stage of planning. The efforts of the last few years are summarized in order to arrive at a better understanding of the spin dynamics in electron positron storage rings and to compare the experimental results with the theory. Polarimeters are not discussed.

  20. Interplanetary magnetic sector polarity inferred from polar geomagnetic field observations

    NASA Technical Reports Server (NTRS)

    Friis-Christensen, E.; Lassen, K.; Wilcox, J. M.; Gonzalez, W.; Colburn, D. S.

    1971-01-01

    In order to infer the interplanetary sector polarity from polar geomagnetic field diurnal variations, measurements were carried out at Godhavn and Thule (Denmark) Geomagnetic Observatories. The inferred interplanetary sector polarity was compared with the polarity observed at the same time by Explorer 33 and 35 magnetometers. It is shown that the polarity (toward or away from the sun) of the interplanetary magnetic field can be reliably inferred from observations of the polar cap geomagnetic fields.

  1. Neutron Polarizers Based on Polarized 3He

    SciTech Connect

    William M. Snow

    2005-05-01

    The goal of this work, which is a collaborative effort between Indiana University, NIST, and Hamilton College, is to extend the technique of polarized neutron scattering into new domains by the development and application of polarized 3He-based neutron spin filters. After the IPNS experiment which measured Zeeman sp[litting in surface scattered neutrons using a polarized 3He cell as a polarization analyzer transporterd by car from Bloomington to Chicago, the Indiana work focused on technical developments to improve the 3He polarization of the Indiana compression system. The compression system was rebuilt with a new valve system which allows gas trapped in the dead volume of the compressors at the end of the piston stroke to be exhausted and conducted back to the optical pumping cell where it can be repolarized. We also incorporated a new intermediate storage volume made at NIST from 1720 glass which will reduce polarization losses between the compressors. Furthermore, we improved the stability of the 1083 nm laser by cooling the LMA rod. We achieved 60% 3he polarization in the optical pumping cell and 87% preservation of the polarization during compression. In parallel we built a magnetically-shielded transport solenoid for use on neutron scattering instruments such as POSY which achieves a fractional field uniformity of better than 10-3 per cm. The field was mapped using an automated 3D field mapping system for in-situ measurement of magnetic field gradients Diluted magnetic semiconductors offer many exciting opportunities for investigation of spintronic effects in solids and are certain to be one of the most active areas of condensed matter physics over then next several years. These materials can act as efficient spin injectors for devices that make use of spin-dependent transport phenomena. We just (late July 2002) finished a neutron reflectivity experiment at NIST on a GaMnAs trilayer film. This material is a ferromagnetic semiconductor which is of interest

  2. Review of Polarized Ion Sources

    NASA Astrophysics Data System (ADS)

    Zelenski, A.

    2016-02-01

    Recent progress in polarized ion sources development is reviewed. New techniques for production of polarized H‑ ion (proton), D‑ (D+) and 3He++ ion beams will be discussed. A novel polarization technique was successfully implemented for the upgrade of the RHIC polarized H‑ ion source to higher intensity and polarization. In this technique, a proton beam inside the high magnetic field solenoid is produced by ionization of the atomic hydrogen beam (from an external source) in the He-gas ionizer cell. Polarized electron capture from the optically-pumped Rb vapor further produces proton polarization (Optically Pumped Polarized Ion Source technique). The upgraded source reliably delivered beam for the 2013 polarized run in RHIC at S = 510 GeV. This was a major factor contributing to RHIC polarization increase to over 60 % for colliding beams. Feasibility studies of a new polarization technique for polarized 3He++ source based on BNL Electron Beam Ion Source is also discussed.

  3. North Polar Dunes

    NASA Technical Reports Server (NTRS)

    2006-01-01

    23 January 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows dark sand dunes in the north polar region of Mars. Surrounding much of the north polar ice cap are fields of sand dunes. In this case, the strongest winds responsible for the dunes blew off the polar cap (not seen here), from the north-northwest (upper left).

    Location near: 76.5oN, 63.7oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Summer

  4. Measurements of Spin Observables in Pseudoscalar-Meson Photoproduction Using Polarized Neutrons in Solid HD

    NASA Astrophysics Data System (ADS)

    Kageya, Tsuneo

    2014-01-01

    Psuedo-scalar meson photo production measurements have been carried out with longitudinally-polarized neutrons using the circularly and linearly polarized photon beams and the CLAS at Thomas Jefferson National Accelerator Facility (Jlab). The experiment aims to obtain a complete set of spin observables on an efficient neutron target. Preliminary E asymmetries for the exclusive reaction, γ + n(p) → π- + p(p), selecting quasi free neutron kinematics are discussed.

  5. Recession of Martian north polar cap - 1979-1980 Viking observations

    NASA Technical Reports Server (NTRS)

    James, P. B.

    1982-01-01

    The polar regression curve for the Martian northern polar cap, derived from Viking observations for the 1979-1980 regression, is discussed, and comparisons with previous regression curves are made. Differences in the curves may be due to dust storms affecting the deposition of the cap. It is not possible to unambiguously ascribe differences between the curves to dynamical effects, since detailed information on the longitudinal dependence, which was an uncontrolled variable, is not available.

  6. Scattering of a modulated pulse by a circular cylinder with longitudinal slots: Reaction in the cylinder

    NASA Astrophysics Data System (ADS)

    Hosono, Hiroyuki

    1995-11-01

    Transient response from a cylinder with longitudinal slots is more complicated than that from a perfect cylinder because the electromagnetic waves are reflected from various parts of the slotted cylinder: exterior surfaces, interior surfaces, and edges. We gave the numerical analysis for E-polarized and H-polarized cases by combining the modified point matching method (MPMM) with the fast inversion of Laplace transform method (FILT). Numerical results for the inner field are presented and discussed. The physical meaning of the transient waveform is discussed in detail. Also, the precision of the analysis is checked carefully.

  7. Measurements of Direct Photon Double Longitudinal Spin Asymmetry at Large Rapidity

    NASA Astrophysics Data System (ADS)

    Bourgeois, Paul

    2008-10-01

    Direct photon production in polarized p-p collisions is expected to be the cleanest measurement of the gluon polarization. Current measurements using inclusive pion production, in the PHENIX central arms, suggest a small contribution from the gluons to the proton spin in the presently accessible Bjorken x range xBj>10-2. The addition of the Nose Cone Calorimeter (NCC) in the large rapidity 1<η<3 will allow PHENIX to access xBj˜10-3. In this talk I will present the prospects of measuring direct photon double longitudinal spin asymmetry ALL employing the NCC.

  8. Creating order with the help of randomness: generating transversely random, longitudinally invariant vector optical fields.

    PubMed

    Khonina, Svetlana N; Golub, Ilya

    2015-09-01

    We show that it is possible to generate transversely random, diffraction-free/longitudinally invariant vector optical fields. The randomness in transverse polarization distribution complements a previously studied one in intensity of scalar Bessel-type beams, adding another degree of freedom to control these beams. Moreover, we show that the relative transversely random phase distribution is also conserved along the optical axis. Thus, intensity, phase, and polarization of Bessel-type beams can be transversely random/arbitrary while invariant upon propagation. Such fields may find applications in encryption/secure communications, optical trapping, etc. PMID:26368714

  9. Polar Environmental Monitoring

    NASA Technical Reports Server (NTRS)

    Nagler, R. G.; Schulteis, A. C.

    1979-01-01

    The present and projected benefits of the polar regions were reviewed and then translated into information needs in order to support the array of polar activities anticipated. These needs included measurement sensitivities for polar environmental data (ice/snow, atmosphere, and ocean data for integrated support) and the processing and delivery requirements which determine the effectiveness of environmental services. An assessment was made of how well electromagnetic signals can be converted into polar environmental information. The array of sensor developments in process or proposed were also evaluated as to the spectral diversity, aperture sizes, and swathing capabilities available to provide these measurements from spacecraft, aircraft, or in situ platforms. Global coverage and local coverage densification options were studied in terms of alternative spacecraft trajectories and aircraft flight paths.

  10. Mercury's South Polar Region

    NASA Video Gallery

    This animation shows 89 wide-angle camera (WAC) images of Mercury’s south polar region acquired by the Mercury Dual Imaging System (MDIS) over one complete Mercury solar day (176 Earth days). Thi...

  11. Interferometric polarization control

    SciTech Connect

    Chuss, David T.; Wollack, Edward J.; Moseley, S. Harvey; Novak, Giles

    2006-07-20

    We develop the Jones and Mueller matrices for structures that allow control of the path length difference between two linear orthogonal polarizations and consider the effect of placing multiple devices in series. Specifically, we find that full polarization modulation (measurement of Stokes Q, U, and V) can be achieved by placing two such modulators in series if the relative angles of the beam-splitting grids with respect to the analyzer orientation are appropriately chosen. Such a device has several potential advantages over a spinning wave plate modulator for measuring astronomical polarization in the far infrared through millimeter: (i) The use of small, linear motions eliminates the need for cryogenic rotational bearings; (ii) the phase flexibility allows measurement of circular as well as linear polarization; and (iii) this architecture allows for both multiwavelength and broadband modulation. We also present initial laboratory results.

  12. Polarization contrast vision

    NASA Astrophysics Data System (ADS)

    Pugh, Edward N.

    1990-05-01

    An attempt is made to establish the possibility that the geometry of certain classes of vertebrate photoreceptors results in a birefringence that allows the animals to utilize the state of polarization of light striking their retinas as a meaningful stimulus parameter. Simulate the photoreceptors as dielectric waveguides using a simple physical model, and augment this theoretical work with empirical measurements of the light guiding properties of photoreceptors in isolated pieces of retina from a green sunfish (Lepomis cyanellus). With a classical conditioning paradigm, this fish's sensitivity to light is modulated by the orientation of the plane of polarization of linearly polarized light. This functional dependence was predicted by a hypothetical antagonistic mechanism between twin cones of two orientations in the animal's retinal mosaic. Further study is planned for the nature of the stimulus to which the fish is sensitive by creating a camera that will generate images based purely upon the contrast between orthogonal polarizations at each point in space.

  13. J / ψ polarization in p + p collisions at √{ s} = 200 GeV in STAR

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Balewski, J.; Banerjee, A.; Barnovska, Z.; Beavis, D. R.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chwastowski, J.; Codrington, M. J. M.; Corliss, R.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; Dhamija, S.; di Ruzza, B.; Didenko, L.; Dilks, C.; Ding, F.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Engle, K. S.; Eppley, G.; Eun, L.; Evdokimov, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Gliske, S.; Grosnick, D.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hajkova, O.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J. W.; Hays-Wehle, J. P.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Korsch, W.; Kotchenda, L.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Leight, W.; LeVine, M. J.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lima, L. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Madagodagettige Don, D. M. M. D.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Munhoz, M. G.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Oliveira, R. A. N.; Pachr, M.; Page, B. S.; Pal, S. K.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Peryt, W.; Pile, P.; Planinic, M.; Pluta, J.; Plyku, D.; Poljak, N.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Pujahari, P. R.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Roy, A.; Ruan, L.; Rusnak, J.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandacz, A.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Singaraju, R. N.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; deSouza, U. G.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Sumbera, M.; Sun, X.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szanto de Toledo, A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Vossen, A.; Wada, M.; Walker, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yan, W.; Yang, C.; Yang, Y.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Zawisza, Y.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, J. L.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.; Zyzak, M.

    2014-12-01

    We report on a polarization measurement of inclusive J / ψ mesons in the di-electron decay channel at mid-rapidity at 2 polarization measurement should help to distinguish between different models of the J / ψ production mechanism since they predict different pT dependences of the J / ψ polarization. In this analysis, J / ψ polarization is studied in the helicity frame. The polarization parameter λθ measured at RHIC becomes smaller towards high pT, indicating more longitudinal J / ψ polarization as pT increases. The result is compared with predictions of presently available models.

  14. EDITORIAL: Polarization Optics

    NASA Astrophysics Data System (ADS)

    Turunen, Jari; Friesem, Asher A.; Friberg, Ari T.

    2004-03-01

    This special issue on Polarization Optics contains one review article and 23 research papers, many of which are based on presentations at the International Commission for Optics Topical Meeting on Polarization Optics, held in Polvijärvi, Finland, between 30 June and 3 July 2003. While this issue should not in any sense be considered as a `proceedings' of this meeting, the possibility of submitting papers to it was widely advertised during the meeting, which was attended by a large fraction of prominent scientists in the field of polarization optics. Thus the quality of papers in this special issue is high. In announcing both the meeting and this special issue, we emphasized that the concept of `polarization optics' should be understood in a wide sense. In fact, all contributions dealing with the vectorial nature of light were welcome. As a result, the papers included here cover a wide range of different aspects of linear and nonlinear polarization optics. Both theoretical and experimental features are discussed. We are pleased to see that the conference and this special issue both reflect the wide diversity of important and novel polarization phenomena in optics. The papers in this special issue, and other recently published works, demonstrate that even though polarization is a fundamental property of electromagnetic fields, interest in it is rapidly increasing. The fundamental relations between partial coherence and partial polarization are currently under vigorous research in electromagnetic coherence theory. In diffractive optics it has been found that the exploitation of the vectorial nature of light can be of great benefit. Fabrication of sophisticated, spatially variable polarization-control elements is becoming possible with the aid of nanolithography. Polarization singularities and the interplay of bulk properties and topology in nanoscale systems have created much enthusiasm. In nonlinear optics, the second harmonic waves generated on reflection and

  15. Active polarization descattering.

    PubMed

    Treibitz, Tali; Schechner, Yoav Y

    2009-03-01

    Vision in scattering media is important but challenging. Images suffer from poor visibility due to backscattering and attenuation. Most prior methods for scene recovery use active illumination scanners (structured and gated), which can be slow and cumbersome, while natural illumination is inapplicable to dark environments. The current paper addresses the need for a non-scanning recovery method, that uses active scene irradiance. We study the formation of images under widefield artificial illumination. Based on the formation model, the paper presents an approach for recovering the object signal. It also yields rough information about the 3D scene structure. The approach can work with compact, simple hardware, having active widefield, polychromatic polarized illumination. The camera is fitted with a polarization analyzer. Two frames of the scene are taken, with different states of the analyzer or polarizer. A recovery algorithm follows the acquisition. It allows both the backscatter and the object reflection to be partially polarized. It thus unifies and generalizes prior polarization-based methods, which had assumed exclusive polarization of either of these components. The approach is limited to an effective range, due to image noise and illumination falloff. Thus, the limits and noise sensitivity are analyzed. We demonstrate the approach in underwater field experiments. PMID:19147870

  16. Longitudinal and transverse pyroelectric effects in a chiral ferroelectric liquid crystal

    SciTech Connect

    Yablonskii, S. V. Bondarchuk, V. V.; Soto-Bustamante, E. A.; Romero-Hasler, P. N.; Ozaki, M.; Yoshino, K.

    2015-04-15

    In this study, we compare the results of experimental investigations of longitudinal and transverse pyroelectric effects in a chiral ferroelectric crystal. In a transverse geometry, we studied freely suspended liquid-crystal films. In both geometries, samples exhibited bistability, demonstrating stable pyroelectric signals of different polarities at zero voltage. It is shown that a bistable cell based on a freely suspended film requires 40 times less energy expenditures as compared to the conventional sandwich-type cell.

  17. Fusion of a polarized projectile with a polarized target

    SciTech Connect

    Christley, J.A.; Johnson, R.C.; Thompson, I.J.

    1995-07-15

    The fusion cross sections for a polarized target with both unpolarized and polarized projectiles are studied. Expressions for the observables are given for the case when both nuclei are polarized. Calculations for fusion of an aligned {sup 165}Ho target with {sup 16}O and polarized {sup 7}Li beams are presented.

  18. Precise polarization measurements via detection of compton scattered electrons

    SciTech Connect

    Tvaskis, Vladas; Dutta, Dipangkar; Gaskell, David J.; Narayan, Amrendra

    2014-01-01

    The Qweak experiment at Jefferson Lab aims to make a 4% measurement of the parity-violating asymmetry in elastic scattering at very low Q{sup 2} of a longitudinally polarized electron beam off a proton target. One of the dominant experimental systematic uncertainties in Qweak will result from determining the beam polarization. A new Compton polarimeter was installed in the fall of 2010 to provide a non-invasive and continuous monitoring of the electron beam polarization in Hall C at Jefferson Lab. The Compton-scattered electrons are detected in four planes of diamond micro-strip detectors. We have achieved the design goals of <1% statistical uncertainty per hour and expect to achieve <1% systematic uncertainty.

  19. Polarization transfer of bremsstrahlung arising from spin-polarized electrons.

    PubMed

    Märtin, R; Weber, G; Barday, R; Fritzsche, Y; Spillmann, U; Chen, W; DuBois, R D; Enders, J; Hegewald, M; Hess, S; Surzhykov, A; Thorn, D B; Trotsenko, S; Wagner, M; Winters, D F A; Yerokhin, V A; Stöhlker, Th

    2012-06-29

    We report on a study of the polarization transfer between transversely polarized incident electrons and the emitted x rays for electron-atom bremsstrahlung. By means of Compton polarimetry we performed for the first time an energy-differential measurement of the complete properties of bremsstrahlung emission related to linear polarization, i.e., the degree of linear polarization as well as the orientation of the polarization axis. For the high-energy end of the bremsstrahlung continuum the experimental results for both observables show a high sensitivity on the initial electron spin polarization and prove that the polarization orientation is virtually independent of the photon energy. PMID:23004992

  20. Rectilinear lattices of polarization vortices with various spatial polarization distributions.

    PubMed

    Fu, Shiyao; Zhang, Shikun; Wang, Tonglu; Gao, Chunqing

    2016-08-01

    In this paper, we propose a type of rectilinear lattices of polarization vortices, each spot in which has mutually independent, and controllable spatial polarization distributions. The lattices are generated by two holograms under special design. In the experiment, the holograms are encoded on two spatial light modulators, and the results fit very well with theory. Our scheme makes it possible to generate multiple polarization vortices with various polarization distributions simultaneously, for instance, radially and azimuthally polarized beams, and can be used in the domains as polarization-based data transmission system, optical manufacture, polarization detection and so on. PMID:27505812

  1. Longitudinal study of fingerprint recognition

    PubMed Central

    Yoon, Soweon; Jain, Anil K.

    2015-01-01

    Human identification by fingerprints is based on the fundamental premise that ridge patterns from distinct fingers are different (uniqueness) and a fingerprint pattern does not change over time (persistence). Although the uniqueness of fingerprints has been investigated by developing statistical models to estimate the probability of error in comparing two random samples of fingerprints, the persistence of fingerprints has remained a general belief based on only a few case studies. In this study, fingerprint match (similarity) scores are analyzed by multilevel statistical models with covariates such as time interval between two fingerprints in comparison, subject’s age, and fingerprint image quality. Longitudinal fingerprint records of 15,597 subjects are sampled from an operational fingerprint database such that each individual has at least five 10-print records over a minimum time span of 5 y. In regard to the persistence of fingerprints, the longitudinal analysis on a single (right index) finger demonstrates that (i) genuine match scores tend to significantly decrease when time interval between two fingerprints in comparison increases, whereas the change in impostor match scores is negligible; and (ii) fingerprint recognition accuracy at operational settings, nevertheless, tends to be stable as the time interval increases up to 12 y, the maximum time span in the dataset. However, the uncertainty of temporal stability of fingerprint recognition accuracy becomes substantially large if either of the two fingerprints being compared is of poor quality. The conclusions drawn from 10-finger fusion analysis coincide with the conclusions from single-finger analysis. PMID:26124106

  2. Longitudinal heritability of childhood aggression.

    PubMed

    Porsch, Robert M; Middeldorp, Christel M; Cherny, Stacey S; Krapohl, Eva; van Beijsterveldt, Catharina E M; Loukola, Anu; Korhonen, Tellervo; Pulkkinen, Lea; Corley, Robin; Rhee, Soo; Kaprio, Jaakko; Rose, Richard R; Hewitt, John K; Sham, Pak; Plomin, Robert; Boomsma, Dorret I; Bartels, Meike

    2016-07-01

    The genetic and environmental contributions to the variation and longitudinal stability in childhood aggressive behavior were assessed in two large twin cohorts, the Netherlands Twin Register (NTR), and the Twins Early Development Study (TEDS; United Kingdom). In NTR, maternal ratings on aggression from the Child Behavior Checklist (CBCL) were available for 10,765 twin pairs at age 7, for 8,557 twin pairs at age 9/10, and for 7,176 twin pairs at age 12. In TEDS, parental ratings of conduct disorder from the Strength and Difficulty Questionnaire (SDQ) were available for 6,897 twin pairs at age 7, for 3,028 twin pairs at age 9 and for 5,716 twin pairs at age 12. In both studies, stability and heritability of aggressive behavioral problems was high. Heritability was on average somewhat, but significantly, lower in TEDS (around 60%) than in NTR (between 50% and 80%) and sex differences were slightly larger in the NTR sample. In both studies, the influence of shared environment was similar: in boys shared environment explained around 20% of the variation in aggression across all ages while in girls its influence was absent around age 7 and only came into play at later ages. Longitudinal genetic correlations were the main reason for stability of aggressive behavior. Individual differences in CBCL-Aggressive Behavior and SDQ-Conduct disorder throughout childhood are driven by a comparable but significantly different genetic architecture. © 2016 Wiley Periodicals, Inc. PMID:26786601

  3. Polarized nuclear target based on parahydrogen induced polarization

    SciTech Connect

    D. Budker, M.P. Ledbetter, S. Appelt, L.S. Bouchard, B. Wojtsekhowski

    2012-12-01

    We discuss a novel concept of a polarized nuclear target for accelerator fixed-target scattering experiments, which is based on parahydrogen induced polarization (PHIP). One may be able to reach a 33% free-proton polarization in the ethane molecule. The potential advantages of such a target include operation at zero magnetic field, fast ({approx}100 HZ) polarization oscillation (akin to polarization reversal), and operation with large intensity of an electron beam.

  4. Polarized nuclear target based on parahydrogen induced polarization

    NASA Astrophysics Data System (ADS)

    Budker, D.; Ledbetter, M. P.; Appelt, S.; Bouchard, L. S.; Wojtsekhowski, B.

    2012-12-01

    We discuss a novel concept of a polarized nuclear target for accelerator fixed-target scattering experiments, which is based on parahydrogen induced polarization (PHIP). One may be able to reach a 33% free-proton polarization in the ethane molecule. The potential advantages of such a target include operation at zero magnetic field, fast (˜100 Hz) polarization oscillation (akin to polarization reversal), and operation with large intensity of an electron beam.

  5. Time reversal invariance in polarized neutron decay

    SciTech Connect

    Wasserman, E.G.

    1994-03-01

    An experiment to measure the time reversal invariance violating (T-violating) triple correlation (D) in the decay of free polarized neutrons has been developed. The detector design incorporates a detector geometry that provides a significant improvement in the sensitivity over that used in the most sensitive of previous experiments. A prototype detector was tested in measurements with a cold neutron beam. Data resulting from the tests are presented. A detailed calculation of systematic effects has been performed and new diagnostic techniques that allow these effects to be measured have been developed. As the result of this work, a new experiment is under way that will improve the sensitivity to D to 3 {times} 10{sup {minus}4} or better. With higher neutron flux a statistical sensitivity of the order 3 {times} 10{sup {minus}5} is ultimately expected. The decay of free polarized neutrons (n {yields} p + e + {bar v}{sub e}) is used to search for T-violation by measuring the triple correlation of the neutron spin polarization, and the electron and proton momenta ({sigma}{sub n} {center_dot} p{sub p} {times} p{sub e}). This correlation changes sign under reversal of the motion. Since final state effects in neutron decay are small, a nonzero coefficient, D, of this correlation indicates the violation of time reversal invariance. D is measured by comparing the numbers of coincidences in electron and proton detectors arranged symmetrically about a longitudinally polarized neutron beam. Particular care must be taken to eliminate residual asymmetries in the detectors or beam as these can lead to significant false effects. The Standard Model predicts negligible T-violating effects in neutron decay. Extensions to the Standard Model include new interactions some of which include CP-violating components. Some of these make first order contributions to D.

  6. Polar low dynamics

    SciTech Connect

    Montgomery, M.T.; Farrell, B.F. )

    1992-12-15

    Polar lows are intense subsynoptic-scale cyclones that form over high-latitude oceans in association with deep cumulus convection and strong ambient baroclinicity. Recent observations indicate that polar lows are generally initiated by a nonaxisymmetric interaction between a surface disturbance and an upper-level mobile trough. Extant theories of polar low formation preclude study of such a process since they either constrain their models to be axisymmetric, or do not explicitly account for his transient interaction. In this work the physics of interacting upper- and lower-level potential vorticity structures is studied as an initial-value problem using a three-dimensional nonlinear geostrophic momentum model that incorporates moist processes and includes strong baroclinic dynamics. Model results illustrate the rapid formation of an intense small-scale cyclone whose structure is consistent with observations of mature polar lows. A conceptual model of polar low development is proposed. In the first stage of development, called induced self-development, a mobile upper trough initiates a rapid low-level spinup due to the enhanced omega response in a conditionally neutral baroclinic atmosphere. A secondary development follows, called diabatic destabilization, that is associated with the production of low-level potential vorticity by diabatic processes. Diabatic destabilization represents a simple mechanism for maintaining the intensity of polar lows until they reach land. In exceptional instances of negligible upper-level forcing, the latter may also describe the gradual intensification of small-scale cyclones in regions of sustained neutrality and surface baroclinicity. Ideas regarding polar low equilibration and prospects for a unified theory of arctic and midlatitude cyclones are discussed. 75 refs., 4 figs., 1 tab.

  7. Sequential Polarity-Reversing Circuit

    NASA Technical Reports Server (NTRS)

    Labaw, Clayton C.

    1994-01-01

    Proposed circuit reverses polarity of electric power supplied to bidirectional dc motor, reversible electro-mechanical actuator, or other device operating in direction depending on polarity. Circuit reverses polarity each time power turned on, without need for additional polarity-reversing or direction signals and circuitry to process them.

  8. Cylindrically polarized nondiffracting optical pulses

    NASA Astrophysics Data System (ADS)

    Ornigotti, Marco; Conti, Claudio; Szameit, Alexander

    2016-07-01

    We extend the concept of radially and azimuthally polarized optical beams to the polychromatic domain by introducing cylindrically polarized nondiffracting optical pulses. In particular, we discuss in detail the case of cylindrically polarized X-waves, both in the paraxial and nonparaxial regime. The explicit expressions for the electric and magnetic fields of cylindrically polarized X-waves are also reported.

  9. Production of polarized vector mesons off nuclei

    SciTech Connect

    Kopeliovich, B. Z.; Nemchik, J.; Schmidt, Ivan

    2007-08-15

    Using the light-cone QCD dipole formalism we investigate manifestations of color transparency (CT) and coherence length (CL) effects in electroproduction of longitudinally (L) and transversally (T) polarized vector mesons. Motivated by forthcoming data from the HERMES experiment we predict both the A and Q{sup 2} dependence of the L/T ratios for {rho}{sup 0} mesons produced coherently and incoherently off nuclei. For an incoherent reaction the CT and CL effects add up and result in a monotonic A dependence of the L/T ratio at different values of Q{sup 2}. In contrast, for a coherent process the contraction of the CL with Q{sup 2} causes an effect opposite to that of CT and we expect quite a nontrivial A dependence.

  10. Polarization twist in perovskite ferrielectrics

    PubMed Central

    Kitanaka, Yuuki; Hirano, Kiyotaka; Ogino, Motohiro; Noguchi, Yuji; Miyayama, Masaru; Moriyoshi, Chikako; Kuroiwa, Yoshihiro

    2016-01-01

    Because the functions of polar materials are governed primarily by their polarization response to external stimuli, the majority of studies have focused on controlling polar lattice distortions. In some perovskite oxides, polar distortions coexist with nonpolar tilts and rotations of oxygen octahedra. The interplay between nonpolar and polar instabilities appears to play a crucial role, raising the question of how to design materials by exploiting their coupling. Here, we introduce the concept of ‘polarization twist’, which offers enhanced control over piezoelectric responses in polar materials. Our experimental and theoretical studies provide direct evidence that a ferrielectric perovskite exhibits a large piezoelectric response because of extended polar distortion, accompanied by nonpolar octahedral rotations, as if twisted polarization relaxes under electric fields. The concept underlying the polarization twist opens new possibilities for developing alternative materials in bulk and thin-film forms. PMID:27586824

  11. Polarization twist in perovskite ferrielectrics.

    PubMed

    Kitanaka, Yuuki; Hirano, Kiyotaka; Ogino, Motohiro; Noguchi, Yuji; Miyayama, Masaru; Moriyoshi, Chikako; Kuroiwa, Yoshihiro

    2016-01-01

    Because the functions of polar materials are governed primarily by their polarization response to external stimuli, the majority of studies have focused on controlling polar lattice distortions. In some perovskite oxides, polar distortions coexist with nonpolar tilts and rotations of oxygen octahedra. The interplay between nonpolar and polar instabilities appears to play a crucial role, raising the question of how to design materials by exploiting their coupling. Here, we introduce the concept of 'polarization twist', which offers enhanced control over piezoelectric responses in polar materials. Our experimental and theoretical studies provide direct evidence that a ferrielectric perovskite exhibits a large piezoelectric response because of extended polar distortion, accompanied by nonpolar octahedral rotations, as if twisted polarization relaxes under electric fields. The concept underlying the polarization twist opens new possibilities for developing alternative materials in bulk and thin-film forms. PMID:27586824

  12. Polar low monitoring

    NASA Astrophysics Data System (ADS)

    Bobylev, Leonid; Zabolotskikh, Elizaveta; Mitnik, Leonid

    2010-05-01

    Polar lows are intense mesoscale atmospheric low pressure weather systems, developing poleward of the main baroclinic zone and associated with high surface wind speeds. Small size and short lifetime, sparse in-situ observations in the regions of their development complicate polar low study. Our knowledge of polar lows and mesocyclones has come almost entirely during the period of satellite remote sensing since, by virtue of their small horizontal scale, it was rarely possible to analyse these lows on conventional weather charts using only the data from the synoptic observing network. However, the effects of intense polar lows have been felt by coastal communities and seafarers since the earliest times. These weather systems are thought to be responsible for the loss of many small vessels over the centuries, although the nature of the storms was not understood and their arrival could not be predicted. The actuality of the polar low research is stipulated by their high destructive power: they are a threat to such businesses as oil and gas exploration, fisheries and shipping. They could worsen because of global warming: a shrinking of sea ice around the North Pole, which thawed to its record minimum in the summer of 2007, is likely to give rise to more powerful storms that form only over open water and can cause hurricane-strength winds. Therefore, study of polar lows, their timely detection, tracking and forecasting represents a challenge for today meteorology. Satellite passive microwave data, starting from Special Sensor Microwave Imager (SSM/I) onboard Defense Meteorological Satellite Program (DMSP) satellite, remain invaluable source of regularly available remotely sensed data to study polar lows. The sounding in this spectral range has several advantages in comparison with observations in visible and infrared ranges and Synthetic Aperture Radar (SAR) data: independence on day time and clouds, regularity and high temporal resolution in Polar Regions. Satellite

  13. Polarization of Starlight

    NASA Astrophysics Data System (ADS)

    Whittet, D. C. B.

    The polarization of starlight is universally attributed to directional extinction arising when dust grains along the line of sight are aligned in the presence of a magnetic field. This phenomenon provides a powerful tool for studying the optical properties of the dust (size, shape, refractive index) and for charting the galactic magnetic field. Current observational constraints at all wavelengths are consistent with a picture in which only the larger grains in the size range responsible for extinction are efficient polarizers. Small grains are much less well aligned and/or more isotropic in shape than large grains. The polarizing grains include silicates, but it is not clear whether they contain appreciable quantities of carbon. The degree of alignment is highly sensitive to ambient physical conditions as well as to particle size. The polarization efficiency per unit extinction declines with increasing density within dark clouds, hindering attempts to map the intracloud magnetic field. However, spectropolarimetric studies of interstellar ice absorption features seen in deeply embedded YSOs indicate that mantled grains within dense molecular clouds can be surprisingly efficient polarizers, suggesting that a qualitatively different alignment mechanism is operating compared with diffuse regions of the ISM. This talk will present a brief overview of key observations and their interpretation, highlight areas of uncertainty, and suggest avenues of future research. The physics of grain alignment is reviewed elsewhere in this meeting (see paper by Roberge).

  14. POLARBEAR CMB Polarization Experiment

    NASA Astrophysics Data System (ADS)

    Nishino, H.; Ade, P.; Akiba, Y.; Anthony, A.; Arnold, K.; Barron, D.; Boettger, D.; Borrill, J.; Chapmann, S.; Chinone, Y.; Dobbs, M. A.; Errard, J.; Fabbian, G.; Feng, C.; Flanigan, D.; Fuller, G.; Ghribi, A.; Grainger, W.; Halverson, N.; Hasegawa, M.; Hattori, K.; Hazumi, M.; Holzapfel, W. L.; Howard, J.; Hyland, P.; Inoue, Y.; Jaffe, A.; Jaehnig, G.; Kaneko, Y.; Katayama, N.; Keating, B.; Kermish, Z.; Kimura, N.; Kisner, T.; Lee, A. T.; Le Jeune, M.; Linder, E.; Lungu, M.; Matsuda, F.; Matsumura, T.; Miller, N. J.; Morii, H.; Moyerman, S.; Myers, M. J.; O'Brient, R.; Okamura, T.; Paar, H.; Peloton, J.; Quealy, E.; Reichardt, C. L.; Richards, P. L.; Ross, C.; Shimizu, A.; Shimon, M.; Shimmin, C.; Sholl, M.; Siritanasak, P.; Spieler, H.; Stebor, N.; Steinbach, B.; Stompor, R.; Suzuki, A.; Suzuki, J.; Tanaka, K.; Tomaru, T.; Tucker, C.; Yadav, A.; Zahn, O.

    POLARBEAR is a ground-based experiment in the Atacama desert in hile, measuring the polarization of the Cosmic Microwave Background (CMB) radiation. One of the science goals of POLARBEAR is to detect the B-mode polarization pattern of the CMB produced by primordial gravitational waves from the epoch of inflation. The detection of the B-mode polarization provides strong evidence for inflationary cosmological models. POLARBEAR is expected to reach a sensitivity to the tensor-to-scalar ratio r = 0.025 at 95% confidence level, using the data from two years of observation. With a beam size of 3.5 arcminutes, POLARBEAR is also sensitive to B-mode polarization signals at small-angular scales produced by weak gravitational lensing of large-scale structure. POLARBEAR is expected to provide a constraint on the sum of neutrino masses because of their effect on the large-scale structure. POLARBEAR was deployed in late 2011 and started observing in early 2012 at 150 GHz with an array of 1,274 polarization sensitive antenna-coupled Transition Edge Sensor (TES) bolometers. The current status of the POLARBEAR experiment is reported.

  15. Polarized protons at RHIC

    SciTech Connect

    Makdisi, Y.

    1992-10-01

    The approval for construction of the Relativistic Heavy Ion Collider (RHIC) provides a potential opportunity to collide polarized proton beams at energies up to 500 GeV in the center of mass and high luminosities approaching 2 {times} 10{sup 32}/cm{sup 2}/sec. This capability is enhanced by the fact that the AGS has already accelerated polarized protons and relies on the newly completed Accumulator/Booster for providing the required polarized proton intensity and a system of spin rotators (Siberian snakes) to retain the polarization. The RHIC Spin Collaboration was formed and submitted a Letter of Intent to construct this polarized collider capability and utilize its physics opportunities. In this presentation, I will discuss the plans to upgrade the AGS, the proposed layout of the RHIC siberian snakes, and timetables. The physics focus is the measurement of the spin dependent parton distributions with such accessible probes including high p(t) jets, direct photons, and Drell Yan. The attainable sensitivities and the progress that has been reached in defining the detector requirements will be outlined.

  16. Polarized protons at RHIC

    SciTech Connect

    Makdisi, Y.

    1992-01-01

    The approval for construction of the Relativistic Heavy Ion Collider (RHIC) provides a potential opportunity to collide polarized proton beams at energies up to 500 GeV in the center of mass and high luminosities approaching 2 {times} 10{sup 32}/cm{sup 2}/sec. This capability is enhanced by the fact that the AGS has already accelerated polarized protons and relies on the newly completed Accumulator/Booster for providing the required polarized proton intensity and a system of spin rotators (Siberian snakes) to retain the polarization. The RHIC Spin Collaboration was formed and submitted a Letter of Intent to construct this polarized collider capability and utilize its physics opportunities. In this presentation, I will discuss the plans to upgrade the AGS, the proposed layout of the RHIC siberian snakes, and timetables. The physics focus is the measurement of the spin dependent parton distributions with such accessible probes including high p(t) jets, direct photons, and Drell Yan. The attainable sensitivities and the progress that has been reached in defining the detector requirements will be outlined.

  17. A Compact Polarization Imager

    NASA Technical Reports Server (NTRS)

    Thompson, Karl E.; Rust, David M.; Chen, Hua

    1995-01-01

    A new type of image detector has been designed to analyze the polarization of light simultaneously at all picture elements (pixels) in a scene. The Integrated Dual Imaging Detector (IDID) consists of a polarizing beamsplitter bonded to a custom-designed charge-coupled device with signal-analysis circuitry, all integrated on a silicon chip. The IDID should simplify the design and operation of imaging polarimeters and spectroscopic imagers used, for example, in atmospheric and solar research. Other applications include environmental monitoring and robot vision. Innovations in the IDID include two interleaved 512 x 1024 pixel imaging arrays (one for each polarization plane), large dynamic range (well depth of 10(exp 6) electrons per pixel), simultaneous readout and display of both images at 10(exp 6) pixels per second, and on-chip analog signal processing to produce polarization maps in real time. When used with a lithium niobate Fabry-Perot etalon or other color filter that can encode spectral information as polarization, the IDID can reveal tiny differences between simultaneous images at two wavelengths.

  18. Artificial polarization components

    NASA Astrophysics Data System (ADS)

    Cescato, L.; Gluch, Ekkehard; Stork, Wilhelm; Streibl, Norbert

    1990-07-01

    High frequency surface relief structures are optically anisotropic and show interesting polarisation properties 1 . These properties can be used to produce polarizations components such as wave plates polarizers. polarizing beamsplitters etc. Our experimental results show that even gratings with relatively low spatial frequency ( periods A ) exhibit a strong phase retardation and can be used as quarter-wave plates. k INTRODUC11ON The artificial birefringence exhibited by ultrahigh frequency gratings of dielectric materials can be used to produce various polarization components2 . Such components have applications in integrated optics as well as in free space optics. In order to produce the high spatial frequencies complex processes such as electron-beam lithography and reactive ion etching are needed. We show in this paper that sinusoidal holographic gratings in photoresist exhibit also a strong phase ret even at relatively long periods. L EXPERIMENTAL MEASUREMENTS To obtain the phase retardation of a lower frequency ( period A ) grating a simple setup as used by Enger and 2 can be applied. In our case however there are three measurements necessary to obtain the phase retardation because transmission of the two perpendicularly polarized beams is different from each other. I GRATING PRODUCTION grating 2 3 4 5 6 7 8 9 period (pmj 0. 74 0. 74 0. 61 0. 54 0. 46 0. 32 0. 54 0. 54 0. 54 ne (sec) 60

  19. Shaping the focal field of radially/azimuthally polarized phase vortex with Zernike polynomials

    NASA Astrophysics Data System (ADS)

    Wei, Lei; Urbach, H. Paul

    2016-06-01

    The focal field properties of radially/azimuthally polarized Zernike polynomials are studied. A method to design the pupil field in order to shape the focal field of radially or azimuthally polarized phase vortex is introduced. With this method, we are able to obtain a pupil field to achieve a longitudinally polarized hollow spot with a depth of focus up to 12λ and 0.28λ lateral resolution (FWHM) for an optical system with numerical aperture 0.99; a pupil field to generate eight focal spots along the optical axis is also obtained with this method.

  20. Longitudinal target-spin asymmetries for deeply virtual Compton scattering

    SciTech Connect

    Seder, E.; Biselli, A.; Pisano, S.; Niccolai, S.; Smith, G. D.; Joo, K.; Adhikari, K.; Amaryan, M. J.; Anderson, M. D.; Anefalos Pereira, S.; Avakian, H.; Battaglieri, M.; Bedlinskiy, I.; Bono, J.; Boiarinov, S.; Bosted, P.; Briscoe, W.; Brock, J.; Brooks, W. K.; Bültmann, S.; Burkert, V. D.; Carman, D. S.; Carlin, C.; Celentano, A.; Chandavar, S.; Charles, G.; Colaneri, L.; Cole, P. L.; Contalbrigo, M.; Crabb, D.; Crede, V.; D’Angelo, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Deur, A.; Djalali, C.; Doughty, D.; Dupre, R.; El Fassi, L.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Fegan, S.; Filippi, A.; Fleming, J. A.; Fradi, A.; Garillon, B.; Garçon, M.; Gevorgyan, N.; Ghandilyan, Y.; Giovanetti, K. L.; Girod, F. X.; Goetz, J. T.; Gohn, W.; Gothe, R. W.; Griffioen, K. A.; Guegan, B.; Guidal, M.; Guo, L.; Hafidi, K.; Hakobyan, H.; Hanretty, C.; Harrison, N.; Hattawy, M.; Hirlinger Saylor, N.; Holtrop, M.; Hughes, S. M.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Jo, H. S.; Joosten, S.; Keith, C. D.; Keller, D.; Khachatryan, G.; Khandaker, M.; Kim, A.; Kim, W.; Klein, A.; Klein, F. J.; Koirala, S.; Kubarovsky, V.; Kuhn, S. E.; Lenisa, P.; Livingston, K.; Lu, H. Y.; MacGregor, I. J. D.; Markov, N.; Mayer, M.; McKinnon, B.; Meekins, D. G.; Mineeva, T.; Mirazita, M.; Mokeev, V.; Montgomery, R.; Moody, C. I.; Moutarde, H.; Movsisyan, A.; Munoz Camacho, C.; Nadel-Turonski, P.; Niculescu, I.; Osipenko, M.; Ostrovidov, A. I.; Paolone, M.; Pappalardo, L. L.; Park, K.; Park, S.; Pasyuk, E.; Peng, P.; Phelps, W.; Pogorelko, O.; Price, J. W.; Prok, Y.; Protopopescu, D.; Puckett, A. J. R.; Ripani, M.; Rizzo, A.; Rosner, G.; Rossi, P.; Roy, P.; Sabatié, F.; Salgado, C.; Schott, D.; Schumacher, R. A.; Senderovich, I.; Simonyan, A.; Skorodumina, I.; Sokhan, D.; Sparveris, N.; Stepanyan, S.; Stoler, P.; Strakovsky, I. I.; Strauch, S.; Sytnik, V.; Taiuti, M.; Tang, W.; Tian, Y.; Ungaro, M.; Voskanyan, H.; Voutier, E.; Walford, N. K.; Watts, D. P.; Wei, X.; Weinstein, L. B.; Wood, M. H.; Zachariou, N.; Zana, L.; Zhang, J.; Zonta, I.

    2015-01-22

    A measurement of the electroproduction of photons off protons in the deeply inelastic regime was performed at Jefferson Lab using a nearly 6-GeV electron beam, a longitudinally polarized proton target and the CEBAF Large Acceptance Spectrometer. Target-spin asymmetries for ep → e'p'y events, which arise from the interference of the deeply virtual Compton scattering and the Bethe-Heitler processes, were extracted over the widest kinematics in Q2, xB, t and Φ, for 166 four-dimensional bins. In the framework of Generalized Parton Distributions (GPDs), at leading twist the t dependence of these asymmetries provides insight on the spatial distribution of the axial charge of the proton, which appears to be concentrated in its center. In conclusion, these results bring important and necessary constraints for the existing parametrizations of chiral-even GPDs.

  1. Longitudinal electron scattering form factors for 54,56Fe

    NASA Astrophysics Data System (ADS)

    Salman, A. D.; Kadhim, D. R.

    2014-09-01

    In this paper, inelastic longitudinal electron scattering form factors for C2 transition have been studied in 54Fe and 56Fe with the aid of shell model calculations. The GX1 effective interaction for the fp-shell is used with the nucleon-nucleon realistic interaction Michigan three-range Yukawa and Modified surface delta interaction as a two-body interactions. The core polarization effects is taken into account through the first-order perturbation theory with the effective charge, which is taken to the proton and the neutron. The effective charge along with the core effects up to 6 ℏw enhanced the calculation very well and improving good agreement with the experimental data.

  2. Longitudinal target-spin asymmetries for deeply virtual compton scattering.

    PubMed

    Seder, E; Biselli, A; Pisano, S; Niccolai, S; Smith, G D; Joo, K; Adhikari, K; Amaryan, M J; Anderson, M D; Anefalos Pereira, S; Avakian, H; Battaglieri, M; Bedlinskiy, I; Bono, J; Boiarinov, S; Bosted, P; Briscoe, W; Brock, J; Brooks, W K; Bültmann, S; Burkert, V D; Carman, D S; Carlin, C; Celentano, A; Chandavar, S; Charles, G; Colaneri, L; Cole, P L; Contalbrigo, M; Crabb, D; Crede, V; D'Angelo, A; Dashyan, N; De Vita, R; De Sanctis, E; Deur, A; Djalali, C; Doughty, D; Dupre, R; El Fassi, L; Elouadrhiri, L; Eugenio, P; Fedotov, G; Fegan, S; Filippi, A; Fleming, J A; Fradi, A; Garillon, B; Garçon, M; Gevorgyan, N; Ghandilyan, Y; Giovanetti, K L; Girod, F X; Goetz, J T; Gohn, W; Gothe, R W; Griffioen, K A; Guegan, B; Guidal, M; Guo, L; Hafidi, K; Hakobyan, H; Hanretty, C; Harrison, N; Hattawy, M; Hirlinger Saylor, N; Holtrop, M; Hughes, S M; Ilieva, Y; Ireland, D G; Ishkhanov, B S; Isupov, E L; Jo, H S; Joosten, S; Keith, C D; Keller, D; Khachatryan, G; Khandaker, M; Kim, A; Kim, W; Klein, A; Klein, F J; Koirala, S; Kubarovsky, V; Kuhn, S E; Lenisa, P; Livingston, K; Lu, H Y; MacGregor, I J D; Markov, N; Mayer, M; McKinnon, B; Meekins, D G; Mineeva, T; Mirazita, M; Mokeev, V; Montgomery, R; Moody, C I; Moutarde, H; Movsisyan, A; Munoz Camacho, C; Nadel-Turonski, P; Niculescu, I; Osipenko, M; Ostrovidov, A I; Paolone, M; Pappalardo, L L; Park, K; Park, S; Pasyuk, E; Peng, P; Phelps, W; Pogorelko, O; Price, J W; Prok, Y; Protopopescu, D; Puckett, A J R; Ripani, M; Rizzo, A; Rosner, G; Rossi, P; Roy, P; Sabatié, F; Salgado, C; Schott, D; Schumacher, R A; Senderovich, I; Simonyan, A; Skorodumina, I; Sokhan, D; Sparveris, N; Stepanyan, S; Stoler, P; Strakovsky, I I; Strauch, S; Sytnik, V; Taiuti, M; Tang, W; Tian, Y; Ungaro, M; Voskanyan, H; Voutier, E; Walford, N K; Watts, D P; Wei, X; Weinstein, L B; Wood, M H; Zachariou, N; Zana, L; Zhang, J; Zonta, I

    2015-01-23

    A measurement of the electroproduction of photons off protons in the deeply inelastic regime was performed at Jefferson Lab using a nearly 6 GeV electron beam, a longitudinally polarized proton target, and the CEBAF Large Acceptance Spectrometer. Target-spin asymmetries for ep→e^{'}p^{'}γ events, which arise from the interference of the deeply virtual Compton scattering and the Bethe-Heitler processes, were extracted over the widest kinematics in Q^{2}, x_{B}, t, and ϕ, for 166 four-dimensional bins. In the framework of generalized parton distributions, at leading twist the t dependence of these asymmetries provides insight into the spatial distribution of the axial charge of the proton, which appears to be concentrated in its center. These results also bring important and necessary constraints for the existing parametrizations of chiral-even generalized parton distributions. PMID:25658994

  3. Longitudinal target-spin asymmetries for deeply virtual Compton scattering

    DOE PAGESBeta

    Seder, E.; Biselli, A.; Pisano, S.; Niccolai, S.; Smith, G. D.; Joo, K.; Adhikari, K.; Amaryan, M. J.; Anderson, M. D.; Anefalos Pereira, S.; et al

    2015-01-22

    A measurement of the electroproduction of photons off protons in the deeply inelastic regime was performed at Jefferson Lab using a nearly 6-GeV electron beam, a longitudinally polarized proton target and the CEBAF Large Acceptance Spectrometer. Target-spin asymmetries for ep → e'p'y events, which arise from the interference of the deeply virtual Compton scattering and the Bethe-Heitler processes, were extracted over the widest kinematics in Q2, xB, t and Φ, for 166 four-dimensional bins. In the framework of Generalized Parton Distributions (GPDs), at leading twist the t dependence of these asymmetries provides insight on the spatial distribution of the axialmore » charge of the proton, which appears to be concentrated in its center. In conclusion, these results bring important and necessary constraints for the existing parametrizations of chiral-even GPDs.« less

  4. Polarized beams at RHIC

    SciTech Connect

    Roser, T.

    1995-11-01

    The Relativistic Heavy Ion Collider (RHIC) at Brookhaven allows for the unique possibility of colliding two 250 GeV polarized proton beams at luminosities of up to 2 {times} 10{sup 32} cm{sup {minus}2} s{sup {minus}1}. A partial Siberian Snake in the AGS has recently been successfully tested and full Siberian Snakes, spin rotators, and polarimeters for RHIC are being developed to make the acceleration of polarized beams to 250 GeV possible. High energy polarized beam collisions will open up the unique physics opportunities of studying spin effects in hard processes, which will allow the study of the spin structure of the proton and also the verification of the many well documented expectations of spin effects in perturbative QCD and parity violation in W and Z production.

  5. A lunar polar expedition

    NASA Technical Reports Server (NTRS)

    Dowling, Richard; Staehle, Robert L.; Svitek, Tomas

    1992-01-01

    Advanced exploration and development in harsh environments require mastery of basic human survival skill. Expeditions into the lethal climates of Earth's polar regions offer useful lessons for tommorrow's lunar pioneers. In Arctic and Antarctic exploration, 'wintering over' was a crucial milestone. The ability to establish a supply base and survive months of polar cold and darkness made extensive travel and exploration possible. Because of the possibility of near-constant solar illumination, the lunar polar regions, unlike Earth's may offer the most hospitable site for habitation. The World Space Foundation is examining a scenario for establishing a five-person expeditionary team on the lunar north pole for one year. This paper is a status report on a point design addressing site selection, transportation, power, and life support requirements.

  6. South Polar Layers

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-516, 17 October 2003

    This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows eroded, stair-stepped layers in the south polar region of Mars. These layers have been considered, for the past three decades, to consist of a mixture of dust and ice. The Mars Polar Lander (MPL) mission was designed to test this hypothesis. However, sadly, MPL was lost during descent in December 1999. This exposure of south polar layered material is located near 86.3oS, 187.7oW. The image covers an area 3 km (1.9 mi) wide and is illuminated by sunlight from the upper left.

  7. Polarized Light from Jupiter

    NASA Technical Reports Server (NTRS)

    2001-01-01

    These images taken through the wide angle camera near closest approach in the deep near-infrared methane band, combined with filters which sense electromagnetic radiation of orthogonal polarization, show that the light from the poles is polarized. That is, the poles appear bright in one image, and dark in the other. Polarized light is most readily scattered by aerosols. These images indicate that the aerosol particles at Jupiter's poles are small and likely consist of aggregates of even smaller particles, whereas the particles at the equator and covering the Great Red Spot are larger. Images like these will allow scientists to ascertain the distribution, size and shape of aerosols, and consequently, the distribution of heat, in Jupiter's atmosphere.

  8. South Polar Scarps

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-438, 31 July 2003

    The terrain of the south polar residual ice cap, made up mostly of frozen carbon dioxide, has come to be known by many as 'swiss cheese terrain,' because many areas of the cap resemble slices of swiss cheese. However, not all of the south polar cap looks like a tasty lunch food. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a series of curving scarps formed by erosion and sublimation of carbon dioxide from the south polar cap. This area is located near 86.3oS, 51.2oW. The image is illuminated by sunlight from the upper left; the area is about 1.5 km (0.9 mi) wide.

  9. Diurnal polar motion

    NASA Technical Reports Server (NTRS)

    Mcclure, P.

    1973-01-01

    An analytical theory is developed to describe diurnal polar motion in the earth which arises as a forced response due to lunisolar torques and tidal deformation. Doodson's expansion of the tide generating potential is used to represent the lunisolar torques. Both the magnitudes and the rates of change of perturbations in the earth's inertia tensor are included in the dynamical equations for the polar motion so as to account for rotational and tidal deformation. It is found that in a deformable earth with Love's number k = 0.29, the angular momentum vector departs by as much as 20 cm from the rotation axis rather than remaining within 1 or 2 cm as it would in a rigid earth. This 20 cm separation is significant in the interpretation of submeter polar motion observations because it necessitates an additional coordinate transformation in order to remove what would otherwise be a 20 cm error source in the conversion between inertial and terrestrial reference systems.

  10. Spring polar ozone behavior

    NASA Technical Reports Server (NTRS)

    Aikin, Arthur C.

    1992-01-01

    Understanding of the springtime behavior of polar stratospheric ozone as of mid 1990 is summarized. Heterogeneous reactions on polar stratospheric clouds as hypothesis for ozone loss are considered and a simplified description of the behavior of Antarctic ozone in winter and spring is given. Evidence that the situation is more complicated than described by the theory is produced. Many unresolved scientific issues remain and some of the most important problems are identified. Ozone changes each spring since 1979 have clearly established for the first time that man made chlorine compounds influence stratospheric ozone. Long before important advances in satellite and in situ investigations, it was Dobson's decision to place a total ozone measuring spectrometer at Halley Bay in Antarctica during the International Geophysical Year and subsequent continuous monitoring which led to the discovery that ozone was being destroyed each spring by chlorine processed by polar stratospheric clouds.

  11. Transverse-longitudinal integrated resonator

    SciTech Connect

    Hutchinson, Donald P; Simpson, Marcus L; Simpson, John T

    2003-03-11

    A transverse-longitudinal integrated optical resonator (TLIR) is disclosed which includes a waveguide, a first and a second subwavelength resonant grating in the waveguide, and at least one photonic band gap resonant structure (PBG) in the waveguide. The PBG is positioned between the first and second subwavelength resonant gratings. An electro-optic waveguide material may be used to permit tuning the TLIR and to permit the TLIR to perform signal modulation and switching. The TLIR may be positioned on a bulk substrate die with one or more electronic and optical devices and may be communicably connected to the same. A method for fabricating a TLIR including fabricating a broadband reflective grating is disclosed. A method for tuning the TLIR's transmission resonance wavelength is also disclosed.

  12. POLARIZED NEUTRONS IN RHIC

    SciTech Connect

    COURANT,E.D.

    1998-04-27

    There does not appear to be any obvious way to accelerate neutrons, polarized or otherwise, to high energies by themselves. To investigate the behavior of polarized neutrons the authors therefore have to obtain them by accelerating them as components of heavier nuclei, and then sorting out the contribution of the neutrons in the analysis of the reactions produced by the heavy ion beams. The best neutron carriers for this purpose are probably {sup 3}He nuclei and deuterons. A polarized deuteron is primarily a combination of a proton and a neutron with their spins pointing in the same direction; in the {sup 3}He nucleus the spins of the two protons are opposite and the net spin (and magnetic moment) is almost the same as that of a free neutron. Polarized ions other than protons may be accelerated, stored and collided in a ring such as RHIC provided the techniques proposed for polarized proton operation can be adapted (or replaced by other strategies) for these ions. To accelerate polarized particles in a ring, one must make provisions for overcoming the depolarizing resonances that occur at certain energies. These resonances arise when the spin tune (ratio of spin precession frequency to orbit frequency) resonates with a component present in the horizontal field. The horizontal field oscillates with the vertical motion of the particles (due to vertical focusing); its frequency spectrum is dominated by the vertical oscillation frequency and its modulation by the periodic structure of the accelerator ring. In addition, the magnet imperfections that distort the closed orbit vertically contain all integral Fourier harmonics of the orbit frequency.

  13. Fears in Czech Adolescents: A Longitudinal Study

    ERIC Educational Resources Information Center

    Michalcáková, Radka; Lacinová, Lenka; Kyjonková, Hana; Bouša, Ondrej; Jelínek, Martin

    2013-01-01

    The present study investigates developmental patterns of fear in adolescence. It is based on longitudinal data collected as a part of the European Longitudinal Study of Pregnancy and Childhood (ELSPAC) project. A total of 186 Czech adolescents (43% girls) were assessed repeatedly at the age of 11, 13, and 15 years. The free-response method was…

  14. 14 CFR 25.145 - Longitudinal control.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Longitudinal control. 25.145 Section 25.145 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Flight Controllability and Maneuverability § 25.145 Longitudinal control. (a) It must be possible,...

  15. Modeling a Longitudinal Relational Research Data Systems

    ERIC Educational Resources Information Center

    Olsen, Michelle D. Hunt

    2010-01-01

    A study was conducted to propose a research-based model for a longitudinal data research system that addressed recommendations from a synthesis of literature related to: (1) needs reported by the U.S. Department of Education, (2) the twelve mandatory elements that define federally approved state longitudinal data systems (SLDS), (3) the…

  16. Microwave Frequency Polarizers

    NASA Technical Reports Server (NTRS)

    Ha, Vien The; Mirel, Paul; Kogut, Alan J.

    2013-01-01

    This article describes the fabrication and analysis of microwave frequency polarizing grids. The grids are designed to measure polarization from the cosmic microwave background. It is effective in the range of 500 to 1500 micron wavelength. It is cryogenic compatible and highly robust to high load impacts. Each grid is fabricated using an array of different assembly processes which vary in the types of tension mechanisms to the shape and size of the grids. We provide a comprehensive study on the analysis of the grids' wire heights, diameters, and spacing.

  17. South Polar Variety

    NASA Technical Reports Server (NTRS)

    2005-01-01

    28 July 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a view of linear troughs and mesas formed in the frozen carbon dioxide of the martian south polar residual cap. This image, obtained in May 2005, is a reminder that not all of the south polar cap landscapes resemble 'swiss cheese.'

    Location near: 86.7oS, 24.8oW Image width: width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Spring

  18. Ultracold polar KRb molecules

    NASA Astrophysics Data System (ADS)

    Neyenhuis, Brian; Chotia, Amodsen; Moses, Steven; Ye, Jun; Jin, Deborah

    2011-05-01

    Ultracold polar molecules in the quantum degenerate regime open the possibility of realizing quantum gases with long-range, and spatially anisotropic, interparticle interactions. Currently, we can create a gas of ultracold fermionic ground-state KRb molecules in with a peak density of 1012 cm-3 and a temperature just 1.4 times the Fermi temperature. We will report on efforts to further cool this gas of molecules. One possibility is to evaporatively cool a spin-polarized molecular Fermi gas confined in quasi-2D, where we would rely on dipole-dipole interactions for rethermalization. We acknowledge funding from NIST, NSF, and AFOSR-MURI.

  19. Polarization encoded color camera.

    PubMed

    Schonbrun, Ethan; Möller, Guðfríður; Di Caprio, Giuseppe

    2014-03-15

    Digital cameras would be colorblind if they did not have pixelated color filters integrated into their image sensors. Integration of conventional fixed filters, however, comes at the expense of an inability to modify the camera's spectral properties. Instead, we demonstrate a micropolarizer-based camera that can reconfigure its spectral response. Color is encoded into a linear polarization state by a chiral dispersive element and then read out in a single exposure. The polarization encoded color camera is capable of capturing three-color images at wavelengths spanning the visible to the near infrared. PMID:24690806

  20. Physics with Polarized Antiprotons

    SciTech Connect

    Lenisa, Paolo

    2008-04-30

    Polarized antiprotons will provide access to a wealth of double- (and single-) spin observables, thereby opening a window to physics uniquely accessible with the HESR at FAIR. This include a first direct measurement of the transversity distribution of the valence quarks in the proton and a first measurement of the moduli and phase of the time-like electric and magnetic form factors G{sub E,M} of the proton. Additional applications of a polarized antiproton beam can be forseen in hadron spectroscopy, and nucleon-antinucleon scattering.

  1. Femtosecond polarization pulse shaping.

    PubMed

    Brixner, T; Gerber, G

    2001-04-15

    We report computer-controlled femtosecond polarization pulse shaping where intensity, momentary frequency, and light polarization are varied as functions of time. For the first time to our knowledge, a pulse shaper is used to modulate the degree of ellipticity as well as the orientation of the elliptical principal axes within a single laser pulse by use of a 256-pixel two-layer liquid-crystal display inside a zero-dispersion compressor. Interferometric stability of the setup is not required. Complete pulse characterization is achieved by dual-channel spectral interferometry. This technology has a large range of applications, especially in the field of quantum control. PMID:18040384

  2. Transverse and longitudinal vibrations in amorphous silicon

    NASA Astrophysics Data System (ADS)

    Beltukov, Y. M.; Fusco, C.; Tanguy, A.; Parshin, D. A.

    2015-12-01

    We show that harmonic vibrations in amorphous silicon can be decomposed to transverse and longitudinal components in all frequency range even in the absence of the well defined wave vector q. For this purpose we define the transverse component of the eigenvector with given ω as a component, which does not change the volumes of Voronoi cells around atoms. The longitudinal component is the remaining orthogonal component. We have found the longitudinal and transverse components of the vibrational density of states for numerical model of amorphous silicon. The vibrations are mostly transverse below 7 THz and above 15 THz. In the frequency interval in between the vibrations have a longitudinal nature. Just this sudden transformation of vibrations at 7 THz from almost transverse to almost longitudinal ones explains the prominent peak in the diffusivity of the amorphous silicon just above 7 THz.

  3. The physics of polarization

    NASA Astrophysics Data System (ADS)

    Landi Degl'Innocenti, Egidio

    This course is intended to give a description of the basic physical concepts which underlie the study and the interpretation of polarization phenomena. Apart from a brief historical introduction (Sect. 1), the course is organized in three parts. A first part (Sects. 2 - 6) covers the most relevant facts about the polarization phenomena that are typically encountered in laboratory applications and in everyday life. In Sect. 2, the modern description of polarization in terms of the Stokes parameters is recalled, whereas Sect. 3 is devoted to introduce the basic tools of laboratory polarimetry, such as the Jones calculus and the Mueller matrices. The polarization phenomena which are met in the reflection and refraction of a beam of radiation at the separation surface between two dielectrics, or between a dielectric and a metal, are recalled in Sect. 4. Finally, Sect. 5 gives an introduction to the phenomena of dichroism and of anomalous dispersion and Sect. 6 summarizes the polarization phenomena that are commonly encountered in everyday life. The second part of this course (Sects. 7-14) deals with the description, within the formalism of classical physics, of the spectro-polarimetric properties of the radiation emitted by accelerated charges. Such properties are derived by taking as starting point the Liénard and Wiechert equations that are recalled and discussed in Sect. 7 both in the general case and in the non-relativistic approximation. The results are developed to find the percentage polarization, the radiation diagram, the cross-section and the spectral characteristics of the radiation emitted in different phenomena particularly relevant from the astrophysical point of view. The emission of a linear antenna is derived in Sect. 8. The other Sections are devoted to Thomson scattering (Sect. 9), Rayleigh scattering (Sect. 10), Mie scattering (Sect. 11), bremsstrahlung radiation (Sect. 12), cyclotron radiation (Sect. 13), and synchrotron radiation (Sect. 14

  4. LSTGEE: longitudinal analysis of neuroimaging data

    NASA Astrophysics Data System (ADS)

    Li, Yimei; Zhu, Hongtu; Chen, Yasheng; An, Hongyu; Gilmore, John; Lin, Weili; Shen, Dinggang

    2009-02-01

    Longitudinal imaging studies are essential to understanding the neural development of neuropsychiatric disorders, substance use disorders, and normal brain. Using appropriate image processing and statistical tools to analyze the imaging, behavioral, and clinical data is critical for optimally exploring and interpreting the findings from those imaging studies. However, the existing imaging processing and statistical methods for analyzing imaging longitudinal measures are primarily developed for cross-sectional neuroimaging studies. The simple use of these cross-sectional tools to longitudinal imaging studies will significantly decrease the statistical power of longitudinal studies in detecting subtle changes of imaging measures and the causal role of time-dependent covariate in disease process. The main objective of this paper is to develop longitudinal statistics toolbox, called LSTGEE, for the analysis of neuroimaging data from longitudinal studies. We develop generalized estimating equations for jointly modeling imaging measures with behavioral and clinical variables from longitudinal studies. We develop a test procedure based on a score test statistic and a resampling method to test linear hypotheses of unknown parameters, such as associations between brain structure and function and covariates of interest, such as IQ, age, gene, diagnostic groups, and severity of disease. We demonstrate the application of our statistical methods to the detection of the changes of the fractional anisotropy across time in a longitudinal neonate study. Particularly, our results demonstrate that the use of longitudinal statistics can dramatically increase the statistical power in detecting the changes of neuroimaging measures. The proposed approach can be applied to longitudinal data with multiple outcomes and accommodate incomplete and unbalanced data, i.e., subjects with different number of measurements.

  5. Phase-Controlled Polarization Modulators

    NASA Technical Reports Server (NTRS)

    Chuss, D. T.; Wollack, E. J.; Novak, G.; Moseley, S. H.; Pisano, G.; Krejny, M.; U-Yen, K.

    2012-01-01

    We report technology development of millimeter/submillimeter polarization modulators that operate by introducing a a variable, controlled phase delay between two orthogonal polarization states. The variable-delay polarization modulator (VPM) operates via the introduction of a variable phase delay between two linear orthogonal polarization states, resulting in a variable mapping of a single linear polarization into a combination of that Stokes parameter and circular (Stokes V) polarization. Characterization of a prototype VPM is presented at 350 and 3000 microns. We also describe a modulator in which a variable phase delay is introduced between right- and left- circular polarization states. In this architecture, linear polarization is fully modulated. Each of these devices consists of a polarization diplexer parallel to and in front of a movable mirror. Modulation involves sub-wavelength translations of the mirror that change the magnitude of the phase delay.

  6. Photoproduction of ω mesons off nuclei and impact of polarization on the meson-nucleon interaction

    NASA Astrophysics Data System (ADS)

    Chudakov, E.; Gevorkyan, S.; Somov, A.

    2016-01-01

    We use photoproduction of ω mesons off complex nuclei to study interactions of transversely and longitudinally polarized vector mesons with nucleons. Whereas the total cross section for interactions of the transversely polarized vector mesons with nucleons σT=σ (VTN ) can be obtained from coherent photoproduction, measurements of vector meson photoproduction in the incoherent region provide a unique opportunity to extract the yet unmeasured total cross section for longitudinally polarized mesons σL=σ (VLN ) . The predictions for the latter strongly depend on the theoretical approaches. This work is stimulated by the construction of the new experiment GlueX at Jefferson Lab, designed to study the photoproduction of mesons in the beam energy range between 5 and 12 GeV.

  7. Radiative production of sneutrinos in e+e- annihilation with polarized beams

    NASA Astrophysics Data System (ADS)

    Franke, F.; Fraas, H.

    1994-04-01

    We give for the process e++e--->ν~+ν~¯+γ of radiative sneutrino production with polarized beams the complete analytic expression for the transition amplitude. For beam energies between 100 and 500 GeV the total cross section, the photon energy spectrum, and photon angular distribution as well as the respective longitudinal polarization asymmetries are computed in representative gaugino-Higgsino mixing scenarios with the sneutrino decaying only into the lightest neutralino. Comparing the results with those for the competing standard process of radiative neutrino production we show that with the expected luminosity for a 500-GeV e+e- collider it would be difficult to identify a sneutrino lighter than both the chargino and the second lightest neutralino. The use of longitudinally polarized beams especially would not facilitate identification of the sneutrino in this mass region.

  8. Azimuthal asymmetries in single polarized proton-proton Drell-Yan processes

    SciTech Connect

    Lu Zhun; Ma Boqiang; Zhu Jiacai

    2011-10-01

    We study the azimuthal asymmetries in proton-proton Drell-Yan processes with one incident proton being transversely or longitudinally polarized. We consider particularly the asymmetries contributed by the leading-twist chiral-odd quark distributions. We analyze the asymmetries with sin(2{phi}+{phi}{sub S}) and sin(2{phi}-{phi}{sub S}) modulations in transverse single polarized p{sup {up_arrow}p} Drell-Yan and sin2{phi} asymmetries in longitudinal single polarized p{sup {yields}p} Drell-Yan at the Relativistic Heavy Ion Collider, the Japan Proton Accelerator Research Complex, E906 (Fermi Lab), and the Nuclotron-based Ion Collider Facility (Joint Institute for Nuclear Research). We show that the measurements of the asymmetries in those facilities can provide valuable information of the chiral-odd structure of the nucleon both in the valence and sea regions.

  9. Photoproduction of ω mesons off nuclei and impact of polarization on the meson-nucleon interaction

    DOE PAGESBeta

    Chudakov, Eugene A.; Gevorkyan, Sergey; Somov, Alexander

    2016-01-25

    We consider photoproduction of ω mesons off complex nuclei to study interactions of transversely and longitudinally polarized vector mesons with nucleons. Whereas the total cross section for interactions of the transversely polarized vector mesons with nucleons σT = σ(VTN) can be obtained from coherent photoproduction, measurements of vector meson photoproduction in the incoherent region provide a unique opportunity to extract the not-yet-measured total cross section for longitudinally polarized mesons σL = σ(VLN). The predictions for the latter strongly depend on the theoretical approaches. Furthermore, this work is stimulated by the construction of the new experiment GlueX at Jefferson Lab, designedmore » to study the photoproduction of mesons in a large beam energy range up to 12 GeV.« less

  10. Variable polarity arc welding

    NASA Technical Reports Server (NTRS)

    Bayless, E. O., Jr.

    1991-01-01

    Technological advances generate within themselves dissatisfactions that lead to further advances in a process. A series of advances in welding technology which culminated in the Variable Polarity Plasma Arc (VPPA) Welding Process and an advance instituted to overcome the latest dissatisfactions with the process: automated VPPA welding are described briefly.

  11. Classical Demonstration of Polarization.

    ERIC Educational Resources Information Center

    Bauman, Robert P.; Moore, Dennis R.

    1980-01-01

    Presents a classical demonstration of polarization for high school students. The initial state of this model, which demonstrates the important concepts of the optical and quantum problems, was developed during the 1973 summer program on lecture demonstration at the U.S. Naval Academy. (HM)

  12. Optical neutron polarizers

    SciTech Connect

    Hayter, J.B.

    1990-01-01

    A neutron wave will be refracted by an appropriately varying potential. Optical neutron polarizers use spatially varying, spin- dependent potentials to refract neutrons of opposite spin states into different directions, so that an unpolarized beam will be split into two beams of complementary polarization by such a device. This paper will concentrate on two methods of producing spin-dependent potentials which are particularly well-suited to polarizing cold neutron beams, namely thin-film structures and field-gradient techniques. Thin-film optical devices, such as supermirror multilayer structures, are usually designed to deviate only one spin-state, so that they offer the possibility of making insertion (transmission) polarizers. Very good supermirrors may now be designed and fabricated, but it is not always straightforward to design mirror-based devices which are useful in real (divergent beam) applications, and some practical configurations will be discussed. Field-gradient devices, which are usually based on multipolar magnets, have tended to be too expensive for general use, but this may change with new developments in superconductivity. Dipolar and hexapolar configurations will be considered, with emphasis on the focusing characteristics of the latter. 21 refs., 7 figs.

  13. Polar processing project

    NASA Astrophysics Data System (ADS)

    Tom, C. N.; Davies, W. J.; Goycochea, J. F.

    1993-09-01

    The purpose of this project was to explore the use of polar processing techniques in SIGINT-related signal processing applications. An investigation of ways to apply the CORDIC arithmetic algorithm to signal processing problems, and an application of the TMC2330 Coordinate Transformer chip in a coprocessor or accelerator board for a Sun workstation are covered.

  14. The polarized EMC effect

    SciTech Connect

    W. Bentz; I. C. Cloet; A. W. Thomas

    2007-02-01

    We calculate both the spin independent and spin dependent nuclear structure functions in an effective quark theory. The nucleon is described as a composite quark-diquark state, and the nucleus is treated in the mean field approximation. We predict a sizable polarized EMC effect, which could be confirmed in future experiments.

  15. A Polarized Universe

    NASA Technical Reports Server (NTRS)

    Wanjek, Christopher

    2003-01-01

    The CMB polarization was produced as light scattered off a primordial cloud of protons and electrons nearly 14 billion years ago, about 400,000 years after the Big Bang. This marks the moment of recombination, when the universe finally cooled enough to allow electrons to join protons. The CMB is the light that broke through the fog.

  16. North Polar Ice Cap

    NASA Technical Reports Server (NTRS)

    1997-01-01

    North polar ice cap of Mars, as seen during mid summer in the northern hemisphere. The reddish areas consist of eolian dust, bright white areas consist of a mixture of water ice and dust, and the dark blue areas consist of sand dunes forming a huge 'collar' around the polar ice cap. (The colors have been enhanced with a decorrelation stretch to better show the color variability.) Shown here is an oblique view of the polar region, as seen with the Viking 1 spacecraft orbiting Mars over latitude 39 degrees north. The spiral bands consist of valleys which form by a combination of the Coriolis forces, wind erosion, and differential sublimation and condensation. In high-resolution images the polar caps are seen to consist of thick sequences of layered deposits, suggesting that cyclical climate changes have occurred on Mars. Cyclical climate changes are readily explained by quasi-periodic changes in the amount and distribution of solar heating resulting from perturbations in orbital and axial elements. Variations in the Earth's orbit have also been linked to the terrestrial climate changes during the ice ages.

  17. Anodic Polarization Curves Revisited

    ERIC Educational Resources Information Center

    Liu, Yue; Drew, Michael G. B.; Liu, Ying; Liu, Lin

    2013-01-01

    An experiment published in this "Journal" has been revisited and it is found that the curve pattern of the anodic polarization curve for iron repeats itself successively when the potential scan is repeated. It is surprising that this observation has not been reported previously in the literature because it immediately brings into…

  18. Optical polarizer material

    DOEpatents

    Ebbers, Christopher A.

    1999-01-01

    Several crystals have been identified which can be grown using standard single crystals growth techniques and which have a high birefringence. The identified crystals include Li.sub.2 CO.sub.3, LiNaCO.sub.3, LiKCO.sub.3, LiRbCO.sub.3 and LiCsCO.sub.3. The condition of high birefringence leads to their application as optical polarizer materials. In one embodiment of the invention, the crystal has the chemical formula LiK.sub.(1-w-x-y) Na.sub.(1-w-x-z) Rb.sub.(1-w-y-z) Cs.sub.(1-x-y-z) CO.sub.3, where w+x+y+z=1. In another embodiment, the crystalline material may be selected from a an alkali metal carbonate and a double salt of alkali metal carbonates, where the polarizer has a Wollaston configuration, a Glan-Thompson configuration or a Glan-Taylor configuration. A method of making an LiNaCO.sub.3 optical polarizer is described. A similar method is shown for making an LiKCO.sub.3 optical polarizer.

  19. Optical polarizer material

    DOEpatents

    Ebbers, C.A.

    1999-08-31

    Several crystals have been identified which can be grown using standard single crystals growth techniques and which have a high birefringence. The identified crystals include Li.sub.2 CO.sub.3, LiNaCO.sub.3, LiKCO.sub.3, LiRbCO.sub.3 and LiCsCO.sub.3. The condition of high birefringence leads to their application as optical polarizer materials. In one embodiment of the invention, the crystal has the chemical formula LiK.sub.(1-w-x-y) Na.sub.(1-w-x-z) Rb.sub.(1-w-y-z) Cs.sub.(1-x-y-z) CO.sub.3, where w+x+y+z=1. In another embodiment, the crystalline material may be selected from a an alkali metal carbonate and a double salt of alkali metal carbonates, where the polarizer has a Wollaston configuration, a Glan-Thompson configuration or a Glan-Taylor configuration. A method of making an LiNaCO.sub.3 optical polarizer is described. A similar method is shown for making an LiKCO.sub.3 optical polarizer.

  20. Planetary polarization nephelometer

    NASA Astrophysics Data System (ADS)

    Banfield, D.; Dissly, R.; Mishchenko, M.; Muñoz, O.; Roos-Serote, M.; Stam, D.; Volten, H.

    2004-02-01

    We have proposed to develop a polarization nephelometer for use on future planetary descent probes. It will measure both the scattered intensity and polarization phase functions of the aerosols it encounters descending through an atmosphere. These measurements will be taken at two wavelengths separated by about an octave, with one light source near 500nm and another near 1μm. Adding polarization measurements to the intensity phase functions greatly increases our ability to constrain the size distribution, shape and chemical composition of the sampled particles. There remain important questions about these parameters of the aerosols on Venus, the giant planets and Titan that can only be addressed with a nephelometer like ours. The NRC Planetary Sciences Decadal Survey has identified probe missions to Venus and Jupiter as a priority. On both of these missions, our proposed instrument would be an excellent candidate for flight. We also expect that future probe missions to Saturn, Uranus, Neptune or Titan would employ our instrument. It could also find use in Earth in situ aerosol studies. We will use a technique to simultaneously measure intensity and polarization phase functions that uses polarization modulation of a light source. This technique has been implemented in laboratory settings, but not with considerations to the environment on a planetary descent probe. We have proposed to design and build a flexible breadboard nephelometer to test the components and concepts of our approach. We would then test the device against well defined aerosols, ensuring that it accurately measures their expected intensity and polarization phase functions. With the knowledge gained in this flexible design, we would then design and build a breadboard polarization nephelometer more suited to integration on a planetary descent probe. To include traceability in the technical requirements of our device, we would also conduct an Observing System Simulation Experiment. In this study, we

  1. Titan's Polar Atmosphere

    NASA Astrophysics Data System (ADS)

    Flasar, F. M.; Achterberg, R. K.; Schinder, P. J.

    2015-12-01

    Cassini CIRS and Radio-Occultation measurements obtained in 2004-2015 have tracked the evolution of temperatures and winds in Titan's polar atmosphere, as the winter season shifted from the northern hemisphere to the southern. The dissolution of the strong circumpolar vortex initially seen in the northern hemisphere has been gradual. There is no evidence of the rapid distortion and disruption forced by planetary waves that can occur on Earth. Indeed, neither Cassini experiment has identified any thermal signature attributable to planetary-scale waves. The south-polar region has turned wintry fairly abruptly: temperature and zonal wind maps from CIRS data show that the 1-mbar temperatures at high southern latitudes in late autumn are already much colder than those at the corresponding latitudes in the north in midwinter, when the first extensive polar measurements were obtained. The south-polar region now has a strong circumpolar vortex, with maximum stratospheric winds occurring near 60° S, in contrast to the northern hemisphere in winter, where the polar vortex was much broader, extending to 20°-30° N. Potential vorticity maps now indicate steep meridional gradients at high southern latitudes, implying a barrier to efficient mixing between the polar region and lower latitudes. Radio-occultations have higher vertical resolution than CIRS, and they have recently probed latitudes as high as 65° in both hemispheres (latitudes closer to the pole are precluded because of the geometry of Earth occultations and the season). Above 80 km at these latitudes, where the radiative damping times are small enough that temperatures have large seasonal variations, the stratosphere in the north has warmed, and it has become much colder in the south. The abrupt transition region with negative vertical temperature gradient between 80 and 100 km, which was seen at high northern latitudes in winter, has weakened, but it is still visible. In the south, one can see the early stage of

  2. Dielectric tensor of tetracene single crystals: the effect of anisotropy on polarized absorption and emission spectra.

    PubMed

    Tavazzi, S; Raimondo, L; Silvestri, L; Spearman, P; Camposeo, A; Polo, M; Pisignano, D

    2008-04-21

    The full UV-visible dielectric tensor and the corresponding directions of the principal axes of triclinic tetracene crystals are reported as deduced either by polarized absorption and ellipsometry measurements or by calculations based on the molecular and crystallographic data. The results allow the attribution of the polarized bands observed in both absorption and photoluminescence emission spectra. In particular, the spectral line shape and polarization of the emission are found to depend on the sample thickness, and the effect is attributed to the modification of the state of polarization of the emitted light during its propagation inside the crystal. Indeed, the directions of polarization of the lowest optical transitions and the directions of the principal axes of the dielectric tensor are demonstrated not to coincide, in contrast to the assumptions typically made in the literature, thus causing the mixed transverse/longitudinal character of light propagation. PMID:18433260

  3. Coherence-polarization properties of fields radiated from transversely periodic electromagnetic sources

    NASA Astrophysics Data System (ADS)

    Santarsiero, M.; de Sande, J. C. G.; Piquero, G.; Gori, F.

    2013-05-01

    Planar electromagnetic sources characterized by a periodic variation of their beam coherence-polarization matrix are investigated, as far as the polarization features of the radiated fields are concerned, within the framework of the paraxial approximation. A propagation scheme based on plane-wave decomposition leads to a longitudinal periodicity of the polarization properties of the field, thus extending the Talbot effect to the case of partially coherent electromagnetic sources. The polarization features of beams radiated from sources of this type are illustrated by means of simple examples. In particular, it is shown that completely unpolarized sources with uniform intensity profiles can be easily realized, for which the propagated field becomes perfectly polarized across some transverse planes, and vice versa.

  4. Radiative corrections to polarization observables in elastic electron-deuteron scattering in leptonic variables

    SciTech Connect

    Gakh, G. I.; Konchatnij, M. I. Merenkov, N. P.

    2012-08-15

    The model-independent QED radiative corrections to polarization observables in elastic scattering of unpolarized and longitudinally polarized electron beams by a deuteron target are calculated in leptonic variables. The experimental setup when the deuteron target is arbitrarily polarized is considered and the procedure for applying the derived results to the vector or tensor polarization of the recoil deuteron is discussed. The calculation is based on taking all essential Feynman diagrams into account, which results in the form of the Drell-Yan representation for the cross section, and the use of the covariant parameterization of the deuteron polarization state. Numerical estimates of the radiative corrections are given in the case where event selection allows undetected particles (photons and electron-positron pairs) and the restriction on the lost invariant mass is used.

  5. The H and D Polarized Target for Spin-Filtering Measurements at COSY

    NASA Astrophysics Data System (ADS)

    Ciullo, Giuseppe; Statera, Marco; Lenisa, Paolo; Nass, Alexander; Tagliente, Giuseppe

    2016-04-01

    In the main frame of the PAX (Polarized Antiproton eXperiments) collaboration, which engaged the challenging purpose of polarizing antiproton beams, the possibility to have H or D polarized targets requires a daily switchable source and its diagnostics: mainly change is a dual cavity tunable for H and D. The commissioning of PAX has been fullfilled, for the transverse case, on the COSY (COoler SYnchrotron) proton ring, achieving milestones on spin-dependent cross-section measurements. Now the longitudinal case could provide sensitive polarization results. An H or D source allows the exploration of the spin-filtering process with a deuterium polarized target, and opens new chances for testing Time Reversal Invariance at COSY (TRIC).

  6. Interplanetary magnetic sector polarity inferred from polar geomagnetic field observations

    NASA Technical Reports Server (NTRS)

    Eriss-Christensen, E.; Lassen, K.; Wilcox, J. M.; Gonzalez, W.; Colburn, D. S.

    1971-01-01

    With the use of a prediction technique it is shown that the polarity (toward or away from the sun) of the interplanetary magnetic field can be reliably inferred from observations of the polar geomagnetic field.

  7. Circularly polarized waves in a plasma with vacuum polarization effects

    SciTech Connect

    Lundin, J.; Stenflo, L.; Brodin, G.; Marklund, M.; Shukla, P. K.

    2007-06-15

    The theory for large amplitude circularly polarized waves propagating along an external magnetic field is extended in order to also include vacuum polarization effects. A general dispersion relation, which unites previous results, is derived.

  8. Lunar Polar Coring Lander

    NASA Technical Reports Server (NTRS)

    Angell, David; Bealmear, David; Benarroche, Patrice; Henry, Alan; Hudson, Raymond; Rivellini, Tommaso; Tolmachoff, Alex

    1990-01-01

    Plans to build a lunar base are presently being studied with a number of considerations. One of the most important considerations is qualifying the presence of water on the Moon. The existence of water on the Moon implies that future lunar settlements may be able to use this resource to produce things such as drinking water and rocket fuel. Due to the very high cost of transporting these materials to the Moon, in situ production could save billions of dollars in operating costs of the lunar base. Scientists have suggested that the polar regions of the Moon may contain some amounts of water ice in the regolith. Six possible mission scenarios are suggested which would allow lunar polar soil samples to be collected for analysis. The options presented are: remote sensing satellite, two unmanned robotic lunar coring missions (one is a sample return and one is a data return only), two combined manned and robotic polar coring missions, and one fully manned core retrieval mission. One of the combined manned and robotic missions has been singled out for detailed analysis. This mission proposes sending at least three unmanned robotic landers to the lunar pole to take core samples as deep as 15 meters. Upon successful completion of the coring operations, a manned mission would be sent to retrieve the samples and perform extensive experiments of the polar region. Man's first step in returning to the Moon is recommended to investigate the issue of lunar polar water. The potential benefits of lunar water more than warrant sending either astronauts, robots or both to the Moon before any permanent facility is constructed.

  9. Modulational instability of finite-amplitude, circularly polarized Alfven waves

    NASA Technical Reports Server (NTRS)

    Derby, N. F., Jr.

    1978-01-01

    The simple theory of the decay instability of Alfven waves is strictly applicable only to a small-amplitude parent wave in a low-beta plasma, but, if the parent wave is circularly polarized, it is possible to analyze the situation without either of these restrictions. Results show that a large-amplitude circularly polarized wave is unstable with respect to decay into three waves, one longitudinal and one transverse wave propagating parallel to the parent wave and one transverse wave propagating antiparallel. The transverse decay products appear at frequencies which are the sum and difference of the frequencies of the parent wave and the longitudinal wave. The decay products are not familiar MHD modes except in the limit of small beta and small amplitude of the parent wave, in which case the decay products are a forward-propagating sound wave and a backward-propagating circularly polarized wave. In this limit the other transverse wave disappears. The effect of finite beta is to reduce the linear growth rate of the instability from the value suggested by the simple theory. Possible applications of these results to the theory of the solar wind are briefly touched upon.

  10. Enhanced polarization by the coherent heterophase interface between polar and non-polar phases

    NASA Astrophysics Data System (ADS)

    Kim, Gi-Yeop; Sung, Kil-Dong; Rhyim, Youngmok; Yoon, Seog-Young; Kim, Min-Soo; Jeong, Soon-Jong; Kim, Kwang-Ho; Ryu, Jungho; Kim, Sung-Dae; Choi, Si-Young

    2016-03-01

    A piezoelectric composite containing the ferroelectric polar (Bi(Na0.8K0.2)0.5TiO3: f-BNKT) and the non-polar (0.94Bi(Na0.75K0.25)0.5TiO3-0.06BiAlO3: BNKT-BA) phases exhibits synergetic properties which combine the beneficial aspects of each phase, i.e., the high saturated polarization (Ps) of the polar phase and the low coercive field (Ec) of the non-polar phase. To understand the origin of such a fruitful outcome from this type of polar/non-polar heterophase structure, comprehensive studies are conducted, including transmission electron microscopy (TEM) and finite element method (FEM) analyses. The TEM results show that the polar/non-polar composite has a core/shell structure in which the polar phase (core) is surrounded by a non-polar phase (shell). In situ electrical biasing TEM experiments visualize that the ferroelectric domains in the polar core are aligned even under an electric field of ~1 kV mm-1, which is much lower than its intrinsic coercive field (~3 kV mm-1). From the FEM analyses, we can find that the enhanced polarization of the polar phase is promoted by an additional internal field at the phase boundary which originates from the preferential polarization of the relaxor-like non-polar phase. From the present study, we conclude that the coherent interface between polar and non-polar phases is a key factor for understanding the enhanced piezoelectric properties of the composite.A piezoelectric composite containing the ferroelectric polar (Bi(Na0.8K0.2)0.5TiO3: f-BNKT) and the non-polar (0.94Bi(Na0.75K0.25)0.5TiO3-0.06BiAlO3: BNKT-BA) phases exhibits synergetic properties which combine the beneficial aspects of each phase, i.e., the high saturated polarization (Ps) of the polar phase and the low coercive field (Ec) of the non-polar phase. To understand the origin of such a fruitful outcome from this type of polar/non-polar heterophase structure, comprehensive studies are conducted, including transmission electron microscopy (TEM) and finite element

  11. Characteristics of volume polarization holography with linear polarization light

    NASA Astrophysics Data System (ADS)

    Zang, Jinliang; Wu, An'an; Liu, Ying; Wang, Jue; Lin, Xiao; Tan, Xiaodi; Shimura, Tsutomu; Kuroda, Kazuo

    2015-10-01

    Volume polarization holographic recording in phenanthrenequinone-doped poly(methyl methacrylate) (PQ-PMMA) photopolymer with linear polarized light is obtained. The characteristics of the volume polarization hologram are experimentally investigated. It is found that beyond the paraxial approximation the polarization states of the holographic reconstruction light are generally different from the signal light. Based on vector wave theoretical analyses and material properties, the special exposure condition for correctly holographic reconstruction is obtained and experimentally demonstrated.

  12. Global Geospace Science/Polar Plasma Laboratory: POLAR

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Global Geospace Science (GGS) Project is discussed as part of the International Solar-Terrestrial Physics (ISTP) Science Initiative. The objectives of Polar Plasma Laboratory (POLAR), one of the two spacecraft to be used by the Project to fill critical gaps in the scientific understanding of solar and plasma physics, are outlined. POLAR Laboratory is described, along with POLAR instrumentation, support subsystems, and orbits. Launch vehicle and injection into orbit are also addressed.

  13. Statistical image analysis of longitudinal RAVENS images

    PubMed Central

    Lee, Seonjoo; Zipunnikov, Vadim; Reich, Daniel S.; Pham, Dzung L.

    2015-01-01

    Regional analysis of volumes examined in normalized space (RAVENS) are transformation images used in the study of brain morphometry. In this paper, RAVENS images are analyzed using a longitudinal variant of voxel-based morphometry (VBM) and longitudinal functional principal component analysis (LFPCA) for high-dimensional images. We demonstrate that the latter overcomes the limitations of standard longitudinal VBM analyses, which does not separate registration errors from other longitudinal changes and baseline patterns. This is especially important in contexts where longitudinal changes are only a small fraction of the overall observed variability, which is typical in normal aging and many chronic diseases. Our simulation study shows that LFPCA effectively separates registration error from baseline and longitudinal signals of interest by decomposing RAVENS images measured at multiple visits into three components: a subject-specific imaging random intercept that quantifies the cross-sectional variability, a subject-specific imaging slope that quantifies the irreversible changes over multiple visits, and a subject-visit specific imaging deviation. We describe strategies to identify baseline/longitudinal variation and registration errors combined with covariates of interest. Our analysis suggests that specific regional brain atrophy and ventricular enlargement are associated with multiple sclerosis (MS) disease progression. PMID:26539071

  14. Bayesian response adaptive randomization using longitudinal outcomes.

    PubMed

    Hatayama, Tomoyoshi; Morita, Satoshi; Sakamaki, Kentaro

    2015-01-01

    The response adaptive randomization (RAR) method is used to increase the number of patients assigned to more efficacious treatment arms in clinical trials. In many trials evaluating longitudinal patient outcomes, RAR methods based only on the final measurement may not benefit significantly from RAR because of its delayed initiation. We propose a Bayesian RAR method to improve RAR performance by accounting for longitudinal patient outcomes (longitudinal RAR). We use a Bayesian linear mixed effects model to analyze longitudinal continuous patient outcomes for calculating a patient allocation probability. In addition, we aim to mitigate the loss of statistical power because of large patient allocation imbalances by embedding adjusters into the patient allocation probability calculation. Using extensive simulation we compared the operating characteristics of our proposed longitudinal RAR method with those of the RAR method based only on the final measurement and with an equal randomization method. Simulation results showed that our proposed longitudinal RAR method assigned more patients to the presumably superior treatment arm compared with the other two methods. In addition, the embedded adjuster effectively worked to prevent extreme patient allocation imbalances. However, our proposed method may not function adequately when the treatment effect difference is moderate or less, and still needs to be modified to deal with unexpectedly large departures from the presumed longitudinal data model. PMID:26099995

  15. Enhanced polarization by the coherent heterophase interface between polar and non-polar phases.

    PubMed

    Kim, Gi-Yeop; Sung, Kil-Dong; Rhyim, Youngmok; Yoon, Seog-Young; Kim, Min-Soo; Jeong, Soon-Jong; Kim, Kwang-Ho; Ryu, Jungho; Kim, Sung-Dae; Choi, Si-Young

    2016-04-14

    A piezoelectric composite containing the ferroelectric polar (Bi(Na0.8K0.2)0.5TiO3: f-BNKT) and the non-polar (0.94Bi(Na0.75K0.25)0.5TiO3-0.06BiAlO3: BNKT-BA) phases exhibits synergetic properties which combine the beneficial aspects of each phase, i.e., the high saturated polarization (Ps) of the polar phase and the low coercive field (Ec) of the non-polar phase. To understand the origin of such a fruitful outcome from this type of polar/non-polar heterophase structure, comprehensive studies are conducted, including transmission electron microscopy (TEM) and finite element method (FEM) analyses. The TEM results show that the polar/non-polar composite has a core/shell structure in which the polar phase (core) is surrounded by a non-polar phase (shell). In situ electrical biasing TEM experiments visualize that the ferroelectric domains in the polar core are aligned even under an electric field of ∼1 kV mm(-1), which is much lower than its intrinsic coercive field (∼3 kV mm(-1)). From the FEM analyses, we can find that the enhanced polarization of the polar phase is promoted by an additional internal field at the phase boundary which originates from the preferential polarization of the relaxor-like non-polar phase. From the present study, we conclude that the coherent interface between polar and non-polar phases is a key factor for understanding the enhanced piezoelectric properties of the composite. PMID:26601654

  16. Nonlinear Accelerator with Transverse Motion Integrable in Normalized Polar Coordinates

    SciTech Connect

    Nagaitsev, S.; Kharkov, Y.; Morozov, I.A.; Zolkin, T.V.; /Chicago U.

    2012-05-01

    Several families of nonlinear accelerator lattices with integrable transverse motion were suggested recently. One of the requirements for the existence of two analytic invariants is a special longitudinal coordinate dependence of fields. This paper presents the particle motion analysis when a problem becomes integrable in the normalized polar coordinates. This case is distinguished from the others: it yields an exact analytical solution and has a uniform longitudinal coordinate dependence of the fields (since the corresponding nonlinear potential is invariant under the transformation from the Cartesian to the normalized coordinates). A number of interesting features are revealed: while the frequency of radial oscillations is independent of the amplitude, the spread of angular frequencies in a beam is absolute. A corresponding spread of frequencies of oscillations in the Cartesian coordinates is evaluated via the simulation of transverse Schottky noise.

  17. Longitudinal oscillation of launch vehicles

    NASA Technical Reports Server (NTRS)

    Glaser, R. F.

    1973-01-01

    During powered flight a vehicle may develop longitudinal self-excited oscillations, so-called oscillations, of its structure. The energy supplying the vibration is tapped from the thrust by the activity of the system itself; that is, oscillation of the structure causes oscillation of the propellant system, especially of the pumps. In this way an oscillating thrust can be created that, by a feedback loop, may sustain the structural oscillation under certain circumstances. Two special features of the system proved to be essential for creation of instability. One is the effect of the inherent time interval that the thrust oscillation is lagging behind the structural oscillation. The other is the decreased of system mass caused by the exhausting of gas. The latter feature may cause an initially stable system to become unstable. To examine the stability of the system, a single mass-spring model, which is the result of a one-term Galerkin approach to the equation of motion, has been considered. The Nyquist stability criterion leads to a stability graph that shows the stability conditions in terms of the system parameter and also demonstrates the significance of time lag, feedback magnitude, and loss of mass. An important conclusion can be drawn from the analysis: large relative displacements of the pump-engine masses favor instability. This is also confirmed by flight measurements.

  18. Longitudinal Variations in Jupiter's Winds

    NASA Technical Reports Server (NTRS)

    Simon-Miller, Amy A.; Gierasch, P. J.; Tierney, G.

    2010-01-01

    Long-term studies of Jupiter's zonal wind field revealed temporal variations on the order of 20 to 40 m/s at many latitudes, greater than the typical data uncertainties of 1 to 10 m/s. No definitive periodicities were evident, however, though some latitudinally-confined signals did appear at periods relevant to the Quasi- Quadrennial Oscillation (Simon-Miller & Gierasch, Icarus, in press). As the QQO appears, from vertical temperature profiles, to propagate downward, it is unclear why a signal is not more obvious, unless other processes dominate over possibly weaker forcing from the QQO. An additional complication is that zonal wind profiles represent an average over some particular set of longitudes for an image pair and most data sets do not offer global wind coverage. Lien avoiding known features, such as the large anticyclonic vortices especially prevalent in the south, there can be distinct variations in longitude. We present results on the full wind field from Voyager and Cassini data, showing apparent longitudinal variations of up to 60 m/s or more. These are particularly obvious near disruptions such as the South Equatorial Disturbance, even when the feature itself is not clearly visible. These two dates represent very different states of the planet for comparison: Voyagers 1 & 2 flew by Jupiter shortly after a global upheaval, while many regions were in a disturbed state, while the Cassini view is typical of a more quiescent period present during much of the 1990s and early 2000s.

  19. Psychiatric resilience: longitudinal twin study†

    PubMed Central

    Amstadter, Ananda B.; Myers, John M.; Kendler, Kenneth S.

    2014-01-01

    Background The source of variability in people’s response to stressful life events is poorly understood. Aims We examine the genetic and environmental underpinning of resilience (i.e. the difference between the twins’ internalising symptoms and their predicted symptoms based on cumulative stressful life events). Method Stressful life event exposure and internalising symptoms were assessed at two time points in 7500 adult twins. Using the residual between actual and predicted internalising symptom total score, twin modelling was conducted for each wave separately and longitudinally. Results Resilience was found to have a moderate genetic heritability at each wave (∼31%). Qualitative gender effects were found. Incorporating error of measurement into the model increased the estimated heritability for the latent construct of resilience (∼50%). When measurement error and occasion-specific effects were removed, environmental influences contributed roughly equally to level of resilience. Conclusions Both genes and environment influence level of psychiatric resilience, and are largely stable over time. Environmental influences can have an enduring effect on resilience. PMID:24723629

  20. Breaking of Longitudinal Akhiezer-Polovin Waves

    NASA Astrophysics Data System (ADS)

    Verma, Prabal Singh; Sengupta, Sudip; Kaw, Predhiman

    2012-03-01

    The breaking of longitudinal Akhiezer-Polovin (AP) waves is demonstrated using a one-dimensional simulation based on the Dawson sheet model. It is found that the AP longitudinal waves break through the process of phase mixing at an amplitude well below the breaking amplitude for AP waves, when subjected to arbitrarily small longitudinal perturbations. Results from the simulation show a good agreement with the Dawson phase mixing formula modified to include relativistic mass variation effects. This result may be of direct relevance to the laser- or particle-beam plasma wakefield experiments.

  1. North Polar Cap

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    This week we will be looking at five examples of laminar wind flow on the north polar cap. On Earth, gravity-driven south polar cap winds are termed 'catabatic' winds. Catabatic winds begin over the smooth expanse of the cap interior due to temperature differences between the atmosphere and the surface. Once begun, the winds sweep outward along the surface of the polar cap toward the sea. As the polar surface slopes down toward sealevel, the wind speeds increase. Catabatic wind speeds in the Antartic can reach several hundreds of miles per hour.

    In the images of the Martian north polar cap we can see these same type of winds. Notice the streamers of dust moving downslope over the darker trough sides, these streamers show the laminar flow regime coming off the cap. Within the trough we see turbulent clouds of dust, kicked up at the trough base as the winds slow down and enter a chaotic flow regime.

    The horizontal lines in these images are due to framelet overlap and lighting conditions over the bright polar cap.

    Image information: VIS instrument. Latitude 86.5, Longitude 64.5 East (295.5 West). 40 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation

  2. North Polar Cap

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    This week we will be looking at five examples of laminar wind flow on the north polar cap. On Earth, gravity-driven south polar cap winds are termed 'catabatic' winds. Catabatic winds begin over the smooth expanse of the cap interior due to temperature differences between the atmosphere and the surface. Once begun, the winds sweep outward along the surface of the polar cap toward the sea. As the polar surface slopes down toward sealevel, the wind speeds increase. Catabatic wind speeds in the Antartic can reach several hundreds of miles per hour.

    In the images of the Martian north polar cap we can see these same type of winds. Notice the streamers of dust moving downslope over the darker trough sides, these streamers show the laminar flow regime coming off the cap. Within the trough we see turbulent clouds of dust, kicked up at the trough base as the winds slow down and enter a chaotic flow regime.

    The horizontal lines in these images are due to framelet overlap and lighting conditions over the bright polar cap.

    Image information:VIS instrument. Latitude 86.5, longitude 57.4 East (302.6 West). 40 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is

  3. North Polar Cap

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    This week we will be looking at five examples of laminar wind flow on the north polar cap. On Earth, gravity-driven south polar cap winds are termed 'catabatic' winds. Catabatic winds begin over the smooth expanse of the cap interior due to temperature differences between the atmosphere and the surface. Once begun, the winds sweep outward along the surface of the polar cap toward the sea. As the polar surface slopes down toward sealevel, the wind speeds increase. Catabatic wind speeds in the Antartic can reach several hundreds of miles per hour.

    In the images of the Martian north polar cap we can see these same type of winds. Notice the streamers of dust moving downslope over the darker trough sides, these streamers show the laminar flow regime coming off the cap. Within the trough we see turbulent clouds of dust, kicked up at the trough base as the winds slow down and enter a chaotic flow regime.

    The horizontal lines in these images are due to framelet overlap and lighting conditions over the bright polar cap.

    Image information: VIS instrument. Latitude 84.3, Longitude 314.4 East (45.6 West). 40 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation

  4. North Polar Cap

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    This week we will be looking at five examples of laminar wind flow on the north polar cap. On Earth, gravity-driven south polar cap winds are termed 'catabatic' winds. Catabatic winds begin over the smooth expanse of the cap interior due to temperature differences between the atmosphere and the surface. Once begun, the winds sweep outward along the surface of the polar cap toward the sea. As the polar surface slopes down toward sealevel, the wind speeds increase. Catabatic wind speeds in the Antartic can reach several hundreds of miles per hour.

    In the images of the Martian north polar cap we can see these same type of winds. Notice the streamers of dust moving downslope over the darker trough sides, these streamers show the laminar flow regime coming off the cap. Within the trough we see turbulent clouds of dust, kicked up at the trough base as the winds slow down and enter a chaotic flow regime.

    The horizontal lines in these images are due to framelet overlap and lighting conditions over the bright polar cap.

    Image information: VIS instrument. Latitude 84.2, Longitude 57.4 East (302.6 West). 40 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation

  5. Titan's Winter Polar Vortex

    NASA Technical Reports Server (NTRS)

    Flasar, F.M.; Achterberg, R.K.; Schinder, P.J.

    2008-01-01

    Titan's atmosphere has provided an interesting study in contrasts and similarities with Earth's. While both have N$_2$ as the dominant constituent and comparable surface pressures $\\sim1$ bar, Titan's next most abundant molecule is CH$_4$, not O$_2$, and the dissociative breakup of CH$_4$ and N$_2$ by sunlight and electron impact leads to a suite of hydrocarbons and nitriles, and ultimately the photochemical smog that enshrouds the moon. In addition, with a 15.95-day period, Titan is a slow rotator compared to Earth. While the mean zonal terrestrial winds are geostrophic, Titan's are mostly cyclostrophic, whipping around the moon in as little as 1 day. Despite the different dynamical regime, Titan's winter stratosphere exhibits several characteristics that should be familiar to terrestrial meteorologists. The cold winter pole near the 1 -mbar level is circumscribed by strong winds (up to 190 m/s) that act as a barrier to mixing with airmasses at lower latitudes. There is evidence of enhancement of several organic species over the winter pole, indicating subsidence. The adiabatic heating associated with this subsidence gives rise to a warm anomaly at the 0.01-mbar level, raising the stratopause two scale heights above its location at equatorial latitudes. Condensate ices have been detected in Titan's lower stratosphere within the winter polar vortex from infrared spectra. Although not always unambiguously identified, their spatial distribution exhibits a sharp gradient, decreasing precipitously across the vortex away from the winter pole. The interesting question of whether there is important heterogeneous chemistry occurring within the polar vortex, analogous to that occurring in the terrestrial polar stratospheric clouds in the ozone holes, has not been addressed. The breakup of Titan's winter polar vortex has not yet been observed. On Earth, the polar vortex is nonlinearly disrupted by interaction with large-amplitude planetary waves. Large-scale waves have not

  6. High Power Polarized Positron Source

    NASA Astrophysics Data System (ADS)

    Mikhailichenko, Alexander

    2009-09-01

    We discuss the basics of polarized positron production by low energy polarized electrons. Efficiency of conversion ˜0.1-1% might be interesting for the Continuous Electron Beam Accelerator Facility (CEBAF) and the International Linear Collider (ILC).

  7. Hyperon polarization: An experimental overview

    SciTech Connect

    Lach, J.

    1992-12-01

    The fact that inclusively produced hyperons are produced with significant polarization was first discovered at Fermilab about seventeen years ago. This and subsequent experiments showed that [Lambda][degree] were produced polarized while [bar [Lambda] [degree

  8. Polarity of the Amphibian Egg

    NASA Technical Reports Server (NTRS)

    Malacinski, G. M.

    1983-01-01

    Amphibian egg polarity and the mechanism which generates the polarity is addressed. Of particular concern is the question of whether the activation rotation which responds to gravity is a prerequisite for normal development.

  9. Direct longitudinal laser acceleration of electrons in free space

    NASA Astrophysics Data System (ADS)

    Carbajo, Sergio; Nanni, Emilio A.; Wong, Liang Jie; Moriena, Gustavo; Keathley, Phillip D.; Laurent, Guillaume; Miller, R. J. Dwayne; Kärtner, Franz X.

    2016-02-01

    pulses and soft-x-ray pulses from optical undulators, J. Phys. B 47, 015601 (2014)] avoiding the need of a medium or guiding structure entirely to achieve strong longitudinal energy transfer. Here we present the first observation of direct longitudinal laser acceleration of nonrelativistic electrons that undergo highly directional multi-GeV /m accelerating gradients. This demonstration opens a new frontier for direct laser-driven particle acceleration capable of creating well collimated and relativistic attosecond electron bunches [C. Varin and M. Piché, Relativistic attosecond electron pulses from a free-space laser-acceleration scheme, Phys. Rev. E 74, 045602 (2006)] and x-ray pulses [A. Sell and F. X. Kärtner, Attosecond electron bunches accelerated and compressed by radially polarized laser pulses and soft-x-ray pulses from optical undulators, J. Phys. B 47, 015601 (2014)].

  10. Polarization of a Helium-Neon Laser.

    ERIC Educational Resources Information Center

    Jones, Edwin R.

    1996-01-01

    Describes an experiment that involves measuring the intensity of laser light passed by a linear polarizer. Discusses polarization effects, orthogonal polarizations, instrumentation, and further experiments. (JRH)

  11. Advanced Strained-Superlattice Photocathodes for Polarized Electron Sources

    SciTech Connect

    Dr. Aaron Moy

    2005-01-31

    Polarized electrons have been essential for high-energy parity-violating experiments and measurements of the nucleon spin structure. The availability of a polarized electron beam was crucial to the success of the Stanford Linear Collider (SLC) in achieving a precise measurement of the electroweak mixing angle, and polarized electron beams will be required for all future linear colliders. Polarized electrons are readily produced by GaAs photocathode sources. When a circularly polarized laser beam tuned to the bandgap minimum is directed to the negative-electron-affinity (NEA) surface of a GaAs crystal, longitudinally polarized electrons are emitted into vacuum. The electron polarization is easily reversed by reversing the laser polarization. The important properties of these photocathodes for accelerator applications are: degree of polarization of the extracted beam; ability to extract sufficient charge to meet accelerator pulse-structure requirements; efficiency and stability of operation; and absence of any asymmetries in the beam properties (charge, position, energy, etc.) upon polarization reversal. The performance of GaAs photocathodes has improved significantly since they were first introduced in 1978 [1]. The theoretical maximum polarization of 50% for natural GaAs was first exceeded in 1991 using the lattice mismatch of a thin InGaAs layer epitaxially grown over a GaAs substrate to generate a strain in the former that broke the natural degeneracy between the heavy- and light-hole valence bands [2]. Polarizations as high as 78% were produced for the SLC from photocathodes based on a thin GaAs epilayer grown on GaAsP [3,4]. After 10 years of experience with many cathode samples at several laboratories [5], the maximum polarization using the GaAs/GaAsP single strained-layer cathode remained limited to 80%, while the quantum efficiency (QE) for a 100-nm epilayer is only 0.3% or less. Two factors were known to limit the polarization of these cathodes: (1) the

  12. Measurement of W Boson Polarization in Top Quark Decay

    SciTech Connect

    Vickey, Trevor Neil

    2004-11-01

    A measurement of the polarization of the W boson from top quark decay is an excellent test of the V-A form of the charged-current weak interaction in the standard model. Since the longitudinal W boson is intimately related to the electroweak symmetry breaking mechanism, and the standard model gives a specific prediction for the fraction of longitudinal W bosons from top decays, it is of particular interest for study. This thesis presents a measurement of W boson polarization in top quark decays through an analysis of the cos{theta}* distribution in the lepton-plus-jets channel of t{bar t} candidate events from p{bar p} collisions at {radical}s = 1.96 TeV. This measurement uses an integrated luminosity of {approx} 162 pb{sup -1} of data collected with the CDF Run II detector, resulting in 31 t{bar t} candidate events with at least one identified b jet. Using a binned likelihood fit to the cos{theta}* distribution from the t{bar t} candidate events found in this sample, the fraction of W bosons with longitudinal polarization is determined to be F{sub 0} = 0.99{sub -0.35}{sup +0.29}(stat.) {+-} 0.19(syst.), F{sub 0} > 0.33 {at} 95% CL. This result is consistent with the standard model prediction, given a top quark mass of 174.3 GeV/c{sup 2}, of F{sub 0} = 0.701 {+-} 0.012.

  13. Polarization Perception Device

    NASA Technical Reports Server (NTRS)

    Whitehead, Victor S. (Inventor); Coulson, Kinsell L. (Inventor)

    1997-01-01

    A polarization perception device comprises a base and a polarizing filter having opposite broad sides and a centerline perpendicular thereto. The filter is mounted on the base for relative rotation and with a major portion of the area of the filter substantially unobstructed on either side. A motor on the base automatically moves the filter angularly about its centerline at a speed slow enough to permit changes in light transmission by virtue of such movement to be perceived as light-dark pulses by a human observer, but fast enough so that the light phase of each such pulse occurs prior to fading of the light phase image of the preceding pulse from the observer's retina. In addition to an observer viewing a scene in real time through the filter while it is so angularly moved, or instead of such observation, the scene can be photographed, filmed or taped by a camera whose lens is positioned behind the filter.

  14. Polarization perception device

    NASA Technical Reports Server (NTRS)

    Whitehead, Victor S. (Inventor); Coulson, Kinsel L. (Inventor)

    1992-01-01

    A polarization perception device comprises a base and a polarizing filter having opposite broad sides and a centerline perpendicular thereto. The filter is mounted on the base for relative rotation and with a major portion of the area of the filter substantially unobstructed on either side. A motor on the base automatically moves the filter angularly about its centerline at a speed slow enough to permit changes in light transmission by virtue of such movement to be perceived as light-dark pulses by a human observer, but fast enough so that the light phase of each such pulse occurs prior to fading of the light phase image of the preceding pulse from the observer's retina. In addition to an observer viewing a scene in real time through the filter while it is so angularly moved, or instead of such observation, the scene can be photographed, filmed or taped by a camera whose lens is positioned behind the filter.

  15. Galactic Diffuse Polarized Emission

    NASA Astrophysics Data System (ADS)

    Carretti, Ettore

    2011-12-01

    Diffuse polarized emission by synchrotron is a key tool to investigate magnetic fields in the Milky Way, particularly the ordered component of the large scale structure. Key observables are the synchrotron emission itself and the RM is by Faraday rotation. In this paper the main properties of the radio polarized diffuse emission and its use to investigate magnetic fields will be reviewed along with our current understanding of the galactic magnetic field and the data sets available. We will then focus on the future perspective discussing RM-synthesis - the new powerful instrument devised to unlock the information encoded in such an emission - and the surveys currently in progress like S-PASS and GMIMS.

  16. Polar Magnetic Field Data

    NASA Technical Reports Server (NTRS)

    Russell, Christopher T.; Hoffman, Robert (Technical Monitor)

    2002-01-01

    At this writing we have received all the CDROMs for the grant period. We have completed generating our timing tables past September 20, 2001. The calibration of the instrument has been checked for the entire mission up to the end of December 2000 and the key parameters provided to the project until the end of December 2000. These data are available to other experimenters over the web at http://www-ssc.igpp.ucla.edu/forms/polar/. High resolution spun data, 8 samples per see, have been created up to November, 2000 and have been made available to the community over the world wide web. This is a new data set that was a major effort this year. Our near term plans are to continue to provide key parameter data to the Polar project with the highest possible speed and to continue to reduce all high resolution magnetometer data and provide these data to the scientific community over the web.

  17. Polar vortex dynamics

    NASA Technical Reports Server (NTRS)

    Mcintyre, Michael

    1988-01-01

    Recent work with high resolution, one-layer numerical models of fluid flows resembling those in the real stratosphere has suggested that: (1) the interiors of strong cyclonic vortices like the Antarctic polar vortex may be almost completely isolated laterally from their surroundings - perhaps even completely isolated, under some circumstances; (2) by contrast, material near the edge of such and isolated region can easily be eroded (or mixed one-sidedly) into the surrounding region; and (3) the erosion characteristically produces extremely steep gradients in isentropic distributions of potential vorticity (PV) and of other tracers, possibly down to horizontal length scales of a few kilometers only. Such length scales may occur both at the edge of the main polar vortex and in smaller features outside it, such as thin filamentary structures, produced by the erosion process.

  18. The polar bear phenomena

    SciTech Connect

    Maw, P.K. ); Lane, M.T.

    1990-02-01

    Results from measuring the thermal profile of polar bear pelts, reflectiveness of the pelts, and total thermal conversion data lead to the conclusion that the pelts from an ultra-efficient thermal diode for solar-thermal conversion. The transfer of the thermal energy from the surface of the fur to the skin where it is absorbed cannot be thermal, and therefore must be radiative. This process must have an efficiency of better than 90:0090 percent to account for measured values. The radiative transfer process is not known at present. To understand it, a detailed knowledge of the microscopic parameters of the pelts must be obtained. This is the current thrust of the polar solar research. If the process can be understood and synthesized,it will provide a major breakthrough in the area of solar-thermal energy conversion.

  19. North Polar Features

    NASA Technical Reports Server (NTRS)

    2004-01-01

    28 November 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows banded terrain of the north polar region of Mars. The bands are exposures of layered material, possibly composed of dust and ice. The dark, rounded to elliptical mounds in this image might be the locations of ancient sand dunes that were completely buried in the north polar layered material. In more recent times, these mounds have been exhumed from within the layered material. Alternatively, the dark features are not ancient, exhumed dunes, but perhaps the remnants of a dark layer of material that once covered the entire area shown in the image. These features are located near 79.9oN, 31.4oW. The image covers an area about 3 km (1.9 mi) wide. Sunlight illuminates the scene from the lower left.

  20. South Polar Details

    NASA Technical Reports Server (NTRS)

    2005-01-01

    22 September 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows details among some of the eroded layer outcrops of the martian south polar region. Much of the south polar region of Mars is covered by a thick unit of layered material. For decades, the layers have been assumed to consist of a mixture of dust and ice, but it is equally possible that the materials are sedimentary rocks. This image was captured during southern spring, at a time when some of the surface was still covered by seasonal carbon dioxide (CO2) frost.

    Location near: 86.5oS, 116.6oW Image width: width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Spring

  1. Alternating-Polarity Arc Welding

    NASA Technical Reports Server (NTRS)

    Schwinghamer, R. J.

    1987-01-01

    Brief reversing polarity of welding current greatly improves quality of welds. NASA technical memorandum recounts progress in art of variable-polarity plasma-arc (VPPA) welding, with emphasis on welding of aluminum-alloy tanks. VPPA welders offer important advantages over conventional single-polarity gas/tungsten arc welders.

  2. Polarized Emissivity and Kirchhoff's law.

    PubMed

    Resnick, A; Persons, C; Lindquist, G

    1999-03-10

    An expression for the polarized emissivity of a material is obtained with the Stokes vector-Mueller matrix polarization formalism. The result obtained is that thermally emitted radiance might have a circular polarization component. In addition, the emissivity depends only on the reflectance matrix. PMID:18305757

  3. Animated Displays IV: Linear Polarization.

    ERIC Educational Resources Information Center

    Chagnon, Paul

    1993-01-01

    Describes several demonstrations that can be easily reproduced to help students understand optical polarization. Displays and supplement text include polarization by reflection; polarization by scattering; liquid crystals; optical activity; calcite; birefringent plastics; retardation plates; photoelasticity; and the "Optical Barber Pole." Contains…

  4. Cryogenic, polar lunar observatories

    NASA Technical Reports Server (NTRS)

    Burke, J. D.

    1988-01-01

    In a geological vein, it is noted that some permanently shadowed regions on the Moon could provide natural passive cooling environments for astronomical detectors. A telescope located in one of the low, dark, polar regions could operate with only passive cooling at 40 K or perhaps lower, depending on how well it could be insulated from the ground and surrounded by radiation shields to block heat and light from any nearby warm or illuminated objects.

  5. Polarized advanced fuel reactors

    SciTech Connect

    Kulsrud, R.M.

    1987-07-01

    The d-/sup 3/He reaction has the same spin dependence as the d-t reaction. It produces no neutrons, so that if the d-d reactivity could be reduced, it would lead to a neutron-lean reactor. The current understanding of the possible suppression of the d-d reactivity by spin polarization is discussed. The question as to whether a suppression is possible is still unresolved. Other advanced fuel reactions are briefly discussed. 11 refs.

  6. Polarization induced doped transistor

    DOEpatents

    Xing, Huili; Jena, Debdeep; Nomoto, Kazuki; Song, Bo; Zhu, Mingda; Hu, Zongyang

    2016-06-07

    A nitride-based field effect transistor (FET) comprises a compositionally graded and polarization induced doped p-layer underlying at least one gate contact and a compositionally graded and doped n-channel underlying a source contact. The n-channel is converted from the p-layer to the n-channel by ion implantation, a buffer underlies the doped p-layer and the n-channel, and a drain underlies the buffer.

  7. Martian polar geological studies

    NASA Technical Reports Server (NTRS)

    Cutts, J. A. J.

    1977-01-01

    Multiple arcs of rugged mountains and adjacent plains on the surface of Mars were examined. These features, located in the southern polar region were photographed by Mariner 9. Comparisons are made with characteristics of a lunar basin and mare; Mare imbrium in particular. The martian feature is interpreted to have originated in the same way as its lunar analog- by volcanic flooding of a large impact basin. Key data and methodology leading to this conclusion are cited.

  8. Measurements Of Spin Observables In Pseudoscalar-Meson Photo-Production Using Polarized Neutrons In Solid HD

    SciTech Connect

    Kageya, Tsuneo

    2014-01-01

    Psuedo-scalar meson photo production measurements have been carried out with longitudinally-polarized neutrons using the circularly and linearly polarized photon beams and the CLAS at Thomas Jefferson National Accelerator Facility (Jlab). The experiment aims to obtain a complete set of spin observables on an efficient neutron target. Preliminary E asymmetries for the exclusive reaction, gamma + n(p)--> pi- + p(p), selecting quasi free neutron kinematics are discussed.

  9. Measurements of Spin Observables in Single Pion Photo-Production from Polarized Quasi-Free Neutrons in Solid HD

    NASA Astrophysics Data System (ADS)

    Kageya, Tsuneo

    Abstract Psuedo-scalar meson photo production measurements have been carried out with longitudinally-polarized neutrons using the circularly and linearly polarized photon beams and the CLAS at Thomas Jefferson National Accelerator Facility (Jlab). The experiment aims to obtain a complete set of spin observables on an effective neutron target using D in HD. Preliminary E and Σ asymmetries for the exclusive reaction, γ + n(p) → π- + p(p), are discussed.

  10. Synchrotron polarization in blazars

    SciTech Connect

    Zhang, Haocheng; Böttcher, Markus; Chen, Xuhui

    2014-07-01

    We present a detailed analysis of time- and energy-dependent synchrotron polarization signatures in a shock-in-jet model for γ-ray blazars. Our calculations employ a full three-dimensional radiation transfer code, assuming a helical magnetic field throughout the jet. The code considers synchrotron emission from an ordered magnetic field, and takes into account all light-travel-time and other relevant geometric effects, while the relevant synchrotron self-Compton and external Compton effects are handled with the two-dimensional Monte-Carlo/Fokker-Planck (MCFP) code. We consider several possible mechanisms through which a relativistic shock propagating through the jet may affect the jet plasma to produce a synchrotron and high-energy flare. Most plausibly, the shock is expected to lead to a compression of the magnetic field, increasing the toroidal field component and thereby changing the direction of the magnetic field in the region affected by the shock. We find that such a scenario leads to correlated synchrotron + synchrotron-self-Compton flaring, associated with substantial variability in the synchrotron polarization percentage and position angle. Most importantly, this scenario naturally explains large polarization angle rotations by ≳ 180°, as observed in connection with γ-ray flares in several blazars, without the need for bent or helical jet trajectories or other nonaxisymmetric jet features.

  11. Understanding ultracold polar molecules

    NASA Astrophysics Data System (ADS)

    Julienne, Paul

    2009-05-01

    The successful production of a dense sample of ultracold ground state KRb polar molecules [1] opens the door to a new era of research with dipolar gases and lattices of such species. This feat was achieved by first associating a K and a Rb atom to make a weakly bound Feshbach molecule and then coherently transferring the population to the ground vibrational level of the molecule. This talk focuses on theoretical issues associated with making and using ultracold polar molecules, using KRb as an example [2]. Full understanding of this species and the processes by which it is made requires taking advantage of accurate molecular potentials [3], ab initio calculations [4], and the properties of the long-range potential. A highly accurate model is available for KRb for all bound states below the ground state separated atom limit and could be constructed for other species. The next step is to develop an understanding of the interactions between polar molecules, and their control in the ultracold domain. Understanding long-range interactions and threshold resonances will be crucial for future work. [1] K.-K. Ni, et al, Science 322, 231(2008). [2] P. S. Julienne, arXiv:0812:1233. [3] Pashov et al., Phys. Rev. A76, 022511 (2007). [4] S. Kotochigova, et al., arXiv:0901.1486.

  12. Pliocene geomagnetic polarity epochs

    USGS Publications Warehouse

    Dalrymple, G.B.; Cox, A.; Doell, Richard R.; Gromme, C.S.

    1967-01-01

    A paleomagnetic and K-Ar dating study of 44 upper Miocene and Pliocene volcanic units from the western United States suggests that the frequency of reversals of the earth's magnetic field during Pliocene time may have been comparable with that of the last 3.6 m.y. Although the data are too limited to permit the formal naming of any new polarity epochs or events, four polarity transitions have been identified: the W10 R/N boundary at 3.7 ?? 0.1 m.y., the A12 N/R boundary at 4.9 ?? 0.1 m.y., the W32 N/R boundary at 9.0 ?? 0.2m.y., and the W36 R/N boundary at 10.8 ?? 0.3 - 1.0 m.y. The loss of absolute resolution of K-Ar dating in older rocks indicates that the use of well defined stratigraphic successions to identify and date polarity transitions will be important in the study of Pliocene and older reversals. ?? 1967.

  13. Synchrotron Polarization in Blazars

    NASA Astrophysics Data System (ADS)

    Zhang, Haocheng; Chen, Xuhui; Böttcher, Markus

    2014-07-01

    We present a detailed analysis of time- and energy-dependent synchrotron polarization signatures in a shock-in-jet model for γ-ray blazars. Our calculations employ a full three-dimensional radiation transfer code, assuming a helical magnetic field throughout the jet. The code considers synchrotron emission from an ordered magnetic field, and takes into account all light-travel-time and other relevant geometric effects, while the relevant synchrotron self-Compton and external Compton effects are handled with the two-dimensional Monte-Carlo/Fokker-Planck (MCFP) code. We consider several possible mechanisms through which a relativistic shock propagating through the jet may affect the jet plasma to produce a synchrotron and high-energy flare. Most plausibly, the shock is expected to lead to a compression of the magnetic field, increasing the toroidal field component and thereby changing the direction of the magnetic field in the region affected by the shock. We find that such a scenario leads to correlated synchrotron + synchrotron-self-Compton flaring, associated with substantial variability in the synchrotron polarization percentage and position angle. Most importantly, this scenario naturally explains large polarization angle rotations by >~ 180°, as observed in connection with γ-ray flares in several blazars, without the need for bent or helical jet trajectories or other nonaxisymmetric jet features.

  14. Transverse-longitudinal coupling in intense beams

    SciTech Connect

    Wang, T.S.F.; Smith, L.

    1981-03-01

    The coupling between transverse and longitudinal perturbations is studied self-consistently by considering a beam of K-V distribution. The analysis is carried out within the context of linearized Vlasov-Maxwell equations and electrostatic approximation. The perturbation is assumed to be azimuthally symmetric but axially non-uniform (k/sub z/ is not equal to 0). It is shown that the coupling affects both the longitudinal and transverse modes significantly in the high density and low frequency region. Two new classes of longitudinal modes are found which would not exist if the transverse motions of particles are neglected. The effect of resistive wall impedance on beam stability is also studied. It is found that the longitudinal impedance can cause the transverse modes also to be weakly unstable.

  15. The Lighthouse Program: A Longitudinal Research Project.

    ERIC Educational Resources Information Center

    LaRose, Barbara

    1986-01-01

    Longitudinal data are presented from the Lighthouse Program for gifted students which features cluster grouping and a quota identification systems to ensure proportionate inclusion of minority students. (Author/CL)

  16. ADDHEALTH - NATIONAL LONGITUDINAL STUDY OF ADOLESCENT HEALTH

    EPA Science Inventory

    This study provides a comprehensive view of the health and health behaviors of adolescents and the antecedents - personal, interpersonal, familial, and environmental of these outcomes. The study features a longitudinal, multi-level design with independent measurement at the indiv...

  17. 14 CFR 23.145 - Longitudinal control.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Longitudinal control. 23.145 Section 23.145... Maneuverability § 23.145 Longitudinal control. (a) With the airplane as nearly as possible in trim at 1.3 VS1, it... application of single-handed control forces exceeding those specified in § 23.143(c). The trimming...

  18. Longitudinal space charge effects near transition

    SciTech Connect

    Pozdeyev,E.; Rodriguez, J.A.; Marti, F.; York, R.C.

    2009-05-04

    Experimental and numerical studies of the longitudinal beam dynamics in the Small Isochronous Ring (SIR) at Michigan State University revealed a fast, space-charge driven instability that did not fit the model of the negative mass instability. This paper proposes a simple analytical model explaining these results. Also, the paper compares the model to result s of experimental and numerical studies of the longitudinal beam dynamics in SIR.

  19. 14 CFR 23.145 - Longitudinal control.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Longitudinal control. 23.145 Section 23.145... Maneuverability § 23.145 Longitudinal control. (a) With the airplane as nearly as possible in trim at 1.3 VS1, it... application of single-handed control forces exceeding those specified in § 23.143(c). The trimming...

  20. Digital Longitudinal Tomography Using Backprojection.

    NASA Astrophysics Data System (ADS)

    Kampp, Thomas Dalton

    1987-09-01

    Conventional tomography allows a single section to be demonstrated on film with a single sweep of an x -ray tube. Each sweep of the x-ray tube exposes the patient to approximately one rad of radiation dose. This tomographic method has been extended by using a backprojection method to allow six degrees of freedom in the selection of the plane to be synthesized. As many planes as desired can be retrospectively tomosynthesized from a single sweep of the apparatus. This can greatly reduce the dose to the patient as well as eliminate patient motion artifacts that would occur with individually acquired slices using the traditional analogue film method. A linear tomographic table was modified by the addition of a digital imaging chain so that a set of projection images could be acquired with each sweep of the apparatus. The digital images were manipulated by a computer to tomosynthesize retrospectively any desired plane. This advanced tomographic system would complement CT which cannot yet match the resolution of this system for longitudinal studies. Various special phantoms were imaged in order to provide data which were used to determine the operating characteristics of this particular system. The characteristics measured are the system gray level response, sampling density, modulation transfer function, small area contrast, detection limits, signal-to-noise ratio, noise Wiener spectrum, and slice thickness. This laboratory piece of equipment could significantly detect approximately 1.7% contrast with a 1 mm pixel size. The MTF values and limiting resolution were approximately one -third of what can be obtained with current CT scanners. The system performed precisely as the computer simulations indicated. The dynamic range of the display is less than that of the image. Windowing of the final image can increase displayed contrast up to the limits imposed by noise. This is an improvement compared to film. With current state -of-the-art equipment, a little engineering and

  1. Polarization of metastable 129Xe

    NASA Astrophysics Data System (ADS)

    Xia, Tian; Morgan, Steven; Jau, Yuan-Yu; Happer, William

    2008-05-01

    We have measured atomic polarization of metastable 129Xe in a pyrex cell by optical pumping, while metastability exchange optical pumping of 3He is routinely done. The atomic polarization of metastable Xe is on the order of 10%. Metastable xenon is created by electrodeless rf discharge. The hyperfine transition of metastable 129Xe is observed by microwave excitation. Atomic polarization can be demonstrated by comparison of the intensities of the transitions between different Zeeman sublevels, while pumping a specific optical transition of metastable Xe with circularly polarized light. This work offers insight into attempts to polarize 129Xe nuclei by metastability exchange optical pumping.

  2. Device For Perception Of Polarization

    NASA Technical Reports Server (NTRS)

    Whitehead, Victor S.; Coulson, Kinsel

    1993-01-01

    Polarized image viewed through rotating polarizing filter appears to pulsate. Optical device enables human observer to perceive polarization of light. Used alone for viewing in real time and/or in conjunction with video or movie camera to record for subsequent detailed quantitative analysis of polarization in scene. Device used in remote sensing to classify portions of scenes according to polarization characteristics, to enhance viewing through atmosphere and oceans and to enhance contrasts. Used to monitor oilspill from air and detect changes in soil moisture and to map wetlands, among many other possible civilian and military applications.

  3. Towards Polarized Antiprotons at FAIR

    SciTech Connect

    Rathmann, Frank

    2007-06-13

    Understanding the interplay of the nuclear interaction with polarized protons and the electromagnetic interaction with polarized electrons in polarized atoms is crucial to progress towards the PAX goal to eventually produce stored polarized antiproton beams at FAIR. Presently, there exist two competing theoretical scenarios: one with substantial spin filtering of (anti)protons by atomic electrons, and a second one suggesting a self-cancellation of the electron contribution to spin filtering. After a brief review of the PAX physics case for polarized antiprotons at FAIR, a detailed discussion of future investigations, including spin-filtering experiments at COSY-Juelich and at the AD of CERN is presented.

  4. Longitudinal Excitons in GaN

    NASA Astrophysics Data System (ADS)

    Reynolds, D. C.; Jogai, B.; Collins, T. C.

    2002-05-01

    Many of the previous investigations of longitudinal excitons have involved reflection and absorption measurements rather than emission. In these measurements it is more difficult to resolve the longitudinal exciton from the Γ5 and Γ6 free excitons in wurtzite material. The longitudinal excitons have energies and oscillator strengths that depend on the direction of propagation and they are not observable along the principal axis of the crystal. In the wurtzite structure, such as GaN, the Γ5 exciton is the pure transverse mode, whereas the longitudinal is a mixed mode going from pure longitudinal, for the propogation direction K perpendicular to C, to pure transverse for K parallel to C. If more than one orientation is present in the sample, it is clear that more than one longitudinal exciton may be seen since it is a mixed mode. In the current experiment we observe more than one mode, which we associate with more than one crystal orientation. This may result from the columnar growth often observed in GaN.

  5. Sensitivity of VIIRS Polarization Measurements

    NASA Technical Reports Server (NTRS)

    Waluschka, Eugene

    2010-01-01

    The design of an optical system typically involves a sensitivity analysis where the various lens parameters, such as lens spacing and curvatures, to name two parameters, are (slightly) varied to see what, if any, effect this has on the performance and to establish manufacturing tolerances. A sinular analysis was performed for the VIIRS instruments polarization measurements to see how real world departures from perfectly linearly polarized light entering VIIRS effects the polarization measurement. The methodology and a few of the results of this polarization sensitivity analysis are presented and applied to the construction of a single polarizer which will cover the VIIRS VIS/NIR spectral range. Keywords: VIIRS, polarization, ray, trace; polarizers, Bolder Vision, MOXTEK

  6. Achievement and steering of light-induced sub-wavelength longitudinal magnetization chain.

    PubMed

    Nie, Zhongquan; Ding, Weiqiang; Shi, Guang; Li, Dongyu; Zhang, Xueru; Wang, Yuxiao; Song, Yinglin

    2015-08-10

    The light-induced magnetization distributions for a high numerical aperture focusing configuration with an azimuthally polarized Bessel-Gaussian beam modulated by optimized vortex binary filters are investigated based on the inverse Faraday effect. It is found that, by adjusting the radii of different rings of the single/ cascaded vortex binary filters, super-long (12λ) and sub-wavelength (0.416λ) longitudinal magnetization chain with single/dual channels can be achieved in the focal region. Such well-behaved magnetization trait is attributed to the mutual effect between the optical polarization singularities of the azimuthally polarized beam and single/cascaded spiral optical elements. In addition, we find that the displacement distance of the longitudinal magnetization chain is proportional to the phase difference between the inner circle and outer ring of the vortex binary filters, thus giving rise to the steerable magnetization chain. It is expected that the research outcomes can be applied in multiple atoms trapping and transport, multilayer magneto-optical data storage, fabrication of magnetic lattices for spin wave operation and development of ultra-compact optomagnetic devices. PMID:26367978

  7. A Clifford Algebra Description of Polarization Optics

    NASA Astrophysics Data System (ADS)

    Yevick, David; Soliman, George

    2014-03-01

    The polarization changes induced by optical components are represented as Clifford algebra transformations. This yields a unified formalism for polarized and partially polarized light and for the frequency dependence of polarization in the presence of polarization mode dispersion and polarization dependent loss. Work supported by NSERC.

  8. South Polar Polygons

    NASA Technical Reports Server (NTRS)

    2005-01-01

    4 July 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a polgyon-cracked surface, into which deep, somewhat kidney-bean-shaped pits have formed. These are landscapes of the martian south polar residual cap. This view was captured during May 2005.

    Location near: 86.9oS, 5.1oW Image width: 1.5 km (0.9 mi) Illumination from: upper left Season Southern Spring

  9. South Polar Scene

    NASA Technical Reports Server (NTRS)

    2004-01-01

    5 February 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a portion of the south polar residual cap. Sunlight illuminates this scene from the upper left, thus the somewhat kidney bean-shaped features are pits, not mounds. These pits and their neighboring polygonal cracks are formed in a material composed mostly of carbon dioxide ice. The image is located near 87.0oS, 5.7oW, and covers an area 3 km (1.9 mi) wide.

  10. Gluon polarization in nucleon

    NASA Astrophysics Data System (ADS)

    Shahveh, Abolfazl; Taghavi-Shahri, Fatemeh; Arash, Firooz

    2010-07-01

    In the context of the so-called valon model, we calculate δg/g and show that although it is small and compatible with the measured values, the gluon contribution to the spin of nucleon can be sizable. The smallness of δg/g in the measured kinematical region should not be interpreted as δg being small. In fact, δg itself at small x, and the first moment of the polarized gluon distribution in the nucleon, Δg (Q2), are large.

  11. Italian Polar Metadata System

    NASA Astrophysics Data System (ADS)

    Longo, S.; Nativi, S.; Leone, C.; Migliorini, S.; Mazari Villanova, L.

    2012-04-01

    Italian Polar Metadata System C.Leone, S.Longo, S.Migliorini, L.Mazari Villanova, S. Nativi The Italian Antarctic Research Programme (PNRA) is a government initiative funding and coordinating scientific research activities in polar regions. PNRA manages two scientific Stations in Antarctica - Concordia (Dome C), jointly operated with the French Polar Institute "Paul Emile Victor", and Mario Zucchelli (Terra Nova Bay, Southern Victoria Land). In addition National Research Council of Italy (CNR) manages one scientific Station in the Arctic Circle (Ny-Alesund-Svalbard Islands), named Dirigibile Italia. PNRA started in 1985 with the first Italian Expedition in Antarctica. Since then each research group has collected data regarding biology and medicine, geodetic observatory, geophysics, geology, glaciology, physics and atmospheric chemistry, earth-sun relationships and astrophysics, oceanography and marine environment, chemistry contamination, law and geographic science, technology, multi and inter disciplinary researches, autonomously with different formats. In 2010 the Italian Ministry of Research assigned the scientific coordination of the Programme to CNR, which is in charge of the management and sharing of the scientific results carried out in the framework of the PNRA. Therefore, CNR is establishing a new distributed cyber(e)-infrastructure to collect, manage, publish and share polar research results. This is a service-based infrastructure building on Web technologies to implement resources (i.e. data, services and documents) discovery, access and visualization; in addition, semantic-enabled functionalities will be provided. The architecture applies the "System of Systems" principles to build incrementally on the existing systems by supplementing but not supplanting their mandates and governance arrangements. This allows to keep the existing capacities as autonomous as possible. This cyber(e)-infrastructure implements multi-disciplinary interoperability following

  12. 'Endurance' Untouched (polar)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This navigation camera mosaic, created from images taken by NASA's Mars Exploration Rover Opportunity on sols 115 and 116 (May 21 and 22, 2004) provides a dramatic view of 'Endurance Crater.' The rover engineering team carefully plotted the safest path into the football field-sized crater, eventually easing the rover down the slopes around sol 130 (June 12, 2004). To the upper left of the crater sits the rover's protective heatshield, which sheltered Opportunity as it passed through the martian atmosphere. The 360-degree view is presented in a polar projection, with geometric and radiometric seam correction.

  13. North Polar Dunes

    NASA Technical Reports Server (NTRS)

    2005-01-01

    10 April 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows low-albedo sand dunes in the north polar region. The slip faces on the dunes face toward the lower left, indicating that the dominant winds in this region blow or blew from the upper right.

    Location near: 82.4oN, 46.5oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Summer

  14. South Polar Erosion

    NASA Technical Reports Server (NTRS)

    2004-01-01

    24 June 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the results of erosion acting upon a layer of material in the south polar region of Mars. The elliptical pit in the lower left corner of the image was once buried beneath this eroding layer, as well. The processes that eroded the material, and the composition of the material, are unknown. The image is located near 80.7oS, 300.9oW, and covers an area about 3 km (1.9 mi) wide. Sunlight illuminates this scene from the top.

  15. South Polar Depression

    NASA Technical Reports Server (NTRS)

    2005-01-01

    14 August 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a circular depression and a suite of eroding mesas of carbon dioxide. These features occur in the south polar residual cap of Mars. The eroding carbon dioxide creates landforms reminiscent of 'Swiss cheese.' The circular feature might indicate the location of a filled, buried impact crater.

    Location near: 86.8oS, 111.0oW Image width: width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Spring

  16. INFLUENCE OF THE POLAR CAP CURRENT ON PULSAR POLARIZATION

    SciTech Connect

    Kumar, D.; Gangadhara, R. T. E-mail: ganga@iiap.res.in

    2012-07-20

    We have developed a model for the polarization of curvature radiation by taking into account the polar-cap-current-induced perturbation on the dipolar magnetic field. We present the effects of the polar cap current on the pulsar radio emission in an artificial case when the rotation effects, such as aberration and retardation, are absent. Our model indicates that the intensity components and the polarization angle inflection point can be shifted to either the leading or the trailing side depending upon the prevailing conditions in the viewing geometry, the non-uniformity in source distribution (modulation), and the polar-cap-current-induced perturbation. Also, we find evidence for the origin of symmetric-type circular polarization in addition to the antisymmetric type. Our model predicts a stronger trailing component compared to that on the leading side of a given cone under some specific conditions.

  17. Short monolithic dual-wavelength single-longitudinal-mode DBR phosphate fiber laser.

    PubMed

    Xiong, Lingyun; Hofmann, Peter; Schülzgen, Axel; Peyghambarian, N; Albert, Jacques

    2014-06-20

    We propose and demonstrate a 5-cm-long monolithic dual-wavelength single-longitudinal mode distributed Bragg reflector (DBR) all-phosphate fiber laser. Strong UV-induced fiber Bragg gratings are directly written in highly Er/Yb codoped phosphate fiber. The separation between gratings is selected as 1 cm to only excite two longitudinal modes in the DBR cavity. By exploiting the spatial hole burning effect and the polarization hole burning effect, stable narrow-linewidth dual-wavelength lasing emission with 38 pm wavelength spacing and a total emitted power of 2.8 mW is obtained from this DBR fiber laser. A microwave signal at 4.58 GHz is generated by the heterodyne detection of the dual-wavelength laser. PMID:24979414

  18. Longitudinal assessment of treatment effects on pulmonary ventilation using 1H/3He MRI multivariate templates

    NASA Astrophysics Data System (ADS)

    Tustison, Nicholas J.; Contrella, Benjamin; Altes, Talissa A.; Avants, Brian B.; de Lange, Eduard E.; Mugler, John P.

    2013-03-01

    The utitlity of pulmonary functional imaging techniques, such as hyperpolarized 3He MRI, has encouraged their inclusion in research studies for longitudinal assessment of disease progression and the study of treatment effects. We present methodology for performing voxelwise statistical analysis of ventilation maps derived from hyper­ polarized 3He MRI which incorporates multivariate template construction using simultaneous acquisition of IH and 3He images. Additional processing steps include intensity normalization, bias correction, 4-D longitudinal segmentation, and generation of expected ventilation maps prior to voxelwise regression analysis. Analysis is demonstrated on a cohort of eight individuals with diagnosed cystic fibrosis (CF) undergoing treatment imaged five times every two weeks with a prescribed treatment schedule.

  19. SCATTERING POLARIZATION IN SOLAR FLARES

    SciTech Connect

    Štěpán, Jiří; Heinzel, Petr

    2013-11-20

    There is ongoing debate about the origin and even the very existence of a high degree of linear polarization of some chromospheric spectral lines observed in solar flares. The standard explanation of these measurements is in terms of the impact polarization caused by non-thermal proton and/or electron beams. In this work, we study the possible role of resonance line polarization due to radiation anisotropy in the inhomogeneous medium of the flare ribbons. We consider a simple two-dimensional model of the flaring chromosphere and we self-consistently solve the non-LTE problem taking into account the role of resonant scattering polarization and of the Hanle effect. Our calculations show that the horizontal plasma inhomogeneities at the boundary of the flare ribbons can lead to a significant radiation anisotropy in the line formation region and, consequently, to a fractional linear polarization of the emergent radiation of the order of several percent. Neglecting the effects of impact polarization, our model can provide a clue for resolving some of the common observational findings, namely: (1) why a high degree of polarization appears mainly at the edges of the flare ribbons; (2) why polarization can also be observed during the gradual phase of a flare; and (3) why polarization is mostly radial or tangential. We conclude that radiation transfer in realistic multi-dimensional models of solar flares needs to be considered as an essential ingredient for understanding the observed spectral line polarization.

  20. Tissue morphodynamics: Translating planar polarity cues into polarized cell behaviors.

    PubMed

    Devenport, Danelle

    2016-07-01

    The ability of cells to collectively orient and align their behaviors is essential in multicellular organisms for unidirectional cilia beating, collective cell movements, oriented cell divisions, and asymmetric cell fate specification. The planar cell polarity pathway coordinates a vast and diverse array of collective cell behaviors by intersecting with downstream pathways that regulate cytoskeletal dynamics and intercellular signaling. How the planar polarity pathway translates directional cues to produce polarized cell behaviors is the focus of this review. PMID:26994528

  1. Polar Rain Gradients and Field-Aligned Polar Cap Potentials

    NASA Technical Reports Server (NTRS)

    Fairfield, D. H.; Wing, S.; Newell, P. T.; Ruohoniemi, J. M.; Gosling, J. T.; Skoug, R. M.

    2008-01-01

    ACE SWEPAM measurements of solar wind field-aligned electrons have been compared with simultaneous measurements of polar rain electrons precipitating over the polar cap and detected by DMSP spacecraft. Such comparisons allow investigation of cross-polarcap gradients in the intensity of otherwise-steady polar rain. The generally good agreement of the distribution functions, f, from the two data sources confirms that direct entry of solar electrons along open field lines is indeed the cause of polar rain. The agreement between the data sets is typically best on the side of the polar cap with most intense polar rain but the DMSP f's in less intense regions can be brought into agreement with ACE measurements by shifting all energies by a fixed amounts that range from tens to several hundred eV. In most cases these shifts are positive which implies that field-aligned potentials of these amounts exist on polar cap field lines which tend to retard the entry of electrons and produce the observed gradients. These retarding potentials undoubtedly appear in order to prevent the entry of low-energy electrons and maintain charge quasi-neutrality that would otherwise be violated since most tailward flowing magnetosheath ions are unable to follow polar rain electrons down to the polar cap. In more limited regions near the boundary of the polar cap there is sometimes evidence for field-aligned potentials of the opposite sign that accelerate polar rain electrons. A solar electron burst is also studied and it is concluded that electrons from such bursts can enter the magnetotail and precipitate in the same manner as polar rain.

  2. Experiments with Fermilab polarized proton and polarized antiproton beams

    SciTech Connect

    Yokosawa, A.

    1990-01-01

    We summarize activities concerning the Fermilab polarized beams. They include a brief description of the polarized-beam facility, measurements of beam polarization by polarimeters, asymmetry measurements in the {pi}{degree} production at high p{sub {perpendicular}} and in the {Lambda} ({Sigma}{degree}), {pi}{sup {plus minus}}, {pi}{degree} production at large x{sub F}, and {Delta}{sigma}{sub L}(pp, {bar p}p) measurements. 18 refs.

  3. Conversion of sunflower multiband radiometer polarization measurements to polarization parameters

    NASA Technical Reports Server (NTRS)

    Biehl, Larry L.

    1995-01-01

    The data processing analysis and conversion of polarization measurements to polarization parameters from the Sunflower multiband radiometer is presented in this final report. Included is: (1) the actual data analysis; (2) the comparison of the averaging techniques and the percent polarization derived from the original and averaged I, Q, U parameters; (3) the polarizer angles used in conversion; (4) the Matlab files; (5) the relative ground size, field of view location, and view zenith angles, and (6) the summary of all the sky data for all dates.

  4. Polar Magnetic Field Experiment

    NASA Technical Reports Server (NTRS)

    Russell, C. T.

    1999-01-01

    This grant covers the initial data reduction and analysis of the magnetic field measurements of the Polar spacecraft. At this writing data for the first three years of the mission have been processed and deposited in the key parameter database. These data are also available in a variety of time resolutions and coordinate systems via a webserver at UCLA that provides both plots and digital data. The flight software has twice been reprogrammed: once to remove a glitch in the data where there were rare collisions between commands in the central processing unit and once to provide burst mode data at 100 samples per second on a regular basis. The instrument continues to function as described in the instrument paper (1.1 in the bibliography attached below). The early observations were compared with observations on the same field lines at lower altitude. The polar magnetic measurements also proved to be most useful for testing the accuracy of MHD models. WE also made important contributions to study of waves and turbulence.

  5. Polarization imaging apparatus

    NASA Technical Reports Server (NTRS)

    Zou, Yingyin Kevin (Inventor); Chen, Qiushui (Inventor); Zhao, Hongzhi (Inventor)

    2010-01-01

    A polarization imaging apparatus measures the Stokes image of a sample. The apparatus consists of an optical lens set 11, a linear polarizer 14 with its optical axis 18, a first variable phase retarder 12 with its optical axis 16 aligned 22.5.degree. to axis 18, a second variable phase retarder 13 with its optical axis 17 aligned 45.degree. to axis 18, a imaging sensor 15 for sensing the intensity images of the sample, a controller 101 and a computer 102. Two variable phase retarders 12 and 13 were controlled independently by a computer 102 through a controller unit 101 which generates a sequential of voltages to control the phase retardations of VPRs 12 and 13. A set of four intensity images, I.sub.0, I.sub.1, I.sub.2 and I.sub.3 of the sample were captured by imaging sensor 15 when the phase retardations of VPRs 12 and 13 were set at (0,0), (.pi.,0), (.pi.,.pi.) and (.pi./2,.pi.), respectively Then four Stokes components of a Stokes image, S.sub.0, S.sub.1, S.sub.2 and S.sub.3 were calculated using the four intensity images.

  6. Macrophage polarization in pathology.

    PubMed

    Sica, Antonio; Erreni, Marco; Allavena, Paola; Porta, Chiara

    2015-11-01

    Macrophages are cells of the innate immunity constituting the mononuclear phagocyte system and endowed with remarkable different roles essential for defense mechanisms, development of tissues, and homeostasis. They derive from hematopoietic precursors and since the early steps of fetal life populate peripheral tissues, a process continuing throughout adult life. Although present essentially in every organ/tissue, macrophages are more abundant in the gastro-intestinal tract, liver, spleen, upper airways, and brain. They have phagocytic and bactericidal activity and produce inflammatory cytokines that are important to drive adaptive immune responses. Macrophage functions are settled in response to microenvironmental signals, which drive the acquisition of polarized programs, whose extremes are simplified in the M1 and M2 dichotomy. Functional skewing of monocyte/macrophage polarization occurs in physiological conditions (e.g., ontogenesis and pregnancy), as well as in pathology (allergic and chronic inflammation, tissue repair, infection, and cancer) and is now considered a key determinant of disease development and/or regression. Here, we will review evidence supporting a dynamic skewing of macrophage functions in disease, which may provide a basis for macrophage-centered therapeutic strategies. PMID:26210152

  7. Joint multiple imputation for longitudinal outcomes and clinical events that truncate longitudinal follow-up.

    PubMed

    Hu, Bo; Li, Liang; Greene, Tom

    2016-07-30

    Longitudinal cohort studies often collect both repeated measurements of longitudinal outcomes and times to clinical events whose occurrence precludes further longitudinal measurements. Although joint modeling of the clinical events and the longitudinal data can be used to provide valid statistical inference for target estimands in certain contexts, the application of joint models in medical literature is currently rather restricted because of the complexity of the joint models and the intensive computation involved. We propose a multiple imputation approach to jointly impute missing data of both the longitudinal and clinical event outcomes. With complete imputed datasets, analysts are then able to use simple and transparent statistical methods and standard statistical software to perform various analyses without dealing with the complications of missing data and joint modeling. We show that the proposed multiple imputation approach is flexible and easy to implement in practice. Numerical results are also provided to demonstrate its performance. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26179943

  8. Longitudinal surface structures (flowstripes) on Antarctic glaciers

    NASA Astrophysics Data System (ADS)

    Glasser, N. F.; Gudmundsson, G. H.

    2012-03-01

    Longitudinal surface structures ("flowstripes") are common on many glaciers but their origin and significance are poorly understood. In this paper we present observations of the development of these longitudinal structures from four different Antarctic glacier systems; the Lambert Glacier/Amery Ice Shelf area, the Taylor and Ferrar Glaciers in the Ross Sea sector, Crane and Jorum Glaciers (ice-shelf tributary glaciers) on the Antarctic Peninsula, and the onset zone of a tributary to the Recovery Glacier Ice Stream in the Filchner Ice Shelf area. Mapping from optical satellite images demonstrates that longitudinal surface structures develop in two main situations: (1) as relatively wide flow stripes within glacier flow units and (2) as relatively narrow flow stripes where there is convergent flow around nunataks or at glacier confluence zones. Our observations indicate that the confluence features are narrower, sharper, and more clearly defined features. They are characterised by linear troughs or depressions on the ice surface and are much more common than the former type. Longitudinal surface structures within glacier flow units have previously been explained as the surface expression of localised bed perturbations but a universal explanation for those forming at glacier confluences is lacking. Here we propose that these features are formed at zones of ice acceleration and extensional flow at glacier confluences. We provide a schematic model for the development of longitudinal surface structures based on extensional flow that can explain their ridge and trough morphology as well as their down-ice persistence.

  9. Enantioselective synthesis of helical polydiacetylene by application of linearly polarized light and magnetic field

    NASA Astrophysics Data System (ADS)

    Xu, Yangyang; Yang, Guang; Xia, Hongyan; Zou, Gang; Zhang, Qijin; Gao, Jiangang

    2014-09-01

    Magnetic optical activity, which can occur in all media and is induced by longitudinal magnetic field, causes the difference in absorption coefficients of left and right circularly polarized light and has the potential for magnetically induced enantioselectivity in chemical reactions. Compared with the well-established technique with circularly polarized light, there are few reports on the production of helical conjugated polymers in a photochemical reaction based on above magnetochiral anisotropy mechanism. Herein, we demonstrate experimentally that the enantioselective polymerization of diacetylene derivative can be achieved in the liquid crystal phase by application of linearly polarized light under a parallel or antiparallel magnetic field. The screw direction of predominant helical polydiacetylene chain can be rigorously controlled with the relative orientation of linearly polarized light and the magnetic field. Moreover, the prepared helical polydiacetylene assemblies can serve as a direct visual probe for the enantioselective recognition of D- or L-lysine.

  10. Measurement of the Gluon Polarization {delta}g/g from Open Charm at COMPASS

    SciTech Connect

    Kunne, Fabienne

    2009-08-04

    We have measured the gluon polarization in the nucleon by detecting charm production via D{sup 0} meson decay to charged K and {pi} in polarized muon scattering off a longitudinally polarized deuteron target. The dominant process for charm production is the photon gluon fusion into a charm anti-charm quark pair. By using all deuteron statistics from COMPASS accumulated between 2002 and 2006, we extract double spin asymmetries in bins of the transverse momentum and the energy of the D{sup 0} meson and we perform a leading order analysis of the data to extract the gluon polarization <{delta}g/g> = -0.49{+-}0.27(stat){+-}0.11(syst) at a Quantum Chromodynamics (QCD) scale {mu}{sup 2} = 13 GeV{sup 2} and at a gluon momentum fraction = 0.11.

  11. Molecular density functional theory of water including density–polarization coupling

    NASA Astrophysics Data System (ADS)

    Jeanmairet, Guillaume; Levy, Nicolas; Levesque, Maximilien; Borgis, Daniel

    2016-06-01

    We present a three-dimensional molecular density functional theory of water derived from first-principles that relies on the particle’s density and multipolar polarization density and includes the density–polarization coupling. This brings two main benefits: (i) scalar density and vectorial multipolar polarization density fields are much more tractable and give more physical insight than the full position and orientation densities, and (ii) it includes the full density–polarization coupling of water, that is known to be non-vanishing but has never been taken into account. Furthermore, the theory requires only the partial charge distribution of a water molecule and three measurable bulk properties, namely the structure factor and the Fourier components of the longitudinal and transverse dielectric susceptibilities.

  12. Molecular density functional theory of water including density-polarization coupling.

    PubMed

    Jeanmairet, Guillaume; Levy, Nicolas; Levesque, Maximilien; Borgis, Daniel

    2016-06-22

    We present a three-dimensional molecular density functional theory of water derived from first-principles that relies on the particle's density and multipolar polarization density and includes the density-polarization coupling. This brings two main benefits: (i) scalar density and vectorial multipolar polarization density fields are much more tractable and give more physical insight than the full position and orientation densities, and (ii) it includes the full density-polarization coupling of water, that is known to be non-vanishing but has never been taken into account. Furthermore, the theory requires only the partial charge distribution of a water molecule and three measurable bulk properties, namely the structure factor and the Fourier components of the longitudinal and transverse dielectric susceptibilities. PMID:27116250

  13. Polar cap electric field distributions related to the interplanetary magnetic field direction

    NASA Technical Reports Server (NTRS)

    Heppner, J. P.

    1972-01-01

    The correlations between the azimuthal direction of the interplanetary magnetic field and the most simple polar cap signatures are discussed. Only the spatial distribution of the dawn-dusk polar cap field is considered. For each OGO 6 traverse across the northern or southern polar cap, the simultaneous values of the interplanetary magnetic field in solar-equatorial coordinates were recorded by the Explorer 33 magnetometer. Histograms of these values are presented and are discussed. The high degree of correlation with the longitudinal angle indicates that the relative geometry of the interplanetary magnetic field and magnetospheric magnetic fields must be fundamental to explaining the distribution of polar cap electric fields. The sign of the solar-equatorial component perpendicular to the sun-earth line appears to be a more critical parameter than the sign of the component toward the sun. The Svalgaard-Mansurov correlation and the correspondence between fast convection and parallel magnetospheric and interplanetary magnetic fields are described.

  14. The polarization of HD 189733

    NASA Astrophysics Data System (ADS)

    Bott, Kimberly; Bailey, Jeremy; Kedziora-Chudczer, Lucyna; Cotton, Daniel V.; Lucas, P. W.; Marshall, Jonathan P.; Hough, J. H.

    2016-06-01

    We present linear polarization observations of the exoplanet system HD 189733 made with the HIgh Precision Polarimetric Instrument (HIPPI) on the Anglo-Australian Telescope (AAT). The observations have higher precision than any previously reported for this object. They do not show the large amplitude polarization variations reported by Berdyugina et al. Our results are consistent with polarization data presented by Wiktorowicz et al. A formal least squares fit of a Rayleigh-Lambert model yields a polarization amplitude of 29.4 ± 15.6 parts per million. We observe a background constant level of polarization of ˜55-70 ppm, which is a little higher than expected for interstellar polarization at the distance of HD 189733.

  15. Measurements of the Neutron Longitudinal Spin Asymmetry A1n and Flavor Decomposition in the Valence Quark Region

    SciTech Connect

    Flay, David J.

    2014-08-01

    The current data for the nucleon-virtual photon longitudinal spin asymmetry A1 on the proton and neutron have shown that the ratio of the polarized-to-unpolarized down-quarkparton distribution functions,Dd=d, tends towards -1/2 at large x, in disagreement with the perturbative QCD prediction that Dd/d approaches 1 but more in line with constituent quark models. As a part of experiment E06-014 in Hall A of Jefferson Lab, double-spin asymmetries were measured in the scattering of a longitudinally polarized electron beam of energies 4.74 and 5.89 GeV from a longitudinally and transversely polarized 3He target in the deep inelastic scattering and resonance region, allowing for the extraction of the neutron asymmetry An1 and the ratios Dd/d and Du/u. We will discuss our analysis of the data and present results for A1 and g1/F1 on both 3He and the neutron, and the resulting quark ratios for the up and down quarks in the kinematic range of 0.2

  16. Dynamic nuclear polarization in diamond

    NASA Astrophysics Data System (ADS)

    Nah, Seungjoo

    2016-07-01

    We study the dynamic nuclear polarization of nitrogen-vacancy (NV) centers in diamond through optical pumping. The polarization is enhanced due to the hyperfine interaction of nuclear spins as applied magnetic fields vary. This is a result of the averaging of excited states due to fast-phonon transitions in the excited states. The effect of dephasing, in the presence of a vibronic band, is shown to have little effect during the dynamic polarization.

  17. Galactic dust polarized emission at high latitudes and CMB polarization

    NASA Astrophysics Data System (ADS)

    Prunet, S.; Sethi, S. K.; Bouchet, F. R.; Miville-Deschenes, M.-A.

    1998-11-01

    With recent instrumental advances, it might become possible to measure the polarization of the Cosmic Microwave Background (CMB), e.g. by future space missions like MAP and Planck Surveyor. In this paper, we estimate the dust polarized emission in our galaxy which is the major foreground to cope with for measuring the CMB polarization in the Wien part of CMB spectrum. We model the dust polarized emission in the galaxy using the three-dimensional HI maps of the Leiden/Dwingeloo survey at high galactic latitudes. We use the fact that the dust emission, for a wide range of wavelengths, has a tight correlation with the HI emission maps of this survey (Boulanger et al. 1996). Assuming the dust grains to be oblate with axis ratio =~ 2/3, which recent studies support, we determine the intrinsic dust polarized emissivity. The distribution of magnetic field with respect to the dust grain distribution is quite uncertain, we thus consider three extreme cases: (1) The magnetic field is aligned with the major axis of the dust structure, (2) the magnetic field has a random direction in the plane perpendicular to the direction of major axis of the dust structure, and (3) the magnetic field is unidirectional throughout. We further assume, as recent observations and theoretical analyses support, that the dust grains align with the magnetic field independently of its strength. The polarization reduction factor from misalignment of the direction of polarization from the plane of the sky and the differential polarization along a line of sight is calculated using these maps, to construct two-dimensional maps of dust polarized emission. We calculate the angular power spectrum of dust polarized emission from these maps and cast it in variables which allow a direct comparison with the polarized component of the CMB. Our results, at frequencies =~ 100 GHz, suggest that: (a) This foreground contamination is smaller than the scalar-induced polarization of the CMB at l ga 200 while the tensor

  18. Magnetic-field-assisted atomic polarization spectroscopy of 4 He

    NASA Astrophysics Data System (ADS)

    Li, Sheng; Wang, Haidong; Wu, Teng; Peng, Xiang; Guo, Hong; Cream Team

    2016-05-01

    Atomic polarization spectroscopy (PS) is a high resolution sub-Doppler atomic spectroscopic technique with free modulation. It is always desirable to obtain a PS signal with zero background as it can provide a more preferable laser frequency stabilization performance. There are many factors that can affect the PS signal background, i.e., the laser power, the laser polarization and the magnetic field. Here, we demonstrate a method for observing and analyzing the effects on the PS signal of 4 He under different magnetic fields. At the beginning, under nearly zero magnetic field, the large asymmetrical PS signal background has been observed and cannot be eliminated by only optically adjusting. Then, we find that the PS signal profile can be changed and controlled by varying the magnetic field with transverse or longitudinal direction and different intensity. The optimized PS signal with symmetrical dispersive profile and zero background is obtained when the magnetic field is chosen and controlled in the transverse direction and more than 20000nT intensity. Similar phenomenon cannot be observed under the longitudinal magnetic field. A theoretical model is also presented, which explains and agrees well with our experimental results.

  19. Impact of longitudinal fields on second harmonic generation in lithium niobate nanopillars

    NASA Astrophysics Data System (ADS)

    Baghban, Mohammad Amin; Gallo, Katia

    2016-09-01

    An optimized focused ion beam process is used to fabricate micrometer-long LiNbO3 nanopillars with diameters varying between 150 and 325 nm. Polarimetric mappings of second harmonic generation from a wavelength of 850 nm demonstrate the ability to modify the polarization features of the nonlinear response through a fine adjustment of the pillar size. The effect is ascribed to the non-negligible contribution of the longitudinal fields associated with sub-wavelength light confinement in the LiNbO3 nanopillars. The results also highlight the importance of a fine control over the nanopillar size in order to effectively engineer their nonlinear response.

  20. Suppression of electron scattering by the longitudinal components of tightly focused laser fields

    SciTech Connect

    Masuda, S.; Kando, M.; Kotaki, H.; Nakajima, K.

    2005-01-01

    Relativistic electron scattering by a high intensity linearly polarized Gaussian (TEM{sub 00} mode) laser beam is studied in detail using three-dimensional numerical simulations. It is observed that the longitudinal components of the electromagnetic field in a tight focus effectively suppress transverse electron scattering in the relativistic laser ponderomotive acceleration scheme. The simulations show that the relativistic ponderomotive acceleration can produce high quality electron bunches characterized by an extremely short bunch length of subfemtosecond, energy spread less than 1%, and normalized transverse emittance less than 10{pi} mm mrad.

  1. Polarization preservation in the AGS

    SciTech Connect

    Ratner, L.G.

    1983-01-01

    The successful operation of a high energy polarized beam at the Argonne Zero Gradient Synchrotron (ZGS) with the concommitant development of depolarizing resonance correction techniques has led to the present project of commissioning such a beam at the Brookhaven Alternating Gradient Synchrotron (AGS). A description of the project was presented at the 1981 National Accelerator Conference. I would like to now present a more detailed description of how we plan to preserve the polarization during acceleration, and to present our game plan for tuning through some 50 resonances and reaching our goal of a 26 GeV polarized proton beam with greater than 60% polarization.

  2. Polarization signals in mantis shrimps

    NASA Astrophysics Data System (ADS)

    Cronin, Thomas W.; Chiou, Tsyr-Huei; Caldwell, Roy L.; Roberts, Nicholas; Marshall, Justin

    2009-08-01

    While color signals are well known as a form of animal communication, a number of animals communicate using signals based on patterns of polarized light reflected from specialized body parts or structures. Mantis shrimps, a group of marine crustaceans, have evolved a great diversity of such signals, several of which are based on photonic structures. These include resonant scattering devices, structures based on layered dichroic molecules, and structures that use birefringent layers to produce circular polarization. Such biological polarizers operate in different spectral regions ranging from the near-UV to medium wavelengths of visible light. In addition to the structures that are specialized for signal production, the eyes of many species of mantis shrimp are adapted to detect linearly polarized light in the ultraviolet and in the green, using specialized sets of photoreceptors with oriented, dichroic visual pigments. Finally, a few mantis shrimp species produce biophotonic retarders within their photoreceptors that permit the detection of circularly polarized light and are thus the only animals known to sense this form of polarization. Mantis shrimps use polarized light in species-specific signals related to mating and territorial defense, and their means of manipulating light's polarization can inspire designs for artificial polarizers and achromatic retarders.

  3. Polarization compensator for optical communications

    NASA Technical Reports Server (NTRS)

    Fitzmaurice, M. W.; Abshire, J. B. (Inventor)

    1976-01-01

    An optical data communication system is provided whereby two orthogonal polarization states of a light beam carrier correspond to digital states. In such a system, automatic polarization compensation is provided by applying a dither modulating voltage to a cell exhibiting the electro-optic effect. The cell controls the relative phase of electric field components of an input light beam enabling the dither frequency component of the difference of the instantaneous powers in the two polarization states to be coherently detected. A signal derived from the coherent detection process is fed back to the cell via an integrator to form polarization bias compensating servo loop ot Type 1.

  4. The SLAC polarized electron source

    SciTech Connect

    Tang, H.; Alley, R.; Frisch, J.

    1995-06-01

    The SLAC polarized electron source employs a photocathode DC high voltage gun with a loadlock and a YAG pumped Ti:sapphire laser system for colliding beam experiments or a flash lamp pumped Ti:sapphire laser for fixed target experiments. It uses a thin, strained GaAs(100) photocathode, and is capable of producing a pulsed beam with a polarization of {ge}80% and a peak current exceeding 10 A. Its operating efficiency has reached 99%. The physics and technology of producing high polarization electron beams from a GaAs photocathode will be reviewed. The prospects of realizing a polarized electron source for future linear colliders will also be discussed.

  5. Optimizing dissolution dynamic nuclear polarization

    NASA Astrophysics Data System (ADS)

    Bornet, Aurélien; Jannin, Sami

    2016-03-01

    This article is a short review of some of our recent developments in dissolution dynamic nuclear polarization (d-DNP). We present the basic principles of d-DNP, and motivate our choice to step away from conventional approaches. We then introduce a modified d-DNP recipe that can be summed up as follows: Using broad line polarizing agents to efficiently polarize 1H spins. Increasing the magnetic field to 6.7 T and above. Applying microwave frequency modulation. Applying 1H-13C cross polarization. Transferring hyperpolarized solution through a magnetic tunnel.

  6. Bunched beam longitudinal instability: Coherent dipole motion

    SciTech Connect

    Zhang, S.Y.; Weng, W.T.

    1993-04-23

    In this paper, the authors present a new formulation for the longitudinal coherent dipole motion, where a quadrature response of the environmental impedance is shown to be the effective longitudinal impedance for the beam instability. The Robinson-Pedersen formulation for the longitudinal dipole motion is also presented, the difference of the two approaches is discussed in the comparison. The results by using the Sacherer integral equation for the coherent dipole motion can generate the same results as by using the other two approaches, except for a scaling difference. The formulation is further generalized to the rigid bunch motion using signal analysis method, where a form factor shows up naturally. Finally, the formulation is applied to solve the coupled bunch instabilities. Examples of the AGS Booster and the AGS coupled bunch instabilities are used to illustrate the applications of the formulation.

  7. Visual analysis of longitudinal brain tumor perfusion

    NASA Astrophysics Data System (ADS)

    Glaßer, Sylvia; Oeltze, Steffen; Preim, Uta; Bjørnerud, Atle; Hauser, Helwig; Preim, Bernhard

    2013-02-01

    In clinical research on diagnosis and evaluation of brain tumors, longitudinal perfusion MRI studies are acquired for tumor grading as well as to monitor and assess treatment response and patient prognosis. Within this work, we demonstrate how visual analysis techniques can be adapted to multidimensional datasets from such studies within a framework to support the computer-aided diagnosis of brain tumors. Our solution builds on two innovations: First, we introduce a pipeline yielding comparative, co-registered quantitative perfusion parameter maps over all time steps of the longitudinal study. Second, based on these time-dependent parameter maps, visual analysis methods were developed and adapted to reveal valuable insight into tumor progression, especially regarding the clinical research area of low grade glioma transformation into high grade gliomas. Our examination of four longitudinal brain studies demonstrates the suitability of the presented visual analysis methods and comprises new possibilities for the clinical researcher to characterize the development of low grade gliomas.

  8. Antiproton beam polarizer using a dense polarized target

    SciTech Connect

    Wojtsekhowski, Bogdan

    2011-05-01

    We describe considerations regarding the spin filtering method for the antiproton beam. The proposed investigation of the double polarization cross section for antiproton to nucleon interaction is outlined. It will use a single path of the antiproton beam through a dense polarized target, e.g. 3He or CH2, followed by a polarimeter.

  9. Polar Cap Pits

    NASA Technical Reports Server (NTRS)

    2005-01-01

    17 August 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows kidney bean-shaped pits, and other pits, formed by erosion in a landscape of frozen carbon dioxide. This images shows one of about a dozen different patterns that are common in various locations across the martian south polar residual cap, an area that has been receiving intense scrutiny by the MGS MOC this year, because it is visible on every orbit and in daylight for most of 2005.

    Location near: 86.9oS, 6.9oW Image width: width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Spring

  10. Reversed-polarity regions

    NASA Technical Reports Server (NTRS)

    Tang, F.

    1982-01-01

    It is found by a statistical study of 58 reversed-polarity regions (RPRs) covering the 11-year period 1969-1979 that RPRs (1) have a lifespan comparable to normal active regions, (2) do not show a tendency to rotate toward a more normal alignment, and (3) have stable configurations that do not suggest stress due to their anomalous magnetic alignment. As in normal regions, RPR magnetic complexity is found to be the primary factor in flare productivity. Weak-field RPRs produce no flares, and regions with complex spots produce more flares than regions with non-complex spots by a factor of five. The main difference between RPRs and normal regions lies in complex spot frequency, with less that 17% of normal active regions having such spots and fewer than 1.8% having long-lived complex ones, while 41% of RPRs have complex spots and 24% have long-lived complex spots.

  11. Interferometric polarization control

    NASA Technical Reports Server (NTRS)

    Wollack, Edward J. (Inventor); Moseley, Samuel H. (Inventor); Novak, Giles A. (Inventor); Chuss, David T. (Inventor)

    2009-01-01

    A signal conditioning module provides a polarimeter capability in a photometric system. The module may include multiple variable delay polarization modulators. Each modulator may include an input port, and a first arm formed to include a first reflector and first rooftop mirror arranged in opposed relationship. The first reflector may direct an input radiation signal to the first rooftop mirror. Each modulator also may include an output port and a second arm formed to include a second reflector and second rooftop mirror arranged in opposed relationship. The second reflector can guide a signal from the second rooftop mirror towards the output port to provide an output radiation signal. A beamsplitting grid may be placed between the first reflector and the first rooftop mirror, and also between the second reflector and the second rooftop mirror. A translation apparatus can provide adjustment relative to optical path length vis-a-vis the first arm, the second arm and the grid.

  12. Interferometric Polarization Control

    NASA Technical Reports Server (NTRS)

    Chuss, David T. (Inventor); Wollack, Edward J. (Inventor); Moseley, Samuel H. (Inventor); Novak, Giles A. (Inventor)

    2008-01-01

    A signal conditioning module provides a polarimeter capability in a photometric system. The module may include multiple variable delay polarization modulators. Each modulator may include an input port, and a first arm formed to include a first reflector and first rooftop mirror arranged in opposed relationship. The first reflector may direct an input radiation signal to the first rooftop mirror. Each modulator also may include an output port and a second arm formed to include a second reflector and second rooftop mirror arranged in opposed relationship. The second reflector can guide a signal from the second rooftop mirror towards the output port to provide an output radiation signal. A beamsplitting grid may be placed between the first reflector and the first rooftop mirror, and also between the second reflector and the second rooftop mirror. A translation apparatus can provide adjustment relative to optical path length vis-a-vis the first arm, the second arm and the grid.

  13. Polar research from satellites

    NASA Technical Reports Server (NTRS)

    Thomas, Robert H.

    1991-01-01

    In the polar regions and climate change section, the topics of ocean/atmosphere heat transfer, trace gases, surface albedo, and response to climate warming are discussed. The satellite instruments section is divided into three parts. Part one is about basic principles and covers, choice of frequencies, algorithms, orbits, and remote sensing techniques. Part two is about passive sensors and covers microwave radiometers, medium-resolution visible and infrared sensors, advanced very high resolution radiometers, optical line scanners, earth radiation budget experiment, coastal zone color scanner, high-resolution imagers, and atmospheric sounding. Part three is about active sensors and covers synthetic aperture radar, radar altimeters, scatterometers, and lidar. There is also a next decade section that is followed by a summary and recommendations section.

  14. South Polar 'Poodle'

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-422, 15 July 2003

    Have you ever stared up at the clouds in the sky and seen the shapes of animals, people, or objects? Sometimes when the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) team is looking at newly-returned pictures from Mars, the same thing happens. This is a picture of pits and scarps in the frozen south polar carbon dioxide ice cap. Sunlight illuminates the scene from the upper right. At the bottom of the picture is a feature that resembles a long, thin poodle; its head faces to the left, the tail to the right. This picture is located near 86.9oS, 55.8oW.

  15. Polarized tritium target development

    SciTech Connect

    Jones, C.E.; Fedchak, J.A.; Kowalczyk, R.S.

    1995-08-01

    Work began on the development of a completely sealed polarized tritium target for experiments at CEBAF. Because of the similarities between optical pumping of tritium and hydrogen, all prototype work is done with hydrogen. We constructed a test station for filling glassware with hydrogen, where we can dissociate molecular hydrogen and monitor the purity of the gas. A simple two-cell glass system was constructed, consisting of a region in which the molecular hydrogen is dissociated with an RF discharge and a region where the atoms can be optically pumped. So far, a clean discharge was obtained in the glassware. With this system, we plan to investigate ways to eliminate the discharge from the optical pumping region and test the quality of the discharge once the pumping cell is coated with drifilm.

  16. South Polar Ice Cap

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-337, 21 April 2003

    This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the 'swiss cheese' pattern of frozen carbon dioxide on the south polar residual cap. Observation of these materials over two Mars years has revealed that the scarps that bound the mesas and small buttes are retreating-the carbon dioxide ice is subliming away-at a rate of about 3 meters (3 yards) per Mars year in some places. The picture covers an area about 900 m (about 900 yards) wide near 87.1oS, 93.7oW. Sunlight illuminates the scene from the upper left.

  17. South Polar Landforms

    NASA Technical Reports Server (NTRS)

    2006-01-01

    8 February 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows an area adjacent to the south polar residual cap that hosts several intricate fracture networks. Each network consists of multiple fractures radiating from a central location. Their origin is not understood -- some investigators have speculated that these are sites of release of carbon dioxide from beneath the ground, but this explanation seems inadequate to explain all attributes of the features. MOC images have shown that these features have not been changing from year to year during the course of the MGS mission.

    Location near: 87.1oS, 234.1oW Image width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Summer

  18. Polar Dust Devil Streaks

    NASA Technical Reports Server (NTRS)

    2004-01-01

    30 June 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image of dunes in the martian north polar region is important because it shows one of the highest northern latitude views of streaks thought to be made by passing dust devils. The dark, thin, filamentary streaks on the dunes and on the adjacent plains were probably formed by dust devils. The dunes occur near 76.6oN, 62.7oW. Dust devil streaks are observed on Mars at very high latitudes, such as this, all the way down to the equator. They are also seen at all elevations, from the deepest parts of the Hellas Basin to the summit of Olympus Mons. This picture covers an area about 3 km (1.9 mi) wide. Sunlight illuminates the scene from the lower left.

  19. Possibilities of polarized protons in Sp anti p S and other high energy hadron colliders

    SciTech Connect

    Courant, E.D.

    1984-01-01

    The requirements for collisions with polarized protons in hadron colliders above 200 GeV are listed and briefly discussed. Particular attention is given to the use of the ''Siberan snake'' to eliminate depolarizing resonances, which occur when the spin precession frequency equals a frequency contained in the spectrum of the field seen by the beam. The Siberian snake is a device which makes the spin precession frequency essentially constant by using spin rotators, which precess the spin by 180/sup 0/ about either the longitudinal or transverse horizontal axis. It is concluded that operation with polarized protons should be possible at all the high energy hadron colliders. (LEW)

  20. Measurements of the elastic electromagnetic form factor ratio {mu}pGEp/GMp via polarization transfer

    SciTech Connect

    Olivier Gayou; Oleksandr Glamazdin; Andrei Afanasev; Arunava Saha; Brendan Fox; Bogdan Wojtsekhowski; C. Chang; Cathleen Jones; Charles Glashausser; Charles Perdrisat; D. Crovelli; Daniel Simon; David Meekins; Demetrius Margaziotis; Dipangkar Dutta; Edgar Kooijman; Elaine Schulte; Edward Brash; Edward Kinney; Eugene Chudakov; Feng Xiong; Franco Garibaldi; Garth Huber; Gerfried Kumbartzki; Guido Urciuoli; Haiyan Gao; Jordan Hovdebo; James Kelly; Javier Gomez; Jens-Ole Hansen; Jian-Ping Chen; John Calarco; John LeRose; Joseph Mitchell; Juncai Gao; Konrad Aniol; Kamal Benslama; Kathy McCormick; Cornelis De Jager; Cornelis de Jager; Kevin Fissum; Krishni Wijesooriya; Louis Bimbot; Ludyvine Morand; Luminita Todor; Moskov Amarian; Marat Rvachev; Mark Jones; Martin Epstein; Meihua Liang; Michael Kuss; Nilanga Liyanage; Adam Sarty; Paul Ulmer; Pete Markowitz; Peter Bosted; R. Holt; Riad Suleiman; Richard Lindgren; Rikki Roche; Robert Michaels; Roman Pomatsalyuk; Ronald Gilman; Ronald Ransome; Stephen Becher; Scott Dumalski; Salvatore Frullani; Seonho Choi; Sergey Malov; Sonja Dieterich; Steffen Strauch; Steve Churchwell; Ting Chang; Viktor Gorbenko; Vina Punjabi; Wang Xu; Xiangdong Ji; Zein-Eddine Meziani; Zhengwei Chai

    2001-09-01

    We present measurements of the ratio of the proton elastic electromagnetic form factors, {mu}pGEp/GMp. The Jefferson Lab Hall A Focal Plane Polarimeter was used to determine the longitudinal and transverse components of the recoil proton polarization in ep elastic scattering; the ratio of these polarization components is proportional to the ratio of the two form factors. These data reproduce the observation of Jones et al. [Phys. Rev. Lett. 84, 1398 (2000)], that the form factor ratio decreases significantly from unity above Q2 = 1 GeV2.

  1. Longitudinal stent deformation during coronary bifurcation stenting.

    PubMed

    Vijayvergiya, Rajesh; Sharma, Prafull; Gupta, Ankush; Goyal, Praveg; Panda, Prashant

    2016-03-01

    A distortion of implanted coronary stent along its longitudinal axis during coronary intervention is known as longitudinal stent deformation (LSD). LSD is frequently seen with newer drug eluting stents (DES), specifically with PROMUS Element stent. It is usually caused by impact of guide catheter tip, or following passage of catheters like balloon catheter, IVUS catheter, guideliner, etc. We hereby report a case of LSD during coronary bifurcation lesion intervention, using two-stents technique. Patient had acute stent thrombosis as a complication of LSD, which was successfully managed. PMID:26811144

  2. North Polar Erg

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    Our topic for the weeks of April 4 and April 11 is dunes on Mars. We will look at the north polar sand sea and at isolated dune fields at lower latitudes. Sand seas on Earth are often called 'ergs,' an Arabic name for dune field. A sand sea differs from a dune field in two ways: 1) a sand sea has a large regional extent, and 2) the individual dunes are large in size and complex in form.

    This VIS image was taken at 82 degrees North latitude during Northern spring. As with yesterday's image, the dunes are still partially frost covered. This region is part of the north polar erg (sand sea), note the complexity and regional coverage of the dunes.

    Image information: VIS instrument. Latitude 81.2, Longitude 118.2 East (241.8 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  3. North Polar Erg

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    Our topic for the weeks of April 4 and April 11 is dunes on Mars. We will look at the north polar sand sea and at isolated dune fields at lower latitudes. Sand seas on Earth are often called 'ergs,' an Arabic name for dune field. A sand sea differs from a dune field in two ways: 1) a sand sea has a large regional extent, and 2) the individual dunes are large in size and complex in form.

    This VIS image was taken at 81 degrees North latitude during Northern spring. This region of the north polar erg is dominated by a different form of dunes than yesterday's image.

    Image information: VIS instrument. Latitude 81.4, Longitude 121.9 East (238.1 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  4. Cretaceous polar climates

    SciTech Connect

    Ziegler, A.M.; Horrell, M.A.; Lottes, A.L.; Gierlowski, T.C.

    1988-01-01

    The Cretaceous, like most Phanerozooic periods, was characterized by ice-free poles. Some still argue that the glacier and sea ice were there, and that the tillites, etc, have been eroded or remain undiscovered. However, diverse floras, dense forests, coal-forming cypress swamps, and dinosaurs, crocodilians, and lungfish are known from areas that were certainly at 75/sup 0/-80/sup 0/ north and south paleolatitude in the Cretaceous, implying that the coastal basins did not experience hard freezes. No deep marine connections to the North Pole existed in the Cretaceous, so oceanic polar heat transport can be discounted. However, the five north-south trending epeiric or rift-related seaways that connected or nearly connected the Tethys to the Arctic would have dampened the seasonal temperature cycle, bringing maritime climates deep into the North American and Eurasian continents and, more importantly, would have served as an energy source and channel for winter storms, much as the Gulf Stream does today. Cyclones have a natural tendency to move poleward, because of the increase in the Coriolis Paramteter, and they transport both sensible and latent heat. The coastal regions of the relatively warm polar ocean in the Cretaceous would have received continuous precipitation during the winter because cyclones would be entering from as many as five directions. Coastal rainfall would also have been abundant in the summer but for a different reason; the land-sea temperature profile would reverse, with the warm land surface drawing in moisture, while clear ice-free conditions over the ocean would allow for solar warming.

  5. Cretaceous polar climates

    SciTech Connect

    Ziegler, A.M.; Horrell, M.A.; Lottes, A.L.; Gierlowski, T.C.

    1988-02-01

    The Cretaceous, like most Phanerozoic periods, was characterized by ice-free poles. Some still argue that the glaciers and sea ice were there, and that the tillites, etc, have been eroded or remain undiscovered. However, diverse floras, dense forests, and coal-forming cypress swamps, and dinosaurs, crocodilians, and lungfish are known from areas that were certainly at 75/degree/-80/degree/ north and south paleolatitude in the Cretaceous, implying that the coastal basins did not experience hard freezes. No deep marine connections to the North Pole existed in the Cretaceous, so oceanic polar heat transport can be discounted. However, the five north-south trending epeiric or rift-related seaways that connected or nearly connected the Tethys to the Arctic would have dampened the seasonal temperature cycle, bring maritime climates deep into the North American and Eurasian continents and, more importantly, would have served as an energy source and channel for winter storms, much as the Gulf Stream does today. Cyclones have a natural tendency to move poleward, because of the increase in the Coriolis Parameter, and they transport both sensible and latent heat. The coastal regions of the relatively warm polar ocean in the Cretaceous would have received continuous precipitation during the winter because cyclones would be entering from as many as five directions. Coastal rainfall would also have been abundant in the summer but for a different reason; the land-sea temperature profile would reverse, with the warm land surface drawing in moisture, while clear ice-free conditions over the ocean would allow for solar warming.

  6. Polarized Sources, Targets and Polarimetry

    NASA Astrophysics Data System (ADS)

    Ciullo, Guiseppe; Contalbrigo, Marco; Lenisa, P.

    2011-01-01

    Remarks on the history of workshops on "spin tools" / E. Steffens -- Polarized proton beams in RHIC / A. Zelenski -- The COSY/Julich polarized H[symbol] and D[symbol] ion source / O. Felden -- The new source of polarized ions for the JINR accelerator complex / V. V. Fimushkin -- Resonance effects in nuclear dichroism - an inexpensive source of tensor-polarized deuterons / H. Seyfarth -- Polarized electrons and positrons at the MESA accelerator / K. Aulenbacher -- Status report of the Darmstadt polarized electron injector / Y. Poltoratska -- The Mott polarimeter at MAMI / V. Tioukine -- Proton polarimetry at the relativistic heavy ion collider / Y. Makdisi -- Polarisation and polarimetry at HERA / B. Sobloher -- Polarisation measurement at the ILC with a Compton polarimeter / C. Bartels -- Time evolution of ground motion-dependent depolarisation at linear colliders / A. Hartin -- Electron beam polarimetry at low energies and its applications / R. Barday -- Polarized solid targets: recent progress and future prospects / C. D. Keith -- HD gas distillation and analysis for HD frozen spin targets / A. D'Angelo -- Electron spin resonance study of hydrogen and alkyl free radicals trapped in solid hydrogen aimed for dynamic nuclear polarization of solid HD / T. Kumada -- Change of ultrafast nuclear-spin polarization upon photoionization by a short laser pulse / T. Nakajima -- Radiation damage and recovery in polarized [symbol]NH[symbol] ammonia targets at Jefferson lab / J. D. Maxwell.Polarized solid proton target in low magnetic field and at high temperature / T. Uesaka -- Pulse structure dependence of the proton spin polarization rate / T. Kawahara -- Proton NMR in the large COMPASS [symbol]NH[symbol] target / J. Koivuniemi -- DNP with TEMPO and trityl radicals in deuterated polystyrene / L. Wang -- The CLIC electron and positron polarized sources / L. Rinolfi -- Status of high intensity polarized electron gun at MIT-Bates / E. Tsentalovich -- Target section for spin

  7. Study of the polarized structure functions of the neutron at low Q**2 using polarized He-3

    SciTech Connect

    S.H. Choi

    2004-06-02

    We have measured the electron-He-3 longitudinal and transverse spin dependent inclusive cross sections {pol}He-3({pol}e, e-prime), mostly in the resonance region (up to W ~ 2.5 GeV), over a wide range of four-momentum transfer (Q**2 = 0.03 - 1GeV**2). The longitudinally polarized electron beam of energy ranging from 0.86 to 5.1 GeV of the Jefferson Lab was scattered at a fixed angle of 15.5 degrees, on a high pressure polarized He-3 target in Hall A. The spin dependent structure functions g_1(x), g_2(x) have been extracted and their moments were evaluated. The GDH integral shows dramatic transition from large Q**2 domain to low Q**2 domain in the Burkhardt-Cottingham sum rule for g_2 seems to hold within experimental errors. d_2 is quite large and positive consistent with the SLAC data but at odds with lattice QCD calculation.

  8. Prospective longitudinal course of aggression among adults with bipolar disorder

    PubMed Central

    Ballester, Javier; Goldstein, Benjamin; Goldstein, Tina R; Yu, Haifeng; Axelson, David; Monk, Kelly; Hickey, Mary Beth; Diler, Rasim S; Sakolsky, Dara J; Sparks, Garrett; Iyengar, Satish; Kupfer, David J; Brent, David A; Birmaher, Boris

    2014-01-01

    Objectives Bipolar disorder (BP) has been associated with increased aggressive behaviors. However, all existing studies are cross-sectional and include forensic or inpatient populations and many do not take into account the effects of comorbid conditions. The goal of this study was to evaluate the longitudinal course of aggression among adult outpatients with BP compared with non-BP patients and healthy controls. Methods Subjects with bipolar I disorder (BP-I)/bipolar II disorder (BP-II) (n = 255), non-BP psychopathology (n = 85), and healthy controls (n = 84) (average 38.9 years, 78.7% female, and 84.9% Caucasian) were evaluated at intake and after two- and four-years of follow-up. Aggression was self-rated using the Aggression Questionnaire (AQ). Comparisons were adjusted for any significant demographic and clinical differences and for multiple comparisons. For subjects with BP, associations of AQ with subtype of BP, current versus past mood episodes, polarity and severity of the current episode, psychosis, and current pharmacological treatment were evaluated. Results In comparison with subjects with non-BP psychiatric disorders and healthy controls, subjects with BP showed persistently higher total and subscale AQ scores (raw and T-scores) during the four-year follow-up. There were no effects of BP subtype, severity or polarity of the current episode, psychosis, and current pharmacological treatments. Subjects in an acute mood episode showed significantly higher AQ scores than euthymic subjects. Conclusions BP, particularly during acute episodes, is associated with increased self-reported verbal and physical aggression, anger, and hostility. These results provide further evidence for the need of treatments to prevent mood recurrences and prompt treatment of acute mood episodes in subjects with BP. PMID:24372913

  9. Fluorescence nanoscopy by polarization modulation and polarization angle narrowing.

    PubMed

    Hafi, Nour; Grunwald, Matthias; van den Heuvel, Laura S; Aspelmeier, Timo; Chen, Jian-Hua; Zagrebelsky, Marta; Schütte, Ole M; Steinem, Claudia; Korte, Martin; Munk, Axel; Walla, Peter J

    2014-05-01

    When excited with rotating linear polarized light, differently oriented fluorescent dyes emit periodic signals peaking at different times. We show that measurement of the average orientation of fluorescent dyes attached to rigid sample structures mapped to regularly defined (50 nm)(2) image nanoareas can provide subdiffraction resolution (super resolution by polarization demodulation, SPoD). Because the polarization angle range for effective excitation of an oriented molecule is rather broad and unspecific, we narrowed this range by simultaneous irradiation with a second, de-excitation, beam possessing a polarization perpendicular to the excitation beam (excitation polarization angle narrowing, ExPAN). This shortened the periodic emission flashes, allowing better discrimination between molecules or nanoareas. Our method requires neither the generation of nanometric interference structures nor the use of switchable or blinking fluorescent probes. We applied the method to standard wide-field microscopy with camera detection and to two-photon scanning microscopy, imaging the fine structural details of neuronal spines. PMID:24705472

  10. Dynamic Nuclear Polarization of 17O: Direct Polarization

    PubMed Central

    Michaelis, Vladimir K.; Corzilius, Björn; Smith, Albert A.; Griffin, Robert G.

    2014-01-01

    Dynamic nuclear polarization of 17O was studied using four different polarizing agents – the biradical TOTAPOL, and the monoradicals trityl and SA-BDPA, as well as a mixture of the latter two. Field profiles, DNP mechanisms and enhancements were measured to better understand and optimize directly polarizing this low-gamma quadrupolar nucleus using both mono- and bi-radical polarizing agents. Enhancements were recorded < 88 K and were > 100 using the trityl (OX063) radical and < 10 with the other polarizing agents. The > 10,000 fold savings in acquisition time enabled a series of biologically relevant small molecules to be studied with small sample sizes and the measurement of various quadrupolar parameters. The results are discussed with comparison to room temperature studies and GIPAW quantum chemical calculations. These experimental results illustrate the strength of high field DNP and the importance of radical selection for studying low-gamma nuclei. PMID:24195759

  11. Polarization effects in radiative decay of a polarized τ lepton

    SciTech Connect

    Gakh, G. I.; Konchatnij, M. I. Korchin, A. Yu.; Merenkov, N. P.

    2015-02-15

    The polarization effects in the one-meson radiative decay of a polarized τ lepton, τ → π{sup −}γν{sub τ}, are investigated. The inner bremsstrahlung and structural amplitudes are taken into account. The asymmetry of the differential decay width caused by the τ-lepton polarization and the Stokes parameters of the emitted photon itself are calculated depending on the polarization of the decaying τ lepton. These physical quantities are estimated numerically for an arbitrary direction of the τ lepton polarization 3-vector in the rest frame. The vector and axial-vector form factors describing the structure-dependent part of the decay amplitude are determined using the chiral effective theory with resonances (RχT)

  12. Apparatus for checking the direction of polarization of shear-wave ultrasonic transducers

    DOEpatents

    Karplus, H.H.B.; Forster, G.A.

    An apparatus for checking the direction of polarization of shear-wave ultrasonic transducers comprises a first planar surface for mounting the shear-wave transducer, a second planar surface inclined at a predetermined angle to the first surface to generate longitudinal waves by mode conversion, and a third planar surface disposed at a second predetermined angle to the first for mounting a longitudinal-wave ultransonic transducer. In an alternate embodiment, two second planar surfaces at the predetermined angle are placed at an angle to each other. The magnitude of the shear wave is a function of the angle between the direction of polarization of the transducer and the mode-conversion surface.

  13. Apparatus for checking the direction of polarization of shear-wave ultrasonic transducers

    DOEpatents

    Karplus, Henry H. B.

    1980-01-01

    An apparatus for checking the direction of polarization of shear-wave ultrasonic transducers comprises a first planar surface for mounting the shear-wave transducer, a second planar surface inclined at a predetermined angle to the first surface to generate longitudinal waves by mode conversion, and a third planar surface disposed at a second predetermined angle to the first for mounting a longitudinal-wave ultrasonic transducer. In an alternate embodiment, two second planar surfaces at the predetermined angle are placed at an angle to each other. The magnitude of the shear wave is a function of the angle between the direction of polarization of the transducer and the mode-conversion surface.

  14. The Quest for Spinning Glue in High-Energy Polarized Proton-Proton Collisions at RHIC

    SciTech Connect

    Surrow, Bernd

    2007-10-26

    The STAR experiment at the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) is carrying out a spin physics program colliding transverse or longitudinal polarized proton beams at {radical}(s) = 200-500 GeV to gain a deeper insight into the spin structure and dynamics of the proton. These studies provide fundamental tests of Quantum Chromodynamics (QCD).One of the main objectives of the STAR spin physics program is the determination of the polarized gluon distribution function through a measurement of the longitudinal double-spin asymmetry, A{sub LL}, for various processes. Recent results will be shown on the measurement of A{sub LL} for inclusive jet production, neutral pion production and charged pion production at {radical}(s) = 200 GeV.

  15. The Color Dipole Picture and the Ratio of the Longitudinal to the Transverse Photoabsorption Cross Section

    SciTech Connect

    Schildknecht, Dieter

    2009-03-23

    The transverse size of qq-bar fluctuations of a longitudinally polarized photon is reduced relative to the transverse size of qq-bar fluctuations of a transversely polarized photon. This implies a model-independent prediction of the ratio R(W{sup 2},Q{sup 2}){identical_to}{sigma}{sub L}/{sigma}{sub T} = 0.375, or, equivalently, F{sub L}/F{sub 2} = 0.27, for x congruent with Q{sup 2}/W{sup 2}<<1 and Q{sup 2} sufficiently large, while R(W{sup 2},Q{sup 2}) 0.50, if this effect is ignored. Experimental data from HERA confirm the transverse-size reduction.

  16. Thermodynamic properties of anisotropic spin ladder in a longitudinal magnetic field

    NASA Astrophysics Data System (ADS)

    Rezania, H.

    2015-08-01

    We address thermodynamic properties of quasi-one dimensional two leg antiferromagnetic ladder in the presence of magnetic field. A generalized bond operator formalism is used to transform the spin model to a hard core bosonic gas. We have implemented Green's function approach to obtain the temperature dependence of spin excitation spectrum in field induced spin polarized phase. The results show energy gap that vanishes at critical magnetic field for fixed values of temperatures. We have also found the temperature dependence of the specific heat and magnetization component in the magnetic field direction for various magnetic field strengths and anisotropies in the Heisenberg interactions on both leg and rung couplings. At low temperatures, the specific heat is found to be monotonically increasing with temperature for magnetic fields in the spin polarized phase region. Furthermore we studied the temperature dependence of the longitudinal magnetization for different magnetic field and anisotropy parameters.

  17. What Can We Learn From Longitudinal Studies of Adult Development?

    PubMed Central

    Schaie, K. Warner

    2005-01-01

    This article distinguishes between normal and pathological aging, provides an interdisciplinary context, and then considers a sample case of cognitive aging. Developmental influences on cognition include the physiological infrastructure, genetic predispositions, and environmental influences. Different types of longitudinal studies are distinguished, and contrasting findings of cross-sectional and longitudinal are examined in the sample case of the Seattle Longitudinal Study. Also considered is the longitudinal context for intervention studies and the role of longitudinal family studies in assessing rate of aging and generational differences in rates of aging. Finally, attention is given to the role of longitudinal studies in the early detection of risk for dementia in advanced age. PMID:16467912

  18. A LOW GAMMA_T INJECTION LATTICE FOR POLARIZED PROTONS IN RHIC

    SciTech Connect

    MONTAG,C.

    2007-06-25

    Polarized protons are injected into the Relativistic Heavy Jon Collider (RHIC) just above transition energy. When installation of a cold partial Siberian snake in the AGS required lowering the injection energy by {Delta}{gamma} = 0.56, the transition energy in RHIC had to be lowered accordingly to ensure proper longitudinal matching. This paper presents lattice modifications implemented to lower the transition energy by {Delta}{gamma}{sub t} = 0.8.

  19. Identification of New Physics Scenarios in Fermion Pair Production at Polarized ILC

    SciTech Connect

    Pankov, A. A.; Tsytrinov, A. V.; Paver, N.

    2007-06-13

    Numerous non-standard scenarios are represented by contactlike effective interactions, that can manifest themselves only via deviations of observables from the Standard Model predictions. If deviations were observed, their source should be identified among the different non-standard interactions. We discuss the identification reach on gravity in compactified extra dimensions and on the ''compositeness inspired'' four-fermion contact interactions, expected at the planned e+e- International Linear Collider (ILC) with both beams longitudinally polarized.

  20. Polarization spectroscopy of tokamak plasmas

    SciTech Connect

    Wroblewski, D.

    1991-09-01

    Measurements of polarization of spectral lines emitted by tokamak plasmas provide information about the plasma internal magnetic field and the current density profile. The methods of polarization spectroscopy, as applied to the tokamak diagnostic, are reviewed with emphasis on the polarimetry of motional Stark effect in hydrogenic neutral beam emissions. 25 refs., 7 figs.

  1. Geomorphology of Triton's polar materials

    NASA Technical Reports Server (NTRS)

    Croft, Steven K.

    1993-01-01

    One of Triton's most debated puzzles is the nature, distribution, and transport of its atmospheric volatiles. The full potential of constraints provided by detailed observations of the morphology and distribution of the polar deposits has not been realized. The objective of this study is characterization of the morphology, distribution, stratigraphy, and geologic setting of Triton's polar materials.

  2. Polar lipids from oat kernels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oat (Avena sativa L.) kernels appear to contain much higher polar lipid concentrations than other plant tissues. We have extracted, identified, and quantified polar lipids from 18 oat genotypes grown in replicated plots in three environments in order to determine genotypic or environmental variation...

  3. Climate Drives Polar Bear Origins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In their provocative analysis of northern bears (“Nuclear genomic sequences reveal that polar bears are an old and distinct bear lineage,” Reports, 20 April, p. 344), F. Hailer et al. use independent nuclear loci to show that polar bears originated during the middle Pleistocene, rather than during t...

  4. Polarization Imaging and Insect Vision

    ERIC Educational Resources Information Center

    Green, Adam S.; Ohmann, Paul R.; Leininger, Nick E.; Kavanaugh, James A.

    2010-01-01

    For several years we have included discussions about insect vision in the optics units of our introductory physics courses. This topic is a natural extension of demonstrations involving Brewster's reflection and Rayleigh scattering of polarized light because many insects heavily rely on optical polarization for navigation and communication.…

  5. Polarization correlations of Dirac particles

    SciTech Connect

    Caban, Pawel; Dziegielewska, Agnieszka; Karmazyn, Anna; Okrasa, Malgorzata

    2010-03-15

    We calculate the polarization correlation function in the Einstein-Podolsky-Rosen-type experiments with relativistic spin-1/2 particles. This function depends monotonically on the particle momenta. Moreover, we also show that the polarization correlation function violates the Clauser-Horn-Shimony-Holt inequality and the degree of this violation can depend on the particle momenta and the motion of observers.

  6. Carbon nanotube fiber terahertz polarizer

    NASA Astrophysics Data System (ADS)

    Zubair, Ahmed; Tsentalovich, Dmitri E.; Young, Colin C.; Heimbeck, Martin S.; Everitt, Henry O.; Pasquali, Matteo; Kono, Junichiro

    2016-04-01

    Conventional, commercially available terahertz (THz) polarizers are made of uniformly and precisely spaced metallic wires. They are fragile and expensive, with performance characteristics highly reliant on wire diameters and spacings. Here, we report a simple and highly error-tolerant method for fabricating a freestanding THz polarizer with nearly ideal performance, reliant on the intrinsically one-dimensional character of conduction electrons in well-aligned carbon nanotubes (CNTs). The polarizer was constructed on a mechanical frame over which we manually wound acid-doped CNT fibers with ultrahigh electrical conductivity. We demonstrated that the polarizer has an extinction ratio of ˜-30 dB with a low insertion loss (<0.5 dB) throughout a frequency range of 0.2-1.1 THz. In addition, we used a THz ellipsometer to measure the Müller matrix of the CNT-fiber polarizer and found comparable attenuation to a commercial metallic wire-grid polarizer. Furthermore, based on the classical theory of light transmission through an array of metallic wires, we demonstrated the most striking difference between the CNT-fiber and metallic wire-grid polarizers: the latter fails to work in the zero-spacing limit, where it acts as a simple mirror, while the former continues to work as an excellent polarizer even in that limit due to the one-dimensional conductivity of individual CNTs.

  7. Receiving signals of any polarization

    NASA Technical Reports Server (NTRS)

    Ohlson, J. E.; Seidel, B. L.; Stelzried, C. H.

    1981-01-01

    Two-channel detection accomodates linear, circular, and elliptical polarization in one receiving unit. Receiver employs orthomode transducer which breaks any type signal into one left and one right circular component. These are processed in separate receiver channels with equal time-delay, and then recombined for data extraction. System eliminates losses due to polarization mismatch.

  8. Short History of Polarized Antiprotons

    SciTech Connect

    Steffens, Erhard

    2008-04-30

    This paper summarizes the attempts and ideas for generating polarized antiproton beams. Such beams are needed for the study of the--largely unknown--spin dependence of nucleon-antinucleon interaction. Emphasis is on spin dependent attenuation of antiprotons on a polarized hydrogen target as the only experimentally tested method.

  9. Generalized Expression for Polarization Density

    SciTech Connect

    Lu Wang and T.S. Hahm

    2009-04-23

    A general polarization density which consists of classical and neoclassical parts is system-atically derived via modern gyrokinetics and bounce-kinetics by employing a phase-space Lagrangian Lie-transform perturbation method. The origins of polarization density are further elucidated. Extending the work on neoclassical polarization for long wavelength compared to ion banana width [M. N. Rosenbluth and F. L. Hinton, Phys. Rev. Lett. 80, 724 (1998)], an analytical formula for the generalized neoclassical polarization including both finite-banana-width (FBW) and finite-Larmor-radius (FLR) effects for arbitrary radial wavelength in comparison to banana width and gyroradius is derived. In additional to the contribution from trapped particles, the contribution of passing particles to the neoclassical polarization is also explicitly calculated. Our analytic expression agrees very well with the previous numerical results for a wide range of radial wavelength.

  10. Scattering Polarization in the Chromosphere

    NASA Technical Reports Server (NTRS)

    Keller, C. U.; Sheeley, N. R., Jr.

    1999-01-01

    Scattering polarization from the photosphere observed close to the solar limb has recently become of interest to study turbulent magnetic fields, abundances, and radiative transfer effects. We extend these studies by measuring the scattering polarization off the limb, i.e. in the chromosphere. However, instrumental effects are much more pronounced and more complicated than those affecting on-disk measurements. In particular, scattered light from the telescope mirrors leads to a new type of instrumental polarization that we describe in detail. The differences between the linearly polarized spectra on the disk and off the limb are often very substantial. Here we show the profiles of HeI D(sub 3), the OI triplet at 777 nm, and the Nal D lines. The change in the latter is in reasonable agreement with the recent modeling efforts of atomic polarization in the lower level by Landi Degl'Innocenti (1998).

  11. Generalized expression for polarization density

    SciTech Connect

    Wang Lu; Hahm, T. S.

    2009-06-15

    A general polarization density which consists of classical and neoclassical parts is systematically derived via modern gyrokinetics and bounce kinetics by employing a phase-space Lagrangian Lie-transform perturbation method. The origins of polarization density are further elucidated. Extending the work on neoclassical polarization for long wavelength compared to ion banana width [M. N. Rosenbluth and F. L. Hinton, Phys. Rev. Lett. 80, 724 (1998)], an analytical formula for the generalized neoclassical polarization including both finite-banana-width and finite-Larmor-radius effects for arbitrary radial wavelength in comparison to banana width and gyroradius is derived. In additional to the contribution from trapped particles, the contribution of passing particles to the neoclassical polarization is also explicitly calculated. The generalized analytic expression agrees very well with the previous numerical results for a wide range of radial wavelength.

  12. E166: Polarized Positrons & Polarimetry

    SciTech Connect

    Schuler, K.Peter; /DESY

    2011-12-06

    A proof-of-principle experiment has been carried out in the Final Focus Test Beam (FFTB) at Stanford Linear Accelerator Center (SLAC) to demonstrate production of polarized positrons in a manner suitable for implementation at the International Linear Collider (ILC). A helical undulator of 2.54 mm period and 1 -m length produced circularly polarized photons with a first harmonic endpoint energy of 8 MeV when traversed by a 46.6 GeV electron beam. The polarized photons were converted to polarized positrons in a 0.2-radiation-length tungsten target. The polarization of these positrons was measured using a Compton transmission polarimeter to have peak value in excess of 80%.

  13. Teaching Technology Longitudinally to Virtual Children

    ERIC Educational Resources Information Center

    Matthews, Lynley

    2010-01-01

    Children of Generation Y are entering our schooling system. These children have always known instant communication and the internet. They possess basic skills in using technology, but they still need to develop a deeper understanding of technology. Teaching longitudinally will increase the learner's confidence and develop a deeper understanding.…

  14. Longitudinal Predictors of High School Completion

    ERIC Educational Resources Information Center

    Barry, Melissa; Reschly, Amy L.

    2012-01-01

    This longitudinal study examined predictors of dropout assessed in elementary school. Student demographic data, achievement, attendance, and ratings of behavior from the Behavior Assessment System for Children were used to predict dropout and completion. Two models, which varied on student sex and race, predicted dropout at rates ranging from 75%…

  15. Longitudinal photosynthetic gradient in crust lichens' thalli.

    PubMed

    Wu, Li; Zhang, Gaoke; Lan, Shubin; Zhang, Delu; Hu, Chunxiang

    2014-05-01

    In order to evaluate the self-shading protection for inner photobionts, the photosynthetic activities of three crust lichens were detected using Microscope-Imaging-PAM. The false color images showed that longitudinal photosynthetic gradient was found in both the green algal lichen Placidium sp. and the cyanolichen Peltula sp. In longitudinal direction, all the four chlorophyll fluorescence parameters Fv/Fm, Yield, qP, and rETR gradually decreased with depth in the thalli of both of these two lichens. In Placidium sp., qN values decreased with depth, whereas an opposite trend was found in Peltula sp. However, no such photosynthetic heterogeneity was found in the thalli of Collema sp. in longitudinal direction. Microscope observation showed that photobiont cells are compactly arranged in Placidium sp. and Peltula sp. while loosely distributed in Collema sp. It was considered that the longitudinal photosynthetic heterogeneity was ascribed to the result of gradual decrease of incidence caused by the compact arrangement of photobiont cells in the thalli. The results indicate a good protection from the self-shading for the inner photobionts against high radiation in crust lichens. PMID:24477924

  16. An Early Intervention Project: A Longitudinal Look.

    ERIC Educational Resources Information Center

    Gordon, Ira J.

    This report describes the longitudinal research conducted in an early intervention program since 1966. The program is characterized by the use of paraprofessionals serving as home visitors and parent educators. Data collection has included measures of children's behavior and development, parent-child interactions, and parent variables such as…

  17. Design and Implementation Issues in Longitudinal Research

    ERIC Educational Resources Information Center

    Ludlow, Larry H.; Pedulla, Joseph; Reagan, Emile Mitescu; Enterline, Sarah; Cannady, Mac; Chappe, Stephanie

    2011-01-01

    To meet demands for accountability, most schools and departments of education at institutions of higher education (IHEs) gather information on their current students and graduates. This paper describes issues to consider when designing a longitudinal data collection and management system, drawing on seven years' experience developing such a…

  18. 14 CFR 23.145 - Longitudinal control.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Longitudinal control. 23.145 Section 23.145 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Flight Controllability and Maneuverability § 23.145...

  19. The Tevatron bunch by bunch longitudinal dampers

    SciTech Connect

    Cheng-Yang Tan and James Steimel

    2002-09-25

    We describe in this paper the Tevatron bunch by bunch dampers. The goal of the dampers is to stop the spontaneous longitudinal beam size blowup of the protons during a store. We will go through the theory and also show the measured results during the commissioning of this system. The system is currently operational and have stopped the beam blowups during a store.

  20. Longitudinal Predictors of Implicit Phonological Awareness Skills

    ERIC Educational Resources Information Center

    Rvachew, Susan

    2006-01-01

    Purpose: The purpose of this study was to examine the longitudinal predictive relationships among variables that may contribute to poor phonological awareness skills in preschool-age children with speech-sound disorders. Method: Forty-seven children with speech-sound disorders were assessed during the spring of their prekindergarten year and again…