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5 results on '"polarization [cross section]"'

1. Measurements of HD(gamma,pi) and Implications for the Convergence of the Gerasimov-Drell-Hern Integral

Author

Hoblit, S., Sandorfi, A.M., Gibson, C., Glückler, H., Hicks, K., Honig, A., Kageya, T., Khandaker, M., Kistner, O.C., Kizilgul, S., Lehmann, A., Lowry, M., Ardashev, K., Lucas, M., Mahon, J., Miceli, L., Moricciani, D., Norum, B., Pap, M., Preedom, B., Seyfarth, H., Schaerf, C., Ströher, H., Bade, C., Thorn, C.E., Whisnant, C.S., Wang, K., Wei, X., Bartalini, O., Blecher, M., Caracappa, A., D'Angelo, D., Di Salvo, R., and Fantini, A.

Subjects
Nuclear Theory, polarized beam [photon], polarized target, Delta(1232), energy dependence, Brookhaven Lab, 0.19-0.42 GeV, photoproduction [pi], deuterium [hydrogen], Drell-Hearn-Gerasimov [sum rule], ddc:550, polarization [cross section], angular distribution, Nuclear Experiment, asymmetry [spin], inelastic scattering [photon nucleon], experimental results
Abstract

We report new measurements of inclusive pi production from frozen-spin HD for polarized photon beams covering the Delta(1232) resonance. These provide data simultaneously on both H and D with nearly complete angular distributions of the spin-difference cross sections entering the Gerasimov-Drell-Hearn (GDH) sum rule. Recent results from Mainz and Bonn exceed the GDH prediction for the proton by 22 mu b, suggesting as yet unmeasured high-energy components. Our pi(0) data reveal a different angular dependence than assumed in Mainz analyses and integrate to a value that is 18 mu b lower, suggesting a more rapid convergence. Our results for deuterium are somewhat lower than published data, considerably more precise, and generally lower than available calculations.

Published
2009
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2. Polarized positrons and electrons at the linear collider

Author

G. Moortgat-Pick, T. Abe, G. Alexander, B. Ananthanarayan, A.A. Babich, V. Bharadwaj, D. Barber, A. Bartl, A. Brachmann, S. Chen, J. Clarke, J.E. Clendenin, J. Dainton, K. Desch, M. Diehl, B. Dobos, T. Dorland, H.K. Dreiner, H. Eberl, J. Ellis, K. Flöttmann, H. Fraas, F. Franco-Sollova, F. Franke, A. Freitas, J. Goodson, J. Gray, A. Han, S. Heinemeyer, S. Hesselbach, T. Hirose, K. Hohenwarter-Sodek, A. Juste, J. Kalinowski, T. Kernreiter, O. Kittel, S. Kraml, U. Langenfeld, W. Majerotto, A. Martinez, H.-U. Martyn, A. Mikhailichenko, C. Milstene, W. Menges, N. Meyners, K. Mönig, K. Moffeit, S. Moretti, O. Nachtmann, F. Nagel, T. Nakanishi, U. Nauenberg, H. Nowak, T. Omori, P. Osland, A.A. Pankov, N. Paver, R. Pitthan, R. Pöschl, W. Porod, J. Proulx, P. Richardson, S. Riemann, S.D. Rindani, T.G. Rizzo, A. Schälicke, P. Schüler, C. Schwanenberger, D. Scott, J. Sheppard, R.K. Singh, A. Sopczak, H. Spiesberger, A. Stahl, H. Steiner, A. Wagner, A.M. Weber, G. Weiglein, G.W. Wilson, M. Woods, P. Zerwas, J. Zhang, F. Zomer, European Organization for Nuclear Research (CERN), Deutsches Elektronen-Synchrotron [Zeuthen] (DESY), Helmholtz-Gemeinschaft = Helmholtz Association, Laboratoire d'Annecy-le-Vieux de Physique Théorique (LAPTH), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire de l'Accélérateur Linéaire (LAL), and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Particle physics, polarized beam [electron], coupling [Higgs particle], search for [graviton], International Linear Collider, transverse [polarization], electroproduction [Z0], Physics beyond the Standard Model, (3gauge boson) [coupling], General Physics and Astronomy, Electron, leptoquark, pair production [top], 01 natural sciences, violation [CP], law.invention, Standard Model, validity test [electroweak interaction], Positron, law, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], new interaction [four-fermion interaction], ddc:530, 010306 general physics, Collider, numerical calculations, higher-dimensional [space-time], search for [Higgs particle], Physics, longitudinal [polarization], search for [sparticle], 010308 nuclear & particles physics, hadronic decay [Z0], Weinberg angle, bibliography, mass [Higgs particle], Polarization (waves), Fundamental interaction, pair production [W], asymmetry [polarization], Centre for High Energy Physics, Physics::Accelerator Physics, polarization [cross section], measurement [polarization], polarized beam [positron], proposed experiment, supersymmetry, polarized beam [particle source]
Abstract

The proposed International Linear Collider (ILC) is well-suited for discovering physics beyond the Standard Model and for precisely unraveling the structure of the underlying physics. The physics return can be maximized by the use of polarized beams. This report shows the paramount role of polarized beams and summarizes the benefits obtained from polarizing the positron beam, as well as the electron beam. The physics case for this option is illustrated explicitly by analyzing reference reactions in different physics scenarios. The results show that positron polarization, combined with the clean experimental environment provided by the linear collider, allows to improve strongly the potential of searches for new particles and the identification of their dynamics, which opens the road to resolve shortcomings of the Standard Model. The report also presents an overview of possible designs for polarizing both beams at the ILC, as well as for measuring their polarization.

Published
2008
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3. Quark helicity distributions in the nucleon for up, down, and strange quarks from semi-inclusive deep-inelastic scattering

Author

Airapetian, A., Akopov, N., Avetissian, E., Marianski, B., Marukyan, H., Masoli, F., Mexner, V., Meyners, N., Mikloukho, O., Miller, C. A., Miyachi, Y., Muccifora, V., Nagaitsev, A., Bailey, P., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W. D., Oganessyan, K., Ohsuga, H., Pickert, N., Potashov, S., Potterveld, D. H., Baturin, V., Raithel, M., Reggiani, D., Reimer, P. E., Reischl, A., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubacek, L., Baumgarten, C., Rubin, J., Ryckbosch, D., Salomatin, Y., Sanjiev, I., Savin, I., Scarlett, C., Schafer, A., Schill, C., Schnell, G., Schuler, K. P., Beckmann, M., Schwind, A., Seele, J., Seidl, R., Seitz, B., Shanidze, R., Shearer, C., Shibata, T. A., Shutov, V., Simani, M. C., Sinram, K., Belostotski, S., Stancari, M., Statera, M., Steffens, E., Steijger, J. J. M., Stenzel, H., Stewart, J., Stosslein, U., Tait, P., Tanaka, H., Taroian, S., Bernreuther, S., Tchuiko, B., Terkulov, A., Tkabladze, A., Trzcinski, A., Tytgat, M., Vandenbroucke, A., van der Nat, P., van der Steenhoven, G., Vetterli, M. C., Vikhrov, V., Bianchi, N., Vincter, M. G., Vogel, C., Vogt, M., Volmer, J., Weiskopf, C., Wendland, J., Wilbert, J., Ybeles Smit, G., Yen, S., Zihlmann, B., Blok, H. P., Zohrabian, H., Zupranski, P., HERMES Collaboration, Blumlein, J., Akopov, Z., Bottcher, H., Borissov, A., Borysenko, A., Bouwhuis, M., Brack, J., Brull, A., Bryzgalov, V., Capitani, G. P., Chiang, H. C., Ciullo, G., Amarian, M., Contalbrigo, M., Dalpiaz, P. F., De Leo, R., De Nardo, L., De Sanctis, E., Devitsin, E., Di Nezza, P., Duren, M., Ehrenfried, M., Elalaoui-Moulay, A., Ammosov, V. V., Elbakian, G., Ellinghaus, F., Elschenbroich, U., Ely, J., Fabbri, R., Fantoni, A., Fechtchenko, A., Felawka, L., Fox, B., Franz, J., Andrus, A., Frullani, S., Gapienko, G., Gapienko, V., Garibaldi, F., Garrow, K., Garutti, E., Gaskell, D., Gavrilov, G., Gharibyan, V., Graw, G., Aschenauer, E. C., Grebeniouk, O., Greeniaus, L. G., Gregor, I. M., Hafidi, K., Hartig, M., Hasch, D., Heesbeen, D., Henoch, M., Hertenberger, R., Hesselink, W. H. A., Augustyniak, W., Hillenbrand, A., Hoek, M., Holler, Y., Hommez, B., Iarygin, G., Ivanilov, A., Izotov, A., Jackson, H. E., Jgoun, A., Kaiser, R., Avakian, R., Kinney, E., Kisselev, A., Konigsmann, K., Kopytin, M., Korotkov, V., Kozlov, V., Krauss, B., Krivokhijine, V. G., Lagamba, L., Lapikas, Louk, Avetissian, A., Laziev, A., Lenisa, P., Liebing, P., Lindemann, T., Linden-Levy, L. A., Lipka, K., Lorenzon, W., Lu, J., Maiheu, B., Makins, N. C. R., (Astro)-Particles Physics, Photo Conversion Materials, and Student Lab and Education

Subjects
Quark, internal [polarized target], Nuclear and High Energy Physics, Particle physics, Strange quark, sea [quark], High Energy Physics::Lattice, deep inelastic scattering [positron deuteron], Hadron, Nuclear Theory, dependence [flavor], Down quark, FOS: Physical sciences, HERMES, 01 natural sciences, High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), density [helicity], 27.5 GeV, Pion, 0103 physical sciences, ddc:530, SDG 14 - Life Below Water, deep inelastic scattering [positron p], 010306 general physics, electroproduction [pi], Physics, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, polarization [quark], Deep inelastic scattering, moment, Baryon, DESY HERA Stor, electroproduction [K], Up quark, valence [quark], polarization [cross section], High Energy Physics::Experiment, polarized beam [positron], asymmetry [spin], experimental results
Abstract

Polarized deep-inelastic scattering data on longitudinally polarized hydrogen and deuterium targets have been used to determine double-spin asymmetries of cross sections. Inclusive and semi-inclusive asymmetries for the production of positive and negative pions from hydrogen were obtained in a reanalysis of previously published data. Inclusive and semi-inclusive asymmetries for the production of negative and positive pions and kaons were measured on a polarized deuterium target. The separate helicity densities for the up and down quarks and the anti-up, anti-down, and strange sea quarks were computed from these asymmetries in a "leading order" QCD analysis. The polarization of the up-quark is positive and that of the down-quark is negative. All extracted sea quark polarizations are consistent with zero, and the light quark sea helicity densities are flavor symmetric within the experimental uncertainties. First and second moments of the extracted quark helicity densities in the measured range are consistent with fits of inclusive data. © 2005 The American Physical Society.

Published
2005
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4. Polarized Parton Distributions Measured at the HERMES Experiment

Author

Jürgen Wendland

Subjects
HERMES experiment, momentum spectrum [quark], Proton, deep inelastic scattering [positron deuteron], High Energy Physics::Lattice, Nuclear Theory, sum rule: Bjorken, HERMES, Parton, electroproduction [hadron], 27.5 GeV, deep inelastic scattering [positron p], Nuclear Experiment, asymmetry [cross section], Spin-½, Physics, Bjorken [sum rule], positron p: deep inelastic scattering, thesis, cross section: polarization, quark: momentum spectrum, valence [quark], quark: valence, polarization [cross section], polarized target: internal, Nucleon, positron: polarized beam, internal [polarized target], Quark, sea [quark], Particle physics, polarization: longitudinal, hadron: electroproduction, structure function [nucleon], dependence: flavor, Nuclear physics, Pion, statistical analysis, tables, cross section: asymmetry, quark: sea, longitudinal [polarization], flavor [dependence], bibliography, polarization [quark], nucleon: structure function, Deep inelastic scattering, moment, positron deuteron: deep inelastic scattering, nucleon: spin, High Energy Physics::Experiment, polarized beam [positron], spin [nucleon], quark: polarization, experimental results
Abstract

Simon Fraser University, Diss., 2003; 219 pp., (2003). doi:10.3204/DESY-THESIS-2003-032, Published by Deutsches Elektronen-Synchrotron, DESY, Hamburg

Published
2004
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5. The gain to polarimetry and $A_{LR}$ measurements from a polarised positron beam in TESLA

Author

Alexander, G. and Reinherz-Aronis, E.

Subjects
positron: polarized beam, longitudinal [polarization], polarized beam [electron], electron: polarized beam, polarization: longitudinal, numerical calculations: DESY TESLA Linac, electron positron: colliding beams, cross section: polarization, DESY TESLA Linac [numerical calculations], polarization: asymmetry, polarization: measurement, 500 GeV-cms [92], asymmetry [polarization], colliding beams [electron positron], polarization [cross section], measurement [polarization], polarized beam [positron], 92: 500 GeV-cms
Abstract

17 pp. (2003)., A thorough analysis is presented on the benefits gained for the left-right asymmetry $A_{LR}$ and beam polarisation measurements by adding a longitudinal polarised positron beam to the $e^+e^−$ linear collider TESLA. Two centre of mass energies were considered, 91 and 500 GeV, where it is assumed that data was collected with a total luminosity of 30 $fb^{−1}$ and 500 $fb^{−1}$ respectively. In the analysis we consider 4-bunch spin-spin configurations setups according to the Blondel scheme and an alternative scheme. The results of these operating modes are compared to the case where the beam polarisations are measured by polarimeters which have a precision of 0.5% and to the situation where only the electron beam is polarised. Whereas a dramatic improvement in the statistical error of ALR is achieved at 91 GeV by the application of the alternative Blondel four-spin configuration scheme, the gain at 500 GeV is rather moderate and is in the range 50 to 70 % for $A_{LR}$=0.15 and about 300% for $A_{LR}$=0.5.

Published
2003
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