Measurement of the spin asymmetry in the photoproduction of pairs of high-p(T) hadrons at HERMES

Authors
Airapetian, A Akopov, N Amarian, M Aschenauer, EC Avakian, H Avakian, R Avetissian, A Bains, B Baumgarten, C Beckmann, M Belostotski, S Belz, JE Benisch, T Bernreuther, S Bianchi, N Blouw, J Bottcher, H Borissov, A Brack, J Brauksiepe, S Braun, B Bruckner, W Brull, A Bulten, HJ Capitani, GP Carter, P Chumney, P Cisbani, E Court, GR Dalpiaz, PF De Sanctis, E De Schepper, D Devitsin, E Huberts, PKAD Di Nezza, P Duren, M Dvoredsky, A Elbakian, G Ely, J Fantoni, A Ferstl, M Fiedler, K Filippone, BW Fischer, H Fox, B Franz, J Frullani, S Funk, MA Garber, Y Garibaldi, F Gavrilov, G Geiger, P Gharibyan, V Golendukhin, A Graw, G Grebeniouk, O Green, PW Greeniaus, LG Grosshauser, C Guidal, M Gute, A Haeberli, W Hansen, JO Hasch, D Hausser, O Heinsius, FH Henderson, R Henoch, M Hertenberger, R Holler, Y Holt, RJ Hoprich, W Ihssen, H Iodice, M Izotov, A Jackson, HE Jgoun, A Kaiser, R Kinney, E Kisselev, A Kitching, P Kobayashi, H Koch, N Konigsmann, K Kolstein, M Kolster, H Korotkov, V Korsch, W Kozlov, V Kramer, LH Kurisuno, M Kyle, G Lachnit, W Lorenzon, W Makins, NCR Martens, FK Martin, JW Masoli, F Mateos, A McAndrew, M McIlhany, K McKeown, RD Meissner, F Menden, FM Metz, A Meyners, N Mikloukho, O Miller, CA Miller, MA Milner, R Most, A Muccifora, V Naryshkin, Y Nathan, AM Neunreither, F Niczyporuk, M Nowak, WD O'Neill, TG Openshaw, R Ouyang, J Owen, BR Pate, SF Potashov, S Potterveld, DH Rakness, G Redwine, R Reolon, AR Ristinen, R Rith, K Rossi, P Rudnitsky, S Ruh, M Ryckbosch, D Sakemi, Y Scarlett, C Schafer, A Schmidt, F Schmitt, H Schnell, G Schuler, KP Schwind, A Seibert, J Shibata, TA Shibatani, K Shin, T Shutov, V Simani, C Simon, A Sinram, K Slavich, P Spengos, M Steffens, E Stenger, J Stewart, J Stoesslein, U Sutter, M Tallini, H Taroian, S Terkulov, A Tipton, B Tytgat, M Uriuoli, GM van de Vyver, R van den Brand, JFJ van der Steenhoven, G van Hunen, JJ Vetterli, MC Vikhrov, V Vincter, MG Visser, J Volk, E Wander, W Wendland, J Williamson, SE Wise, T Woller, K Yoneyama, S Zohrabian, H
Citation
A. Airapetian et al., Measurement of the spin asymmetry in the photoproduction of pairs of high-p(T) hadrons at HERMES, PHYS REV L, 84(12), 2000, pp. 2584-2588
Citations number
35
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
PHYSICAL REVIEW LETTERS
ISSN journal
0031-9007 → ACNP
Volume
84
Issue
12
Year of publication
2000
Pages
2584 - 2588
Database
ISI
SICI code
0031-9007(20000320)84:12<2584:MOTSAI>2.0.ZU;2-Z
Abstract
We present a measurement of the longitudinal spin asymmetry Ali in photopro duction of pairs of hadrons with high transverse momentum pi. Data were acc umulated by the HERMES experiment using a 27.5 GeV polarized positron beam and a polarized hydrogen target internal to the HERA storage ring. For h(+) h(-) pairs with p(T)(h1) > 1.5 GeV/c and p(T)(h2) > 1.0 GeV/c, the measured asymmetry is A(parallel to) = -0.28 +/- 0.12(stat) +/- 0.02(syst). This ne gative value is in contrast to the positive asymmetries typically measured in deep inelastic scattering: from protons, and is interpreted to arise fro m a positive gluon polarization.