Ratios of Helicity Amplitudes for Exclusive rho-0 Electroproduction
Creators: name: The HERMES Collaboration
name: Airapetian, A.
name: Akopov, N.
name: Akopov, Z.
name: Aschenauer, E. C.
name: Augustyniak, W.
name: Avakian, R.
name: Avetissian, A.
name: Avetisyan, E.
name: Belostotski, S.
name: Bianchi, N.
name: Blok, H. P.
name: Borissov, A.
name: Bowles, J.
name: Bryzgalov, V.
name: Burns, J.
name: Capiluppi, M.
name: Capitani, G. P.
name: Cisbani, E.
name: Ciullo, G.
name: Contalbrigo, M.
name: Dalpiaz, P. F.
name: Deconinck, W.
name: De Leo, R.
name: De Nardo, L.
name: De Sanctis, E.
name: Diefenthaler, M.
name: Di Nezza, P.
name: Dueren, M.
name: Ehrenfried, M.
name: Elbakian, G.
name: Ellinghaus, F.
name: Fabbri, R.
name: Fantoni, A.
name: Felawka, L.
name: Frullani, S.
name: Gabbert, D.
name: Gapienko, G.
name: Gapienko, V.
name: Garibaldi, F.
name: Gavrilov, G.
name: Gharibyan, V.
name: Giordano, F.
name: Gliske, S.
name: Golembiovskaya, M.
name: Hadjidakis, C.
name: Hartig, M.
name: Hasch, D.
name: Hill, G.
name: Hillenbrand, A.
name: Hoek, M.
name: Holler, Y.
name: Hristova, I.
name: Imazu, Y.
name: Ivanilov, A.
name: Jackson, H. E.
name: Jo, H. S.
name: Joosten, S.
name: Kaiser, R.
name: Karyan, G.
name: Keri, T.
name: Kinney, E.
name: Kisselev, A.
name: Kobayashi, N.
name: Korotkov, V.
name: Kozlov, V.
name: Kravchenko, P.
name: Krivokhijine, V. G.
name: Lagamba, L.
name: Lamb, R.
name: Lapikas, L.
name: Lehmann, I.
name: Lenisa, P.
name: Linden-Levy, L. A.
name: Ruiz, A. Lopez
name: Lorenzon, W.
name: Lu, X. -G.
name: Lu, X. -R.
name: Ma, B. -Q.
name: Mahon, D.
name: Makins, N. C. R.
name: Manaenkov, S. I.
name: Manfre, L.
name: Mao, Y.
name: Marianski, B.
name: de la Ossa, A. Martinez
name: Marukyan, H.
name: Miller, C. A.
name: Miyachi, Y.
name: Movsisyan, A.
name: Muccifora, V.
name: Murray, M.
name: Mussgiller, A.
name: Nappi, E.
name: Naryshkin, Y.
name: Nass, A.
name: Negodaev, M.
name: Nowak, W. -D.
name: Pappalardo, L. L.
name: Perez-Benito, R.
name: Pickert, N.
name: Reimer, P. E.
name: Reolon, A. R.
name: Riedl, C.
name: Rith, K.
name: Rosner, G.
name: Rostomyan, A.
name: Rubin, J.
name: Ryckbosch, D.
name: Salomatin, Y.
name: Sanftl, F.
name: Schaefer, A.
name: Schnell, G.
name: Schueler, K. P.
name: Seitz, B.
name: Shibata, T. -A.
name: Shutov, V.
name: Stancari, M.
name: Statera, M.
name: Steffens, E.
name: Steijger, J. J. M.
name: Stinzing, F.
name: Taroian, S.
name: Terkulov, A.
name: Trzcinski, A.
name: Tytgat, M.
name: Vandenbroucke, A.
name: Van Haarlem, Y.
name: Van Hulse, C.
name: Veretennikov, D.
name: Vikhrov, V.
name: Vilardi, I.
name: Wang, S.
name: Yaschenko, S.
name: Yen, S.
name: Yu, W.
name: Zihlmann, B.
name: Zupranski, P.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: Exclusive rho^0-meson electroproduction is studied in the HERMES experiment, using a 27.6 GeV longitudinally polarized electron/positron beam and unpolarized hydrogen and deuterium targets in the kinematic region 0.5 GeV^2 &lt; Q^2 &lt; 7.0 GeV^2, 3.0 GeV &lt; W &lt; 6.3 GeV, and -t' &lt; 0.4 GeV^2. Real and imaginary parts of the ratios of the natural-parity-exchange helicity amplitudes T_{11} (γ^*_T --&gt; ρ_T), T_{01} (γ^*_T --&gt; ρ_L), T_{10} (γ^*_L --&gt; ρ_T), and T_{1-1} (γ^*_{-T} --&gt;ρ_T) to T_{00} (γ^*_L --&gt; ρ_L) are extracted from the data. For the unnatural-parity-exchange amplitude U_{11}, the ratio |U_{11}/T_{00}| is obtained. The Q^2 and t' dependences of these ratios are presented and compared with perturbative QCD predictions.
description: 27 pages, 8 tables, 13 figures; minor textual changes on pages 2, 3,9, 10, 11, and some changes to the list of references