Beam-helicity asymmetry in associated electroproduction of real photons ep[arrow right]e[gamma][pi]N in the [Delta]-resonance region

• Published in: The journal of high energy physics 2014-01, Vol.2014 (1), p.1
• Main Authors: Airapetian, A, Akopov, N, Aschenauer, E C, Augustyniak, W, Avakian, R, Avetisyan, E, Blok, H P, Böttcher, H, Borissov, A, Bowles, J, Brodski, I, Bryzgalov, V, Burns, J, Capitani, G P, Cisbani, E, Contalbrigo, M, Dalpiaz, P F, Deconinck, W, De Leo, R, De Sanctis, E, Diefenthaler, M, Di Nezza, P, Elbakian, G, Ellinghaus, F, Fabbri, R, Frullani, S, Gapienko, V, García, J Garay, Garibaldi, F, Gavrilov, G, Giordano, F, Hartig, M, Hasch, D, Hristova, I, Ivanilov, A, Joosten, S, Kaiser, R, Karyan, G, Keri, T, Kinney, E, Kisselev, A, Kozlov, V, Krivokhijine, V G, Lagamba, L, Lehmann, I, Lenisa, P, Lorenzon, W, Lu, X-g, Ma, B-q, Mahon, D, Makins, N C, R, Manaenkov, S I, Mao, Y, Marukyan, H, Miller, C A, Miyachi, Y, Movsisyan, A, Muccifora, V, Murray, M, Mussgiller, A, Naryshkin, Y, Nass, A, Negodaev, M, Nowak, W-d, Pappalardo, L L, Perez-benito, R, Petrosyan, A, Reimer, P E, Reolon, A R, Rith, K, Rosner, G, Rostomyan, A, Rubin, J, Ryckbosch, D, Schäfer, A, Schnell, G, Seitz, B, Shibata, T-a, Stahl, M, Statera, M, Steffens, E, Steijger, J J, M, Stewart, J, Stinzing, F, Taroian, S, Terkulov, A, Truty, R, Trzcinski, A, Tytgat, M, Van Haarlem, Y, Van Hulse, C, Vikhrov, V, Vilardi, I, Wang, S, Yaschenko, S, Ye, Z, Yen, S, Zagrebelnyy, V, Zihlmann, B, Zupranski, P
• Format: Article
• Language: English
• Subjects: High energy physics
• ISSN: 1029-8479
• DOI: 10.1007/JHEP01(2014)077

The beam-helicity asymmetry in associated electroproduction of real photons, ep[arrow right]eγ[pi]N , in the [Delta](1232)-resonance region is measured using the longitudinally polarized Hera positron beam and an unpolarized hydrogen target. Azimuthal Fourier amplitudes of this asymmetry are extracted separately for two channels, ep[arrow right]eγ[pi]^sup 0^ p and ep[arrow right]eγ[pi]^sup +^ n, from a data set collected with a recoil detector. All asymmetry amplitudes are found to be consistent with zero.