Beam-helicity asymmetry in associated electroproduction of real photons \(ep \to e\gamma \pi N\) in the \(\Delta\)-resonance region

• Published in: arXiv.org 2014-02
• Main Authors: The HERMES Collaboration, Airapetian, A, Akopov, N, Augustyniak, W, Avakian, R, Avetissian, A, Avetisyan, E, Blok, H P, Böttcher, H, Borissov, A, Bowles, J, Brodski, I, Bryzgalov, V, Burns, J, Cisbani, E, Ciullo, G, Contalbrigo, M, Dalpiaz, P F, Deconinck, W, De Leo, R, De Sanctis, E, Diefenthaler, M, P Di Nezza, Düren, M, Ehrenfried, M, Elbakian, G, Etzelmüller, E, Frullani, S, Gapienko, G, Gapienko, V, J Garay García, Garibaldi, F, Gavrilov, G, Gharibyan, V, Giordano, F, Gliske, S, Hartig, M, Holler, Y, Hristova, I, Jackson, H E, Joosten, S, Kaiser, R, Kinney, E, Kisselev, A, Korotkov, V, Kravchenko, P, Krivokhijine, V G, Lagamba, L, Lapikás, L, Lehmann, I, Lenisa, P, Lorenzon, W, X -G Lu, -Q, B, Mahon, D, Makins, N C R, Manaenkov, S I, Mao, Y, Marianski, B, Marukyan, H, Miller, C A, Miyachi, Y, Movsisyan, A, Muccifora, V, Murray, M, Naryshkin, Y, Nass, A, Negodaev, M, W -D Nowak, Pappalardo, L L, Perez-Benito, R, Petrosyan, A, Reimer, P E, Riedl, C, Rith, K, Rosner, G, Rostomyan, A, Rubin, J, Ryckbosch, D, Salomatin, Y, Schnell, G, Seitz, B, T -A Shibata, Stahl, M, Statera, M, Steffens, E, Steijger, J J M, Stewart, J, Stinzing, F, Terkulov, A, Tytgat, M, C Van Hulse, Vikhrov, V, Vilardi, I, Wang, S, Z Ye, Yen, S, Zagrebelnyy, V, Zihlmann, B, Zupranski, P
• Format: Article
• Language: English
• Subjects: Amplitudes; Asymmetry; Helicity; Photons; Positron beams; Recoil
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1310.5081

The beam-helicity asymmetry in associated electroproduction of real photons, \(ep\to e\gamma \pi N\), 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, \(ep\to e\gamma \pi^0 p\) and \(ep\to e\gamma \pi^+ n\), from a data set collected with a recoil detector. All asymmetry amplitudes are found to be consistent with zero.