Beam-helicity asymmetry arising from deeply virtual compton scattering measured with kinematically complete event reconstruction

Airapetian, A. et al. (2012) Beam-helicity asymmetry arising from deeply virtual compton scattering measured with kinematically complete event reconstruction. Journal of High Energy Physics, 2012(42), (doi: 10.1007/JHEP10(2012)042)

Abstract

The beam-helicity asymmetry in exclusive electroproduction of real photons by the longitudinally polarized Hera positron beam scattering off an unpolarized hydrogen target is measured at Hermes. The asymmetry arises from deeply virtual Compton scattering and its interference with the Bethe-Heitler process. Azimuthal amplitudes of the beam-helicity asymmetry are extracted from a data sample consisting of ep → epγ events with detection of all particles in the final state including the recoiling proton. The installation of a recoil detector, while reducing the acceptance of the experiment, allows the elimination of background from ep → eN πγ events, which was estimated to contribute an average of about 12% to the signal in previous Hermes publications. The removal of this background from the present data sample is shown to increase the magnitude of the leading asymmetry amplitude by 0.054 ± 0.016 to −0.328 ± 0.027 (stat.) ± 0.045 (syst.).

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Mahon, Dr David and Murray, Dr Morgan and Hoek, Mr Matthias and Shearer, Dr Craig and Keri, Dr Tibor and Burns, Mr Jonathan and Kaiser, Professor Ralf and Lehmann, Dr Inti and Seitz, Dr Bjoern and Rosner, Professor Guenther
• Authors: Airapetian, A., Akopov, N., Akopov, Z., Aschenauer, E. C., Augustyniak, W., Avakian, R., Avetissian, A., Avetisyan, E., Belostotski, S., Blok, H. P., Borissov, A., Bowles, J., Brodski, I., Bryzgalov, V., Burns, J., Capiluppi, M., Capitani, G. P., Cisbani, E., Ciullo, G., Contalbrigo, M., Dalpiaz, P. F., Deconinck, W., Leo, R., Nardo, L., Sanctis, E., Diefenthaler, M., Nezza, P., Düren, M., Ehrenfried, M., Elbakian, G., Ellinghaus, F., Etzelmüller, E., Fabbri, R., Fantoni, A., Felawka, L., Frullani, S., Gapienko, G., Gapienko, V., Garibaldi, F., Gavrilov, G., Gharibyan, V., Giordano, F., Gliske, S., Golembiovskaya, M., Gregor, I. M., Guler, H., Hartig, M., Hasch, D., Hillenbrand, A., Hoek, M., Holler, Y., Hristova, I., Ivanilov, A., Jackson, H. E., Jo, H. S., Joosten, S., Kaiser, R., Karyan, G., Keri, T., Kinney, E., Kisselev, A., Korotkov, V., Kozlov, V., Krauss, B., Kravchenko, P., Krivokhijine, V. G., Lagamba, L., Lapikás, L., Lehmann, I., Lenisa, P., Ruiz, A. L., Lorenzon, W., Lu, S., Lu, X., Ma, B.-Q., Mahon, D., Makins, N. C. R., Manaenkov, S. I., Manfré, L., Mao, Y., Marianski, B., Ossa, A. M., Marukyan, H., Miller, C. A., Miyachi, Y., Movsisyan, A., Murray, M., Mussgiller, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W.-D., Osborne, A., Pappalardo, L. L., Perez-Benito, R., Petrosyan, A., Reimer, P. E., Reolon, A. R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubacek, L., Rubin, J., Ryckbosch, D., Schäfer, A., Schnell, G., Schüler, K. P., Seitz, B., Shearer, C., Shibata, T.-A., Shutov, V., Stancari, M., Statera, M., Steijger, J. J. M., Stewart, J., Taroian, S., Terkulov, A., Truty, R., Trzcinski, A., Tytgat, M., Haarlem, Y., Hulse, C., Veretennikov, D., Vikhrov, V., Vilardi, I., Wang, S., Yaschenko, S., Ye, Z., Yen, S., Zagrebelnyy, V., Zeiler, D., Zihlmann, B., and Zupranski, P.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Journal of High Energy Physics
• Journal Abbr.: J. High Energy Phys.
• Publisher: Springer-Verlag
• ISSN: 1029-8479
• ISSN (Online): 1029-8479
• Copyright Holders: Copyright © 2012 The Authors
• First Published: First published in Journal of High Energy Physics 2012:42
• Publisher Policy: Reproduced under a Creative Commons License