










Item type: | Article | ||||
---|---|---|---|---|---|
Journal or Publication Title: | Journal of High Energy Physics | ||||
Publisher: | SPRINGER | ||||
Place of Publication: | NEW YORK | ||||
Volume: | 2012 | ||||
Number of Issue or Book Chapter: | 10 | ||||
Date: | 2012 | ||||
Institutions: | Physics > Institute of Theroretical Physics > Chair Professor Schäfer > Group Andreas Schäfer | ||||
Identification Number: |
| ||||
Keywords: | EP; Lepton-Nucleon Scattering | ||||
Dewey Decimal Classification: | 500 Science > 530 Physics | ||||
Status: | Published | ||||
Refereed: | Yes, this version has been refereed | ||||
Created at the University of Regensburg: | Yes | ||||
Item ID: | 63290 |
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 ...

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 -> ep gamma 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 pi gamma 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.).
Metadata last modified: 19 Dec 2024 09:35