publication . Article . Preprint . 2014

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

Luigi Lagamba; Michael Tytgat; Xianguo Lu; Wouter Deconinck; Paul Reimer; Evaristo Cisbani; Naryshkin Iurii; Frank Ellinghaus;
Open Access English
  • Published: 01 Jan 2014 Journal: JOURNAL OF HIGH ENERGY PHYSICS (issn: 1029-8479, Copyright policy)
  • Publisher: SPRINGER
Abstract
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.
Subjects
arXiv: High Energy Physics::ExperimentPhysics::Accelerator Physics
free text keywords: Physics and Astronomy, QCD, Lepton-Nucleon Scattering, Polarization, Photon production, VIRTUAL COMPTON-SCATTERING, CROSS-SECTIONS, SPIN, HERA, DEPENDENCE, LIMIT, interaction [positron p], internal [target], recoil [detector], longitudinal [polarized beam], asymmetry [helicity], electroproduction [pi], associated production [photon], DESY HERA Stor, Delta(1232), scattering amplitude, HERMES, experimental results, positron p --> nucleon pi electron photon, 27.6 GeV, Nuclear and High Energy Physics, High Energy Physics - Experiment, Nuclear Experiment, ddc:530
Funded by
NSERC
Project
  • Funder: Natural Sciences and Engineering Research Council of Canada (NSERC)
,
EC| HADRONPHYSICS3
Project
HADRONPHYSICS3
Study of Strongly Interacting Matter
  • Funder: European Commission (EC)
  • Project Code: 283286
  • Funding stream: FP7 | SP4 | INFRA
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