Eur. Phys. J. C 23, 301-310 (2002)
https://doi.org/10.1007/s100520100883

Perturbative and non-perturbative QCD corrections to wide-angle Compton scattering

¹ Faculty of Human Development, Kobe University, Nada, Kobe 657-8501, Japan
² Fachbereich Physik, Universität Wuppertal, 42097 Wuppertal, Germany

Received: 31 October 2001
Revised: 11 December 2001
Published online: 8 February 2002

Abstract

We investigate corrections to the handbag approach for wide-angle Compton scattering off protons at moderately large momentum transfer: the photon--parton subprocess is calculated to next-to-leading order in α_s and contributions from the generalized parton distribution E are taken into account. Photon and proton helicity flip amplitudes are non-zero due to these corrections, which leads to a wealth of polarization phenomena in Compton scattering. Thus, for instance, the incoming photon asymmetry or the transverse polarization of the proton is non-zero, although small.