QED radiative effects in the processes of exclusive photon electroproduction from polarized protons with the next-to-leading accuracy

Abstract

Radiative effects in the electroproduction of photons in polarized $ep$ scattering are calculated with next-to-leading-order accuracy. The contributions of loops and two-photon emission are presented in analytical form. The covariant approach of Bardin and Shumeiko is used to extract the infrared divergence. All contributions to the radiative correction are presented in the form of the correction to the leptonic tensor thus allowing for further applications in other experiments, e.g., deep inelastic scattering. The radiative corrections to the cross sections and polarization asymmetries are analyzed numerically for the kinematical conditions of the current measurement at Jefferson Lab. Specific attention is paid to analyzing kinematical conditions for the process with a large radiative effect when the momenta of two photons in the final state are collinear with the momenta of the initial and final electrons, respectively.