DVCS and associated processes at HERMES

Abstract

Deeply virtual Compton scattering provides information about the structure of nucleon in the framework of generalized parton distributions. During the last 13 years, DVCS was extensively studied at the HERMES experiment through measurement of various cross-section asymmetries. Due to unique experimental conditions, HERMES has collected a wealth of data on scattering polarized electron and positron beams off unpolarized and longitudinally polarized hydrogen and deuterium targets, as well as off transversely polarized hydrogen targets. The variety of measured asymmetries provides sensitivity to real and/or imaginary parts of different combination of Compton form factors, and thus related GPDs. The HERMES recoil detector is used to separate pure DVCS from associated DVCS processes involving resonance production.