Exploring GPDs through the photoproduction of a $γρ$ pair

Abstract

We describe the process $γN \to γ\,ρN'$ in the generalized Bjorken regime where the $γ\,ρ$ pair has a large invariant mass. In the collinear QCD factorization framework, the amplitude gives access to both chiral-even and chiral-odd quark generalized parton distributions (GPDs), and is insensitive to gluon GPDs. The separation of longitudinally and transversely polarized $ρ$ meson production allows to distinguish chiral-even and chiral-odd contributions. Production rates are estimated in the kinematics of the near-future JLab~12-GeV experiments.

6 pages, 3 figures, to appear in the proceedings of XXV International Workshop on Deep-Inelastic Scattering and Related Subject - DIS 2017, 3-7 April 2017, University of Birmingham, UK