Measurements of DVCS and High |t| Vector Meson Production at HERA

Abstract

Measurements of Deeply Virtual Compton Scattering (DVCS) are presented using data collected by the H1 and ZEUS experiments at HERA. The transition from a virtual photon to an on-shell particle is expected to necessitate the use of skewed parton distributions for a theoretical description. The results are compared to theoretical predictions. Diffractive vector meson production measurements from H1 and ZEUS are also presented in which the magnitude of the four-momentum transfer squared |t| at the proton vertex is large. A large |t| is expected to make it possible to perform a perturbative calculation. The results are compared to recent theoretical predictions performed within the framework of perturbative QCD.