Dual parameterization of generalized parton distributions and description of DVCS data

Abstract

We discuss a new leading-order parameterization of generalized parton distributions of the proton, which is based on the idea of duality. In its minimal version, the parameterization is defined by the usual quark singlet parton distributions and the form factors of the energy-momentum tensor. We demonstrate that our parameterization describes very well the absolute value, the Q^2-dependence and the W-dependence of the HERA data on the total DVCS cross section and contains no free parameters in that kinematics. The parameterization suits especially well the low-x_{Bj} region, which allows us to advocate it as a better alternative to the frequently used double distribution parameterization of the GPDs.