New framework for extracting GPDs from exclusive photon electroproduction

Abstract

Recently, a new framework for studying generic $2\to 3$ hard exclusive reactions, referred to as single-diffractive hard exclusive processes, has been introduced to provide a cleaner separation of the underlying physical mechanisms. In this work, we expand this formalism to the case of exclusive real-photon electroproduction off a nucleon, $e(\ell )+N(p)\to e({\ell }^{\prime })+N(p^{\prime })+{\hat{I}}^3(q^{\prime })$, which represents the classical channel for accessing generalized parton distributions (GPDs) in nucleons and nuclei. This extension enables a more systematic and physically transparent formulation of the reaction dynamics, paving the way for improved extractions of GPDs from experimental data as compared to existing approaches.

Match to published version. Main text: 30 pages, 12 figures. Appendix: 17 pages, 1 figure