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, $e(\ell )+N(p)\to e({\ell }^{\prime })+N(p^{\prime })+\gamma (q^{\prime })$, 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.

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