Extraction of the Parton Momentum-Fraction Dependence of Generalized Parton Distributions from Exclusive Photoproduction

TL;DR

This paper demonstrates a method to extract the $x$ dependence of generalized parton distributions (GPDs) from exclusive photoproduction processes, highlighting enhanced sensitivity and potential for experimental measurement at JLab and future facilities.

Contribution

It introduces a quantitative approach to extract the $x$ dependence of GPDs from photoproduction cross sections and asymmetries, improving understanding of hadron structure.

Findings

Enhanced sensitivity to GPD $x$ dependence in photoproduction

Potential for measuring asymmetries with photon polarization and hadron spin

Feasibility of extraction at JLab Hall D and future experiments

Abstract

The $x$ dependence of hadrons' generalized parton distributions (GPDs) $\mathcal{F}(x,\xi,t)$ is the most difficult to extract from the existing known processes, while the $\xi$ and $t$ dependence are uniquely determined by the kinematics of the scattered hadron. We study the single diffractive hard exclusive processes for extracting GPDs in the photoproduction. We demonstrate quantitatively the enhanced sensitivity on extracting the $x$ dependence of various GPDs from the photoproduction cross sections, as well as the asymmetries constructed from photon polarization and hadron spin that could be measured at JLab Hall D by GlueX Collaboration and future facilities.