Revealing transversity GPDs through the photoproduction of a photon and a $\rho$ meson

TL;DR

This paper proposes a method to access transversity generalized parton distributions (GPDs) through the photoproduction of a photon and a $ ho$ meson, demonstrating its potential measurability at JLab.

Contribution

It introduces a novel approach to probe chiral-odd GPDs via wide angle photoproduction of a photon and a $ ho$ meson, with calculations at leading order in $ extalpha_s$.

Findings

Cross-section for transversely polarized $ ho$ meson production calculated.

Method sensitive to chiral-odd GPDs demonstrated.

Potential for experimental measurement at JLab shown.

Abstract

Photoproduction of a pair of particles with large invariant mass is a natural extension of collinear QCD factorization theorems which have been much studied for deeply virtual Compton scattering and deeply virtual meson production. We discuss the production of a photon and a meson, where the wide angle Compton scattering on a meson subprocess factorizes from generalized parton distribution. We calculate at dominant twist and leading order in $\alpha_s$, the production cross-section of a transversely polarized $\rho$ meson which is sensitive to chiral-odd GPDs, and show that it may be measurable in near future JLab experiments.