Hard photoproduction of a diphoton with a large invariant mass

TL;DR

This paper investigates the production of high invariant mass diphotons via hard photoproduction, utilizing generalized parton distributions to analyze the process's unique amplitude structure and observable asymmetries.

Contribution

It introduces a novel analysis of diphoton photoproduction at large invariant mass, highlighting the amplitude's analytic structure and potential for probing nucleon GPDs.

Findings

Calculated unpolarized cross sections.

Analyzed angular asymmetry with linearly polarized photons.

Identified the process as a new probe of nucleon structure.

Abstract

The electromagnetic probe has proven to be a very efficient way to access the $3-$dimensional structure of the nucleon, particularly thanks to the exclusive Compton processes. We explore the hard photoproduction of a large invariant mass diphoton in the kinematical regime where the diphoton is nearly forward and its invariant mass is the hard scale enabling to factorize the scattering amplitude in terms of generalized parton distributions. This amplitude has a very peculiar and interesting analytic structure. We calculate unpolarized cross sections and the angular asymmetry triggered by a linearly polarized photon beam.