NLO collinear factorization of large mass diphoton photoproduction amplitude

TL;DR

This paper extends collinear QCD factorization to large mass diphoton photoproduction at NLO, enabling more reliable extraction of generalized parton distributions from complex 2->3 processes.

Contribution

It demonstrates the extension of factorization proofs to 2->3 processes, specifically for large mass diphoton production, at NLO accuracy.

Findings

Collinear divergences are absorbed by GPD evolution.

Factorization is validated for 2->3 processes at NLO.

Enables new reactions for GPD extraction.

Abstract

We calculate large mass diphoton exclusive photoproduction in the framework of collinear QCD factorization at next to leading order in {\alpha}s and at leading twist. Collinear divergences of the coefficient function are absorbed by the evolution of the generalized parton distributions (GPDs). This result enlarges the existing factorization proofs to 2 -> 3 processes, opening new reactions to a trustable extraction of GPDs.