Photon Fragmentation in Large-Q2 ep Collisions at Next-to-Leading Order QCD

TL;DR

This paper investigates photon production in high-Q2 deep inelastic scattering, providing NLO QCD calculations for photon-jet events to help understand quark-to-photon fragmentation and guide future experimental comparisons.

Contribution

It offers the first NLO QCD predictions for photon fragmentation in ep collisions at large Q2, focusing on the differential cross section with respect to photon momentum fraction.

Findings

Numerical results for the photon momentum fraction distribution at large z_gamma.

Demonstrates the sensitivity of the cross section to the quark-to-photon fragmentation function.

Provides theoretical predictions ready for comparison with future HERA data.

Abstract

We study the production of photons accompanied by jets in large-Q2 deep inelastic scattering. Numerical results for the cross section differential with respect to the fraction of momentum z_gamma carried by a photon inside a jet at large z_gamma, up to O(alpha alpha_s) in perturbative QCD, are presented. The sensitivity to the fragmentation contribution allows one to study the quark-to-photon fragmentation function. Our results can be confronted with future experimental data from HERA.