Direct photon production at HERA, the Tevatron and the LHC

TL;DR

This paper reviews recent prompt-photon measurements at HERA and the Tevatron, compares them with theoretical models, and discusses implications for future LHC experiments, focusing on QCD predictions and uncertainties.

Contribution

It provides a comprehensive comparison of experimental data with NLO QCD and Monte Carlo models, highlighting areas for future research at the LHC.

Findings

Good agreement between measurements and NLO QCD predictions

Identified uncertainties from scale choices and gluon density

Guidance for future photon measurements at the LHC

Abstract

We review several most recent prompt-photon measurements at HERA and the Tevatron and discuss their implication for future measurements at the LHC. A comparison to Monte Carlo models, as well as to NLO QCD predictions based on the standard DGLAP and the kT-factorization approaches is discussed. Effects from renormalization and factorization scale uncertainties, as well as uncertainties on the gluon density distribution inside a proton are discussed.