QCD radiative corrections to prompt diphoton production in association with a jet at hadron colliders

TL;DR

The paper computes the QCD NLO corrections in αs to the irreducible background pp → γγ + jet relevant for Higgs plus jet searches at the LHC, using a general-purpose partonic Monte Carlo with dipole subtraction and a smooth photon isolation to maintain infrared safety. It systematically derives LO and NLO cross sections, incorporating real-emission and virtual corrections, with detailed color and helicity decompositions implemented in NLOJET++. The results reveal large radiative corrections highly sensitive to photon-isolation parameters and selection cuts, with new subprocesses contributing significantly at NLO and the gg-initiated piece remaining modest; importantly, a fixed K-factor fails to capture these effects. The study underscores the need for precise, isolation-aware predictions for background modeling in Higgs analyses at the LHC and provides a framework for detailed, differential background assessments.

Abstract

We compute the next-to-leading order corrections in $α_s$ to prompt diphoton production in association with a jet at hadron colliders. We use a next-to-leading order general-purpose partonic Monte Carlo event generator that allows the computation of a rate differential in the produced photons and hadrons.