One-loop corrections to five-parton amplitudes with external photons
Adrian Signer
TL;DR
The paper shows how to obtain one-loop five-parton amplitudes with external photons by mapping known QCD one-loop results, through controlled replacements of gluons by photons and careful treatment of color structures and fermion-loop contributions. It systematically builds photonic amplitudes for cases with one external quark pair and with two external quark pairs, giving explicit helicity-structured subamplitudes and addressing both loop-coupled and externally-coupled photon couplings. This enables accurate predictions for photon-involved jet processes in ep and hadron-collider environments, leveraging established QCD amplitudes.
Abstract
Recently the calculations of all five-parton one-loop QCD amplitudes have been completed. In this letter we describe how to get the corresponding amplitudes with one gluon replaced by a photon and we give the explicit results for the process $0 \to 2q 2Q 1\y$.