Conversion of Photons to Dileptons in the Kroll-Wada and Parton Shower Approaches

Abstract

Low-invariant-mass dilepton production is a sensitive probe of the properties of the quark-gluon plasma, accessed experimentally through the internal conversion of direct and virtual photons into lepton pairs. We compare the traditional Kroll-Wada formalism for this conversion with a parton-shower-based description, finding that the parton shower approach offers improved accuracy in describing the dilepton invariant-mass spectrum, particularly towards larger invariant masses where phase-space suppression effects become relevant.