Combining QCD and electroweak corrections to dilepton production in the framework of the FEWZ simulation code

Abstract

We combine the next-to-next-to-leading order QCD corrections to lepton-pair production through the Drell-Yan mechanism with the next-to-leading order (NLO) electroweak corrections within the framework of the Fully Exclusive W and Z Production (FEWZ) simulation code. Control over both sources of higher-order contributions is necessary for measurements where percent-level theoretical predictions are crucial and in phase-space regions where the NLO electroweak corrections grow large. The inclusion of both corrections in a single simulation code eliminates the need to separately incorporate such effects as final-state radiation and electroweak Sudakov logarithms when comparing many experimental results to theory. We recalculate the NLO electroweak corrections in the complex-mass scheme for both massless and massive final-state leptons, and modify the QCD corrections in the original FEWZ code to maintain consistency with the complex-mass scheme to the lowest order. We present phenomenological results for LHC studies that include both next-to-next-to-leading order QCD and NLO electroweak corrections. In addition, we study several interesting kinematics features induced by experimental cuts in the distribution of photon radiation at the LHC.