Wgamma and Zgamma production at the LHC in NNLO QCD

TL;DR

This paper presents a detailed NNLO QCD calculation for Wgamma and Zgamma production at the LHC, including leptonic decays and photon radiation, improving theoretical predictions and agreement with experimental data.

Contribution

It provides the first fully differential NNLO QCD computation for Wgamma and Zgamma production, incorporating spin correlations, off-shell effects, and photon radiation.

Findings

NNLO corrections range from 8% to 17% for Zgamma production.

NNLO effects are 19% to 26% for Wgamma production, enhancing data agreement.

Jet veto reduces the impact of QCD corrections.

Abstract

We consider the production of Wgamma and Zgamma pairs at the LHC, and report on the fully differential computation of next-to-next-to-leading order (NNLO) corrections in QCD perturbation theory. The calculation includes leptonic vector-boson decays with the corresponding spin correlations, off-shell effects and final-state photon radiation. We present numerical results for pp collisions at 7 TeV, and compare them with available ATLAS data. In the case of Zgamma production, the impact of NNLO corrections is generally moderate, ranging from 8% to 17%, depending on the applied cuts. In the case of Wgamma production, the NNLO effects are more important, and range from 19% to 26%, thereby improving the agreement of the theoretical predictions with the data. As expected, a veto against jets significantly reduces the impact of QCD radiative corrections.