Wgamma and Zgamma production at the LHC in NNLO QCD

TL;DR

This paper presents a comprehensive NNLO QCD calculation for Wγ and Zγ production at the LHC, including decay, spin, off-shell effects, and photon radiation, improving theoretical predictions and agreement with experimental data.

Contribution

It provides the first fully differential NNLO QCD computation for Wγ and Zγ production, incorporating detailed effects and comparisons with LHC data.

Findings

NNLO corrections range from 8% to 18% for Zγ production.

NNLO effects are more significant, 19% to 26%, for Wγ production.

Jet veto reduces the impact of QCD radiative corrections.

Abstract

We consider the production of $W\gamma$ and $Z\gamma$ pairs at hadron colliders. We report on the complete fully differential computation of radiative corrections at next-to-next-to-leading order (NNLO) in QCD perturbation theory. The calculation includes the leptonic decay of the vector boson with the corresponding spin correlations, off shell effects and final-state photon radiation. We present numerical results for $pp$ collisions at 7 and 8 TeV and we compare them with available LHC data. In the case of $Z\gamma$ production, the impact of NNLO corrections is generally moderate, ranging from 8% to 18%, depending on the applied cuts. In the case of $W\gamma$ 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, the impact of QCD radiative corrections is significantly reduced when a jet veto is applied.