QCD Corrections in SMEFT Fits to $WZ$ and $WW$ Production

TL;DR

This paper analyzes the impact of NLO QCD corrections within the SMEFT framework on $WZ$ and $WW$ production at the LHC, highlighting the significance of including these corrections for accurate limits on new physics couplings.

Contribution

It provides the first implementation of NLO QCD SMEFT corrections for $WZ$ and $WW$ production in a publicly available tool, demonstrating their importance in experimental analyses.

Findings

NLO QCD SMEFT corrections significantly affect $WZ$ production limits.

Effects on $WW$ production are comparatively smaller.

Dominance of $ ext{O}(1/ ext{Lambda}^4)$ terms in the analysis.

Abstract

We investigate the role of anomalous gauge boson and fermion couplings on the production of $WZ$ and $W^+W^-$ pairs at the LHC to NLO QCD in the Standard Model effective field theory, including dimension-6 operators. Our results are implemented in a publicly available version of the POWHEG-BOX. We combine our $WZ$ results in the leptonic final state $e\nu \mu^+\mu^-$ with previous $W^+W^-$ results to demonstrate the numerical effects of NLO QCD corrections on the limits on effective couplings derived from ATLAS and CMS 8 and 13 TeV differential measurements. Our study demonstrates the importance of including NLO QCD SMEFT corrections in the $WZ$ analysis, while the effects on $WW$ production are smaller. We also show that the $\mathcal{O}(1/\Lambda^4)$ contributions dominate the analysis, where $\Lambda$ is the high energy scale associated with the SMEFT.