QCD corrections in Standard Model EFT fits to $WZ$ and $WW$ production

We investigate the role of anomalous gauge boson and fermion couplings in the production of $WZ$ and W⁺W^– pairs at the LHC to next-to-leading-order (NLO) QCD in the Standard Model effective field theory (SMEFT), including dimension-six operators. Our results are implemented in a publicly available version of the powheg-box. We combine our $WZ$ results in the leptonic final state eνμ⁺μ^– 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 O(1/Λ⁴) contributions dominate the analysis, where Λ is the high-energy scale associated with the SMEFT.