Anomalous coupling, top-mass and parton-shower effects in ${W^+W^-}$ production

TL;DR

This paper presents a detailed NLO QCD calculation of W+W- production including EFT operators, combined with parton shower simulations, to analyze anomalous couplings and top-mass effects in proton-proton collisions.

Contribution

It introduces a combined NLO and EFT matrix element framework with parton shower effects for W+W- production, incorporating dimension-eight operators and top-mass effects.

Findings

EFT operators significantly affect W+W- production observables.

Parton shower effects modify the impact of anomalous couplings.

Uncertainties from scale variations are quantified.

Abstract

We calculate the process $pp\to W^+W^-\to e^+ \nu_e \mu^-\bar{\nu}_\mu$ at NLO QCD, including also effective field theory (EFT) operators mediating the $ggW^+W^-$ interaction, which first occur at dimension eight. We further combine the NLO and EFT matrix elements produced by GoSam with the HERWIG7/MATCHBOX framework, which offers the possibility to study the impact of a parton shower. We assess the effects of the anomalous couplings by comparing them to top-mass effects as well as uncertainties related to variations of the renormalisation, factorisation and hard shower scales.