QCD Corrections and Non-standard Three Vector Boson Couplings in $W^+W^-$ Production at Hadron Colliders

TL;DR

This paper advances the study of WWV couplings by performing a full $O(\alpha_s)$ QCD calculation of $pp\to W^+W^-+X$ with leptonic decays, including general CP-conserving $WW\gamma$ and $WWZ$ interactions via form-factor unitarization. It demonstrates that NLO QCD corrections and $t\bar t$ backgrounds can significantly degrade sensitivity to anomalous couplings unless jet vetoes or hadronic transverse momentum cuts are applied. The work derives 95% CL limits for anomalous couplings at the Tevatron and LHC across several luminosities and scenarios (including HISZ), and compares the reach to other di-boson channels, highlighting the complementary role of $W^+W^-$ production in constraining the $WWV$ vertices. Overall, it provides practical guidance for exploiting high-energy diboson data to test the non-Abelian structure of the electroweak sector with realistic detector and background conditions.

Abstract

The process $p\,p\hskip-7pt\hbox{$^{^{(\!-\!)}}$} \rightarrow W^{+} W^{-} + X \rightarrow \ell^+_1 ν_1 \ell^-_2 \bar ν_2 + X$ is calculated to ${\cal O}(α_s)$ for general $C$ and $P$ conserving $WWV$ couplings ($V=γ,\, Z$). The prospects for probing the $WWV$ couplings in this reaction are explored. The impact of ${\cal O}(α_s)$ QCD corrections and various background processes on the observability of non-standard $WWV$ couplings in $W^+ W^-$ production at the Tevatron and the Large Hadron Collider (LHC) is discussed in detail. Sensitivity limits for anomalous $WWV$ couplings are derived at next-to-leading order for the Tevatron and LHC center of mass energies, and are compared to the bounds which can be achieved in other processes. Unless a jet veto or a cut on the total transverse momentum of the hadrons in the event is imposed, the ${\cal O}(α_s)$ QCD corrections and the background from top quark production decrease the sensitivity of $p\,p\hskip-7pt\hbox{$^{^{(\!-\!)}}$} \rightarrow W^{+} W^{-} + X \rightarrow \ell^+_1 ν_1 \ell^-_2 \bar ν_2 + X$ to anomalous $WWV$ couplings by a factor two to five.