$W^+W^-$ production at hadron colliders in NNLO QCD

TL;DR

This paper provides the first NNLO QCD predictions for on-shell $W^+W^-$ production at hadron colliders, improving theoretical precision and addressing top-quark resonance contamination.

Contribution

It introduces next-to-next-to-leading order QCD calculations for $W^+W^-$ production, including analysis of top-quark resonance separation methods.

Findings

Inclusive $W^+W^-$ cross section increases by 9% at 7 TeV and 12% at 14 TeV.

Residual perturbative uncertainty is reduced to about 3%.

Top-quark resonance contamination can be effectively separated without losing precision.

Abstract

Charged gauge boson pair production at the Large Hadron Collider allows detailed probes of the fundamental structure of electroweak interactions. We present precise theoretical predictions for on-shell $W^+W^-$ production that include, for the first time, QCD effects up to next-to-next-to-leading order in perturbation theory. As compared to next-to-leading order, the inclusive $W^+W^-$ cross section is enhanced by 9% at 7 TeV and 12% at 14 TeV. The residual perturbative uncertainty is at the 3% level. The severe contamination of the $W^+W^-$ cross section due to top-quark resonances is discussed in detail. Comparing different definitions of top-free $W^+W^-$ production in the four and five flavour number schemes, we demonstrate that top-quark resonances can be separated from the inclusive $W^+W^-$ cross section without significant loss of theoretical precision.