$W^+W^-$ production at the LHC: fiducial cross sections and distributions in NNLO QCD

TL;DR

This paper provides the first fully differential NNLO QCD predictions for $W^+W^-$ production at the LHC, including leptonic decays, spin correlations, and off-shell effects, aiding precision measurements and new physics searches.

Contribution

It introduces the first fully differential NNLO QCD calculations for $W^+W^-$ production, incorporating leptonic decays, spin correlations, and off-shell effects at the LHC.

Findings

Large NNLO corrections to inclusive $W^+W^-$ cross section.

Fiducial cuts significantly affect perturbative behavior.

Differential NNLO predictions are crucial for LHC physics analyses.

Abstract

We consider QCD radiative corrections to $W^+W^-$ production at the LHC and present the first fully differential predictions for this process at next-to-next-to-leading order (NNLO) in perturbation theory. Our computation consistently includes the leptonic decays of the $W$ bosons, taking into account spin correlations, off-shell effects and non-resonant contributions. Detailed predictions are presented for the different-flavour channel $pp\to\mu^+e^-\nu_\mu {\bar \nu}_e+X$ at $\sqrt{s}=8$ and $13$ TeV. In particular, we discuss fiducial cross sections and distributions in the presence of standard selection cuts used in experimental $W^+W^-$ and $H\to W^+W^-$ analyses at the LHC. The inclusive $W^+W^-$ cross section receives large NNLO corrections, and, due to the presence of a jet veto, typical fiducial cuts have a sizeable influence on the behaviour of the perturbative expansion. The availability of differential NNLO predictions, both for inclusive and fiducial observables, will play an important role in the rich physics programme that is based on precision studies of $W^+W^-$ signatures at the LHC.