NLO QCD corrections to pp/ppbar --> WW+jet+X including leptonic W-boson decays

TL;DR

This paper calculates next-to-leading order QCD corrections for W-boson pair production with a jet at colliders, improving background predictions for Higgs and new physics searches by including leptonic decays and analyzing differential cross sections.

Contribution

It provides the first detailed NLO QCD correction calculations for pp/ppbar --> WW+jet including leptonic W decays, with a focus on differential distributions and scale stability.

Findings

QCD corrections stabilize total cross section predictions.

Scale dependence is reduced with a jet veto at the LHC.

Differential cross sections are distorted by NLO corrections.

Abstract

We report on the calculation of the next-to-leading order QCD corrections to the production of W-boson pairs in association with a hard jet at the Tevatron and the LHC, which is an important source of background for Higgs and new-physics searches. Leptonic decays of the W bosons are included by applying an improved version of the narrow-width approximation that treats the W bosons as on-shell particles, but keeps the information on the W spin. Contributions from external bottom quarks are neglected, because they are either numerically suppressed or should be attributed to different processes such as Wt or ttbar production. A survey of differential NLO QCD cross sections is provided both for the LHC and the Tevatron. The QCD corrections stabilize the leading-order prediction for the cross section with respect to scale variations. However, the scale dependence of the next-to-leading order results for the LHC is only reduced considerably if a veto against the emission of a second hard jet is applied. In general, the corrections do not simply rescale the differential leading-order cross sections. In particular, their shapes are distorted if an additional energy scale is involved.