Next-to-leading-order electroweak corrections to $pp \to W^+W^-\to$ 4 leptons at the LHC

TL;DR

This paper calculates the first next-to-leading-order electroweak corrections to W-boson pair production at the LHC, including leptonic decays and off-shell effects, crucial for accurate background modeling in Higgs studies.

Contribution

It provides a comprehensive calculation of electroweak corrections with full off-shell effects, comparing complex-mass scheme results to the double-pole approximation.

Findings

Small and intermediate scale distributions agree within fractions of a percent.

Differences in distributions grow to over 10% at TeV scales.

Off-shell effects are significant for precise background estimation.

Abstract

We present results of the first calculation of next-to-leading-order electroweak corrections to W-boson pair production at the LHC that fully takes into account leptonic W-boson decays and off-shell effects. Employing realistic event selections, we discuss the corrections in situations that are typical for the study of W-boson pairs as a signal process or of Higgs-boson decays $H\to W W^*$, to which W-boson pair production represents an irreducible background. In particular, we compare the full off-shell results, obtained treating the W-boson resonances in the complex-mass scheme, to previous results in the so-called double-pole approximation, which is based on an expansion of the loop amplitudes about the W resonance poles. At small and intermediate scales, i.e. in particular in angular and rapidity distributions, the two approaches show the expected agreement at the level of fractions of a percent, but larger differences appear in the TeV range. For transverse-momentum distributions, the differences can even exceed the 10% level in the TeV range where "background diagrams" with one instead of two resonant W bosons gain in importance because of recoil effects.