Off-shell effects for t-channel and s-channel single-top production at NLO in QCD

TL;DR

This paper calculates off-shell effects in single-top production at NLO in QCD for Tevatron and LHC, showing small but sometimes significant deviations near kinematic edges.

Contribution

It extends previous calculations by including non-factorizable off-shell effects beyond the narrow-width approximation in single-top production.

Findings

Off-shell effects are generally small.

Significant near kinematic end-points.

Impacts specific distributions.

Abstract

In this work we present a calculation of both t-channel and s-channel single-top production at next-to-leading order in QCD for the Tevatron and for the LHC at a centre-of-mass energy of 7 TeV. All the cross sections and kinematical distributions presented include leading non-factorizable corrections arising from interferences of the production and decay subprocesses, extending previous results beyond the narrow-width approximation. The new off-shell effects are found to be generally small, but can be sizeable close to kinematical end-points and for specific distributions.