Top Quark Pair Production in Association with a Jet with NLO QCD Off-Shell Effects at the Large Hadron Collider

TL;DR

This paper provides the first fully realistic NLO QCD calculation of top quark pair production with an associated jet at the LHC, including off-shell effects and non-resonant diagrams, improving accuracy of theoretical predictions.

Contribution

It introduces the first comprehensive NLO QCD computation for top quark pair production with a jet, incorporating off-shell and non-resonant effects for realistic collider predictions.

Findings

NLO predictions reduce scale dependence by over 3 times.

Total cross section decreases by about 13% at NLO compared to LO.

Off-shell effects are estimated to be below 2%.

Abstract

We present a complete description of top quark pair production in association with a jet in the dilepton channel. Our calculation is accurate to next-to-leading order in QCD (NLO) and includes all non-resonant diagrams, interferences and off-shell effects of the top quark. Moreover, non-resonant and off-shell effects due to the finite W gauge boson width are taken into account. This calculation constitutes the first fully realistic NLO computation for top quark pair production with a final state jet in hadronic collisions. Numerical results for differential distributions as well as total cross sections are presented for the Large Hadron Collider (LHC) at 8 TeV. With our inclusive cuts, NLO predictions reduce the unphysical scale dependence by more than a factor of 3 and lower the total rate by about 13% compared to leading order QCD (LO) predictions. In addition, the size of the top quark off-shell effects is estimated to be below 2%.