Top Quark Pair Production in Association with a Jet with Next-to-Leading-Order QCD Off-Shell Effects at the Large Hadron Collider

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 (NLO) in QCD and includes all nonresonant diagrams, interferences, and off-shell effects of the top quark. Moreover, nonresonant 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 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 predictions. In addition, the size of the top quark off-shell effects is estimated to be below 2%.

NNLO QCD predictions for fully-differential top-quark pair production at the Tevatron

“…We should also mention the most recent calculations of this type, where off-shell effects could even be included in associated production [26,27]. As far as NNLO corrections are concerned, it should be possible to work in the Narrow Width Approximation as done at NLO in [28][29][30][31].…”

Top quark pair production in association with a jet with NLO QCD off-shell effects

“…Recently, also the approximation of on-shell top-quark decays has been dropped and the calculation of the full process pp → e + ν e µ −ν µ bb j + X has been presented in Ref. [30]. Representative Feynman diagrams for the leading-order production at O(α 3 s α 4 ) are shown in Fig.…”

NLO QCD predictions for off-shell t t ¯ $$ t\overline{t} $$ and t t ¯ H $$ t\overline{t}H $$ production and decay at a linear collider

“…[36]. For hadron colliders, corresponding NLO QCD corrections to top-quark pair production in association with a Higgs boson [37] or a jet [38,39] including leptonic decays have also been studied.…”