B1b: Precision top-quark physics at the LHC

The goal of the project is to provide state-of-the-art theoretical predictions for a broad class of processes that involve top quark pair production with an additional final state. We consider the process pp → tt + X, where X=H,W, Z, photon, jet, di-photon, bb, tt, di-jet. Depending on the final state, results for the LHC with higher order corrections at unprecedented level will be provided in the form of flexible Monte Carlo programs that can be used to generate any infrared safe observable. Specifically, the precision will be increased in two directions: either through the inclusion of full off-shell effects at NLO QCD + NLO electroweak for top-quark pair production in association with additional final state particles, or through the calculation of NNLO QCD corrections for pp → tt + X, where X is the Higgs boson or a weak boson.

(a) Full NLO QCD including off-shell effects: state of the art theoretical predictions for $ pp \to t \bar t + X$ ($X=H,\gamma, Z, W^\pm, \gamma\gamma,jj, b\bar{b}, t\bar{t}$), both in the dilepton and lepton-plus-jet decay channel; calculation of electroweak corrections to $t \bar t + X$, matching to parton shower.
(b) NNLO QCD predictions (total and differential) for $pp \to t \bar t H$, decays in the narrow width approximation; very precise $y_t$ extraction; differential NNLO predictions for $pp \to t \bar t \gamma, t \bar t Z, t \bar t W^\pm$.