t(t)over-barH production at NNLO: the flavour off-diagonal channels

We consider QCD radiative corrections to the associated production of a heavy-quark pair (QQ (Q) over barF) with a generic colourless system F at hadron colliders. We discuss the resummation formalism for the production of the Q (Q) over barF system at small values of its total transverse momentum q(T). We present the results of the corresponding resummation coefficients at next-to-leading and, partly, next-to-next-to-leading order. The perturbative expansion of the resummation formula leads to the explicit ingredients that can be used to apply the q(T) subtraction formalism to fixed-order calculations for this class of processes. We use the q(T) subtraction formalism to perform a fully differential perturbative computation for the production of a top-antitop quark pair and a Higgs boson. At next-to-leading order we compare our results with those obtained with established subtraction methods and we find complete agreement. We present, for the first time, the results for the flavour off-diagonal partonic channels at the next-to-next-to-leading order.

Automated summary

In this study, we investigate the QCD radiative corrections for the associated production of a heavy-quark pair with a generic colorless system at hadron colliders. The resummation formalism for the production of the heavy-quark pair system at small values of its total transverse momentum is discussed, and the results of the corresponding resummation coefficients at next-to-leading and next-to-next-to-leading order are presented. The perturbative expansion of the resummation formula provides explicit ingredients for applying the q(T) subtraction formalism to fixed-order calculations, and a fully differential perturbative computation is performed for top-antitop quark pair and Higgs boson production, showing agreement with established subtraction methods. Also, results for the flavor off-diagonal partonic channels at the next-to-next-to-leading order are presented for the first time.