{t {{bar{t}}}H} production at NNLO: the flavour off-diagonal channels

Stefano Catani,Stefan Kallweit,Ignacio Fabre,Massimiliano Grazzini

doi:10.1140/epjc/s10052-021-09247-w

Abstract

We consider QCD radiative corrections to the associated production of a heavy-quark pair (Q{{bar{Q}}}) with a generic colourless system F at hadron colliders. We discuss the resummation formalism for the production of the Q{{bar{Q}}}F 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.

Highlights

The observation of Higgs boson production in association with a top quark–antiquark pair was reported by the ATLAS and CMS collaborations in 2018 [1,2]
In this paper we have considered the associated production of the SM Higgs boson with a top-quark pair, and, more generally, processes in which heavy-quark pairs are produced in association with a colourless final-state system F
We have implemented for the first time the qT subtraction formalism for ttH production, and we have presented first quantitative results at next-to-leading order (NLO) and next-to-next-to-leading order (NNLO)

Summary

Introduction

The observation of Higgs boson production in association with a top quark–antiquark (tt) pair was reported by the ATLAS and CMS collaborations in 2018 [1,2]. We present the explicit results of the resummation coefficients at NLO and, partly, NNLO for the process of associated production of an arbitrary number of heavy quark-antiquark pairs and a generic colourless system F [43].

Results

Conclusion