Associated production of a top pair and a Higgs boson beyond NLO

Abstract

We consider soft gluon emission corrections to the production of a top-antitop pair in association with a Higgs boson at hadron colliders. In particular, we present a softgluon resummation formula for this production process and gather all elements needed to evaluate it at next-to-next-to-leading logarithmic order. We employ these results to obtain approximate next-to-next-to-leading order (NNLO) formulas, and implement them in a bespoke parton-level Monte Carlo program which can be used to calculate the total cross section along with arbitrary differential distributions. We use this tool to study the phenomenological impact of the approximate NNLO corrections, finding that they increase the total cross section and the differential distributions which we evaluated in this work.

Soft gluon resummation for associated t t ¯ H $$ \mathrm{t}\overline{\mathrm{t}}\mathrm{H} $$ production at the LHC

“…After the arXiv publication of this paper, ref. [58] appeared. The results of [58] seem to support our conclusion regarding the importance of the corrections from beyond the absolute threshold region.…”

The next-to-next-to-leading order soft function for top quark pair production

“…This is relevant to the production processes of top quark pairs associated with a Higgs boson or an electroweak gauge boson. At the NLO, the general result of [33] can be utilized, and has been successfully applied to ttH production in [63,64], to ttW production in [91,92], and to ttZ production in [93]. It remains open whether a similar general result can be derived at the NNLO, which we leave for future work.…”

“…In fact, since the NLO soft function involves 2-parton correlations at most, the same calculation can be applied to scattering processes with more than two colored particles in the final state. This has been done, e.g., for the case of ttH production in [63,64], and can be extended to more complicated processes such the simultaneous production of two tt pairs. In order to calculate the NNLO soft…”

“…While the formalism can be applied to any reference frame, in the following, we will work in the center-of-mass frame of the two incoming partons, which are not only good for demonstration purposes, and are also adopted in many existing calculations. For example, this corresponds to the PIM kinematics in [33,59,60] for tt production, in [61,62] for stop pair production, and in [63,64] for ttH production. Schematically, we are considering partonic processes of the form…”

Theory overview for ttH and tH production

“…1 The current status of theoretical predictions for ttH is quite satisfactory: next-to-leading-order (NLO) predictions in QCD are known since some time [7][8][9][10], and have been matched to parton-shower [11][12][13]. The computation of weak and electroweak (EW) corrections is instead more recent [14][15][16] as well as predictions including the effects of soft-gluon resummation [17,18]. An impressive result, given its computational complexity, is the recent calculation of NLO QCD corrections to the process pp → Hbbe + µ − νν including both resonant and non resonant contributions [19].…”