Higgs production in association with a top-antitop pair in the Standard Model Effective Field Theory at NLO in QCD

TL;DR

This paper computes NLO QCD corrections for Higgs production with a top-antitop pair within the Standard Model Effective Field Theory, analyzing the impact of three dimension-six operators on cross sections, decay rates, and constraints at the LHC.

Contribution

It provides the first detailed NLO QCD analysis of Higgs-top interactions with three key EFT operators, including their effects on various production and decay processes.

Findings

NLO corrections significantly improve prediction accuracy.

Operators modify Higgs production and decay rates.

Results enable better constraints on EFT operators at the LHC.

Abstract

We present the results of the computation of the next-to-leading order QCD corrections to the production cross section of a Higgs boson in association with a top-antitop pair at the LHC, including the three relevant dimension-six operators ($O_{t \varphi }, O_{\varphi G}, O_{tG}$) of the standard model effective field theory. These operators also contribute to the production of Higgs bosons in loop-induced processes at the LHC, such as inclusive Higgs, $Hj$ and $HH$ production, and modify the Higgs decay branching ratios for which we also provide predictions. We perform a detailed study of the cross sections and their uncertainties at the total as well as differential level and of the structure of the effective field theory at NLO including renormalisation group effects. Finally, we show how the combination of information coming from measurements of these production processes will allow to constrain the three operators at the current and future LHC runs. Our results lead to a significant improvement of the accuracy and precision of the deviations expected from higher-dimensional operators in the SM in both the top-quark and the Higgs-boson sectors and provide a necessary ingredient for performing a global EFT fit to the LHC data at NLO accuracy.