Production and decay of the Higgs boson in association with top quarks

TL;DR

This paper presents a detailed calculation of next-to-leading order QCD corrections for Higgs boson production with top quarks at the LHC, including off-shell effects, various decay channels, and theoretical uncertainties.

Contribution

It provides the first comprehensive NLO QCD analysis of Higgs production with top quarks, incorporating off-shell effects, multiple decay modes, and PDF uncertainties.

Findings

NLO QCD corrections significantly affect cross sections and distributions.

Off-shell effects are comparable to narrow-width approximation in certain kinematic regions.

The impact of bottom-quark PDFs on the results is quantified.

Abstract

We report on the calculation of the next-lo-leading order QCD corrections to Higgs boson production and decay in association with top quarks. We consider leptonic decays of top quarks leading to the hadronic process $pp\to e^+\nu_e\, \mu^-\bar{\nu}_\mu \, b\bar{b}\,H\, (H\to X)$ at the LHC with $\sqrt{s}=13$ TeV. All resonant as well as non-resonant Feynman diagrams, interferences and off-shell effects are included for the top quark and $W$ gauge boson. Decays of the Higgs boson, on the other hand, are included in the narrow-width-approximation. Specifically, we consider Higgs boson decays into $b\bar{b}$, $\tau^+\tau^-$, $\gamma\gamma$ and $e^+e^-e^+e^-$. Numerical results are given at the integrated and differential fiducial level for various factorisation and renormalisation scale choices and different PDF sets. We study the main theoretical uncertainties that are associated with neglected higher order terms in the perturbative expansion and with different parametrisations of the PDFs. Furthermore, we examine the size of the off-shell effects by an explicit comparison to the calculation in the full narrow-width-approximation. Finally, the impact of the contributions induced by the bottom-quark parton density is investigated.