NLO QCD corrections to off-shell top-antitop production with leptonic decays in association with a Higgs boson at the LHC

TL;DR

This paper presents a detailed NLO QCD calculation of off-shell top-antitop production with a Higgs boson at the LHC, including decay, off-shell effects, and interferences, providing improved theoretical predictions.

Contribution

It provides the first full NLO QCD computation of off-shell top-antitop-Higgs production with decay, including all non-resonant and interference effects at the LHC.

Findings

Dynamical scale improves perturbative stability in high-energy tails.

Integrated cross section differs by only about 1% between fixed and dynamical scales.

K factor for the process is approximately 1.17.

Abstract

We compute the hadronic production of top-antitop pairs in association with a Higgs boson at next-to-leading-order QCD, including the decay of the top and antitop quark into bottom quarks and leptons. Our computation is based on full leading and next-to-leading-order matrix elements for $e^+ \nu_e \mu^-\bar{\nu}_\mu b \bar{b} H(j)$ and includes all non-resonant contributions, off-shell effects and interferences. Numerical results for the integrated cross section and several differential distributions are given for the LHC operating at 13 TeV using a fixed and a dynamical factorization and renormalization scale. The use of the dynamical instead of the fixed scale improves the perturbative stability in high-energy tails of most distributions, while the integrated cross section is hardly affected differing by only about one per cent and leading to the same K factor of 1.17.