Higgs boson production in association with top quarks in the POWHEG BOX

TL;DR

This paper presents a next-to-leading order QCD calculation of Higgs boson production with top quarks, interfaced with parton-shower generators, including uncertainties and spin-correlation effects, now available in POWHEG BOX.

Contribution

It introduces a NLO QCD calculation for top+antitop+Higgs production in POWHEG BOX, incorporating spin correlations and comparing shower algorithms, with results relevant for LHC analyses.

Findings

Quantified theoretical uncertainties from scale choices and shower algorithms.

Demonstrated the significance of spin correlations in decay distributions.

Provided a publicly available code for improved simulation accuracy.

Abstract

We present results from the analytic calculation of top+antitop+Higgs hadronic production at Next-to-Leading Order in QCD interfaced with parton-shower Monte Carlo event generators in the POWHEG BOX framework. We consider kinematic distributions of the top quark and Higgs boson at the 8 TeV Large Hadron Collider and study the theoretical uncertainties due to specific choices of renormalization/factorization scales and parton-showering algorithms, namely PYTHIA and HERWIG. The importance of spin-correlations in the production and decay stages of a top/antitop quark is discussed on the example of kinematic distributions of leptons originating from the top/antitop decays. The corresponding code is now part of the public release of the POWHEG BOX.