Hadronic decays of Higgs boson at NNLO matched with parton shower

TL;DR

This paper provides advanced predictions for Higgs boson hadronic decays at NNLO in QCD, matched with parton shower, enhancing accuracy in modeling decay processes for future collider experiments.

Contribution

It introduces a novel NNLO+PS framework for Higgs decays, including full bottom-quark mass dependence and improved accuracy in decay simulations.

Findings

Accurate decay predictions at NNLO matched with parton shower.

Quantified perturbative uncertainties in decay modeling.

Highlighted areas for future improvements in theoretical calculations.

Abstract

We present predictions for hadronic decays of the Higgs boson at next-to-next-to-leading order (NNLO) in QCD matched with parton shower based on the POWHEG framework. Those include decays into bottom quarks with full bottom-quark mass dependence, light quarks, and gluons in the heavy top quark effective theory. Our calculations describe exclusive decays of the Higgs boson with leading logarithmic accuracy in the Sudakov region and next-to-leading order (NLO) accuracy matched with parton shower in the three-jet region, with normalizations fixed to the partial width at NNLO. We estimated remaining perturbative uncertainties taking typical event shape variables as an example and demonstrated the need of future improvements on both parton shower and matrix element calculations. The calculations can be used immediately in evaluations of the physics performances of detector designs for future Higgs factories.