Resummed predictions for hadronic Higgs boson decays

TL;DR

This paper develops a high-precision theoretical prediction for the distribution of a specific jet-related observable in Higgs boson decays, combining resummation and fixed-order calculations for improved accuracy.

Contribution

It introduces a NNLL' resummed calculation for the 2-jettiness distribution in Higgs decays, matched with NNLO fixed-order results, using Soft-Collinear Effective Theory and GENEVA framework.

Findings

Provides a fully exclusive NNLO event generator matched to PYTHIA8.

Extends the validity of predictions across all resolution variable values.

Achieves high-precision predictions for Higgs decay observables.

Abstract

We present the NNLL$'$ resummed $2$-jettiness distribution for decays of the Standard Model Higgs boson to a $b\bar{b}$-quark pair and to gluons. The calculation exploits a factorisation formula derived using Soft-Collinear Effective Theory, in which large logarithms of the $2$-jettiness are resummed by renormalisation group evolution of the hard, soft and jet contributions to the differential decay rate. We match the resummed predictions to the fixed-order NNLO result using the GENEVA framework, extending the validity of the results to all values of the resolution variable and providing a fully exclusive NNLO event generator matched to the PYTHIA8 parton shower.