Higgs boson decay into photons at four loops

TL;DR

This paper presents four-loop QCD corrections to the Higgs boson decay into two photons, enhancing theoretical precision to match upcoming experimental accuracy at the one percent level.

Contribution

It provides the first four-loop QCD corrections to the Higgs to photon form factor and incorporates gluon emission effects at NNLO, improving decay width predictions.

Findings

Four-loop QCD corrections computed in large top mass expansion.

First NNLO contributions from gluon emission included.

Residual uncertainties from higher orders estimated.

Abstract

Future precision measurements of Higgs boson decays will determine the branching fraction for the decay into two photons with a precision at the one percent level. To fully exploit such measurements, equally precise theoretical predictions need to be available. To this end we compute four-loop QCD corrections in the large top quark mass expansion to the Higgs boson--photon form factor, which enter the two-photon decay width at next-to-next-to-next-to-leading order. Furthermore we obtain corrections to the two-photon decay width stemming from the emission of additional gluons, which contribute for the first time at next-to-next-to-leading order. Finally, we combine our results with other available perturbative corrections and estimate the residual uncertainty due to missing higher-order contributions.