Higgs boson decay into photons at four loops

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.

Notes on interplay of the QCD and EW perturbative corrections to the pole-running top-quark mass ratio

“…The similar situation may be revealed for the decay width of the Higgs boson in two photons from the results of Ref. [36], where the four-loop QCD correction was first computed and the twoloop EW one was presented (see original works [37,38], where this EW term was calculated). As follows from these manuscripts, the two-loop EW contribution is very close in magnitude to the two-loop QCD one (and it is significantly larger than the three-and four-loop QCD corrections) and has the opposite sign to it.…”