Study of the standard model Higgs boson partial widths and branching fractions

Abstract

The discovery of the Higgs boson, with a mass known to be better than the percent level, enables precision Higgs boson analyses for the first time. Toward this goal, we define an expansion formalism of the Higgs boson partial widths and branching fractions that facilitates such studies. This expansion yields the observables as a perturbative expansion around reference values of Standard Model input observables (quark masses, QCD coupling constant, etc.). We compute the coefficients of the expansion using state-of-the- art results. We also study the various sources of uncertainties in computing the partial widths and branching fractions more precisely. We discuss the impact of these results with efforts to discern new physics through precision Higgs boson studies.