Role of low-energy observables in precision Higgs boson analyses

A conventional approach to precision calculations of Higgs boson observables uses quark masses m(c) and m(b) as inputs. However, quark masses are single numbers that hide a variety of low-energy data from which they are extracted, and also hide the various sources of theoretical uncertainties and correlations with additional input parameters such as as alpha(s). Higher-precision calculations, which are needed to give meaning to future measurements, require more direct engagement with the low-energy data in a global analysis. We present an initial calculation in this direction, which illustrates the procedure and reveals some of the theory uncertainties that challenge subpercent determinations of Higgs boson partial widths.