Measuring hadronic Higgs boson branching ratios at future lepton colliders

Abstract

Abstract We present a novel strategy for the simultaneous measurement of Higgs-boson branching ratios into gluons and light quarks at a future lepton collider operating in the Higgs-factory mode. Our method is based on template fits to global event-shape observables, and in particular fractional energy correlations, thereby exploiting differences in the QCD radiation patterns of quarks and gluons. In a constrained fit of the deviations of the light-flavour hadronic Higgs-boson branching ratios from their Standard Model expectations, based on an integrated luminosity of $$5\,\text {ab}^{-1}$$ 5 ab - 1 , we obtain $$68\%$$ 68 % confidence level limits of $$\mu _{gg}=1 \pm 0.05$$ μ gg = 1 ± 0.05 and $$\mu _{q\bar{q}}<21$$ μ q q ¯ < 21 .