Exclusive weak radiative Higgs decays in the standard model and beyond

Abstract

We perform a detailed study of the exclusive Higgs decays h → MZ and h → MW, where M is a pseudoscalar or vector meson, using the QCD factorization approach. We allow for the presence of new-physics effects in the form of modified Higgs couplings to gauge bosons and fermions, including the possibility of flavor-changing Higgs couplings. We show that the decays h → VZ exhibit a strong sensitivity to the effective CP-even and CP-odd hγZ couplings. When combined with a measurement of the h → γZ decay rate, this can be used to extract these couplings up to a sign ambiguity in the CP-odd coefficient. Some of the h → MW decay modes can be used to probe for flavor-violating Higgs couplings involving the top quark.