Decays of Higgs Boson into Pseudoscalar Meson Pair of Different Flavours

Abstract

The flavour-changing quark-Higgs coupling does not arise at the tree level in the Standard Model. It is, however, induced by one-loop effects. In this paper, we present an exact calculation of the Higgs-penguin vertex in the tHooft-Feynman gauge. Renormalization of the vertex is effected by a prescription by Chia and Chong which gives an expression for the counter term identical to that obtained by employing Ward-Takahashi identity. The on-shell vertex function for the Higgs-penguin vertex is obtained, and its dependence on Higgs mass is investigated. Our calculation is applied to the following process: decays of Higgs boson into pseudoscalar meson pair of different flavours: Kpi and BK. The coupling of pseudoscalar meson to quark is effected through a gamma5 coupling. The decay rates are found to be very small.