Radiative Corrections to the Higgs Boson Decay into a Longitudinal W-Boson Pair in a Two-Doublet Model

The decay rate of a (neutral) Higgs boson ($H$) going into a longitudinal $W$-boson pair is calculated by including one loop radiative corrections in a two-Higgs doublet model. It is assumed that the Higgs boson $H$ is much heavier than the $W$ boson and a full use has been made of the equivalence theorem. A possibility is explored extensively that the precise measurement of the decay rate of $H$ could be useful as a probe of the other neutral as well as charged Higgs bosons through potentially important radiative corrections. It is pointed out that, for some choice of the parameters, the radiative corrections are sizable and that there exist a possibility of extracting useful information on the other Higgs boson masses.