B → K * γ Decay in Top-Quark Two-Higgs-Doublet Model

By employing the QCD factorization approach for the exclusive B→Vγ decays, we study the exclusive decay B→K*γ in the top-quark two-Higgs-doublet model (T2HDM). Within the considered parameter space, we find the following conclusions (a) A light charged-Higgs boson with a mass about 200 GeV is clearly excluded by the date of B→K*γ decay, and this lower limit is comparable with that from the inclusive B→Xsγ decay; (b) The theoretical predictions for CP asymmetry of B→K*γ in the T2HDM is always less than 1% in size; and (c) The isospin symmetry breaking for B→K*γ decay in the SM and T2HDM considered here is around 6% in size and well consistent with the data and the general expectations.