Exclusive $B\to (K^{\ast },\rho )\gamma$ decays in the general two-Higgs-doublet models

By employing the QCD factorization approach, we calculated the next-to-leading order new physics contributions to the branching ratios, CP asymmetries, isospin and U-spin symmetry breaking of the exclusive decays $B \to V \gamma$($V=K^, \rho$), induced by the charged Higgs penguins in the general two-Higgs-doublet models. Within the considered parameter space, we found that (a) the new physics corrections to the observables are generally small in the model I and model III-A, moderate in model II, but large in model III-B; (b) from the well measured branching ratios and upper limits, a lower bound of $\text{mhp}>200$ GeV in model II was obtained, while the allowed range of $\text{mhp}$ in model III-B is $226\le \text{mhp}\le 293$ GeV; these bounds are comparable with those from the inclusive $B\to X_s\gamma$ decay; ©the NLO Wilson coefficient $C_7(m_b)$ in model III-B is positive and disfavered by the measured value of isospin symmetry breaking $\Delta_{0-}^{exp} (K^\gamma) = (3.9 \pm 4.8)%$, but still can not be excluded if we take the large errors into account; (d) the CP asymmetry $\text{acp}(B\to \rho \gamma )$ in model III-B has an opposite sign with the one in the standard model (SM), which may be used as a good observable to distinguish the SM from model III-B; (e) the isospin symmetry breaking $\mathrm{\Delta }(\rho \gamma )$ is less than 10% in the region of $\gamma =[40\sim 70{]}^{\circ }$ preferred by the global fit result, but can be as large as 20 to 40% in the regions of $\gamma \le {10}^{\circ }$ and $\gamma \geq 120^\circ$\mathrm{.}TheSMandmodelIII-Bpredictionsfor$\Delta(\rho \gamma)$ are opposite in sign for small or large values of the CKM angles; (f) the U-spin symmetry breaking $\mathrm{\Delta }U(K^{\ast },\rho )$ in the SM and the general two-Higgs-doublet models is generally small in size: $\sim {10}^{-7}$.