Charmless B_sâ†'VV Decays In The Two-Higgs-doublet Model

The study of nonleptonic charmless decays of B mesons offers not only great oppor-tunities to test the standard model but also powerful means to seek new physics beyond the standard model.There has been remarkable progress in the study of nonleptonic charm-less B decays in recent years,both experimentally and theoretically.On the experimental aspect,many nonleptonic charmless B decays have been oberserved.In the near future,more B decay channels will be measured with great precision.On the theoretical aspect,scientists have proposed many methods in the calculations of the nonfactorizable effects of the hadronic matrix elements,such as the QCD factorization approach.the perturbative QCD approach etc.In this paper.we use QCD factorization approach to analyze the nonleptonic charmless decays of Bs to two light vector mesons in the framework of the standard model and the two-Higgs-doublet model.Starting from the framework of the standard model and the two-Higgs-doublet model,we focus on the study of the new physics contributions to the Wilson coefficients first.And then,we outline the necessary theoretical points of the QCD factorization approach for calculating the decay amplitudes and the braching ratios of the charmless Bsâ†'VV de-cays. According to the input parameters, we calculate the braching ratios at different scales in both models.The main conclusions are as follows:(1)The new physics contributions are significant to Wilson coefficients C7(?). C8g,in other words,they are significant to penguin dominated decay modes.(2)For the decay modes dominated by external W emission,the new physics corrections are very small in size:δB<3%.(3)For color-suppressed tree-dominated decays modes,the new physics corrections can not be ignored,up to20%.(4)For penguin dominated decay modes.the new physics corrections are large in size:δB>50%.(5)For the decay modes dominated by color-suppressed internal W emission and penguin diagrams are very small in size:δB<1%.(6)In the two-Higgs-doublet model(â…¢),the braching ratios of nine nonleptonic charmless decays of Bs mesons are sensitive to the variations of the mass MH+.They all decrease with the increase of MH+and approach the results in the standard model.