Exclusive B→Vγ Decays in the T2HDM 

Author  ChengZuoZuo 
Tutor  XiaoZhenJun 
School  Nanjing Normal University 
Course  Theoretical Physics 
Keywords  QCD factorization approach B mesons radiative decays Topquark twoHiggsdoublet model(T2HDM) Branching ratio New physics corrections 
CLC  O571.32 
Type  Master's thesis 
Year  2006 
Downloads  31 
Quotes  0 
In the framework of the standard model(SM) and the topquark twoHiggsdoublet model(T2HDM),we made a systematic study of the exclusive radiative decays B → V_γ,and found some interesting results.In first two chapters, we made a review of the theoretical framework of B physics in the SM and T2HDM’s. We presented the extraction of Wilson coefficients, the evolvement of the renormalization group, and current experimental measurements of CP violation of B meson system. We listed the basic formulas needed in calculation and made a brief discussion of the current and near future B meson experiments. We also gave a brief description of the popular methods of calculating the hadron matrix elements, and discussed the QCD factorization in details.In chapter 3, we describe briefly the basic structures of the topquark twoHiggsdoublet model, give a brief review about the calculation of B → V_γ(V = K*,ρ) at NLO in QCD factorization in the SM and present the needed analytical formulas for the calculation of Wilson coefficients and physical observables.In chapter 4, in the framework of SM and T2HDM, we calculated the new physics corrections on the branching ratios, CP asymmetries,isospin and Uspin symmetry breaking of the decays B →V_γ(V = K*,ρ), induced by the charged Higgs penguins in the T2HDM, compared the theoretical predictions with those currently available experimental measurements. We found that: The new physics corrections to the physical observables under consideration in this paper are generally small in the T2HDM’s. And therefore the theoretical predictions in the SM and T2HDM are always in good agreement with the corresponding data. In T2HDM, when tanβ = 50, the ranges of M_H ≥ 613GeV are still allowed by the measured B(B → K*γ). From the experimental upper bounds on B(B → ργ), we find the lower limit M_H ≥ 412GeV, when the 3a theoretical errors are also taken into