Phenomenological Studies Of Weak Decays Of Several B-flavored Mesons

With the in-depth development of the International Large Hadron Collider LHC and the SuperKEKb/Belle-? experiment of the Super-b factory,integrated luminosity has been greatly improved,many flavor-b meson decays that have not been measured before will be observed,which will push the research on b-physics to a new peak.The nonleptonic two-body flavor-b meson decays are important in testing the standard model,processing the calculation methods of hadron matrix elements(QCD factorization,perturbative QCD et al.),finding anomalies,and exploring the indirect signals of new physics in it.As more decay modes are detected experimentally,it will provide us with a richer decay process,and at the same time put more stringent requirements on the accuracy of the theoretical prediction of flavor-b meson.In this paper,the decays of Bu,d,s*?Du,d,s*V,?(nS)?BcV(n=1,2,3)and Bu,d,s?SM(M=P,V,S,T)will be systematically studied.Firstly,this article studies the decays of Bu,d,s*?Du,d,s*V within the naive factorization.The similar process of B meson,for example,the decays of Bd,s*?Dd,s*V and Bd,s*?Dd,sV have only 3 helicity amplitudes,however,the initial and final states of Bq*?Dq*V decays are all vector mesons,such decays have 7 helicity amplitudes in total.Through the analysis of the helicity states corresponding to these 7 helicity amplitudes,it is found that there is a very clear hierarchical structure for the 7 helicity amplitudes,this relationship is confirmed by the numerical calculation of the branching fractions and helicity fractions.Then,the decays of ?(nS)?BcV(n=1,2,3)and Bu,d,s?SM(M=P.V.S,T)are studied within the QCD factorization.The QCD corrections to the transverse amplitudes of ?(nS)?Bc?and BcK*(n=1,2,3)decays are first evaluated at next-to-leading order.Compared with the longitudinal polarization amplitude,the transverse corrections of ?(nS)?BcV(n=1,2,3)decay is much smaller,but the power-suppressed transverse corrections account about 10%that cannot be ignored.Finally,the decays of Bs0?K0*(1430)+K-+c.c.and Bs0?K0*(1430)0K0+c.c.are observed by the LHCb collaboration,which is the first international observation of the decays of Bs meson to a scalar particle.In addition,there are also abundant experimental data on the decays of Bu,Bd to scalar particle.Therefore,we further studied the nonleptonic two-body decays of B?SM.Taking B?SP,SV as examples,the theoretical prediction of Bu,d,s?K0*(1430)P/V(P=K,?;V=K*,?,?,?)decays are given.The accurate calculation and phenomenological analysis of the decay of B?SM can not only help to study the properties of scalar particles(S),but also have important scientific significance in searching for possible abnormal phenomena and indirect signal of new physics in the decays of B?SM.