Phenomenological Study Of The ?(1s)?B_cP,B_cV Decays

In recent years,in order to further examine the standard model and explore new physics beyond the model,more researchers are applied themselves to the study of b physics.The??1S?particle is abb bound state,and large amount of??1S?events have been accumulated at Belle.With the running of high-luminosity dedicated heavy-flavor factories,more and more??nS?events will be collected at the large hadron collider LHC and SuperKEKB,which provide a good opportunity for the study of heavy-flavor quarkonium.In this paper,we phenomenologically study the two-body nonleptonic weak decay of??1S?meson.Firstly,we introduce the standard model and CKM matrix.And then we expound the basic theory of studying B meson decay,including the effective Hamiltonian and Wilson coefficient,and several calculation methods of hadronic matrix elements,especially,the perturbative QCD factorization approach.Finally,we present our works,including the following two parts:?1?We present the phenomenological study of??1S??B_c P?P=?,K?decay with the pQCD approach.We calculate the decay amplitudes and then provide the decay branching ratio.It is found that Br???1S??B_c??>Br???1S??B_cK?.Branching ratio for the??1S??B_c?decay can reach up to10^-11,and the??1S??B_c?decay should be sought for and observed at the LHC.The uncertainties in the calculation come from the CKM parameters,the selection of renormalization scalem,masses of b and c quarks,and hadronic parameters.?2?We present the phenomenological study of??1S??B_c?decay with the p QCD approach.We calculate the decay amplitudes about this process.It is found that the branching ratio for the??1S??B_c?decay can reach up to10^-9,and the contributions to branching ratio mainly come from the longitudinal polarization.This process might be measurable at the LHC and SuperKEKB.