Branching Ratio And CP Asymmetry Of B�'K～*K(η～(′)) Decays In The Perturbative QCD Approach

CP violation in B meson system, test of the standard model exactly and searching for evidence of new physics are three important goals both in theoretical and experimental particle physics. In the experiment side, the B factories in America and Japan have been running since 1999, lots of important experiment data are given: for example, CP violation in neutral B meson, branching ratios of B→ππ,πk et al. Especially the Large Hadron Collider(LHC-b) will put into run at the end of this year, the branching ratio of order 10^-6 will be detected with good statistics in the coming ten years. Now is the golden ages of heavy flavor. In the theory side, because of the complex of many scales and degrees of freedom in studying B decays, there exists many difficulties, particularly in the calculation of hadronic matrix elements. We have to use the phenomenological models. The commonly used methods include simply factorization, QCD factorization(QCDF) and perturbative QCD(pQCD).In this paper, we study some nonleptonic decay modes of B mesons in pQCD approach, which is based on k_T factorization, and get some significative results. We firstly give a review of low energy effective Hamiltonian and various approaches for dealing with hadronic matrix elements, especially the pQCD approach, discuss the CP violation in B systems. and then, we evaluate the B→K*K and K*η^(') decays and compare our results with other model predictions and experiment data, the possible resource of error is discussed. At last, a prospect for pQCD approach is given. Our main results are as following:The branching ratios of decay B→K*K are well below experimental upper limits, and some of our results are larger than QCDF predictions. For the decay B→K*η^(') the pQCD predictions are consistent with QCDF ones, but less than the experimental measurement for the decays involvingη' final state.Our prediction of CP violation in B→K*K decay agree with QCDF ones within standard errors and the results for decay B→K*η^(') are small.There exist large uncertainties mainly coming from form parameter of B meson and the weak angels. The branching ratios are small and sensitive to new physics, therefore can be used to test standard model exactly and signal new physics.Non-leptonic B decays is an important topic in particle physics, any breakthrough in theory may attract much attention. We are waiting for more progresses.