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

Up to now, the B fatories at KEK and SLAC have collected about 800 million events of B — B|- pair production. Based on so large amount of data we are not only able to probe the origin of CP violation, but to explore rich QCD dynamics involved in exclusive B meson decays. B decays provide a good place to study the fruitful dynamics of QCD, to test the Standard Model, to investigate the CP violation, to search for the signal or evidence of new physics beyond the standard model. Because the large theoretical uncertainties cannot compete with the more precise experimental data, we come to one stage that experiment goes ahead of theory. The theory in B physics have to meet great challenge from the experiment. The problem of exclusive B decays lies in a very large number of degrees of freedom and too many scales. One of the most difficulties is the calculation of hardronic matrix elements. There are many methods in dealing with this problem, such as naive factorization, generalized factorization, QCD (BBNS) factorization approach, perturbative QCD (pQCD) factorization approach.In this paper,we study two-body charmless hardronic B meson decays by employing the perturbative QCD approach based on k_T factorization. First of all, we introduce the effective theory and four-quark operators of related mesons, and then present them a brief view about the factorization approach,the pQCD. Using Sudakov suppression factor and wave function, we can predict the decay widths and branching ratios of those decay models under consideration. At last, we calculate B → πη^(′)} decays, show numerical results about their branching ratios and CP-violating asymmetries of those four B → πη^(′) decays. The effects of the major uncertainties are also taken into cinsideration. These rare decays are good place to search for the signal of new physics. Many decay we calculated have small branching ratios, which may be sensitive to new physics.Studying the non-leptonic decay of B meson is an important task in particle physics, and any breakthrough in theory may take new blood to this field. The construction and application in studies of PQCD factorization approach is indeed a great progress in B physics.We...