Calculation Pure Annihilation Type Decay Of B Meson In Perturbative QCD

We are now in the era of B physics. 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 new physics. 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 theorists 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, general factorization, BBNS approach, perturbative QCD (pQCD) approach.There is one type of special B decays, because quarks in final states are different from the ones in B meson, so they can occur only via annihilation type diagrams in the Standard Model. In this paper,we calculate some decays in perturbative QCD approach based on kT factorization. First of all, we introduce the effective theory and four-quark operators. Furthermore, in order to give a view about pQCD, we take example for B - Ds-K+. Using Sudakov factor and wave function, we predict the decay widths and branching ratios. At last, we calculate another eight decays, with discussing many uncertain factors. Many decay we calculated have small branching ratios, which may be sensitive to new physics.Studying the non-lepton decay of B meson is an important task in particle physics. Any small breakthrough in theory may take new blood to this field. Based on factorization, perturbative QCD (pQCD) have made a progress in B physics. We expect that experiments can further test this theory in future.