For B_(s)?(D^*,(?)^*)[R?]K⁺K Phenomenological Study Of Two-body Decay Processes Of The ^- Type

The gauge group of the Standard Model(SM)theory of particle physics is SU(3)c�SU(2)L�U(1)Y.In the framework of the SM,one can describe the strong interaction,the weak and electromagnetic interactions simultaneously.Since B-mesons are heavy,there exist many decay channels to be calculated theoretically and measured experimentally.Therefore,the study of B meson physics becomes an very important area of the Standard Model.Studies of the B meson decays are crucial for the precision test of the SM and the search for the origin of CP violation.On the experimental side,The BaBar and Belle collaborations discovered the CP violation in the B meson system,measured the branching ratios of the hundreds of B meson decay channels.It has promoted the development of the related theoretical studies.On the theory side,the calculations of B meson two body hadronic decays have been relatively mature,and there are three kinds of methods:(1)phenomenological methods,such as the naive factorization approach and the generalized factorization approach;(2)QCD-based kinematic methods,such as the QCD factorization method,the perturbative QCD(PQCD)factorization approach,and the soft collinear effectiveness theory(SCET);(3)Some methods based on the SU(3)F flavor symmetry.When compared with the B meson two-body decays,one has to consider both the resonant contributions and the non-resonant contributions for the three-body hadronic decays of B mesons,as well as the momentum distribution of three final state particles and the interactions between the final particles.Therefore,the three-body decays are more complex than the two-body hadronic B meson decays.But they can provide more opportunities for theoretical and experimental researches.In the review part of this thesis,we first introduce the basic theoretical knowledge of B meson physics,and then present several calculation methods of the hadron matrix elements and the theoretical framework of B meson three-body decays.In the work part,we study the S,P and D wave resonance contributions to three-body decays B(s)?(D*,D*)[R?]K+Kby employing the PQCD factorization approach,then give a detailed analysis of the theoretical results.We found the following main points:(1)By introducing the two-meson distribution amplitude ?KK,we studied the quasi-twobody decays B(s)?(D*,D*)[R?]K+K-,calculated the branching ratios.The PQCD predictions for the branching ratios of most considered decay channels do agree well with currently available data within errors.(2)For most B(s)?D*R?D*KK decays,their branching ratios are at the order 10-9 to 10-7;but in the order of 10-7 to 10-5 for the B(s)?D*R?D*KK decay modes.The reason is that the B(s)?D*transition is CKM favored relative to the B(s)?D*transition.(3)Moreover,we calculated the polarization fractions of the vector-vector and vector-tensor decay modes in detail.For most decay channels,the transverse polarization is found to be similar in size with the longitudinal one,which is quite different from the general expectation in the factorization assumption.More precise data from the LHCb and the future Belle ? will test our predictions.At the end of the paper,the author makes a brief summary of the whole paper and an expectation for the future development of the B meson physics.we hope that both experiments and theories can be further developed and improved.