Search for exclusive two body decays of B meson going to D meson(s) resonance at Belle

This thesis presents the study of B + → Ds+pi 0, B0 → Ds* +pi- and B0 → Ds*-K+ decays based on a data sample consisting of 274.8 million BB¯ events collected at KEKB accelerator located at KEK in Tsukuba, Japan. KEKB is an asymmetric collider in which electrons and positrons collides at energies 8.5 GeV and 3.0 GeV respectively. The electron-positron collisions produce Upsilon(4S) mesons which instantly, decays into a B0B¯0 or a B+B- pair.; B0 → Ds* +pi- and B+ → Ds*+pi0 decays can be used to measure the magnitude of the CKM matrix element Vub. Also the process for B0 → D s*+pi- decay is the same as that for the doubly Cabibbo suppressed B0 → D*+pi-. Its rate thus provides important input for the measurement of sin(2&phis;1 + &phis;3) in the time dependent CP violation measurements of B 0 → D*+pi-. B¯0 → Ds* +K- decays may provide information on W-exchange diagrams and final state interactions. The branching fractions for B0 → Ds* +pi- and B¯0 → Ds*+K-, are (2.14+/-0.81+/-0.26+/-0.54) x 10-5 and (1.64+/-0.66+/-0.23+/-0.41) x 10-5 respectively. The branching fraction of B+ → Ds*+pi0 is (2.43+/-1.12+/-0.42+/-0.61) x 10-5. First the statistical uncertainty is shown and the second is systematic uncertainty excluding the systematic uncertainty of the branching fraction of Ds → &phis;pi. The third error from the systematic uncertainty of the branching fraction of Ds → &phis;pi.