Du, DS (reprint author), CHINESE ACAD SCI,INST HIGH ENERGY PHYS,POB 918 4,BEIJING 100039,PEOPLES R CHINA.
Using the PQCD method we calculate the W-exchange and the W-annihilation processes of B mesons, which in general involve a charm quark or anti-quark in the final state. The nonvanishing amplitudes of these processes are found to be suppressed by a factor of m(c)/m(b) compared to the tree or the time-like penguin processes, but some of them are within the reach of observation at the future B-factories, and (B) over bar (0)(d) --> Ds+K- whose branching ratio is found to be 6.6 x 10(-6) can be found even before the B-factory era. Comparisons with the results based on the BSW model are also given. (C) 1997 Published by Elsevier Science B.V.