Inst High Energy Phys, Beijing 100039, Peoples R China
; CCAST, World Lab, Beijing 100080, Peoples R China
We calculate the B --> P, B --> V (P is the light pseudoscalar meson, V the light vector meson) form factors in the large-recoil limit in the perturbative QCD approach, including both the vector (axial vector) and tensor operators. In general there are two leading components phi(B) and phi(B) for the B meson wave functions. We consider both contributions of them. Sudakov effects (k(perpendicular to) and threshold resummation) are included to regulate the soft end-point singularity. By choosing the hard scale as the maximum virtualities of the internal particles in the hard b quark decay amplitudes, Sudakov factors can effectively suppress the long-distance soft contribution. The hard contribution can be dominant in these approaches.