Abstract
We study the angular distributions of the baryon-antibaryon low-mass enhancements in the three-body baryonic B decays of B→pp̄M (M=K and π) in the framework of the perturbative QCD. By writing the most general forms for the transition form factors of B→pp̄, we find that the angular distribution asymmetry in B-→pp̄K- measured by Belle Collaboration can be explained. We give a quantitative description on the Dalitz plot asymmetry in B-→pp̄K- shown by BABAR Collaboration and demonstrate that it is equivalent to the angular asymmetry. In addition, we present our results on B̄0→pp̄KS and B-→pp̄π- and we obtain that their angular asymmetries are -0.35±0.11 and 0.45±0.10, respectively, which can be tested by the ongoing experiments at the B factories. © 2006 The American Physical Society.