Study of the decay mechanism for B+→pp¯K+ and B+→pp¯π+

Abstract We study the characteristics of the low mass p p ¯ enhancements near threshold in the three-body decays B + → p p ¯ K + and B + → p p ¯ π + . We observe that the proton polar angle distributions in the p p ¯ helicity frame in the two decays have the opposite polarity, and measure the forward-backward asymmetries as a function of the p p ¯ mass for the p p ¯ K + mode. We also search for the intermediate two-body decays, B + → p ¯ Δ + + and B + → p Δ ¯ 0 , and set upper limits on their branching fractions. These results are obtained from a 414 fb −1 data sample that contains 449 × 10 6 B B ¯ events collected near the ϒ ( 4 S ) resonance with the Belle detector at the KEKB asymmetric-energy e + e − collider.