Measurement of the B+ --> p pbar K+ Branching Fraction and Study of the Decay Dynamics

TL;DR

This study measures the branching fraction of B+ --> p pbar K+ decay, observes low mass enhancement, and searches for pentaquark states, providing insights into decay dynamics and underlying mechanisms.

Contribution

It provides the first measurement of the B+ --> p pbar K+ branching fraction and sets limits on pentaquark production, advancing understanding of decay processes and exotic states.

Findings

Branching fraction Br(B+ --> p pbar K+) = (6.7 +/- 0.5 +/- 0.4) x 10^{-6}

Observation of low ppbar mass enhancement

Limits set on pentaquark Theta*++ production at 10^{-7} level

Abstract

With a sample of 232x10^6 Upsilon(4S) --> BBbar events collected with the BaBar detector, we study the decay B+ --> p pbar K+ excluding charmonium decays to ppbar. We measure a branching fraction Br(B+ --> p pbar K+)=(6.7+/-0.5+/-0.4)x10^{-6}. An enhancement at low ppbar mass is observed and the Dalitz plot asymmetry suggests dominance of the penguin amplitude in this B decay. We search for a pentaquark candidate Theta*++ decaying into pK+ in the mass range 1.43 to 2.00 GeV/c2 and set limits on Br(B+ --> Theta*++pbar)xBr(Theta*++ --> pK+) at the 10^{-7} level.