Observation of $B^{\pm}\to p \bar{p} K^{\pm}$

TL;DR

This paper reports the first observation of the decay mode $B^{"+} o p ar{p} K^{"+}$, measuring its branching fraction and analyzing the $p ar{p}$ mass spectrum, providing new insights into baryonic $b o s$ transitions.

Contribution

First observation of a baryonic $b o s$ transition decay mode with detailed measurement of its branching fraction and mass spectrum analysis.

Findings

Branching fraction measured as (4.3^{+1.1}_{-0.9} ext{(stat)} ext{±} 0.5 ext{(syst)})×10^{-6}

$p ar{p}$ mass spectrum peaks at low mass, inconsistent with phase space

Upper limits set for related decay modes

Abstract

We report the observation of the decay mode $B^{\pm}\to p \bar{p} K^{\pm}$ based on an analysis of 29.4 fb$^{-1}$ of data collected by the Belle detector at KEKB. This is the first example of a $b\to s$ transition with baryons in the final state. The $p \bar{p}$ mass spectrum in this decay is inconsistent with phase space and is peaked at low mass. The branching fraction for this decay is measured to be ${\cal B}(B^{\pm}\to p \bar{p} K^{\pm}) =(4.3^{+1.1}_{-0.9}({\rm stat})\pm 0.5({\rm syst}))\times 10^{-6}.$ We also report upper limits for the decays $B^0\to p \bar{p} K_S$ and $B^{\pm}\to p \bar{p} \pi^{\pm}$.