Study of J\psi decaying into \omega p \bar p

TL;DR

This study measures the decay rate of J/psi into omega and proton-antiproton pairs, finding no significant near-threshold enhancement and setting an upper limit on possible exotic states.

Contribution

First measurement of the branching fraction for J/psi to omega p p-bar decay with a large data sample, and a search for near-threshold p p-bar enhancement with no significant signal found.

Findings

Branching fraction measured as (9.8 ± 0.3 ± 1.4)×10^{-4}

No significant p p-bar threshold enhancement observed

Upper limit set on J/psi to omega X(1860) decay at 1.5×10^{-5}

Abstract

The decay $J/\psi \to \omega p \bar p$ is studied using a $5.8 \times 10^7$ $J/\psi$ event sample accumulated with the BES II detector at the Beijing electron-positron collider. The decay branching fraction is measured to be $B(J/\psi \to \omega p \bar p)=(9.8\pm 0.3\pm 1.4)\times 10^{-4}$. No significant enhancement near the $p\bar p$ mass threshold is observed, and an upper limit of $B(J/\psi \to \omega X(1860))B(X(1860)\to p\bar p)$$ $$< 1.5 \times 10^{-5}$ is determined at the 95% confidence level, where X(1860) designates the near-threshold enhancement seen in the $p\bar p$ mass spectrum in $J/\psi \to \gamma p \bar p$ decays.