Measurement of the Branching Fraction for J/\psi -> p \bar{p}\eta and p \bar{p} \eta^{'}

TL;DR

This paper measures the probabilities of J/psi decaying into proton-antiproton pairs with eta and eta' mesons, providing experimental data that supports theoretical predictions based on soft-pion theorems.

Contribution

First measurement of J/psi decay branching fractions to p p̄ η and p p̄ η' using BESII data, confirming theoretical expectations.

Findings

Branching fraction for J/psi to p p̄ η determined.

Branching fraction for J/psi to p p̄ η' determined.

The ratio of decay widths agrees with soft-pion theorem predictions.

Abstract

Using 58$\times 10^{6}$ $\jpsi$ events collected with the Beijing Spectrometer (BESII) at the Beijing Electron Positron Collider (BEPC), the branching fractions of $\jpsi$ to $p\bar{p}\eta$ and $p\bar{p}\etap$ are determined. The ratio $\frac{\Gamma(\jpsi\rar\ppb\eta)}{\Gamma(\jpsi\rar\ppb)}$ obtained by this analysis agrees with expectations based on soft-pion theorem calculations.