Paper detail

First measurements of J/Psi decays into $Σ^+ \barΣ^-$ and $Ξ^0 \barΞ^0$

Based on 58 million J/Psi events collected with the BESII detector at the BEPC, the baryon pair processes J/Psi to $Σ^+ \barΣ^-$ and J/Psi to $Ξ^0 \barΞ^0$ are observed for the first time. The branching fractions are measured to be ${\cal B}(J/Psi to Σ^+ \barΣ^-)=(1.50\pm 0.10\pm 0.22)\times 10^{-3}$ and ${\cal B}(J/Psi to Ξ^0 \barΞ^0)=(1.20\pm 0.12\pm 0.21)\times 10^{-3}$, where the first errors are statistical and the second ones are systematic.