Studies of xi (2230) in J/ psi radiative decays.

The BES experiment at the Beijing electron-positron collider has observed the $\ensuremath{\xi}$(2230) signal in ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$, ${K}^{+}{K}^{\ensuremath{-}}$, ${K}_{S}^{0}{K}_{S}^{0}$, and $p\overline{p}$ final states with $4.6\ensuremath{\sigma}$, $4.1\ensuremath{\sigma}$, $4.0\ensuremath{\sigma}$, and $3.8\ensuremath{\sigma}$ statistical significances, respectively. The new observations of two nonstrange decay modes of $\ensuremath{\xi}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ and $p\overline{p}$ are important evidence for the glueball interpretation of the $\ensuremath{\xi}(2230)$.