Glueballs: Charmonium decay andp¯pannihilation

The vector glueball $O$, made of 3 valence gluons, is expected to be “clean”: it mixes less with quarkonia, but mediates OZI violations. The recent $0^{++}$ glueball candidate and the persistence of the $J/\psi ,{\psi }^{\prime }\to \rho \pi$ puzzle suggest $m_O\simeq m_{J/\psi },$ with mixing angle $\sim 2°$–$4°$; hence, $\Gamma (O\to \rho \pi$, $K^{+}{K}^{-}$, $e^{+}{e}^{-})\sim$MeV, few keV, few eV. Lower and upper bounds on ${\Gamma }_O$ can be argued from $e^{+}{e}^{-}\to \rho \pi$ energy scan data and the condition $B(O\to \rho \pi )>B(J/\psi \to \rho \pi )$. $O$ dominance may explain the “large” OZI violation in ${}^1{S}_0\left(\mathrm{p¯}p\right)\to \phi \gamma$ vs $\omega \gamma$.