Scalar Glueball and Friends

Abstract

The $f_0(1500)$ is identified in three glueball favoured production mechanisms: $p\bar{p}$ annihilation, $\psi \to \gamma f_0$ and Central Production. The production rate for glueballs in $\psi \to \gamma G$ has been quantified and the $f_0(1500)$ is found to be consistent with a glueball - $q\bar{q}$ mixture. We illustrate a remarkable property of central production where kinematic cuts appear to make a systematic separation between glueballs and $q\bar{q}$ of the same $J^{PC}$. When the cut favouring glueballs is applied, the $f_0(1500)$ and other enigmatic states appear prominently while confirmed $q\bar{q}$ states are empirically suppressed.