Exotics glueballs, hybrids, etc

Predictions for glueball masses have been made in all approaches lattice calculations, QCD sum rules, bag models, effective Lagrangians and potential models. There is an extensive literature on the subject see Kopke and Wermes (1989). 

Theoretical predictions for the masses of those glueballs, which have been most intensively searched for, are shown in Fig. 12.10. 

One can make a naive estimate of the production rate for the various species of particles, mesons (M), hybrids (H) and glueballs (Q) by simply counting powers of em and strong coupling constants (Chanowitz, 1987). 

The experimental situation is still extremely controversial. We mention 

As already mentioned, radiative J/ decay is the type of reaction where evidence for glueballs might be particularly clean. The 7 energy spectrum in 

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