A new view of the 0- and 2+ glueballs

Abstract

Data on $J/\Psi \to \gamma (\rho \rho )$ demand a broad $0^{-}$ $\rho \rho$ signal, attributable to a glueball with a mass of 1750--2100 MeV. Decays of this broad state to $\rho \rho$, $\omega \omega$, $K^{\ast }{\bar{K}}^{\ast }$ and $\varphi \varphi$ channels agree well with flavour blindness. The narrow $\iota (1440)$ may be attributed to mixing between the glueball and the $s\bar{s}$ radial excitation. The latter is pushed down in mass by repulsion between the two levels. We conjecture that the $2^{+}$ glueball may likewise be broad. Mixing between it and the $2^3{P}_{2}q\bar{q}$ and $s\bar{s}$ radial excitation can explain the appearance of $f_2(1565)$ and a $2^{+}$ $\Theta (1710)$ at masses lower than anticipated. Mixing with higher $q\bar{q}$ states can explain the $2^{+}$ resonance at 1920 MeV and also $\varphi \varphi$ signals observed by Etkin et al. and by the JETSET collaboration.

Comments: 15 pages + 3 postscript figures