Glueballs under harmonic confinement

The glueball spectrum is studied on the basis of a harmonic confinement model proposed and studied earlier for quark systems. A Bethe-Salpeter framework with an instantaneous approximation for the kernel is used for the dynamics. An explicit mass formula including spin-dependent effects is obtained in terms of only an overall spring constant, which in turn is determined by the corresponding quantity for hadron ($q\overline{q}, \mathrm{qqq}$) spectroscopy. The final spectrum is consistent with the limited experimental data available and qualitatively similar to bag-model results with QCD corrections.