Glueballs from Improved Lattice Actions
  The low-lying glueball masses and the hadronic scale $r_0$ are computed in lattice SU(3) gauge theory with the aim of establishing the effectiveness of the improved action approach in removing finite-spacing artifacts. The use of anisotropic lattices in which the temporal spacing is much smaller than that in the spatial directions allows much more efficient glueball mass measurements. 
Colin Morningstar, Mike Peardon