Finite-size effects for lattice glueball masses
We have measured the lattice size dependence of the lightest glueball mass in SU(2) and SU(3) gauge theory at =2.2 and 2.3 [SU(2)] and =6.0 [SU(3)]. We observe an increase in the glueball mass when the lattice size shrinks below a critical value. The magnitude of this length scale, which we interpret as the physical size of the glueball, is roughly the same for SU(2) and SU(3) when expressed in un