An Analytic Variational Study of the Mass Spectrum in 2+1 Dimensional   SU(3) Hamiltonian Lattice Gauge Theory
  We calculate the masses of the lowest lying eigenstates of improved SU(2) and SU(3) lattice gauge theory in 2+1 dimensions using an analytic variational approach. The ground state is approximated by a one plaquette trial state and mass gaps are calculated in the symmetric and antisymmetric sectors by minimising over a suitable basis of rectangular states. 
Jesse Carlsson, John A.L. McIntosh, Bruce H.J. McKellar and Lloyd C.L.   Hollenberg