Mass Gap and Confinement in (2+1)-Dimensional Yang-Mills Theory
  Using a gauge-invariant matrix parametrization of the gauge fields, we present an analysis of how the mass gap arises in (2+1)-dimensional Yang-Mills theory. We further derive an analytical continuum expression for the vacuum wavefunction and based on this we calculate the string tension which is in excellent agreement with Monte Carlo simulations of the corresponding lattice gauge theory. 
Dimitra Karabali