Studies on the Chiral Order Parameter in the Schwinger Model
  Based on an analytical technique using a unitary transformation and the variational method, we study the chiral order parameter in the Schwinger model in the lattice formalism with Kogut-Susskind fermions. The fermion condensate $\langle {\bar\Psi} \Psi \rangle $ for any coupling constant and fermion mass are calculated. Chiral symmetry is shown to be broken in the massless limit and good scaling behavior is obtained. 
Jen-Fa Min and Huei-Shih Liao