A Two-Dimensional Model with Chiral Condensates and Cooper Pairs Having   QCD-like Phase Structure
  We describe how a generalization of the original Gross-Neveu model from U(N) to O(N) flavor symmetry leads to the appearance of a pairing condensate at high density, in agreement with the conjectured phenomenon of color superconductivity in $(3+1)$-dimensional QCD. Moreover, the model displays a rich phase structure which closely resembles the one expected in two-flavor QCD. 
Alan Chodos, Hisakazu Minakata, Fred Cooper, Anupam Singh, and Wenjin   Mao