Chiral Condensate and Short-Time Evolution of QCD(1+1) on the Light-Cone
  Chiral condensates in the trivial light-cone vacuum emerge if defined as short-time limits of fermion propagators. In gauge theories, the necessary inclusion of a gauge string in combination with the characteristic light-cone infrared singularities contain the relevant non-perturbative ingredients responsible for formation of the condensate, as demonstrated for the 't Hooft model. 
Matthias Burkardt, Frieder Lenz, and Michael Thies