Disoriented chiral condensate in the presence of dissipation and noise

We have investigated the phase transition and disoriented chiral condensate domain formation in linear σ model. Solving the Langevin equation for the linear σ model, we have shown that, for zero mass pions, the σ-model fields undergo a phase transition above a certain temperature (Tc). For finite mass pions, there is no phase transition. It was also shown that for zero mass pions, σ-model fields, thermalized at a temperature above Tc, when cooled down rapidly, disoriented chiral condensate domains are formed, quite late in the evolution. For massive pions, no large disoriented chiral condensate domain is formed