Enhancement of Critical Slowing Down in Chiral Phase Transition

The linear Langevin equation that describes the dynamics of the chiral phase transition above the critical temperature is derived by applying the projection operator method to the Nambu-Jona-Lasinio model at finite temperature and density. The relaxation time of the critical fluctuations increases as the temperature approaches toward the critical temperature because of the critical slowing down. The critical slowing down is enhanced in low temperature and large chemical potential region and around the tricritical point.