Nonequilibrium effects in dynamic symmetry breaking

Abstract: We present a dynamic model based on the linear sigma model with constituent quarks that allows for studying the explicit propagation of fluctuations at a chiral critical point and a first-order phase transition. The coupled dynamics of the sigma field and the quarks is derived selfconsistently. Hereby, the sigma field evolves according to a semiclassical Langevin equation of motion, while the evolution of the quarks is described fluid dynamically in order to model the expansion of a hot fireball in heavy-ion collisions. Dissipative processes and fluctuations in the Langevin equation are allowed under the assumption of energy-momentum conservation of the coupled system. We study the evolution of the constituent quark masses in this nonequilibrium set up.