Nonequilibrium effects in dynamic symmetry breaking

TL;DR

This paper introduces a dynamic model combining a Langevin equation for the sigma field with fluid dynamics for quarks to study nonequilibrium effects during phase transitions in heavy-ion collisions.

Contribution

It presents a self-consistent, coupled dynamical framework for modeling fluctuations and dissipation near a chiral critical point and first-order phase transition.

Findings

Analysis of sigma field fluctuations during phase transitions

Evolution of constituent quark masses in nonequilibrium conditions

Insights into dissipative processes in heavy-ion collision dynamics

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.