Chiral fluid dynamics with explicit propagation of the Polyakov loop

TL;DR

This paper develops a dynamical model combining chiral and deconfinement phase transitions, capturing nonequilibrium effects like supercooling and domain formation through coupled Langevin equations and fluid dynamics.

Contribution

It introduces a fully dynamical framework with explicit propagation of the Polyakov loop and sigma field, incorporating stochastic effects and energy-momentum conservation.

Findings

Observed critical slowing down near the critical point

Detected enhancement of long wavelength modes at the critical point

Simulated supercooling and domain formation during first order transition

Abstract

We present a fully dynamical model to study nonequilibrium effects in both the chiral and the deconfinement phase transition. The sigma field and the Polyakov loop as the corresponding order parameters are propagated by Langevin equations of motion. The locally thermalized background is provided by a fluid of quarks and antiquarks. Allowing for an exchange of energy and momentum through dissipative and stochastic processes we ensure that the total energy of the coupled system remains conserved. We study its relaxational dynamics in different quench scenarios and are able to observe critical slowing down as well as the enhancement of long wavelength modes at the critical point. During the fluid dynamical expansion of a hot plasma fireball typical nonequilibrium effects like supercooling and domain formation occur when the system evolves through the first order phase transition.