The impact of dissipation and noise on fluctuations in chiral fluid dynamics

Understand

We investigate the nonequilibrium evolution of the sigma field coupled to a fluid dynamic expansion of a hot fireball to model the chiral phase transition in heavy-ion collisions.

• The dissipative processes and fluctuations are allowed under the assumption that the total energy of the coupled system is conserved.
• We use the linear sigma model with constituent quarks to investigate the effects of the chiral phase transition on the equilibration and excitation of the sigma modes.
• The quark fluid acts as a heat bath in local thermal equilibrium and the sigma field evolves according to a semiclassical stochastic Langevin equation of motion.