2011/05/10 by Marlene Nahrgang, Nahrgang, Marlene, C. Herold +9 · 1 citation
Physics and Astronomy · #Cosmology and Gravitation Theories #FOS: Physical sciences #High-Energy Particle Collisions Research #Nuclear Theory (nucl-th) #Theoretical and Computational Physics #nucl-th
paper · pdf · doi:10.48550/arxiv.1105.1962
openalex publication_date 2011/05/10 · arxiv created 2011/10/21 · arxiv updated 2011/10/24 · openalex created_date 2022/10/02 · openalex updated_date 2026/07/28
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. The effects of supercooling and reheating in a first order phase transition are observed when the sigma field relaxes to equilibrium with the quark fluid. Nonequilibrium fluctuations at the first order phase transition lead to an increase in the intensity of sigma fluctuations in comparison to a scenario with a critical point.