Viscous effects on the dynamical evolution of QCD matter during the first-order confinement phase transition in heavy-ion collisions

TL;DR

This paper explores how viscosity influences the evolution of QCD matter during a first-order phase transition in heavy-ion collisions, highlighting its impact on transition timescales through theoretical modeling and numerical analysis.

Contribution

It introduces a detailed analysis of viscous effects on the QCD phase transition using the MIT bag model and hadron resonance gas model, providing new insights into transition dynamics.

Findings

Viscous pressure affects the energy balance during the phase transition.

Viscosity influences the timescale of the QCD phase transition.

Numerical results demonstrate the significance of viscous effects.

Abstract

We investigate viscous effects on the dynamical evolution of QCD matter during the first-order phase transition, which may happen in heavy-ion collisions. We first obtain the first-order phase transition line in the QCD phase diagram under the Gibbs condition by using the MIT bag model and the hadron resonance gas model for the equation of state of partons and hadrons. The viscous pressure, which corresponds to the friction in the energy balance, is then derived from the energy and net baryon number conservation during the phase transition. We find that the viscous pressure relates to the thermodynamic change of the two-phase state and thus affects the timescale of the phase transition. Numerical results are presented for demonstrations.