Evolution of Hot, Dissipative Quark Matter in Relativistic Nuclear Collisions

TL;DR

This paper models the evolution of quark-gluon plasma in heavy-ion collisions using causal dissipative fluid dynamics, revealing viscous effects influence flow and correlation measurements.

Contribution

It introduces a causal dissipative fluid dynamic model for quark-gluon plasma evolution, improving upon standard acausal theories.

Findings

Viscous effects increase transverse flow.

Viscosity decreases the ratio R_out/R_side.

Longitudinal pressure reduction impacts flow dynamics.

Abstract

Non-ideal fluid dynamics with cylindrical symmetry in transverse direction and longitudinal scaling flow is employed to simulate the space-time evolution of the quark-gluon plasma produced in heavy-ion collisions at RHIC energies. The dynamical expansion is studied as a function of initial energy density and initial time. A causal theory of dissipative fluid dynamics is used instead of the standard theories which are acausal. We compute the parton momentum spectra and HBT radii from two-particle correlation functions. We find that, in non-ideal fluid dynamics, the reduction of the longitudinal pressure due to viscous effects leads to an increase of transverse flow and a decrease of the ratio $R_{out}/R_{side}$ as compared to the ideal fluid approximation.