Viscous Hydrodynamics and Relativistic Heavy Ion Collisions

TL;DR

This paper introduces a fully three-dimensional viscous hydrodynamics model for relativistic heavy ion collisions, compares it with 2D models, and assesses its impact on mid-rapidity observables at RHIC energies.

Contribution

It presents the first fully three-dimensional viscous hydrodynamics model and compares its results to previous 2D models, improving the understanding of collision dynamics.

Findings

Modest differences observed between 2D and 3D models at mid-rapidity.

The 3D model is numerically accurate and feasible for heavy ion collision simulations.

Comparison shows 3D effects are small at high RHIC energies.

Abstract

The matter created in relativistic heavy ion collisions is fairly well described by ideal hydrodynamics, and somewhat better described by viscous hydrodynamics. To this point, most viscous calculations have been two-dimensional, based on an assumption of Bjorken boost invariance along the beam axis. Here, first results are presented for a fully three-dimensional viscous model. The model is described and tests of the numerical accuracy of the code are presented. Two- and three-dimensional runs are compared, and modest changes are observed for mid-rapidity observables at the highest RHIC (Relativistic Heavy Ion Collider) energies.