Vorticity in Heavy-Ion Collisions

TL;DR

This paper investigates the generation and properties of flow vorticity in heavy-ion collisions at RHIC and LHC energies using the HIJING model, analyzing various definitions, distributions, fluctuations, and evolution of vorticity and flow helicity.

Contribution

It provides a comprehensive analysis of vorticity and flow helicity in heavy-ion collisions, including their dependence on collision parameters and definitions, which was not extensively studied before.

Findings

Vorticity varies with impact parameter and collision energy.

Significant event-by-event fluctuations in vorticity magnitude and direction.

Spatial distribution of flow helicity shows characteristic patterns.

Abstract

We study the event-by-event generation of flow vorticity in RHIC Au + Au collisions and LHC Pb + Pb collisions by using the HIJING model. Different definitions of the vorticity field and velocity field are considered. A variety of properties of the vorticity are explored, including the impact parameter dependence, the collision energy dependence, the spatial distribution, the event-by-event fluctuation of the magnitude and azimuthal direction, and the time evolution. In addition, the spatial distribution of the flow helicity is also studied.