Flow Vorticity in Peripheral High Energy Heavy Ion Collisions

TL;DR

This paper investigates the development and persistence of vorticity in peripheral high energy heavy ion collisions, highlighting the effects of initial angular momentum and fluid viscosity on vorticity evolution.

Contribution

It provides new insights into how initial angular momentum generates and sustains vorticity in the quark-gluon plasma during heavy ion collisions.

Findings

Vorticity is significant at freeze-out despite expansion and dissipation.

Vorticity in the reaction plane exceeds that caused by fluctuations.

Low viscosity QGP maintains vorticity longer during expansion.

Abstract

The vorticity development is studied in the reaction plane of peripheral relativistic heavy ion reactions where the initial state has substantial angular momentum. The earlier predicted rotation effect and Kelvin Helmholtz Instability, lead to significant initial vorticity and circulation. In low viscosity QGP this vorticity remains still significant at the time of freeze out of the system, even if damping due to the explosive expansion and the dissipation decreases the vorticity and circulation. In the reaction plane the vorticity arises from the initial angular momentum, and it is stronger than in the transverse plane where vorticity is caused by random fluctuations only.