Femto-cyclones and hyperon polarization in Heavy-Ion Collisions

TL;DR

This paper investigates vorticity and hyperon polarization in heavy-ion collisions, revealing toroidal vortex structures and their impact on hyperon polarization, using a kinetic model that conserves angular momentum accurately.

Contribution

It demonstrates the formation of toroidal vorticity structures and links them to hyperon polarization in heavy-ion collisions, advancing understanding of fluid dynamics in such events.

Findings

Toroidal vorticity structures (vortex sheets) are formed.

Hyperon polarization is of the order of a few percent.

Angular momentum conservation is accurately maintained in the model.

Abstract

We study the structure of vorticity and hydrodynamic helicity fields in peripheral heavy-ion collisions using the kinetic Quark-Gluon String Model. The angular momentum conservation within this model holds with a good accuracy. We observe the formation of specific toroidal structures of vorticity field (vortex sheets). Their existence is mirrored in the polarization of hyperons of the percent order.