Vorticity and hyperon polarization at NICA energies

TL;DR

This paper investigates fluid vorticity and hyperon polarization in heavy-ion collisions at NICA energies using a hybrid model, successfully matching some experimental data but not all observed polarization phenomena.

Contribution

It introduces a comprehensive model incorporating hadronic and partonic degrees of freedom to study vorticity and hyperon polarization at NICA energies.

Findings

Vorticity properties in peripheral Au+Au collisions at 7.7 GeV are demonstrated.

The model's $ ext{Lambda}$ polarization agrees with STAR data.

The model fails to explain high anti-hyperon $ar{ ext{Lambda}}$ polarization.

Abstract

We study the formation of fluid vorticity and the hyperon polarization in heavy-ion collisions at NICA energies in the framework of the Parton-Hadron-String Dynamic Model, taking into account both hadronic and quark-gluonic (partonic) degrees of freedom. The vorticity properties in peripheral Au+Au collisions at $\sqrt{s_{NN}}=$7.7\,GeV are demonstrated and confronted with other models. The obtained result for the $\Lambda$ polarization is in agreement with the experimental data by the STAR collaboration, whereas the model is not able to explain the observed high values of the anti-hyperon $\bar\Lambda$ polarization.