# Estimates of hyperon polarization in heavy-ion collisions at collision energies $\sqrt{s_{NN}}=$ 4--40 GeV

## TL;DR

This paper estimates hyperon polarization in heavy-ion collisions at energies 4-40 GeV using a thermodynamical model and three-fluid dynamics, successfully matching experimental data and revealing energy-dependent polarization behavior.

## Contribution

It introduces a thermodynamical approach combined with 3FD modeling to estimate hyperon polarization across a range of collision energies, aligning well with experimental results.

## Key findings

- Midrapidity polarization matches STAR data.
- Total polarization increases with collision energy.
- High-energy polarization is significant in fragmentation regions.

## Abstract

Global polarization of $\Lambda$ and $\bar{\Lambda}$ hyperons in Au+Au collisions at collision energies $\sqrt{s_{NN}}=$ 4-40 GeV in the midrapidity region and total polarization, i.e. averaged over all rapidities, are studied within the scope of the thermodynamical approach. The relevant vorticity is simulated within the model of the three-fluid dynamics (3FD). It is found that the performed rough estimate of the global midrapidity polarization quite satisfactorily reproduces the experimental STAR data on the polarization, especially its collision-energy dependence. The total polarization increases with the collision energy rise, which is in contrast to the decrease of the midrapidity polarization. This suggests that at high collision energies the polarization reaches high values in fragmentation regions.