Two-component source to explain $\Lambda$ and $\bar{\Lambda}$ global polarization in non-central heavy-ion collisions

TL;DR

This paper proposes a two-component model with a core and corona to explain the energy-dependent differences in $ extLambda$ and $ar{ extLambda}$ polarization observed in heavy-ion collisions.

Contribution

It introduces a novel two-component source model that quantitatively reproduces the polarization differences across collision energies.

Findings

The model matches experimental polarization data.

Polarization differences increase at lower energies.

Core-corona structure explains polarization variation.

Abstract

The STAR Beam Energy Scan program has found a difference in the global polarization of $\Lambda$s and $\bar{\Lambda}$s produced in $Au+Au$ collisions. This difference is larger for lower center of mass collision energies. In this work we show that a two-component source, consisting of a high density core and a lower density corona, can describe quantitatively the $\Lambda$ and $\bar{\Lambda}$ polarization as a function of collision energy.