Hyperon polarization measurements in heavy-ion collisions

Abstract

In non-central heavy-ion collisions, a large orbital angular momentum of the colliding system is produced, which is then partially transferred to the created medium, resulting in the particle polarization on average along the initial angular momentum, known as global polarization. It was predicted almost 20 years ago and the first observation of $\Lambda$ global polarization was made by the STAR Collaboration in 2017. Since then, a lot of progress have been made in the polarization measurements including global polarization of multistrange hyperons and the polarization along the beam direction induced by azimuthal anisotropic flow. In these proceedings, we present recent experimental progress on the hyperon polarization measurements in heavy-ion collisions.