Speakers
Description
The observation of hyperon global polarization along the system's angular momentum has revealed the existence of large vorticities in the medium created by heavy-ion collisions.
Using the high-statistics data collected by the STAR experiment during the RHIC Beam Energy Scan II (BES-II) program with upgraded detector systems, we present the global polarization measurements for $\Lambda$, $\bar\Lambda$, $\Xi^{\pm}$ and $\Omega^{\pm}$ hyperons in Au+Au collisions at BES-II energies ($\sqrt{s_{\mathrm{NN}}} = 7.7, 9.2, 11.5, 14.6, 17.3, 19.6, 27$ GeV). Specifically, we focus on the possible differences in polarization between $\Lambda$ and $\bar\Lambda$, as well as the polarization behaviors observed in different hyperons ($\Xi^{\pm}$ and $\Omega^{\pm}$).
These results provide new insights into the polarization mechanism and vorticity fields in heavy-ion collisions as well as additional constraints on the properties and dynamics of the hot and dense matter created in these collisions.
