Global hyperon polarization and effects of decay feeddown

Abstract

We study the global polarizations of $\Lambda$, ${\Xi }^{-}$, and ${\Omega }^{-}$ hyperons in noncentral Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}=$ 7.7-200 GeV. We highlight the importance of effect of decay feeddown to the measured global polarization. With the decay contributions taken into account, the global polarization ordering $P_{{\Omega }^{-}}>P_{{\Xi }^{-}}>P_{\Lambda }$ can be naturally explained, which is consistent with the observation recently reported from the STAR experiment from Au+Au collisions at 200 GeV. We also extend our calculations to predict expectations from the RHIC-BES II data.

Comments: 4 pages, 2 figures, contribution to 19th International Conference on Strangeness in Quark Matter (SQM2021)