Global hyperon polarization and effects of decay feeddown

¹ Key Laboratory of Nuclear Physics and Ion-beam Application (MOE), Fudan University, Shanghai 200433, China
² Department of Physics and Center for Field Theory and Particle Physics, Fudan University, Shanghai 200433, China
³ Department of Physics and Astronomy, University of California, Los Angeles, CA 90095, USA

^* e-mail: lihui_fd@fudan.edu.cn
^** e-mail: xiaxl@fudan.edu.cn
^*** e-mail: huangxuguang@fudan.edu.cn
^**** e-mail: huanzhonghuang@fudan.edu.cn

Published online: 1 February 2022

Abstract

We study the global polarizations of Λ, Ξ⁻, and Ω⁻ hyperons in noncentral Au + Au collisions at √S_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_Ω− > P_Ξ− > P_Λ 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.