Global polarization measurement in Au+Au collisions
Phys.Rev.C 76 (2007) 024915, 2007.
The collaboration

Abstract (data abstract)
The system created in non-central relativistic nucleus-nucleus collisions possesses large orbital angular momentum. Due to spin-orbit coupling, particles produced in such a system could become globally polarized along the direction of the system angular momentum. We present the results of Lambda and anti-Lambda hyperon global polarization measurements in Au+Au collisions at $\sqrt{s_NN}$=62.4 GeV and 200 GeV performed with the STAR detector at RHIC. The observed global polarization of $\Lambda$ and $\overline{\Lambda}$ hyperons in the STAR acceptance is consistent with zero within the precision of the measurements. The obtained upper limit, $|P_{\Lambda,\overline{\Lambda}}|$ <= 0.02, is compared to the theoretical values discussed recently in the literature.

Version 2 modifications: See PHYSICAL REVIEW C 95, 039906(E) (2017): polarization parameters in Figs. 3-8 are plotted with wrong signs