(-Λ)-超子在RHIC的Au+Au碰撞中的整体极化

(-Λ)-Hyperon Global Polarization in Au+Au Collisions at RHIC

We present the (-Λ)-hyperon global polarization in Au Au collisions at (√SNN)=62GeV and 200GeV measured with the STAR detector at RHIC. The observed (-Λ)-hyperon global polarization is consistent with zero,what is in agreement with recent measurements of A global polarization, as well as φ(1020) and K*0(892) vector mesons spin alignment with respect to the reaction plane. The possible dependence of the global polarization on relative azimuthal angle between the orbital momentum of the system and the hyperon 3-momentum is discussed. The corresponding systematic uncertainty due to detector acceptance is found to be less than 20%.