The system created in non central relativistic nucleus-nucleus collision possesses large angular orbital momentum. Particles produced in such a system are predicted to be polarized along the collision reaction plane direction. Such global polarization originates from transformation of the orbital angular momentum of the system into the particle's spin. Since the angular momentum of the system is perpendicular to the collision reaction plane this effect can be studied by methods used to extract directed flow in flow analysis.
We present results of the global polarization measurements in Au+Au collisions at 62 and 200 GeV obtained with the STAR detector at RHIC. The global polarization of the system is examined by measuring the polarization of strange hyperons with respect to the collision reaction plane. The hyperon polarization assessed via anisotropy in angular distribution of decay products in the hyperon's rest frame measured with respect to the collision reaction plane.