Two-Component Source To Explain Lambda And (Lambda)Over-Bar Global Polarization In Non-Central Heavy-Ion Collisions

The STAR Beam Energy Scan program has found a difference in the global polarization of Lambda s and (Lambda) over bars produced in Au + Au collisions. This difference is larger for lower center of mass collision energies. In this work we show that a two-component source, consisting of a high density core and a lower density corona, can describe quantitatively the Lambda and (Lambda) over bar polarizations as a function of collision energy.