Two-component source to explain $Lambda$ and $bar{Lambda}$ 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 $bar{Lambda}$s 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 $bar{Lambda}$ polarization as a function of collision energy.