Core meets corona: a two-component source to explain Lambda and anti-Lambda global polarization in semi-central heavy-ion collisions

Understand

We compute the Lambda and anti-Lambda global polarization in semi-central heavy-ion collisions modeling the source as consisting of a high-density core and a less dense corona.

• We show that when more Lambdas than anti-Lambdas are produced in the corona, and this is combined with a smaller number of Lambdas coming from the core, as compared to those coming from the corona, an amplification effect for the anti-Lambda with respect to that of Lambda polarization can occur.
• This amplification becomes more important for lower collision energies and quantitatively accounts for the Lambda and anti-Lambda polarizations measured by the STAR beam energy scan.