Investigating different $\Lambda$ and $\bar\Lambda$ polarizations in relativistic heavy-ion collisions

Understand

Based on the chiral kinetic equations of motion, spin polarizations of various quarks, due to the magnetic field induced by spectator protons as well as the quark-antiquark vector interaction, are studied within a partonic transport approach.

• Although the magnetic field in QGP enhances the splitting of the spin polarizations of partons compared to the results under the magnetic field in vacuum, the spin polarizations of $s$ and $\bar s$ quarks are also sensitive to the quark-antiquark vector interaction, challenging that the different $\Lambda$ and $\bar \Lambda$ spin polarization is a good measure of the magnetic field in relativistic heavy-ion collisions.
• It is also found that there is no way to obtain the large splitting of the spin polarization between $\Lambda$ and $\bar \Lambda$ at $\sqrt{s_{NN}}=7.7$ GeV with partonic dynamics.