A hydrodynamic study of hyperon spin polarization in relativistic heavy ion collisions

Understand

We perform a systematic study of the spin polarization of hyperons in heavy-ion collisions using the MUSIC hydrodynamic model with A Multi-Phase Transport (AMPT) pre-equilibrium dynamics.

• Our model calculations nicely describe the measured collision-energy, centrality, rapidity, and $p_T$ dependence of $\Lambda$ polarization.
• We also study and predict the global spin polarization of $\Xi^-$ and $\Omega^-$ as a function of collision energy, which provides a baseline for the studies of the magnetic moment, spin, and mass dependence of the spin polarization.
• For the local spin polarization, we calculate the radial and azimuthal components of the transverse $\Lambda$ polarization and find specific modulating behavior which could reflect the circular vortical structure.