Global polarization of $\mathrm{\Lambda }$ and $\overline{\mathrm{\Lambda }}$ is calculated based on the axial vortical effect (AVE). Simulations are performed within the three-fluid dynamics model. Equations of state with a deconfinement transition result in a good agreement with STAR data for both $\mathrm{\Lambda }$ and $\overline{\mathrm{\Lambda }}$ polarization, in particular, with the $\mathrm{\Lambda }\text{−}\overline{\mathrm{\Lambda }}$ splitting. Suppression of the gravitational-anomaly contribution required for the data reproduction is in agreement with predictions of the QCD lattice simulations. Predictions for the global polarization in forthcoming experiments at lower collision energies are made. These forthcoming data will provide a critical test for the AVE and thermodynamic mechanisms of the polarization.

• Received 29 June 2020
• Accepted 22 September 2020

DOI:https://doi.org/10.1103/PhysRevC.102.044904