Global polarization of $\mathrm{\Lambda }$ and $\overline{\mathrm{\Lambda }}$ hyperons in $\mathrm{Au}+\mathrm{Au}$ collisions at collision energies $\sqrt{s_{NN}}=4–40\mathrm{GeV}$ in the midrapidity region and total polarization, i.e., averaged over all rapidities, are studied within the scope of the thermodynamical approach. The relevant vorticity is simulated within the model of the three-fluid dynamics (3FD). It is found that the performed rough estimate of the global midrapidity polarization quite satisfactorily reproduces the experimental STAR data on the polarization, especially its collision-energy dependence. The total polarization increases with the collision energy rise, which is in contrast to the decrease of the midrapidity polarization. This suggests that at high collision energies the polarization reaches high values in fragmentation regions.

• Received 19 March 2019
• Revised 21 May 2019

DOI:https://doi.org/10.1103/PhysRevC.100.014908