Abstract
The polarizations of and hyperons are important quantities in extracting the fluid vorticity of the strongly coupled quark gluon plasma and the magnitude of the magnetic field created in off-central heavy-ion collisions, through the spin-vorticity and spin-magnetic coupling. We computed the energy dependence of the global polarization in off-central Au+Au collisions in the energy range GeV using a multiphase transport model. The observed polarizations with two different impact parameters agree quantitatively with recent STAR measurements. The energy dependence of the global polarization is decomposed as energy dependence of the distribution at hadronization and the space-time distribution of the fluid-vorticity field. The visualization of both the distribution and the fluid-vorticity field show a smaller tilt at higher collisional energies, which indicates that the smaller global polarization at higher collisional energies is caused by a smaller angular momentum deposition at midrapidity.
- Received 7 April 2017
DOI:https://doi.org/10.1103/PhysRevC.96.054908
©2017 American Physical Society