Year: 2025
Type: article
Abstract: Based on the model of three-fluid dynamics (3FD), the global $Λ$ polarization ($P_Λ$) is calculated in Au+Au collisions at 3 $\leq\sqrt{s_{NN}}\leq$ 9 GeV, in which high baryon density is achieved. Various contributions to $P_Λ$ are considered: those from the thermal vorticity, meson field, thermal shear and spin-Hall effect. Feed-down from higher-lying resonances is also taken into account. The results are compared with available data. Special attention is payed to the collision energies of $\sqrt{s_{NN}}=$ 3, 3.2, 3.5, 3.9, and 4.5 GeV, for which a thorough scan of the energy, rapidity, and centrality dependence of $P_Λ$ is performed. The results for 3 GeV reasonably well reproduce the corresponding STAR data. While the results at $\sqrt{s_{NN}}=$ 3.2, 3.5, 3.9, and 4.5 GeV can be considered as predictions for results of measurements within the STAR fixed-target (STAR-FXT) programthat are expected in the nearest future. It is predicted that a broad maximum of $P_Λ$ is reached at $\sqrt{s_{NN}}\approx$ 3--3.9 GeV, exact position of which depends on the centrality and width of the midrapidity range of observation. Impact of the meson-field, thermal-shear and spin-Hall-effect contributions to $P_Λ$ is also studied.
Source: Physical Review C
DOI: 10.1103/qn56-fvnq
Author: Yu. B. Ivanov
Institutions: Kurchatov Institute, Joint Institute for Nuclear Research
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4411091170