Light Hypernuclei Production in Au+Au Collisions at $\sqrt{s_{NN}}=$ 3 GeV within Thermodynamic Approach

Abstract

Simulations of the $\Lambda$-hyperon and light-hypernuclei production in Au+Au collisions at $\sqrt{s_{NN}}=$ 3 GeV were performed within updated Three-fluid Hydrodynamics-based Event Simulator Extended by UrQMD (Ultra-relativistic Quantum Molecular Dynamics) final State interactions (THESEUS). The light (hyper)nuclei are treated thermodynamically, i.e. they are considered on the equal basis with hadrons. The only additional parameter is related to the late freeze-out that imitates the afterburner stage for the light (hyper)nuclei because the UrQMD is not able to dynamically treat them. The calculation of hypernuclei production is completely similar to that of light nuclei. The hypernuclei results are compared with recent STAR data. It is found that the calculated midrapidity $_\Lambda^3$H/$\Lambda$ ratio falls within the error bars of the experimental point. It is remarkable that large difference between the $t/p$ and $_\Lambda^3$H/$\Lambda$ ratios is reproduced without any additional parameters. Rapidity distributions of $_\Lambda^3$H/$\Lambda$ and $_\Lambda^4$He/$\Lambda$ ratios are predicted. Midrapidity mean transverse momenta of protons, $\Lambda$s and light (hyper)nuclei in central collisions well agree with the data. The calculated directed flow also reasonably well reproduces of the data.