The 14th Workshop on QCD Phase Transition and Relativistic Heavy-Ion Physics (QPT 2021)

The RHIC Beam Energy Scan (BES) program was proposed to study the Quantum Chromodynamics phase transition and to locate the onset of deconfinement. As a sensitive probe to the transition from the hadron gas to the Quark-Gluon Plasma, the particle ratios of strange hadrons are measured to study the properties of nuclear matter and extract the chemical freeze-out parameters [1,2]. Recently, the production of strange hadrons (K_s^0,Λ,Λ ̅,Ξ^-,Ξ ̅^+,Ω^-,Ω ̅^+,and ϕ) at mid-rapidity (|y|<0.5) in Au+Au collisions at √(s_NN )=54.4 GeV were measured by the STAR experiment at RHIC. In this talk, transverse momentum spectra, nuclear modification factor R_cp, baryon-to-meson ratio, as well as the overall integrated yields of these strange hadrons at √(s_NN )=54.4 GeV are presented. In particular, the multi-strange baryon-to-meson ratio N(Ω^-+Ω ̅^+)/[2N(ϕ)] at √(s_NN )=54.4 GeV is studied and compared to previous measurements at other BES energies [3]. The strange-hadron-to-pion ratios versus charged hadron multiplicity are also studied and compared to the measurements in heavy-ion collisions at higher energies. [1] Phys. Rev. C 102, 034909 (2020) [2] Phys. Rev. C 96, 044904 (2017) [3] Phys. Rev. C 93, 021903(R) (2016)