Strange Hadron Production in Au+Au Collisions at RHIC Beam Energy Scan

Abstract

Strangeness production has been suggested to be a sensitive probe to the early-time dynamics of the nuclear matter created in heavy-ion collisions. Transverse momentum distributions and yields of strange hadrons provide important information on their production mechanisms and can help us probe the properties of the created medium and its evolution. Thanks to the high statistics data taken during the STAR BES-II program in 2018-2021, a series of measurements on the properties of strangeness production at low energies are carried out. In these proceedings, the production of K−, KS0, ϕ, Λ, and Ξ− in Au+Au collisions at √SNN = 3 GeV are presented. The strange hadron transverse momentum spectra, rapidity density distributions, and particle ratios are shown. These results are compared with UrQMD model calculations, and the extracted kinetic freeze-out parameters are discussed and compared with the ones from higher collision energies.