Hadron production in Au+Au collisions from STAR fixed-target experiment

¹ Key Laboratory of Quark and Lepton Physics (MOE) and Institute of Particle Physics, Central China Normal University, Wuhan 430079, China
² School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 101408, China

^* e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Published online: 17 April 2026

Abstract

Strange hadrons have been suggested as sensitive probes for the medium properties of the nuclear matter created in heavy-ion collisions. A dense baryon-rich medium is formed during collisions at center-of-mass energies of a few-GeV. Since strange hadrons are produced near or below the threshold, their phase space distribution and yield ratio may provide strong constraints on the equation of state (EoS) of high baryon density matter. In this contribution, recent results on strange hadron production in Au + Au collisions at √s_NN = 3.2, 3.5, 3.9, 4.5, 5.2 and 6.2 GeV from the STAR experiment in fixed-target mode are presented. The transverse momentum spectra (p_T), rapidity density distributions (dN/dy) of strange hadrons and their yield ratios will be presented as a function of centrality and collision energy. An enhancement of the the Λ/K_s⁰ yield-ratio is observed above √s_NN = 3.9 GeV. We will also explore the evolution of their kinetic freeze-out temperature T_Kin and average radial expansion flow velocity (ß_T) extracted from the Blast-Wave model in the reported energy range. The physics implications will be studied by comparing to model calculations.