Strangeness production in different collision systems and at different collision energies with the STAR experiment

Tsinghua University, Beijing 100084, China

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Published online: 17 April 2026

Abstract

Strangeness production has been suggested as a sensitive probe to the early dynamics of the deconfined matter created in heavy-ion collisions. In these proceedings, we report new measurements of strange hadron (K_s⁰, Λ, Λ̅, Ξ, Ξ̅, ϕ, Ω, Ω̅) production in Au+Au collisions at √s_NN = 7.7, 9.2, 11.5, 14.6, 19.6 GeV and in O+O, Zr+Zr and Ru+Ru collisions at √s_NN = 200 GeV. The presented results include transverse momentum spectra, rapidity distributions, nuclear modification factors (R_CP), antibaryon-to-baryon ratio, and Ω-to-ϕ ratios. A significant Ω-to-ϕ enhancement is observed in central Au+Au collisions at √s_NN≥7.7 GeV, with a similar trend in O+O and isobar (Zr+Zr, Ru+Ru) collisions at 200 GeV, where the enhancement grows from peripheral to central events. The results hint at a possible Ω-to-ϕ enhancement pattern that appears consistent at similar N_part values across different collision systems at √s_NN = 200 GeV.