Speaker
Description
High-energy nuclear collisions provide a unique environment to study isospin transport in strongly interacting QCD matter. While the strong interaction approximately conserves isospin, collisions involving nuclei with different neutron-to-proton $(N/Z)$ ratios offer a direct way to investigate how the initial isospin of the system is reflected in final-state hadron production. Charged-to-neutral kaon ratio $[(K^++K^-)/2K_s^0]$ is particularly sensitive to these effects, and recently, the NA61/SHINE collaboration has reported an enhanced charged-to-neutral kaon ratio in central collisions beyond current theoretical expectations[1-2].
We present the first precision measurements of charged ($K^{\pm}$) and neutral ($K_s^{0}$) kaon production in Ru+Ru, Zr+Zr, and O+O collisions at $\sqrt{s_{NN}} = 200~$GeV with the STAR experiment. The charged-to-neutral kaon ratio is measured as a function of transverse momentum and collision centrality. In addition, transverse momentum spectra and integrated yields of charged and neutral kaons will be presented. The results will be compared with state-of-the-art thermodynamic and transport models, and their implications for isospin dynamics and strange-hadron production will be discussed.
- H. Adhikary $et~al.$ (NA61/SHINE), Nature Commun. 16 (2025) 1, 2849.
- M. Gazdzicki $et~al.$, arXiv.2604.16005.
