Speaker
Description
Strangeness production is a sensitive probe of quark-gluon plasma formation and of how it varies with collision-system size. In central heavy-ion collisions at both RHIC and LHC, significant $\Omega$/$\phi$ ratio enhancement with relation to peripheral collisions has been observed at intermediate transverse momentum. It is also reported by ALICE that the strange-hadron-to-pion yield ratios exhibit approximate multiplicity scaling across collision systems at LHC energies. Whether this trend extends to the top RHIC energy remains an open question. The new datasets of Au+Au, isobar (Ru+Ru and Zr+Zr), O+O and d+Au taken by the STAR detector provide an opportunity to look into different colliding systems to investigate the dependence of strange hardron production on system size at $\sqrt{s_{\text{NN}}}$ = 200 GeV. The Au+Au, d+Au, and O+O systems benefit from the extended kinematic coverage provided by the iTPC upgrade, which increased the rapidity coverage and improved particle-identification capabilities compared to previous results.
In this talk, we will present the measurements of strange hadron ($\phi$, $\Lambda$, $\overline{\Lambda}$, $\Xi^{-}$, $\overline{\Xi}^{+}$, $\Omega^{-}$, $\overline{\Omega}^{+}$) production in Au+Au, isobar, O+O and d+Au collisions at $\sqrt{s_{\text{NN}}}$ = 200 GeV at mid-rapidity ($|y| < 0.5$), including transverse-momentum spectra, mean transverse momentum and yield ratios to pions. Additionally, the $\Omega/\phi$ ratios and the comparison between experimental data and model calculations in these colliding systems will be shown.
