Collision centrality and energy dependence of strange hadron production in Au + Au collisions at sNN=7.7 –54.4 GeV

Abstract

We apply an equal-velocity quark combination model to systematically study the transverse momentum (${p}_{T}$) spectra of identified hadrons ${K}_{S}^{0}, \ensuremath{\phi}, \mathrm{\ensuremath{\Lambda}}, {\mathrm{\ensuremath{\Xi}}}^{\ensuremath{-}}, {\mathrm{\ensuremath{\Omega}}}^{\ensuremath{-}}, \overline{\mathrm{\ensuremath{\Lambda}}}, {\overline{\mathrm{\ensuremath{\Xi}}}}^{+}, {\overline{\mathrm{\ensuremath{\Omega}}}}^{+}, p, \overline{p}, {\ensuremath{\pi}}^{+}$, and ${\ensuremath{\pi}}^{\ensuremath{-}}$ at midrapidity in $\mathrm{Au}+\mathrm{Au}$ collisions at $\sqrt{{s}_{NN}}=7.7$, 11.5, 19.6, 27, 39, 54.4 GeV. The relative deviation between model calculations and experimental data of these 12 hadrons is generally about 10% in central collisions even at low collision energies and is weakly increased in peripheral collisions. We systematically explain the dependence of two baryon-to-meson ratios $\overline{\mathrm{\ensuremath{\Lambda}}}/{K}_{S}^{0}$ and $\mathrm{\ensuremath{\Omega}}/\ensuremath{\phi}$ on ${p}_{T}$, collision centrality, and collision energy by the property of quark ${p}_{T}$ spectra at hadronization. We derive the analytic relations between ${R}_{CP}$ of hadrons and those of quarks, and we use them to naturally explain the species and ${p}_{T}$ dependence of ${R}_{CP}$ of those strange hadrons.