Production and enhancement of (multi-) strange hadrons in Au+Au collisions at sNN=200 GeV RHIC energy and Pb+Pb collisions at sNN=2.76 TeV LHC energy

Abstract

In this article, we investigate $\mathrm{Au}+\mathrm{Au}$ and $\mathrm{Pb}+\mathrm{Pb}$ collision systems to understand the (multi-) strange hadron production at Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) energies using the Monte Carlo $\mathrm{HYDJET}++$ model. We study the ${p}_{T}$ spectra, particle ratios, and strangeness enhancement factor for (multi-) strange hadrons. The ${p}_{T}$ spectra of ${K}^{+}({K}^{\ensuremath{-}})$, ${K}_{s}^{0}$, $\mathrm{\ensuremath{\Lambda}}(\overline{\mathrm{\ensuremath{\Lambda}}})$, ${\mathrm{\ensuremath{\Xi}}}^{\ensuremath{-}}({\overline{\mathrm{\ensuremath{\Xi}}}}^{+})$, and ${\mathrm{\ensuremath{\Omega}}}^{\ensuremath{-}}({\overline{\mathrm{\ensuremath{\Omega}}}}^{+})$ are shown for both $\mathrm{Au}+\mathrm{Au}$ and $\mathrm{Pb}+\mathrm{Pb}$ collision systems in various centrality intervals. We find that the strange quark thermalization might not be achieved by the model for multistrange baryons toward peripheral collisions. The ${p}_{T}$-differential particle ratios, focused on strange hadron-to-meson ratios, are reported for 0--5% and 40--60% centrality intervals for both the collision systems. We observe an enhancement in the particle ratios at intermediate ${p}_{T}$ region. ${p}_{T}$ integrated strange-to-nonstrange ratios suggest that chemical equilibrium might not be achieved for multistrange hadrons. We report the strangeness enhancement factor for $\mathrm{\ensuremath{\Lambda}}(\overline{\mathrm{\ensuremath{\Lambda}}})$, ${\mathrm{\ensuremath{\Xi}}}^{\ensuremath{-}}({\overline{\mathrm{\ensuremath{\Xi}}}}^{+})$, and ${\mathrm{\ensuremath{\Omega}}}^{\ensuremath{-}}+{\overline{\mathrm{\ensuremath{\Omega}}}}^{+}$ at both RHIC and LHC energies. An increase in the enhancement factor is observed with the increase in strangeness content of the baryons. We also observe that enhancement is higher in $\mathrm{Au}+\mathrm{Au}$ collisions than in $\mathrm{Pb}+\mathrm{Pb}$ collisions. Further, we compare the $\mathrm{HYDJET}++$ results with the experimental data and various other simulation models, wherever possible.