Analyses of the collective properties of hadronic matter in Au-Au collisions at 54.4 GeV

Abstract

We investigated the strange hadrons transverse momentum (${p}_{T}$) spectra in Au-Au collision at $\sqrt{{s}_{NN}}=54.4\text{ }\text{ }\mathrm{GeV}$ in the framework of modified Hagedorn function with embedded flow. It is found that the model can describe the particle spectra well. We extracted the kinetic freeze-out temperature ${T}_{0}$, transverse flow velocity ${\ensuremath{\beta}}_{T}$, kinetic freeze-out volume $V$, mean transverse momentum $⟨{p}_{T}⟩$, the entropy parameter $n$, and the multiplicity parameter ${N}_{0}$. We reported that all these parameters increase towards the central collisions. The larger kinetic freeze-out temperature, transverse flow velocity, kinetic freeze-out volume, and the entropy parameter ($n$) in central collisions compared to peripheral collisions show the early decoupling of the particles in central collisions. In addition, all the above parameters are mass dependent. The kinetic freeze-out temperature (${T}_{0}$), the entropy parameter $n$, and mean transverse momentum ($⟨{p}_{T}⟩$) are larger for massive particles, while the transverse flow velocity (${\ensuremath{\beta}}_{T}$), kinetic freeze-out volume ($V$), and the multiplicity parameter (${N}_{0}$) show the opposite behavior. Larger ${T}_{0}$, $n$, and smaller ${\ensuremath{\beta}}_{T}$ as well as $V$ of the heavier particles indicate the early freeze-out of the heavier particles, while larger $⟨{p}_{T}⟩$ for the heavier particles evince that the effect of radial flow is stronger in heavier particles. The separate set of parameters for each particle shows the multiple kinetic freeze-out scenario, where the mass-dependent kinetic freeze-out volume shows the volume differential freeze-out scenario. We also checked the correlation among different parameters, which include the correlation of ${T}_{0}$ and ${\ensuremath{\beta}}_{T}$, ${T}_{0}$ and $V$, ${\ensuremath{\beta}}_{T}$ and $V$, $⟨{p}_{T}⟩$ and ${T}_{0}$, $⟨{p}_{T}⟩$ and ${\ensuremath{\beta}}_{T}$, $⟨{p}_{T}⟩$, and $V$, $n$ and ${T}_{0}$, $n$ and ${\ensuremath{\beta}}_{T}$, and $n$ and $V$, and they all are observed to have positive correlations with each other which validates our results.