Dependence of Temperatures and Kinetic Freeze-Out Volume on Centrality in Au-Au and Pb-Pb Collisions at High Energy

Abstract

Centrality-dependent double-differential transverse momentum spectra of negatively charged particles (π−, K−, and p¯) at the mid(pseudo)rapidity interval in nuclear collisions are analyzed by the standard distribution in terms of multicomponent. The experimental data measured in gold-gold (Au-Au) collisions by the PHENIX Collaboration at the Relativistic Heavy Ion Collider (RHIC) and in lead-lead (Pb-Pb) collisions by the ALICE Collaboration at the Large Hadron Collider (LHC) are studied. The effective temperature, initial temperature, kinetic freeze-out temperature, transverse flow velocity, and kinetic freeze-out volume are extracted from the fitting to transverse momentum spectra. We observed that the mentioned five quantities increase with the increase of event centrality due to the fact that the average transverse momentum increases with the increase of event centrality. This renders that larger momentum (energy) transfer and further multiple scattering had happened in central centrality.

Effects of Coalescence and Isospin Symmetry on the Freezeout of Light Nuclei and Their Anti-particles

“…However, the collisions become less violent as the centrality decreases and less number of participants involve in the interactions which results in comparatively low kinetic freezeout temperature. This is in agreement with[11][12][13][14][15][16], but in disagreement with[17][18][19][20].…”

Study of Dependence of Kinetic Freezeout Temperature on the Production Cross-Section of Particles in Various Centrality Intervals in Au–Au and Pb–Pb Collisions at High Energies

“…The non-strange particles have a larger production cross-section than the strange or multi-strange particles; therefore, the non-strange particles freezeout later than the strange (multi-strange) particles. This result is consistent with that of our recent work [ 10 ]; however, in [ 10 ], the authors also observed a separate decoupling of strange and multi-strange particles. It is noteworthy that the observed at the RHIC is lower than that of the LHC.…”

“…It is very important to search for the correct trend of with energy and centrality. Furthermore, there are different kinetic freezeout scenarios found in the literature, which include single, double, triple and multiple kinetic freezeout scenarios [ 5 , 6 , 7 , 8 , 9 , 10 ]. In the single kinetic freezeout scenario, one set of parameters is used for the strange, multi-strange and non-strange particles.…”

“…In contrast, in the multiple kinetic freezeout scenario, separate sets of parameters are used for each particle. The trend of transverse flow velocity ( ) and freezeout volume ( V ) with energy is an increasing trend in most of the literature [ 6 , 11 , 12 , 13 , 14 , 15 , 16 ]. Most of the literature claims to show a decreasing (or invariant) trend of and V from central to peripheral collisions [ 10 , 15 , 16 , 17 , 18 ].…”

Study of Proton, Deuteron, and Triton at 54.4 GeV

“…In high-energy collisions, there are two types of particle production process: (1) soft process ad (2) hard process. For soft process, there are various methods which include but are not limited to blast wave model with boltzmann Gibbs statistics [5][6][7], blast wave model with Tsallis statistics [8][9][10], Hage-dorn thermal model [20], and standard distribution [33,34]. We are interested in the blast wave model with Tsallis statistics.…”