Observation of non-homogeneous scenarios for different temperatures in hadron(nucleus)-nucleus collisions at RHIC and LHC energies

Abstract

We used the modified Hagedron function and analyzed the experimental data measured by the BRAHMS, STAR, PHENIX, and ALICE Collaborations in Copper-Copper, Gold-Gold, deuteron-Gold, Lead-Lead, proton-Lead and proton–proton collisions, and extracted the related parameters (kinetic freezeout temperature, transverse flow velocity, kinetic freezeout volume, mean transverse momentum, and initial temperature) from the transverse momentum spectra of the particles (non-strange and strange particles). We observed that all the above parameters increase from peripheral to central collisions, except transverse flow velocity, which remains unchanged. The kinetic freezeout temperature depends on the particle’s interaction cross-section such that a larger cross-section corresponds to a smaller T 0 and reveals the two kinetic freezeout scenarios. Similarly, the initial temperature follows the mass dependency of the particle, and it increases with the particle mass. The transverse flow velocity and mean transverse momentum depend on the particle’s mass. The former decreases while the latter increases with the mass of the particle. Furthermore, different freezeout surfaces for different particles are observed as the kinetic freezeout volume decrease for heavier particles. We also extracted the entropy index-parameter “ n ” and the parameter N 0 , the former remains almost unchanged while the latter decreases from central collisions to the periphery. Furthermore, the kinetic freezeout temperature, transverse flow velocity, kinetic freezeout volume, initial temperature, mean transverse momentum and the parameter N 0 at LHC are larger than that of RHIC, showing their dependence on the collision cross-section and collision energy. • The modified Hagedron function analyzes the experimental data measured by the BRAHMS, STAR, PHENIX, and ALICE Collaborations in different collision systems and energies. • Kinetic freeze-out temperature (T 0 ), transverse flow velocity ( β T ), kinetic freeze-out volume (V), mean transverse momentum (<p T >), and initial temperature (Ti) are extracted from the transverse momentum spectra of the particles. • The parameters increase from peripheral to central collisions, except transverse flow velocity, which remains unchanged. • The T 0 is cross-section dependent. A larger cross-section corresponds to a smaller T 0 and reveals the two kinetic freeze scenarios while the initial temperature increases with the particle’s mass. • The β T and <p T > depend on the particle mass. The former decrease while the latter increase. • Furthermore, different freeze-out surfaces for different particles are observed as the V decrease for heavier particles. • Furthermore, the parameters at LHC are more significant than at RHIC, showing their dependence on the collision cross-section and energy.