Unified thermal freeze-out model and its parameters at RHIC

Abstract

The variation of the parameters (thermal freeze-out temperature, transverse collective flow velocity parameter, distribution width and the nuclear transparency parameters a and b ) of the unified statistical thermal freeze-out model of multi-particle production with the center of mass energy, s NN have been studied at RHIC. We find that the transverse collective flow velocity parameter increases with the increase in s NN . The thermal/hydro-dynamical freeze-out temperature is found to decrease with the increase in s NN . It is found that the freeze-out of doubly and triply strange particles occur at somewhat earlier times compared to non-strange and singly strange hadronic species during the evolution of the fireball at each energy. The value of “ a ” is found to increase with the decrease in energy while as the value of “ b ” is found to increase with the increase in center of mass energy.