THERMINATOR simulations and PHENIX images of a heavy tail of particle emission in 200 GeV Au+Au collisions

Abstract

Correlation between emitted particles from a thermalized medium carry important information about the space-time extent and the dynamics of the particle emitting source. Pion emission source functions S(r) have been measured in PHENIX using an imaging technique, and it has been found that it contains a heavy (power-law) tail. It leads us to the assumption that there is a halo of secondary pions, surrounding the core system that undergoes the hydrodynamical evolution. THERMINATOR, a Monte Carlo event generator designed for studies in relativistic heavy-ion collisions is used to model and investigate the influence of resonance decays on the tail of particle emission source. It lacks the implementation of rescattering, which, as we have learnt from previous Hadron Rescattering Code simulations, is a possible explanation of the power-law tail. Our studies also have shown that none of the pion sources alone are responsible for the tail: either the resonance decays or rescattering or a combination of these effects is a possible cause of the heavy tail.