Space–time evolution of ultra-relativistic heavy ion collisions and hadronic spectra Original Research Article

The space–time evolution of the hot and dense matter formed after the collisions of heavy nuclei at ultra-relativistic energies is investigated using (3+1)-dimensional hydrodynamical models. The effects of the spectral shift of the hadronic properties are incorporated in the equation of state (EOS) of the evolving matter. In-medium shift of hadronic properties are considered for Quantum Hadrodynamics (QHD) and universal scaling scenarios. It is found that the EOS for the hadronic matter for universal scaling of hadronic masses (except pseudoscalar) is similar to the recent lattice results. We observe that the space–time volume of the hadronic matter at the freeze-out is considerably different from the one when medium effects on the hadrons are ignored. The transverse mass spectra of pions and protons of the NA49 Collaboration are analyzed in the present framework.