Statistical Hadronization as a Snapshot of a dynamical Fireball Evolution

Statistical hadronization models are extremly succesful in describing measured ratios of hadrons produced in heavy-ion collisions for a wide range of beam energies from SIS to RHIC. Using the idea of statistical hadronization at the phase boundary within the framework of a recently proposed dynamical model for the thermodynamics of fireballs, we establish a relation between the equation of state (EoS) in the partonic phase probed at the phase transition temperature T_C and the measured hadron ratios. In this way, the ratios can be predicted parameter-free. We demonstrate that this framework gives a consistent description of conditions both at SPS and RHIC. As the data on dilepton emission from heavy ion collisions give evidence for strong in-medium modifications of hadronic properties, we schematically investigate the sensitivity of our results to such modifications and qualitatively sketch a consistent scenario involving such in-medium effects.