Mixed-phase model and softest point effect

Basic points of the statistical mixed-phase model constructed to describe the thermodynamics of a QCD phase transition are discussed. Physical constraints on the choice of model parameters are considered. Within this approach, modifications are proposed that are aimed at improving the treatment of hadron-hadron interactions within a nonlinear mean-field model of nuclear matter and at taking into account one-gluon-exchange corrections in the plasma sector of the thermodynamic potential of the mixed phase. It is shown that, within the model in question, it is possible to reproduce both the results of lattice calculations that simulate a QCD phase transition and the thermodynamic characteristics of hadronic systems as computed on the basis of modern approaches, The softest point of the equation of state is analyzed on the basis of the statistical mixed-phase model with reference to the possible formation of a long-lived fireball in nuclear collisions (softest point effect). The results obtained in this way are contrasted against the picture that emerges from the two-phase model of deconfinement. The possibilities of experimentally observing the softest point effect as a signal from the QCD phase transition are discussed.