Maximum freeze-out baryon density in nuclear collisions

Using simple parametrizations of the thermodynamicfreeze-out parameters vextracted from the data over a wide beam-energyrange, we reexpress the hadronic freeze-out line in terms of theunderlying dynamical quantities, the net baryon density rhoB and theenergy density epsilon, which are subject to local conservation laws.This analysis makes it apparent that rhoB exhibits a maximum as thecollision energy is decreased. This maximum freeze-out density hasmu=400-500 MeV, which is above the critical value, and it is reached fora fixed-target bombarding energy of 20-30 A GeV.