  Central collisions of gold nuclei are simulated by several existing models
and the central net baryon density rho and the energy density eps are extracted
at successive times, for beam kinetic energies of 5-40 GeV per nucleon. The
resulting trajectories in the (rho,eps) phase plane are discussed from the
perspective of experimentally exploring the expected first-order hadronization
phase transition with the planned FAIR at GSI or in a low-energy campaign at
RHIC.
