PARTICLE DENSITIES AT THE CENTER REGION IN HIGH ENERGY HEAVY-ION COLLISIONS

Based on the two-chain model by A.Capella et al. the rapidity distributions of the multiplicity in high energy heavy-ion collisions, especially in head-on collisions, are discussed. The energy density at the center region in head-on collisions is estimated for different incident energies and different heavy ions. It is shown that the condition of the phase transition to the quark-gluon plasma can be realized in heavy-ion collisions at several tens of GeV.