Consequences of a covariant description of heavy-ion reactions at intermediate energies

Heavy-ion collisions at intermediate energies are studied by using a new relativistic quantum molecular dynamics (RQMD) code, which is a covariant generalization of the quantum molecular dynamics (QMD) approach. We show that this new implementation is able to produce the same results in the nonrelativistic limit (i.e., 50 MeV/nucleon) as the noncovariant QMD. Such a comparison is not available in the literature. At higher energies (i.e., 1.5 GeV/nucleon and 2 GeV/nucleon) RQMD and QMD give different results in respect to the time evolution of the phase space, for example for the directed transverse flow. These differences show that consequences of a covarient description of heavy-ion reactions within the framework of RQMD exist even at intermediate energies