Mean field effects in heavy-ion collisions at AGS energies

The question whether mean field effects exist in heavy-ion collisions at AGS energies is studied in the framework of A Relativistic Transport (ART) model. It is found that in central collisions of Au+Au at $P_{beam}/A=$11.6 GeV/c a simple, Skyrme-type nuclear mean field satisfying the causality requirement reduces the maximum baryon and energy densities reached in the cascade model by about 30\% and 40\%, respectively. The mean field affects the inclusive, single particle observables of various hadrons by at most 20\%. We show, however, that the mean field causes a factor of 2.5 increase in the strength of the baryon transverse collective flow.