Antibaryon production in hot and dense nuclear matter

The production of antibaryons is calculated in a microscopic transport approach employing multiple meson fusion reactions according to detailed balance relations with respect to baryon-antibaryon annihilation. It is found that the abundancies of antiprotons as observed from peripheral to central collisions of $Pb + Pb$ at the SPS and $Au + Au$ at the AGS can approximately be described on the basis of multiple interactions of 'formed' hadronic states which drive the system to chemical equilibrium by flavor exchange or quark rearrangement reactions.