Pion-production in heavy-ion collisions at SIS energies

We investigate the production of pions in heavy-ion collisions in the energy range of 1-2 GeV/A. The dynamics of the nucleus-nucleus collisions is described by a set of coupled transport equations of the Boltzmann-Uehling-Uhlenbeck type for baryons and mesons. Besides the N(938) and the Delta(1232) we also take into account nucleon resonances up to masses of 1.95 GeV/c(2) as well as pi-, eta- and rho-mesons. We study in detail the influence of the higher baryonic resonances and the 2 pi-production channels (NN --> NN pi pi) on the pion spectra in comparison to pi(-) data from Ar + KCl collisions at 1.8 GeV/A and pi(0)-data for Au + Au at 1.0 GeV/A, We, furthermore, present a detailed comparison of differential pion angular distributions with the BEVALAC data for Ar + KCl at 1.8 GeV/A. The general agreement obtained indicates that the overall reaction dynamics is well described by our novel transport approach.