NEAR-THRESHOLD PARTICLE-PRODUCTION IN HEAVY-ION COLLISIONS

Recent results on pi0, pi+/-, eta, K+/- and pBAR-production obtained at SIS are summarized. Systematics for particle spectra and production probabilities have been established. The subthreshold production of eta, K+ and pBAR has been observed and the importance of multi-step production processes is emphasized. At bombarding energies of 1-2 GeV/u there is evidence for a gradual transition to resonance matter with about 30% of the baryons excited to DELTA,N* resonances corresponding to a density rho(N*,DELTA) almost-equal-to rho0. The future perspectives of the field, in particular the potential of dilepton emission in heavy ion collisions is outlined.