Particle Production in Heavy Ion Collisions

The yield and the phase-space distributions of particles produced in heavy-ion collisions are sensitive to the reaction dynamics and to the conditions inside the dense and hot fireball. At beam energies where the number of produced particles is still small as compared to the number of participating nucleons, newly created particles can be used as probes for dense baryonic matter. In particular, experimental data on strangeness production at SIS energies, together with their theoretical interpretation based on microscopic transport theory, permit to explore fundamental aspects of modern nuclear physics: the determination of the nuclear equation-of-state at high baryon densities and the properties of hadrons in dense nuclear matter. Experimental data and theoretical results will be reviewed.