The Winter School "Nuclear Matter and Heavy Ion Collisions", a NATO Research Workshop held at Les Houches in February 89, has been devoted to recent developments in nuclear matter theory and to the study of central heavy ion collisions in which quasi macroscopic nuclear systems can be formed at various temperatures and densities. At in cident energies below 100 Me V per nucleon, the kinematic conditions are favourable for producing transient hot nuclei with temperatures of the order of a few MeV. At higher ener gies (100 MeV < E/A < 1-2 GeV) heavy ion collisions offer the possibility of investigating the properties of hot and dense nuclear systems. The Workshop has been motivated by important theoretical developments in transport equations whicll make it possible to relate microscopic descriptions of heavy ion collisions to nuclear matter theory and by the need to review the large body of data available on heavy ion collisions and discuss future experimental programs. This discussion was especially timely a few months before the new SIS/ESR Heavy Ion Fa.cility starts operating in Darmstadt. The School consisted mostly of series of lectures on nuclear matter, transport equations and the dynamics of heavy ion collisions. The data and their interpretation were exten sively discussed; the information carried by the various types of particles emitted during the collisions (photons, lepton pairs, pions, hons, nucleons, fragments) has been particu larlyemphasized. Specialized topics were presented as shorter contributions by participants.

Inhalt
Invited Papers.- Nuclear Matter with Non-Relativistic Potentials: Present Status.- A Relativistic Theory of Nuclear Matter.- Elements of a Relativistic Microscopic Theory of Hadronic Matter in Equilibrium and Non-Equilibrium.- Hot Nuclear Matter.- to Non-Relativistic Transport Theories.- Relativistic Transport Theory of Fluctuating Fields For Hadrons.- Pion Absorption in Nuclei.- Formation and Decay of Hot Nuclei: The Experimental Situation.- Multifragmentation Of Nuclei.- Nuclear Matter and Fragmenting Nuclei.- Collective Phenomena in Relativistic Heavy Ion Collisions: The Experimental Situation.- Inclusive Experiments, Correlations and Pion Production Data.- Confrontation of Theoretical Approaches and Experimental Data on High Energy Heavy Ion Collisions.- Momentum Dependent Mean Fields in The BUU Model of Heavy Ion Collisions.- Hard Photons and Subthreshold Mesons From Nucleus-Nucleus Collisions.- Measurements of e+e- Pair Production at The Bevalac.- Status Of The SIS/ESR-Project at GSI.- Contributed Papers.- Heavy Ions at Saturne.- Pion Polarisations in The Relativistic Dirac-Brueckner Model.- Cut-Off And Effective Meson Field Theory.- A Non-Perturbative Transport Theory For Nuclear Collective Motion.- Timescale of Particle Emission Using Nuclear Interferometry.- Determination of Time Scales in Intermediate Energy Reactions.- Fragment Production and Nuclear Freezeout.- A Excitation in Nuclei by Heavy Ion Charge-Exchange Reactions.- Momentum Dependent Potentials in Relativistic Heavy Ion Collisions.- Classical Models Of Heavy Ion Collisions.- Relativistic Molecular Dynamics and The Relativistic Vlasov Equation.- Stability Conditions and Vibration Modes of Self-Consistent Vlasov Solutions with Diffuse Surface.- Sideward Flow of Charged Particles and Neutrons in HeavyIon Collisions.- Dilepton Radiation From Hot Nuclear Matter and Nucleon-Nucleon Collisions.- Kaon And Pion Production in the Reaction Silicon (14.5 MeV) on Gold.- Participants.