Probing The Nuclear Paradigm With Heavy Ion Reactions - Proceedings Of The International School Of Heavy Ion Physics

Major developments have taken place during the last few years in the study of the nuclear paradigm as a result of recent detector and accelerator developments, and of improved theoretical models.The active use of 4-π detectors to measure the gamma decay of excited nuclei has been instrumental in exploring the consequences of extremely high rotational frequencies and excitation energies in the nuclear structure. The identification of superdeformed bands, of limiting temperature for the detection of giant resonances, and of rotational damping, are conspicuous examples of this novel type of research. Studies of the disassembling of the nucleus have been systematically carried out, and the results interpreted in terms of transport models.At even higher temperatures one expects to have a completely new regime of hot dense matter, where the hadronic properties become strongly renormalized by the medium.Furthermore, studies of the properties of the nucleon as a many-body system of quarks and gluons displaying collective degrees of freedom which are damped by couplings to more complicated states, are providing a detailed and consistent picture of the nuclear paradigm.Important progress is also taking place in situations essentially opposite to the scenarios described above, namely in the study of correlations in nuclear matter at very low temperature and density.