The RIKEN Symposium was held in December of 1989 with 3 main goals in mind. The first goal was to survey the present status of studies in nuclear collective motion and nuclear reaction dynamics. The second goal was to look into future directions of the two topics. The third goal of the Symposium was to commemorate the work of the late Professor Taro Tamura.

The proceedings of the symposium on Nuclear Collective Motion and Nuclear Reaction Dynamics is dedicated to three main areas: to survey the present state of studies in nuclear collective motion and nuclear reaction dynamics, to study the possible future directions of these two topics and to commemorate the work of the late Taro Tamura.

These proceedings contain selected topics covering various fields of collective motion and nuclear dynamics, ranging from low to high energies, from nuclear structure to reaction mechanisms, from regular stable to chaotic systems, and from fragmentation to fusion. Several ways of investigating the nuclear systems are presented: electron scattering radioactive beams, fragmenting projectiles, beta and double beta decays, and cluster emission. Their behaviour, under some extreme situations such as superdeformation, high spin states, high temperature, and relativisitic energy, is described within various theoretical formalisms.

Over the last decade one of the most active areas of research in nuclear physics has been the study of systems of nucleons in various dynamical situations. Heavy-ion collisions at beam energies in the range 30-150 MeV per nucleon, where subnucleaonic degrees of freedom can be considered as frozen, allow such systems to be studied in detail. Nuclear

This workshop was established as a forum for experts from different subfields in nuclear dynamics to investigate unifying concepts of nuclear reactions in different beam energy regimes. The proceedings contain an overview of recent experimental and theoretical progress in nuclear dynamics from ultra-subbarrier fusion studies to the physics of the quark-gluon plasma at AGS, CERN, and RHIC energies.

The two most important developments in nuclear physics were the shell model and the collective model. The former gives the formal framework for a description of nuclei in terms of interacting neutrons and protons. The latter provides a very physical but phenomenological framework for interpreting the observed properties of nuclei. A third approach, based on variational and mean-field methods, brings these two perspectives together in terms of the so-called unified models. Together, these three approaches provide the foundations on which nuclear physics is based. They need to be understood by everyone practicing or teaching nuclear physics, and all those who wish to gain an understanding of the foundations of the models and their relationships to microscopic theory as given by recent developments in terms of dynamical symmetries.This book provides a simple presentation of the models and theory of nuclear collective structure, with an emphasis on the physical content and the ways they are used to interpret data. Part 1 presents the basic phenomenological collective vibrational and rotational models as introduced by Bohr and Mottelson and their many colleagues. It also describes the extensions of these models to parallel unified models in which neutrons and protons move in a mean-field with collective degrees of freedom. Part 2 presents the predominant theories used to describe the collective properties of nuclei in terms of interacting nucleons. These theories, which are shared with other many-body systems, are shown to emerge naturally from the unified models of Part 1.