The proceedings of the 4th Italy-Japan Symposium on Heavy Ion Physics cover the following fields of nuclear physics: heavy ion nuclear reactions; nuclei under extreme conditions; nuclear astrophysics; photon detectors and physics; technology of RI beams and experimental instrumentation; application of RI beams.

This symposium was organized in order to discuss recent developments and future perspectives in intermediate-energy heavy-ion physics. The subjects included sub-barrier fusion, superheavy elements, fission; halo, skin nuclei; multi-fragmentation, collective flow, compression; properties of hot nuclei; high spin and exotic nuclear shapes; nuclear astrophysics; applications; facilities.

The book is a collection of papers from the Proceedings of the 5th Italy-Japan Symposium 'Recent Achievements and Perspectives in Nuclear Physics', held in Naples as part of the framework of the INFN-RIKEN Research Collaboration Program. The meeting was devoted to recent achievements and new challenges in the different fields of nuclear physics, with the aim to promote new collaborations between the two communities and thereby enhance the development of nuclear physics in the two countries. Particularly interesting are the topics dedicated to radioactive beams and innovative instrumentation: the prospects for future accelerators and experimental setups as well as novel future research directions. These projects are of key importance for the future of heavy ion nuclear physics.

The interest in understanding the physical world that we live in, the origin of its formation and evolution, is reflected in the world-wide activities in Europe, the USA and Japan to set up powerful research facilities providing beams of radioactive nuclei of various kinds, and beams of extremely large energies. At the same time, complex and large detector arrays with improved technical capabilities are built either around these facilities or independently (dedicated to cosmic rays). Recently, spectacular progress has been made in superheavy nuclei, cold binary and ternary fission, nuclear shell structure and nuclear astrophysics, to mention only a few directions. The energy spectrum of cosmic rays exceeds the upper limits provided by artificial accelerators. An international collaboration has committed itself to the installation of an extremely large area detector array, AUGER, in order to study the highest particle energies in the Universe.

This proceedings volume gives a consistent overview of various theoretical and experimental programs which study the dynamics of nucleus-nucleus collisions from low to ultra-relativistic energies. The contributions concentrate on the following topics: cold fragmentation of nuclear matter, pre-equilibrium and thermalization, thermal and chemical equilibration, fragmentation and correlations in intermediate energy collisions, dynamical properties of hot and dense nuclear matter in medium effects, resonance and strange nuclear matter, and signals of the deconfined state.High quality data obtained using experimental devices close to 4π geometries and recent theoretical developments are presented. They illustrate the significant progress made during the last few years in understanding the properties of nuclear matter in extreme conditions of pressure and temperature.This book serves as a graduate textbook and as a reference work on recent developments in this area.

This symposium focuses on new developments in the fields of experimental and theoretical nuclear physics, including nuclear dynamics, nuclear structure including hypernuclei, nuclear matter, nuclear astrophysics, applications. The participants also reported on the innovative instrumentation, including future large-scale facility both in Japan and Italy that will be essential for future studies.