Exotic Nuclei Exon2004

Abstract

British Library Cataloguing-in-Publication Data (France) and GSI (Germany). According to this the Symposium had four cochairmen: Profs. Yu.Ts.Oganessian, T.Motobayashi, D.Goutte and G.Muenzenberg. The main goal of the Symposium was to discuss the latest results on the production and study of the properties of the lightest to heaviest nuclei, as well as the plans for fkture joint investigations in the field of exotic nuclei. The results were summarized during a round table discussion.The topics of the Symposium could be conditionally divided into:Methods The big interest in the synthesis of new isotopes of the light elements could explain the numerous reports on this topic. In principle, in the region of neutron-rich isotopes of light elements the nucleon dripline has been reached.Here search is carried out of quasi-stationary states in super neutron-rich systems. Of great interest from this point of view are the super neutron-rich isotopes of hydrogen (4H, 5H, 6H, 7H), helium (9He, "He), as well as the multineutron systems (the tetraneutron). Considerable success in this direction has been achieved at FLNR, JINR. Using 6He and t beams information was obtained on resonance states in 4H and 5H. In a joint FLNR -RIKEN experiment the superheavy isotopes of hydrogen (7H) and helium ('He) were studied. Search for the tetraneutron was carried out in experiments at GANIL. In these experiments the breakup of the neutron-rich *He and I4Be nuclei was used. Twelve events were registered in a neutron detector that could be interpreted as bound states in the system of 4 neutrons. In the d(8He,6Li)4n-reaction, studied at GANIL, a resonance at 2.5 MeV was observed and interpreted as corresponding to the tetraneutron. However, these preliminary results need to be checked with higher statistics. concerns their stability, the magicity of these nuclei was of no importance. New magic numbers N = 6, 16 and 32 were discovered. Moreover, the presence of two shapes -spherical and deformed -was found to exist close to the magic numbers. In that, a significant role belongs to deformation. Many theoretical and experimental studies have been dedicated to these properties. Direct experiments to measure the deformation of nuclei close to the N = 20 shell (32Mg) were carried out. They confirmed the presence of deformation in this nucleus. For the first time a method, based on the nuclear magnetic resonance (NMR), was used. Experiments of precision y-spectroscopy with radioactive ion beams using the detectors EXOGAM, AGATA and EUROGAM were also performed. Nuclear masses in the region of N = 20-28 have also been measured. The results of all these experiments have shown that we are dealing with a new region of nuclei ("island of inversion"). Exotic nuclei manifest their unusual properties also in reactions with other nuclei. Recently new interesting results were obtained in experiments aimed at the measurement of excitation functions of total reaction cross sections, fusionfission and evaporation residue reactions. Such reactions were investigat...