Shell structure of neutron-rich light nuclei: New vista

Abstract

The structure of neutron-rich light nuclei can be investigated by means of in-beam gamma spectroscopy using both stable and radioactive beams. Two of such experiments have been recently performed at GANIL. i) Secondary beams of neutron-rich Ge, Zn and Ni isotopes around N=40 were produced from the fragmentation of primary 70Zn and 86Kr beams, and analyzed by means of the LISE3 spectrometer. For the transitions between the 0+ ground state and the first 2+ state, B(E2) values have been extracted from Coulomb excitation cross-section measurement. Some of the obtained results related to the effectiveness of the N=40 spherical sub-shell closure are discussed. ii) In-beam γ-spectroscopy of neutron-rich nuclei around 32Mg produced by fragmentation of 36S have been recently performed. Gamma decay of relatively high-lying excited states have been measured in a large number of exotic light nuclei. New results obtained in a number of neutron-rich nuclei around N=20 are presented.