Systematic studies on the exotic properties of isotopes from oxygen to calcium Original Research Article

Systematic calculations of the ground state properties of nuclei with proton number Z=8–20 have been made by the macroscopic–microscopic (MM) model with isospin-dependent spin–orbit potential. Special emphases are placed on the exotic properties of neutron-rich nuclei, the evolution of deformations and the shell structures. The calculated binding energies agree well with the experimental data. The calculations well reproduce the deformations for both nuclei near stability-line and drip-line. The calculations extend the boundaries of the island of inversion and show that 28–32Ne, 29–33Na and 30–34Mg belong to the island. The large deformations and exotic properties of nuclei around N=20 are discussed and their origin are explained. We stress that both protons and neutrons play important roles in the formation of the large deformations and the appearance of the island of inversion. The properties of nuclei around N=28 are also discussed. The calculations show that the N=28 shell seems to disappear in Mg, Al and Si isotopes. We show that most exotic properties of sd and pf shell nuclei can be understood in MM model.