Narrow Results

This paper refers to another attempt to search for spherical double shell closure nuclei beyond Z = 82, N = 126. All calculations and results are based on a newly developed approach entitled as simple effective interaction (SEI). Our results predict that the combination of magic nucleus occurs at N = 182 (Z = 114, 120, 126). All possible evidences for the occurrence of magic nuclei are discussed systematically. And, the obtained results for all observables are compared with the relativistic mean field theory for NL3 parameter.

The present contribution focuses on three recent experimental achievements obtained at the GANIL facility on the study of the N = 28 shell closure south to the doubly magic nucleus . First, the single particle energies of the neutron fp states in ⁴⁷Ar have been determined by transfer (d,p) reaction using a radioactive beam of . A reduction of the N = 28 gap and of the SO splittings of the f and p states is found. Second, an E0 isomer has been discovered in which is suggestive of a shape mixing. Third, the energy of the first 2⁺ state of has been obtained through in-beam γ-ray emission induced by a 2 protons knock-out reaction. Its low value, 770(19) keV, points to a large deformation there. The gradual change from spherical to deformation in the N = 28 isotones from Z = 20 to Z = 14 is ascribed to specific proton-neutron interactions and to enhanced quadrupole correlations. A global description of all the physics involved at N = 28 is derived along with experimental results.