Single-particle structure of the N = 20 and N = 28 isotones within the dispersive optical model

Abstract

The neutron single-particle characteristics of the N = 20, 28 isotones at 8 < Z < 30 was calculated within the dispersive optical model. The global parameters of the spin-orbit and imaginary parts of the potential as well as surface absorption independent on neutron-proton asymmetry and increased diffuseness at large neutron excess were used in the calculations. The suitability of the global parameters to predict the evolution of the neutron single-particle structure of nuclei near the neutron drip line was investigated. The following results are in agreement with the available experimental data: the reduction of the particle-hole energy gaps, the degeneration of the 1f7/2 and 2p states and then a change in the 1f7/2 , 2p3/2 level sequence and more rapid reduction of the 2p-splitting in comparison with the 1f-splitting with decreasing Z. The predictive power of the dispersive optical model with respect to neutron-rich nuclei is demonstrated.