Evolution of the Neutron Single-Particle Structure of Neutron-Rich Isotones with N=28 in the Dispersive Optical Model

摘要

The evolution of the single-particle characteristics of isotones with N = 28 upon approaching the neutron drip line has been calculated using a dispersive optical model. According to the calculation, the particle-hole gap N = 28 sharply decreases with an excess of neutrons so that the 1f(7/2), 2p(3/2) and 2p(1/2) states are almost degenerate at the neutron drip line with an occupation probability close to 0.5. Due to the Jahn-Teller effect, the degeneracy of these states is one of the causes of deformation of neutron-rich isotones with N = 28.