A ferro-deformation at the open quantum system with protons, Z = 8, neutrons, N = 20: 28O (1605.00370v1)

Abstract: We offer a possibility that the nuclear system with protons, Z = 8 has a large deformation at neutrons, N = 20; 28O that is beyond the neutron drip line. According to our previous works [arXiv: 1604.05013, 1604.02786, 1604.01017], it is expected that the ferro-deformation would occur at Z = 8, N = 20 through a shape phase transition at N = 18 out of N =16. The shape transition can be explained in terms of isospin dependent spin-orbital interactions between neutrons in the d3/2 orbital and protons in the d5/2 orbital, by yielding both the neutron and the proton pseudo-shell configurations built on each combined subshells. We argue that such a large deformation at N = 18 would be responsible for the 26O to be unbound, leading to a ground state neutron emitter. The ferro-deformation is mapped on the nuclear chart such that is around the following critical proton, neutron coordinates, (Z, N); (64, 104), (40, 64), (20, 40), (8, 20). This configuration depicts a beautiful pattern coming from a harmonious order in the microscopic quantum world.