New subshell closure at N=58 emerging in neutron-rich nuclei beyond Ni78
The structure of neutron-rich nuclei beyond Ni78 was studied using postaccelerated radioactive beams of Ga83,84,85 utilizing βγ and β-nγ spectroscopy. Our data, when combined with energy level systematics, suggests a possible new spherical subshell closure at N=58 is created by the nearly degenerated ν3s1/2 and ν2d5/2 orbitals being well separated from other orbitals above N=50. The near degeneracy of these states could be evidenced by isomerism in this region. The energies of the 21+ and proposed 41+ states observed in N=52 Ge84 are interpreted as an indication of a possible weakening of the doubly magic Ni78 core for nuclei beyond N=50. The experimental evidence is supported by spherical HFB calculations using the SkOT functional involving the tensor term in the nucleon-nucleon interaction. © 2010 The American Physical Society.
Publication Source (Journal or Book title)
Physical Review C - Nuclear Physics
Winger, J., Rykaczewski, K., Gross, C., Grzywacz, R., Batchelder, J., Goodin, C., Hamilton, J., Ilyushkin, S., Korgul, A., Królas, W., Liddick, S., Mazzocchi, C., Padgett, S., Piechaczek, A., Rajabali, M., Shapira, D., Zganjar, E., & Dobaczewski, J. (2010). New subshell closure at N=58 emerging in neutron-rich nuclei beyond Ni78. Physical Review C - Nuclear Physics, 81 (4) https://doi.org/10.1103/PhysRevC.81.044303