Description of N = 7 ∼ 9 Isotones with a Modified Single-Particle Potential

Abstract

We study the level structures of N = 7 ∼ 9 isotones and their mirror nuclei in the framework of the single-particle potential model. Considering the limitation of the conventional potential-model calculation, the isospin-dependent l2 coupling is newly introduced in the average potential. The modified model gives a unified description for the structures of all studied nuclei. Calculations self-consistently produce the s-d level inversion in N = 9 isotones and their mirror nuclei. Meanwhile, the s-p level inversion in the mirror nuclei 11Be and 11N is reproduced. The study confirms the neutron halo structures in 11Be(2s1/2), 11Be(1p1/2), 12B(2s1/2), 14B(2s1/2), 13C(2s1/2), 15C(2s1/2) and the proton halo structure in 17F(2s1/2). The agreement between theory and experiment indicates that the inclusion of the l2 coupling is a feasible way to explain the abnormal structures of exotic light nuclei.

Ordering of the0d5/2and1s1/2proton levels in light nuclei

“…[30]. The width of this state [Γ = 0.85 (15) MeV] is consistent with a single-proton state [Γ sp ≈ 0.9 MeV] so there are no additional uncertainties. The excitation energy of the 5/2 + state was adopted from the work of Ref.…”

“…A sub-set of literature has focused specifically on s-state protons or on the relative energies of 1/2 + and 5/2 + states in sd-shell nuclei, including Refs. [8][9][10][11][12][13][14][15] and other papers referred to therein.…”

Ordering of the $0d_{5/2}$ and $1s_{1/2}$ proton levels in light nuclei

“…A sub-set of the literature has focused specifically on s-state protons or on the relative energies of 1/2 + and 5/2 + states in sd-shell nuclei, including Refs. [8][9][10][11][12][13][14][15] and other papers referred to therein.…”