Abstract
Attention is fixed on shells in toroidal nuclei in the intermediate-mass region using a toroidal single-particle potential. We find toroidal shells in the intermediate-mass region with large single-particle energy gaps at various nucleon numbers. These toroidal shells are located at different toroidal deformations characterized by the aspect ratios of the toroidal major radius to the toroidal minor radius, and they provide extra stability at various toroidal deformations. Relative to a toroidal core, the Bohr–Mottelson spin-aligning particle-hole excitations may be constructed to occupy the lowest single-particle Routhian energies to lead to toroidal high-spin isomers with different spins. Furthermore, because a nucleon in a toroidal nucleus possesses a vorticity quantum number, toroidal vortex nuclei may be constructed by making particle-hole excitations in which nucleons of one type of vorticity are promoted to populate unoccupied single-particle orbitals of the opposite vorticity. Methods for producing toroidal high-spin isomers and toroidal vortex nuclei are discussed.
