A simple model of nucleons coupled to angular momentum zero (s-pairs)
occupying the valance shell of a semi-magic nuclei is considered. The model has
a separable, orbit dependent pairing interaction which dominates over the
kinetic term. It is shown that such an interaction leads to an exactly solvable
model whose (0+) eigenstates and energies can be computed very easily with the
help of the algebraic Bethe ansatz method. It is also shown that the model has
a supersymmetry which connects the spectra of some semimagic nuclei. The
results obtained from this model for the semimagic Ni isotopes from 58Ni to
68Ni are given. In addition, a new and easier technique for calculating the
energy eigenvalues from the Bethe ansatz equations is also presented.Comment: Talk given at the International Conference on Nuclear Physics and
Astrophysics: From Stable Beams to Exotic Nuclei, Cappadocia, June 200
