Equivalence of the spherical and deformed shell-model approach to intruder states

K. Heyde, C. De Coster, J. Ryckebusch, M. Waroquier
Physics Letters B
218 (3), 287-290
Published while none of the authors were employed at the CMM


We point out that the description of intruder states, incorporating particle-hole (ph) excitation across a closed shell in the spherical shell model or a description starting from the Nilsson model are equivalent. We furthermore indicate that the major part of the nucleon-nucleon interaction, responsible for the low excitation energy of intruder states comes as a two-body proton-neutron quadrupole interaction in the spherical shell model. In the deformed shell model, quadrupole binding energy is gained mainly through the one-body part of the potential.