Simple relations for nuclear moments, ch. 2

The electric quadrupole moments of quasi-rotational states in even-even nuclei are studied. A collective model is used to describe the nuclear properties. In this model, a deformed nucleus is taken to consist of two parts, an inner superfluid core, which does not participate in the collective motion, plus an outer fluid, which moves bodily about it. Such a description is the collective analogon of the individual-particle shell-model. It is shown that within the limits of this so-called rotationally invariant core model there is a relation between the quadrupole moment and the excitation energy of a rotational state. This relation, which is linear to first order, proves insensitive to the exact form of the nuclear matter density distribution. Calculated values are compared with experimentally known quadrupole moments. For the mass region A = 18-208 good overall agreement is observed