J. Jolie et H. Lehmann, ON THE INFLUENCE OF THE O(5) SYMMETRY ON SHAPE COEXISTENCE IN ATOMIC-NUCLEI, Physics letters. Section B, 342(1-4), 1995, pp. 1-5
It is shown how the O(5) symmetry present in both the U(5) and O(6) li
mits of the IBM leads to some very drastic effects concerning the coex
istence of normal and intruder states and their mixing. These effects
might be more generally present than anticipated.