Mixed Symmetry States in Even—Even ^96—108Mo Nuclei

Excitation energies and clcctromagnetic transition strengths in even-even 96-108Mo muclei have been dcscribed systcmatically by using the proton-neutron interacting boson model (IBM-2). It appears that the properties oflow-lying levels in these isotopes, for which the comparison between experimcnt and theory is possible, can be satisfac-torily described by the IBM-2 model, provided proper account is taken of the presence at low energy of statcs having amixed-symmetry character. It seems possible to identify, in each isotope, a few states having such a character, the lowestones being either 2+2 or 2+3 levels. It is found that these nuclei are in the transition from U(5) to SU(3).