COEXISTENCE IN EVEN-EVEN CD NUCLEI - GLOBAL STRUCTURE AND LOCAL PERTURBATIONS

The even-even Cd nuclei near neutron number N = 66 are indicative of t he presence of two rather distinct families of excitations: anharmonic quadrupole vibrations and more deformed intruder particle-hole excita tions. We discuss these excitations as mainly coexisting families of s tates forming the global structure of these nuclei. Then, we investiga te how local large perturbations can cause strong mixing between the t wo families. The coupling is studied in detail and a particular set of selection rules governing the mixing leads to the introduction of a n ew basis in order to discuss the interaction between vibrational and i ntruder 9 excitations. Numerical applications are carried out for Cd-1 12,114.