Spectroscopy of 111 Cd : Challenging the Particle-Vibration Model

Quadrupole collectivity has traditionally been studied through the measurement of electric quadrupole moments. Recently it has been shown that g factors can be sensitive to the nature of collective excitations in a way that electric quadrupole moments are not [1]. In this new investigation the g factors of excited states in Cd were measured and compared with the predictions of particle-vibration and particle-rotor models. Particle-γ angular correlations were also measured following Coulomb excitation with 90 MeV S beams from the ANU 14UD Pelletron accelerator. Particular attention was focused on the 5/2 and 3/2 states reported [2] at 752.8 and 754.9 keV, respectively. No population of the purported 3/2 state was observed.