Quadrupole collective properties of 114Cd

Abstract

The nucleus 114Cd has been Coulomb excited using beams of 16O, 40Ca, 58Ni and 208Pb. Several new states have been observed and an almost complete set of reduced E2 matrix elements for the lowest-lying positive-parity states in 114Cd have been measured. In total, about 40 E2 matrix elements have been determined in a model-independent way, including the static quadrupole moments of the 4 + 1, 6 + 1, 2 + 2 and 2 + 3 states. Large negative static quadrupole moments were found for the 4 + 1 and 6 + 1 states and a large positive quadrupole moment for the 2 + 2 state. All E2 matrix elements involved in the deexcitation of the quintuplet of states at an energy of about 1.2 Me V were determined. The data are compared with predictions by various models, including a configuration mixing calculation within the framework of the IBA model, the harmonic vibrator and a model in which the states of a near-harmonic vibrator are mixed with those of a rotational intruder band with a large deformation. Although no perfect match is obtained, the data favour a vibration-like structure involving levels up to the four-quadrupole phonon multiplet.