Multiple Coulomb excitation of a 70Ge beam and the interpretation of the 02+ state as a deformed intruder
Abstract:Electromagnetic properties of the low-lying states in a 70Ge nucleus were studied through the multiple Coulomb excitation of a 70Ge beam with a natPb target. Relative γ-ray intensities were measured as a function of emission angle relative to the scattered projectile. Sixteen E2 matrix elements, including diagonal ones, for 6 low-lying states have been determined using the least-squares search code GOSIA. The expectation values 〈Q2〉 of 01+ and 02+ states in 70Ge are compared with those in 72, 74, 76Ge. Simple mixing calculations indicate that the 02+ states in 70Ge and 72Se can be treated as deformed intruder states. It is shown that the deformed intruder becomes the ground state in 74Kr. These interpretations of the 02+ states in this region are compared with the potential-energy surface calculations by the Nilsson-Strutinsky model, which allow to interpret the experimental results in a qualitative way from the theoretical point of view.