Structure of low-lying states by (α,α′) inelastic scattering at 25 MeV (I). 70,72,74,76Ge isotopes

Abstract

Abstract Differential cross sections were measured for elastic and inelastic scattering of 25 MeV α-particles from 70,72,74,76 Ge. Coupled-channels calculations based on the asymmetric rotor model and the vibrational model were performed for the 0 1 + -2 1 + -2 2 + -4 1 + and 0 1 + -2 1 + -0 2 + -2 1 + -4 1 + -3 − states, respectively. The asymmetric rotor model describes better than the vibrational model the even-parity excited states. A change in the nuclear structure between 70,72 Ge and 74,76 Ge is indicated by our data when comparing the angular distributions of the 0 1 + , 2 1 + and 3 − states. An oblate to prolate shape deformation between 70 Ge and 72,74,76 Ge is consistent with our results, as deduced from the study of the 2 2 + angular distributions in the context of the asymmetric rotor model.