IBM-2 configuration mixing and its geometric interpretation for germanium isotopes

The low energy spectra, electric quadrupole transitions, and quadrupole moments for the germanium isotopes are determined in the formalism of the IBM-2 with configuration mixing. These calculated observables reproduce well the available experimental information including the newly obtained data for radioactive neutron-rich 78,80,82 Ge isotopes. Using a matrix formulation, a geometric interpretation of the model was established. The two energy surfaces determined after mixing, carry information about the deformation parameters of the nucleus. For the even-even Ge isotopes the obtained results are consistent with the shape transition that takes place around the neutron number N = 40. (Author)