Evidence for rigid triaxial deformation at low energy in76Ge

Abstract

Excited states of ${}^{76}$Ge have been populated in above-barrier Coulomb excitation and inelastic scattering of a 530-MeV ${}^{76}$Ge beam on a ${}^{238}$U target and studied using in-beam $\ensuremath{\gamma}$-ray spectroscopy with the Gammasphere array. The $\ensuremath{\gamma}$ band was extended considerably and one new band was identified. Comparisons of the $\ensuremath{\gamma}$ band with collective- and shell-model calculations suggest that ${}^{76}$Ge may be a rare example of a nucleus exhibiting rigid triaxial deformation in the low-lying states.