Absence of Low-Energy Shape Coexistence in $^{80}\mathrm{Ge}$: The Nonobservation of a Proposed Excited ${0}_{2}^{+}$ Level at 639 keV
Résumé
The Ge80 structure was investigated in a high-statistics β-decay experiment of Ga80 using the GRIFFIN spectrometer at TRIUMF-ISAC through γ, β-e, e-γ, and γ-γ spectroscopy. No evidence was found for the recently reported 02+ 639-keV level suggested as evidence for low-energy shape coexistence in Ge80. Large-scale shell model calculations performed in Ge78,80,82 place the 02+ level in Ge80 at 2 MeV. The new experimental evidence combined with shell model predictions indicate that low-energy shape coexistence is not present in Ge80.