Evidence of a spherical to prolate shape transition in the germanium nuclei

Directional correlation of γ transitions inGe72following the decay ofGa<

“…The static quadrupole moments of the 6rst 2+ excited states of ' ' ' Ge have been measured recently using re-orientation effects in Coulomb excitation [8] and the results are in good agreement with the above calculations except that the oblate to prolate shape transition occurs at N=40. Kumar [28] has employed the dynamic deformation model to calculate the spectra of " ' ' Ge.…”

“…The calculations suggest that the 02 state in this nucleus is collective and deformed and probably is the bandhead of a rotational band. The value of the quadrupole moment of the 2~s tate in Ge as well as the experimentally observed transition from an oblate to prolate shape [8] in going &om Ge to Ge is well reproduced. According to these authors, strong mixing of prolate and oblate intrinsic shapes is responsible for a complicated structure of Ge.…”

“…The calculated potential energies indicate a shape transition &om a nearly spherical Ge to an oblate transitional Ge to an oblate deformed 4Ge. The predicted spherical to oblate shape transition at N=40 is, however, not borne out by the experimental results of the quadrupole moments of the first 2+ excited states in these nuclei [8].…”

“…Unfortunately the quadrupole moment data is not available in many cases to draw detailed conclusions; it may be worth pointing out here that the sign of Q2+ in even Ge nuclei does change at N=40 (Ref. [8]). …”

Shape Coexistence in Even-Even Ge Isotopes - Complete Spectroscopy with Coulomb Excitation -

“…beams. 17,IS) In 70Ge, six 'Y-rays were observed and included in the fitting routine. Totally 12 E2 reduced matrix elements were tentatively determined, including 3 diagonal matrix elements.…”