Band crossing and shape evolution inGe73

The spectroscopy of Ge73 has been investigated via the Zn70(Li7,3np)Ge73 fusion-evaporation reaction. A previously known band built on the ν(f5/2) orbital is extended up to higher-spin states and a new rotational band built on the ν(g9/2) orbital is established. The observed band crossing and shape evolution induced by the alignment in Ge73 are studied in comparison with the similar structures in the neighboring N=41 isotones and the cranked Woods–Saxon–Strutinsky calculations by means of total-Routhian-surface (TRS) methods. The inversion of the order of the g9/2 neutron and the g9/2 proton crossing frequency observed in the negative-parity ν(f5/2) bands between Ge73 and Se75, Kr77 can be ascribed to their different triaxial deformations. At higher spins, both the ν(f5/2) and ν(g9/2) bands in Ge73 undergo a shape evolution with sizable alignments occurring. The characters of large signature splitting in ν(g9/2) band of Ge73 are discussed.Received 13 September 2015DOI:https://doi.org/10.1103/PhysRevC.92.054302©2015 American Physical Society