Abstract
A rotational band was observed for the first time in by means of γ-γ-γ and γ-γ-γ-γ measurements of prompt fission γ rays from by using the Gammasphere multidetector array. Projected shell model and potential-energy surface calculations were performed and were compared to the experimental data of and the previously reported . Configurations and spin-parity were assigned to the ground level, low-lying levels, and rotational bandheads of the two Nb isotopes. The new rotational band in was interpreted as a band with a configuration π1/2[431] × ν5/2[532]. The same spin-parity and configuration were assigned to the analogous band in . π1/2[431] × ν5/2[413], were assigned to the 0.66-μs isomer and explained the 2 isomeric decay to the ground in . The proton intruder orbital π1/2[431] plays an important role in shape evolution with regard to triaxial deformation in these neutron-rich Nb isotopes.
8 More- Received 26 November 2013
- Revised 27 January 2014
DOI:https://doi.org/10.1103/PhysRevC.89.044326
©2014 American Physical Society