Return of collective rotation in 157Er and 158Er at ultrahigh spin.
Paul ES., Twin PJ., Evans AO., Pipidis A., Riley MA., Simpson J., Appelbe DE., Campbell DB., Choy PTW., Clark RM., Cromaz M., Fallon P., Görgen A., Joss DT., Lee IY., Macchiavelli AO., Nolan PJ., Ward D., Ragnarsson I.
A new frontier of discrete-line gamma-ray spectroscopy at ultrahigh spin has been opened in the rare-earth nuclei (157,158) Er. Four rotational structures, displaying high moments of inertia, have been identified, which extend up to spin approximately 65 variant Planck's over 2pi and bypass the band-terminating states in these nuclei which occur at approximately 45 variant Planck's over 2pi. Cranked Nilsson-Strutinsky calculations suggest that these structures arise from well-deformed triaxial configurations that lie in a valley of favored shell energy which also includes the triaxial strongly deformed bands in (161-167) Lu.