title: Return of collective rotation in 157Er and 158Er at ultrahigh spin.
abstract: 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.
authors.affiliation: Oliver Lodge Laboratory, University of Liverpool, Liverpool, UK.
authors.forename: E S
authors.initials: ES
authors.lastname: Paul
authors.forename: P J
authors.initials: PJ
authors.lastname: Twin
authors.forename: A O
authors.initials: AO
authors.lastname: Evans
authors.forename: A
authors.initials: A
authors.lastname: Pipidis
authors.forename: M A
authors.initials: MA
authors.lastname: Riley
authors.forename: J
authors.initials: J
authors.lastname: Simpson
authors.forename: D E
authors.initials: DE
authors.lastname: Appelbe
authors.forename: D B
authors.initials: DB
authors.lastname: Campbell
authors.forename: P T W
authors.initials: PT
authors.lastname: Choy
authors.forename: R M
authors.initials: RM
authors.lastname: Clark
authors.forename: M
authors.initials: M
authors.lastname: Cromaz
authors.forename: P
authors.initials: P
authors.lastname: Fallon
authors.forename: A
authors.initials: A
authors.lastname: Görgen
authors.forename: D T
authors.initials: DT
authors.lastname: Joss
authors.forename: I Y
authors.initials: IY
authors.lastname: Lee
authors.forename: A O
authors.initials: AO
authors.lastname: Macchiavelli
authors.forename: P J
authors.initials: PJ
authors.lastname: Nolan
authors.forename: D
authors.initials: D
authors.lastname: Ward
authors.forename: I
authors.initials: I
authors.lastname: Ragnarsson