Coexistence of octupole deformation and beta and gamma vibrational bands in Ce-148

From gamma-gamma-gamma and gamma-gamma-gamma-gamma coincidence studies of spontaneous fission of Cf-252, new high spin states in Ce-148 were identified. The octupole bands with s = +1 and s = -1 are expanded with spins with 28(+) and 18(-), respectively. Importantly, a 1 gamma vibrational band has been established up to 14(+) and a 1 beta vibrational band up to 6(+). The levels in gamma and beta bands in Ce-148 are compared systematically to those in neighboring Nd-150 and Sm-152 isotones. This comparison informs the role of deformation and shape transition in this mass region. New 3(-) and 5(-) members of the s = +1 octupole band were observed. (C) 2021 Elsevier B.V. All rights reserved.