New excited states in 142Ba and 144Ce are investigated by means of prompt γ-ray spectroscopy of the radiation following spontaneous fission of 252Cf. Measurements of angular correlations and the observed branchings allowed the assignment of spins and parities with confidence. The new measurements are reinforced by shell-model calculations where energy levels, electric transitions, and magnetic moments are consistent with experimental data. The presence of collectivity in the N=86isotones is confirmed by clear signatures of soft triaxial γ bands in both nuclei.
Naïdja, H., Nowacki, F., Bounthong, B., Czerwinski, M., Rząca-Urban, T., Rogiński, T., Urban, W., Wiśniewski, J., Sieja, K., Smith, A. G., Smith, J. F., Simpson, G. S., Ahmad, I., & Greene, J. P. (2017). New excitations in 142Ba and 144Ce: Evolution of γ bands in the N=86 isotones. Physical Review C, 95, . https://doi.org/10.1103/PhysRevC.95.064303