Deformation and mixing of coexisting shapes in neutron-deficient polonium isotopes

Abstract
Coulomb-excitation experiments are performed with postaccelerated beams of neutron-deficient 196,198,200,202Po isotopes at the REX-ISOLDE facility. A set of matrix elements, coupling the low-lying states in these isotopes, is extracted. In the two heaviest isotopes, 200,202Po, the transitional and diagonal matrix elements of the 2+ 1 state are determined. In 196,198Po multistep Coulomb excitation is observed, populating the 4+ 1 , 0+ 2 , and 2+ 2 states. The experimental results are compared to the results from the measurement of mean-square charge radii in polonium isotopes, confirming the onset of deformation from 196Po onwards. Three model descriptions are used to compare to the data. Calculations with the beyond-mean-field model, the interacting boson model, and the general Bohr Hamiltonian model show partial agreement with the experimental data. Finally, calculations with a phenomenological two-level mixing model hint at the mixing of a spherical structure with a weakly deformed rotational structure.
Language
English
Published in
Physical Review C
Citation
  • Kesteloot, N., Bastin, B., Gaffney, L. P., Wrzosek-Lipska, K., Auranen, K., Bauer, C., Bender, M., Bildstein, V., Blazhev, A., Bönig, S., Bree, N., Clément, E., Cocolios, T. E., Damyanova, A., Darby, I., De Witte, H., Julio, D. D., Diriken, J., Fransen, C., . . . Zielińska, M. (2015). Deformation and mixing of coexisting shapes in neutron-deficient polonium isotopes. Physical Review C, 92(5), Article 054301. https://doi.org/10.1103/PhysRevC.92.054301
License
CC BY 3.0Open Access
Copyright© Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License.

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