1. Evidence of oblate-prolate shape coexistence in the strongly-deformed nucleus Cs
- Author
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Zheng, K.K., Petrache, C.M., Zhang, Z.H., Zhao, P.W., Wang, Y.K., Astier, A., Lv, B.F., Greenlees, P.T., Grahn, T., Julin, R., Juutinen, S., Luoma, M., Ojala, J., Pakarinen, J., Partanen, J., Rahkila, P., Ruotsalainen, P., Sandzelius, M., Sarén, J., Tann, H., Uusitalo, J., Zimba, G., Cederwall, B., Aktas, Ö., Ertoprak, A., Zhang, W., Guo, S., Liu, M.L., Kuti, I., Nyakó, B.M., Sohler, D., Timár, J., Andreoiu, C., Doncel, M., Joss, D.T., and Page, R.D.
- Abstract
Prolate-oblate shape coexistence close to the ground state in the strongly-deformed proton-rich A≈120 nuclei is reported for the first time. One of the four reported bands in $^{119}$Cs, built on a 11/2− state at 670 keV, consists of nearly degenerate signature partners, and has properties which unequivocally indicate the strongly-coupled πh11/2[505]11/2− configuration associated with oblate shape. Together with the decoupled πh11/2[541]3/2− band built on the 11/2− prolate state at 110 keV, for which a half-life of T1/2=55(5)μs has been measured, the new bands bring evidence of shape coexistence at low spin in the proton-rich strongly deformed A≈120 nuclei, a phenomenon predicted since long time, but not yet observed. Calculations using the particle-number conserving cranked shell model and two dimensional tilted axis cranking covariant density functional theory support and well reproduce the observed oblate and prolate coexisting low-energy states in $^{119}$Cs.
- Published
- 2021