High-spin states in Ce 136 : Systematics of collective oblate rotation
1990; American Institute of Physics; Volume: 41; Issue: 4 Linguagem: Inglês
10.1103/physrevc.41.1576
ISSN1538-4497
AutoresE. S. Paul, D. B. Fossan, Y. Liang, R. Ma, N. Xu, R. Wadsworth, Iredell Jenkins, P. J. Nolan,
Tópico(s)Rare-earth and actinide compounds
ResumoThe level structure of the transitional even-even $^{136}\mathrm{Ce}$ nucleus has been investigated using the $^{122}\mathrm{Sn}$${(}^{18}$O, 4n\ensuremath{\gamma}) reaction. The prominent structure observed at high spin is a \ensuremath{\Delta}I=1 rotational band, populated with \ensuremath{\sim}25% intensity of the ${2}^{+}$\ensuremath{\rightarrow}${0}^{+}$ transition, which has a low dynamic moment of inertia 20${\mathrm{\ensuremath{\Elzxh}}}^{2}$ ${\mathrm{MeV}}^{\mathrm{\ensuremath{-}}1}$ for frequencies below \ensuremath{\Elzxh}\ensuremath{\omega}=0.45 MeV. This band is interpreted in terms of a two-quasiproton-two-quasineutron configuration with a shape close to the collectively rotating \ensuremath{\gamma}=-60\ifmmode^\circ\else\textdegree\fi{} oblate shape, and is related to the oblate \ensuremath{\pi}${\mathit{h}}_{11/2}$\ensuremath{\bigotimes}[\ensuremath{\nu}${\mathit{h}}_{11/2}$${]}^{2}$ configuration seen in several nearby odd-Z nuclei. The systematics of such oblate rotational bands in this mass region are discussed. Other \ensuremath{\Delta}I=2 bands, built on states including ${\mathit{h}}_{11/2}$ quasineutron orbitals, are also associated with collective oblate rotation. In addition, tentative evidence is presented for a weak band (2% intensity), showing an enhanced dynamic moment of inertia \ensuremath{\sim}57${\mathrm{\ensuremath{\Elzxh}}}^{2}$ ${\mathrm{MeV}}^{\mathrm{\ensuremath{-}}1}$, built on the highly deformed [\ensuremath{\nu}${\mathit{i}}_{13/2}$${]}^{2}$ prolate configuration.
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