Octupole correlations in the structure of O2 bands in the N=88 nuclei150Sm Gd

Knowledge of the exact microscopic structure of the 01 + ground state and first excited 02 + state in 150Sm is required to understand the branching of double β decay to these states from 150Nd. The detailed spectroscopy of 150Sm and 152Gd has been studied using (α,xn) reactions and the γ -ray arrays AFRODITE and JUROGAM II. Consistently strong E1 transitions are observed between the excited Kπ = 02 + bands and the lowest negative parity bands in both nuclei. These results are discussed in terms of the possible permanent octupole deformation in the first excited Kπ = 02 + band and also in terms of the “tidal wave” model of Frauendorf.Web of Scienc

Congruent band structures in

We have used the ($\alpha$, 2n) and ($\alpha$, 4n) reactions and the AFRODITE $\gamma$ -ray spectrometer to make a comprehensive study of the nucleus 154Gd below \ensuremath 20\hbar . While the first excited 02 + state at 681 keV is usually considered to be the head of a \ensuremath K^{\pi}=0^{+} $\beta$ -vibrational band, we propose that the data are best described as two separate vacuum states, the ground state and the 681 keV level, each with its own $\gamma$ and octupole vibrations, pairing and alignments. The implications of this finding, for understanding the structure of transitional rare-earth nuclei, are discussed