0000000000216956
AUTHOR
S.n.t. Majola
Spectroscopy of low-spin states in $^{157}\mathrm{Dy}$: Search for evidence of enhanced octupole correlations
Low-spin states of 157Dy have been studied using the JUROGAM II array, following the 155Gd ({\alpha}, 2n) reaction at a beam energy of 25 MeV. The level scheme of 157Dy has been expanded with four new bands. Rotational structures built on the [523]5/2- and [402]3/2+ neutron orbitals constitute new additions to the level scheme as do many of the inter- and intra-band transitions. This manuscript also reports the observation of cross I- to (I-1)- and I- to (I-1)+ E1 dipole transitions inter-linking structures built on the [523]5/2- (band 5) and [402]3/2+ (band 7) neutron orbitals. These interlacing band structures are interpreted as the bands of parity doublets with simplex quantum number s =…
Octupole correlations in the structure of 0$_2^+$ bands in the N=88 nuclei 150Sm and 152Gd
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. peerReviewed
First candidates for $\gamma$ vibrational bands built on the $[505]11/{2}^{-}$ neutron orbital in odd-$A$ Dy isotopes
Rotational structures have been measured using the Jurogam II and GAMMASPHERE arrays at low spin following the 155Gd({\alpha},2n)157Dy and 148Nd(12C, 5n)155Dy reactions at 25 and 65 MeV, respectively. We report high-K bands, which are conjectured to be the first candidates of a K{\pi}= 2+ {\gamma} vibrational band, built on the [505]11/2- neutron orbital, in both odd-A 155, 157Dy isotopes. The coupling of the first excited K=0+ states or the so-called \b{eta} vibrational bands at 661 and 676 keV in 154Dy and 156Dy to the [505]11/2- orbital, to produce a K{\pi}=11/2- band, was not observed in both 155Dy and 157Dy, respectively. The implication of these findings on the interpretation of the f…