4 research outputs found
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 (, 2n) and (, 4n) reactions and the AFRODITE -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^{+}
-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 and octupole vibrations, pairing and alignments. The implications of this finding, for understanding the structure of transitional rare-earth nuclei, are discussed
Candidate chiral bands in (198)Tl
High-spin states in 198Tl were studied using the 197Au(α, 3n) reaction. The level scheme was considerably extended including two new bands and several non-yrast levels. One of the new bands is possibly a chiral partner to the yrast πh9/2 ⊗ νi−1 13/2 band. Two-quasiparticle-plus-triaxial-rotor model calculations suggest an aplanar orientation of the total angular momenta for these bands, thus supporting possible chirality
Possible chirality in the doubly-odd Tl-198 nucleus: Residual interaction at play
A candidate for chiral bands was found in (198)Tl for the first time in a mass region of oblate (or nonaxial with gamma >= 30 degrees) deformed nuclei. Two bands show very similar quasiparticle alignments, moments of inertia, and B(M1)/B(E2) ratios. They have a relative excitation energy of about 500 keV and different patterns of energy staggering. Calculations using the two-quasiparticle-plus-triaxial-rotor model with residual proton-neutron interaction included show that a triaxial deformation with gamma similar to 44 degrees agrees very well with all the experimental observations. Furthennore, considerable energy staggering for both partner bands was calculated for this pi h(9/2) circle times vi(13/2)(-1) configuration at gamma - 30 degrees, suggesting that chiral bands may have substantial energy staggering