Back to Search
Start Over
Observation of $\gamma$-vibrations and alignments built on non-ground-state configurations in 156Dy
- Source :
- Phys. Rev. C 91, 034330 (2015)
- Publication Year :
- 2020
-
Abstract
- The exact nature of the lowest $K^\pi =2_\gamma ^+$ rotational bands in all deformed nuclei remains obscure. Traditionally they are assumed to be collective vibrations of the nuclear shape in the $\gamma$ degree of freedom perpendicular to the nuclear symmetry axis. Very few such $\gamma$-bands have been traced past the usual back-bending rotational alignments of high-j nucleons. We have investigated the structure of positive-parity bands in the N=90 nucleus 156Dy, using the 148Nd(12C,4n)156Dy reaction at 65 MeV, observing the resulting ${\gamma}$-ray transitions with the Gammasphere array. The even- and odd-spin members of the $K^\pi =2_\gamma^+$ $\gamma$-band are observed to 32+ and 31+ respectively. This rotational band faithfully tracks the ground-state configuration to the highest spins. The members of a possible $\gamma$-vibration built on the aligned yrast S-band are observed to spins 28+ and 27+. An even-spin positive-parity band, observed to spin 24+, is a candidate for an aligned S-band built on the seniority-zero configuration of the $0_2^+$ state at 676 keV. The crossing of this band with the $0_2^+$ band is at $\hbar\omega$= 0.28(1) MeV and is consistent with the configuration of the $0_2^+$ band not producing any blocking of the monopole pairing.<br />Comment: Published in Physics Review C
- Subjects :
- Nuclear Experiment
Nuclear Theory
Subjects
Details
- Database :
- arXiv
- Journal :
- Phys. Rev. C 91, 034330 (2015)
- Publication Type :
- Report
- Accession number :
- edsarx.2005.04706
- Document Type :
- Working Paper
- Full Text :
- https://doi.org/10.1103/PhysRevC.91.034330