论文标题
观察$γ$ - 振动和对准以156dy的非地面配置建立的
Observation of $γ$-vibrations and alignments built on non-ground-state configurations in 156Dy
论文作者
论文摘要
所有变形核中最低$ k^π=2_γ^+$旋转带的确切性质仍然晦涩难懂。传统上，假定它们是垂直于核对称轴的$γ$自由度的核形状的集体振动。很少有这样的$γ$ - 带被追溯到高J核的通常的背面旋转对齐。我们使用148nd（12c，4n）156 y 156 y的正性带的结构，在65 meV时，观察到与伽马米阵列的$γ$ -Ray跃迁。 $ k^π=2_γ^+ $ $γ$ -ban的偶数和奇数成员分别被观察到32+和31+。该旋转带忠实地跟踪地面配置到最高的旋转。观察到在对齐的yrast s波段上建造的可能的$γ$振动的成员被观察到旋转28+和27+。观察到的旋转24+的均匀旋转正率频段是基于676 KEV的$ 0_2^+$ state的零零配置的对齐S波段的候选者。该乐队与$ 0_2^+$ band的交叉处于$ \hbarΩ$ = 0.28（1）MEV，并且与$ 0_2^+$ band的配置一致，而不会产生任何封锁单极配对。
The exact nature of the lowest $K^π=2_γ^+$ rotational bands in all deformed nuclei remains obscure. Traditionally they are assumed to be collective vibrations of the nuclear shape in the $γ$ degree of freedom perpendicular to the nuclear symmetry axis. Very few such $γ$-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 $γ$-ray transitions with the Gammasphere array. The even- and odd-spin members of the $K^π=2_γ^+$ $γ$-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 $γ$-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 $\hbarω$= 0.28(1) MeV and is consistent with the configuration of the $0_2^+$ band not producing any blocking of the monopole pairing.
