论文标题
$^{207} $ AT：29/2 $^{+} $ isomeric状态的高自旋光谱
High-spin spectroscopy in $^{207}$At: Evidence of a 29/2$^{+}$ isomeric state
论文作者
论文摘要
首次建立$^{207} $中已知的25/2 $^{+} $ isomer上方的yrast和近字母元状态。该级别方案将扩展到47/2 $ \ HBAR $和6.5 MEV，并增加了大约60个新的$γ$ -Ray转换。重新审视25/2 $^{+} $ isomer的半衰期，并推导$ t_ {1/2} $ = 107.5（9）NS的值。迄今未观察到的29/2 $^{+} $ ISOMER的证据在$^{207} $中呈现。 $ b（e3）$值的系统研究，以推翻邻近的奇数 - $ a $ at Isotopes中的29/2 $^{+} $ isomer，这表明该州在$^{207} $ in in 2 $ - $ 4.5 $ $ $ s范围内的半寿命。将实验结果与使用$ z $ = 50 $ - $ 126，$ n $ = 82 $ - $ 184模型空间进行的KHM3Y有效相互作用进行的大规模壳模计算进行了比较。在相邻核中具有类似态的激发态和异构体的定性比较提供了对$^{207} $的结构的进一步见解。
Yrast and near-yrast states above the known 25/2$^{+}$ isomer in $^{207}$At are established for the first time. The level scheme is extended up to 47/2$\hbar$ and 6.5 MeV with the addition of about 60 new $γ$-ray transitions. The half-life of the 25/2$^{+}$ isomer is revisited and a value of $T_{1/2}$ = 107.5(9) ns is deduced. Evidence of a hitherto unobserved 29/2$^{+}$ isomer in $^{207}$At is presented. A systematic study of $B(E3)$ values for the transitions de-exciting the 29/2$^{+}$ isomer in the neighboring odd-$A$ At isotopes suggests a half-life in the 2$-$4.5 $μ$s range for this state in $^{207}$At. The experimental results are compared with large-scale shell-model calculations performed using the KHM3Y effective interaction in the $Z$ = 50$-$126, $N$ = 82$-$184 model space and an overall good agreement is noted between the theory and the experiment. A qualitative comparison of the excited states and the isomers with analogous states in neighboring nuclei provides further insight into the structure of $^{207}$At.
