直接测量^{148}Dy中增强的八极集体性
Direct measurement of Enhanced octupole collectivity in 148Dy
另 8 家 · 查看机构详情
- University of Liverpool（利物浦大学）
- CERN（欧洲核子研究组织）
- University of Surrey（萨里大学）
- Tongji University（同济大学）
- TRIUMF（特利昂姆夫实验室）
- University of British Columbia（不列颠哥伦比亚大学）
- Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro（意大利国家核物理研究所莱尼亚罗国家实验室）
- Università degli Studi di Padova（帕多瓦大学）
- Simon Fraser University（西蒙菲莎大学）
- University of Guelph（圭尔夫大学）
- University of Regina（里贾纳大学）
机构由 AI 辅助整理，请以论文原文为准。
浏览论文内容
中文总结 AI 辅助
通过测量^{148}Dy的$B(E3)$跃迁强度，发现其为$N=82$壳层最大值，直接证实了$Z=64$以外增强的八极集体性，并扩展了八极集体性的边界。
中文摘要 AI 辅助
通过使用TRIUMF ISAC-I设施的GRIFFIN谱仪，经由^{148m}Ho的$\beta^+/EC$衰变布居了$^{148}_{~66}$Dy的激发态。结合广义质心差（GCD）方法测量$3_1^-$能级的平均寿命，以及$3_1^-\rightarrow0_1^+$ $\gamma$射线衰变的分支比，进行了联合测量。根据这些结果，确定了$^{148}_{~66}$Dy中增强的电八极$B(E3;3_1^-\rightarrow0_1^+)$跃迁强度为46(3) W.u.。这是跨越$N=82$闭合中子壳层所测得的最大值，并为$Z=64$以外增强的八极集体性提供了直接证据。将$B(E3; 3^-_1 \rightarrow 0^+_1)$强度沿$N=82$同中子素链的演化与使用SkI3和SkM$^*$ Skyrme能量密度泛函的准粒子随机相位近似（QRPA）计算以及大规模壳模型（SM）计算进行了比较。这一结果将增强八极集体性的边界扩展到了远离所谓的“八极幻数”$Z=56$和$N=88$的区域。
英文摘要
Excited states in $^{148}_{~66}$Dy were populated via $β^+/EC$ decay of $^{148m}$Ho using the GRIFFIN spectrometer at the TRIUMF ISAC-I facility. A combined measurement of the mean lifetime of the $3_1^-$ level using the Generalized Centroid Difference (GCD) method and branching fraction of the $3_1^-\rightarrow0_1^+$ $γ$-ray decay has been performed. From these results, an enhanced electric octupole $B(E3;3_1^-\rightarrow0_1^+)$ transition strength of 46(3)~W.u. has been determined in $^{148}_{~66}$Dy. This is the largest measured value across the closed neutron shell at $N=82$ and provides direct evidence of enhanced octupole collectivity beyond $Z=64$. The evolution of the $B(E3; 3^-_1 \rightarrow 0^+_1)$ strength along the $N=82$ isotonic chain is compared with quasiparticle random-phase approximation (QRPA) calculations using the SkI3 and SkM$^*$ Skyrme energy-density functionals, as well as with large-scale shell-model (SM) calculations. This result extends the boundaries of enhanced octupole collectivity far from the so-called `octupole magic numbers' $Z=56$ and $N=88$.
