$^{53}$Ca中的电磁跃迁强度：$5/2^{-}$态的寿命
Electromagnetic transition strength in $^{53}$Ca: the lifetime of the $5/2^{-}$ state
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中文总结 AI 辅助
该研究首次测量了$^{53}$Ca中$5/2^{-}$态的寿命，得到约化跃迁概率$B(E2)$的下限，并与壳模型和从头算计算对比，为富中子钙同位素的理论描述提供了严格基准。
中文摘要 AI 辅助
在RIKEN的放射性同位素束工厂（RIBF）进行了$^{53}$Ca的高分辨率在束${\gamma}$射线谱学实验。通过从$^{55}$Sc放射性束流中发生单中子移除和单质子移除反应，布居了$^{53}$Ca的激发态，并使用HiCARI混合锗探测器阵列探测发射的${\gamma}$射线。首次通过分析由相对论反冲速度引起的多普勒展宽${\gamma}$射线线形，测量了$^{53}$Ca中第一激发$5/2^{-}$态的寿命。推导出其寿命为${\tau} = 11.3_{-11.3}^{+5.3(stat)+3(sys)}$ ps，对应在1${\sigma}$置信水平下约化跃迁概率$B(E2;5/2^{-}{\rightarrow}1/2^{-}) > 2.6 e^{2}fm^{4}$，最佳拟合值为$4.5 e^{2}fm^{4}$。将测得的跃迁强度与最先进的壳模型和从头算（ab initio）计算结果进行了比较，为壳模型哈密顿量和有效电荷以及现代从头算描述接近潜在$N$ = 40壳闭合的富中子钙同位素提供了严格的基准。
英文摘要
High-resolution in-beam $γ$-ray spectroscopy of $^{53}$Ca was performed at the Radioactive Isotope Beam Factory (RIBF) at RIKEN. Excited states in $^{53}$Ca were populated via one-neutron and one-proton removal reactions from a $^{55}$Sc radioactive beam, and the emitted $γ$ rays were detected using the HiCARI hybrid germanium detector array. The lifetime of the first excited $5/2^{-}$ state in $^{53}$Ca was measured for the first time through an analysis of Doppler-roadened $γ$-ray line shapes arising from relativistic recoil velocities. A lifetime of $τ = 11.3_{-11.3}^{+5.3(stat)+3(sys)}$ ps was deduced, corresponding to a reduced transition probability of $B(E2;5/2^{-}{\rightarrow}1/2^{-}) > 2.6 e^{2}fm^{4}$ at the 1$σ$ level, with a best-fit value of $4.5 e^{2}fm^{4}$. The measured transition strength is compared with state-of-the-art shell-model and ab initio calculations, providing a stringent benchmark for shell-model Hamiltonians and effective charges and modern ab initio descriptions of the neutron-rich calcium isotopes approaching the potential $N$ = 40 shell closure.
发表机构
- University of York（约克大学）
- Lawrence Berkeley National Laboratory（劳伦斯伯克利国家实验室）
- RIKEN Nishina Center（理化学研究所仁科加速器中心）
- Instituto de Estructura de la Materia, CSIC（西班牙科学理事会材料结构研究所）
- Department of Physics, University of Tokyo（东京大学物理学系）
- Michigan State University（密歇根州立大学）
- TRIUMF（特利昂夫）
- McGill University（麦吉尔大学）
- Texas A&M University（德克萨斯农工大学）
- Center for Computational Sciences, University of Tsukuba（筑波大学计算科学中心）
机构由 AI 辅助整理，请以论文原文为准。
