29Na: defining the edge of the island of inversion for Z=11.
29Na: defining the edge of the island of inversion for Z=11.
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DOI：
10.1103/physrevlett.94.162501
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发表时间：
2004-11
影响因子：
8.6
通讯作者：
V. Tripathi;S. Tabor;P. Mantica;C. Hoffman;M. Wiedeking;A. Davies;S. Liddick;W. Mueller;T. Otsuka;A. Stolz;B. Tomlin;Y. Utsuno;A. Volya
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文献类型：
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作者：
V. Tripathi;S. Tabor;P. Mantica;C. Hoffman;M. Wiedeking;A. Davies;S. Liddick;W. Mueller;T. Otsuka;A. Stolz;B. Tomlin;Y. Utsuno;A. Volya
用β延迟γ能谱研究了奇异Na同位素（28，29）Na的低能结构。Z=10-12的N=20的同位素被认为属于“反转岛”，其中入侵者配置占主导地位的基态波函数。然而，这是一个悬而未决的问题，从正常的过渡到入侵者占主导地位的配置发生在同位素链。目前的工作，提出了第一个详细的光谱（28，29）Na，清楚地表明，这种过渡的Na同位素之间发生28 Na（N=17）和29 Na（N=18），支持较小的N=20壳层间隙在富中子sd壳核。在β衰变分支比、入侵者主导的低能级光谱和壳模型分析中发现了反转壳结构的证据。
The low-energy level structure of the exotic Na isotopes (28,29)Na has been investigated through beta-delayed gamma spectroscopy. The N=20 isotones for Z=10-12 are considered to belong to the "island of inversion" where intruder configurations dominate the ground state wave function. However, it is an open question as to where and how the transition from normal to intruder dominated configurations happens in an isotopic chain. The present work, which presents the first detailed spectroscopy of (28,29)Na, clearly demonstrates that such a transition in the Na isotopes occurs between 28Na (N=17) and 29Na (N=18), supporting the smaller N=20 shell gap in neutron-rich sd shell nuclei. The evidence for inverted shell structure is found in beta-decay branching ratios, intruder dominated spectroscopy of low-lying states, and shell model analysis.