发表机构
Université de Bordeaux, CNRS/IN2P3, LP2I Bordeaux, UMR 5797; Université de Strasbourg, CNRS, IPHC UMR 7178; Université de Caen Normandie, ENSICAEN, CNRS/IN2P3, LPC Caen UMR6534; SCK·CEN, Belgian Nuclear Research Centre; Grand Accélérateur National d’Ions Lourds (GANIL); Normandie Univ., UNICAEN; University of Jyväskylä（波尔多大学; 斯特拉斯堡大学; 诺曼底卡昂大学; 比利时核研究中心; 重离子国家加速器; 诺曼底大学; 于韦斯屈莱大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
通过JYFLTRAP彭宁阱质谱仪精确测量$^{68-70}$Co质量，结合壳模型计算，发现侵入态随中子数增加而降低，在$^{70}$Co中形成反转岛，并强调3N力对结合能描述的关键作用。
AI 中文摘要
利用IGISOL设施的JYFLTRAP彭宁阱质谱仪，对$^{68-70}$Co的基态和同核异能态进行了质量测量。这些质量测量中，$^{68}$Co和$^{70}$Co的同核异能态质量是首次测得，其余态的质量精度则大幅提高，从而消除了$N=40$之外质量面上的歧义。同时确定了$^{68}$Co和$^{70}$Co中低自旋态与高自旋态的排序。结合大规模壳模型和离散非正交壳模型计算的结果表明，随着中子数的增加，侵入态逐渐降低，最终在$^{70}$Co中导致反转。这些发现澄清了先前提出的相互矛盾的解释。最后，我们证明了在$N=40$附近的反转岛中，纳入诱导有效3N力对于一致描述结合能的重要性。
英文摘要
Mass measurements of the ground and isomeric states of $^{68-70}$Co have been performed using the JYFLTRAP Penning-trap mass spectrometer at the IGISOL facility. The masses were measured, either for the first time for the isomeric states of $^{68}$Co and $^{70}$Co, or with greatly improved precision for the others, removing ambiguities in the mass surface beyond $N=40$. The ordering of the low and high-spin states in $^{68}$Co and $^{70}$Co has also been established. The results, supported by Large-Scale Shell Model and Discrete Non-Orthogonal Shell-Model calculations, show a gradual lowering of intruder states with increasing neutron number, eventually leading to an inversion in $^{70}$Co. These findings clarify previously proposed contradictory interpretations. Finally, we demonstrate the importance of including induced effective 3N forces for a consistent description of binding energies in the island of inversion near $N=40$.
