Isomers close to the doubly magic nucleus Ni (, ) provide essential information on the shell evolution and shape coexistence far from stability. The existence of a long-lived isomeric state in Cu has been debated for a long time. We have performed high-precision mass measurements of Cu with the JYFLTRAP double Penning trap mass spectrometer at the Ion Guide Isotope Separator On-Line facility and confirm the existence of such an isomeric state with an excitation energy keV. Based on the ratio of detected ground- and isomeric-state ions as a function of time, we show that the isomer is the shorter-living state previously considered as the ground state of Cu. The result can potentially change the conclusions made in previous works related to the spin-parity and charge radius of the Cu ground state. Additionally, the new Cu reaction -value has an impact on the astrophysical rapid neutron-capture process.

中文翻译：

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寻找已久的异构体原来是76Cu的基态


接近双魔核 Ni (, ) 的异构体提供了有关壳演化和远离稳定的形状共存的重要信息。 Cu 中是否存在长寿命异构态一直存在争议。我们在离子引导同位素在线分离器设施中使用 JYFLTRAP 双潘宁阱质谱仪对 Cu 进行了高精度质量测量，并确认了这种激发能 keV 的同分异构态的存在。根据检测到的基态离子和异构态离子随时间变化的比率，我们表明异构体是先前被认为是 Cu 基态的寿命较短的状态。该结果可能会改变之前有关铜基态自旋宇称和电荷半径的工作中得出的结论。此外，新的铜反应值对天体物理快速中子捕获过程有影响。