Studying Gamow-Teller transitions and the assignment of isomeric and ground states at N = 50
Studying Gamow-Teller transitions and the assignment of isomeric and ground states at N = 50
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研究 N = 50 时的伽莫夫-泰勒跃迁以及异构体和基态的分配
DOI：
10.1016/j.physletb.2023.137833
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发表时间：
2023
影响因子：
4.4
通讯作者：
Mollaebrahimi A
中科院分区：
文献类型：
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作者：
Mollaebrahimi A
在德国GSI的FRS离子捕集器（FRS- ic）上，对100 Sn以下N= 50壳包附近的缺中子核素进行了直接质量测量。124 Xe的弹丸破碎产生核，在碎片分离器FRS中分离，并送入FRS- ic。使用FRS-IC的多反射飞行时间质谱仪测量了14个基态和两个异构体的质量，相对质量不确定度低至1× 10−7，包括98 Cd和97 Rh的首次直接质量测量。对于98个Cd，得到了新的Q EC= 5437±67 keV，从而得到了5个观测到的跃迁（0+ 1+）的加总伽莫-泰勒（GT）强度B (GT)= 2.94−0.28+ 0.32。用最先进的壳模型方法对这一结果进行了研究，首次在实验中观察到的GT跃迁点光谱与N= 50等音完全一致。首次测定了94 Rh下长寿命异构体态的激发能为293±21 keV。这与壳层模型计算一起，可以理解94 Rh中的水平顺序。
Direct mass measurements of neutron-deficient nuclides around the N= 50 shell closure below 100 Sn were performed at the FRS Ion Catcher (FRS-IC) at GSI, Germany. The nuclei were produced by projectile fragmentation of 124 Xe, separated in the fragment separator FRS and delivered to the FRS-IC. The masses of 14 ground states and two isomers were measured with relative mass uncertainties down to 1× 10− 7 using the multiple-reflection time-of-flight mass spectrometer of the FRS-IC, including the first direct mass measurements of 98 Cd and 97 Rh. A new Q EC= 5437±67 keV was obtained for 98 Cd, resulting in a summed Gamow-Teller (GT) strength for the five observed transitions (0+⟶ 1+) as B (GT)= 2.94− 0.28+ 0.32. Investigation of this result in state-of-the-art shell model approaches accounting for the first time experimentally observed spectrum of GT transitions points to a perfect agreement for N= 50 isotones. The excitation energy of the long-lived isomeric state in 94 Rh was determined for the first time to be 293±21 keV. This, together with the shell model calculations, allows the level ordering in 94 Rh to be understood.