Two-neutrino double electron capture on 124Xe based on an effective theory and the nuclear shell model
Two-neutrino double electron capture on 124Xe based on an effective theory and the nuclear shell model
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DOI：
10.1016/j.physletb.2019.134885
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发表时间：
2018-09
影响因子：
4.4
通讯作者：
E. Pérez;J. Menendez;A. Schwenk;A. Schwenk
中科院分区：
文献类型：
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作者：
E. Pérez;J. Menendez;A. Schwenk;A. Schwenk
基于有效理论(ET)和大规模壳层模型计算，我们研究了124Xe上的两个中微子双电子俘获，这两种现代核结构方法已经用Gamow-Teller和双β衰变数据进行了检验。在ET中，低能常数适合于电子俘获和氙气周围的β−跃迁。对于核壳模型，我们使用了一个大组态空间中的相互作用，它再现了这个质量区域中的原子核的光谱。对于主导跃迁到124Te基态，Et的半衰期T1/2 2νECEC=(1.3−18)×10 2 2y，壳层模型的T1/2 2νECEC=(0.4 3−2.9)×10 2 2 y。ET的不确定性导致半衰期几乎与目前的实验极限完全一致，并且在很大程度上在正在进行的实验的范围内。壳层模型的半衰期范围与ET重叠，但超出当前限制的范围较小。因此，我们的发现表明，124Xe上的双中微子双电子俘获很有可能被正在进行的或未来的实验所发现。此外，我们还给出了对124Te激发态的双中微子双电子俘获的结果。
We study the two-neutrino double electron capture on 124 Xe based on an effective theory (ET) and large-scale shell model calculations, two modern nuclear structure approaches that have been tested against Gamow-Teller and double-beta decay data. In the ET, the low-energy constants are fit to electron capture and β− transitions around xenon. For the nuclear shell model, we use an interaction in a large configuration space that reproduces the spectroscopy of nuclei in this mass region. For the dominant transition to the 124 Te ground state, we find half-lives T 1/2 2 ν ECEC=(1.3− 18)× 10 22 y for the ET and T 1/2 2 ν ECEC=(0.43− 2.9)× 10 22 y for the shell model. The ET uncertainty leads to a half-life almost entirely consistent with present experimental limits and largely within the reach of ongoing experiments. The shell model half-life range overlaps with the ET, but extends less beyond current limits. Our findings thus suggest that the two-neutrino double electron capture on 124 Xe has a good chance to be discovered by ongoing or future experiments. In addition, we present results for the two-neutrino double electron capture to excited states of 124 Te.