Theoretical analysis and predictions for the double electron capture of $^{124}$Xe
Comenius University in Bratislava（布拉迪斯拉发康斯坦丁神学家大学）；International Centre for Advanced Training and Research in Physics（高级培训与物理研究中心）；“Horia Hulubei” National Institute of Physics and Nuclear Engineering（霍里亚·胡卢贝伊国家物理与核工程研究所）；University of Bucharest（布加勒斯特大学）；Central Michigan University（中密歇根大学）；Czech Technical University in Prague（捷克理工大学）
Ovidiu Niţescu, Stefan Ghinescu, Vasile-Alin Sevestrean, Mihai Horoi, Fedor Šimkovic, Sabin Stoica
We provide a complete theoretical description of the two-neutrino electron capture in $^{124}$Xe, improving both the nuclear and the atomic structure calculations. We improve the general formalism through the use of the Taylor expansion method, leading to higher order terms in the decay rate of the process. The nuclear part is treated with pn-QRPA and interacting shell model (ISM) methods. The nuclear matrix elements (NMEs) are calculated with the pn-QRPA method with spin restoration by fixing the input parameters so that the experimental decay rate is reproduced, resulting in values significantly lower than in previous calculations. The validity of the pn-QRPA NMEs is tested by showing their values to be comparable with the ones for double-beta decay with emission of two electrons of $^{128,130}$Te, which have similar pairing features. Within the ISM, we reproduce the total experimental half-life within a factor of two and predict the capture fraction to the KK channel of about 74\%. We also predict the capture fractions to other decay channels and show that for the cumulative decay to the $\rm{KL_{1}}$-$\rm{KO_{1}}$ channels, a capture fraction of about 24\% could be observed experimentally. On the atomic side, calculations are improved by accounting for the Pauli blocking of the decay of innermost nucleon states and by considering all $s$-wave electrons available for capture, expanding beyond the K and L$_1$ orbitals considered in previous studies. We also provide improved atomic relaxation energies of the final atomic states of $^{124}$Te, which may be used as input for background modeling in liquid Xenon experiments.
Muon capture on deuteron using local chiral potentials
利用手征有效场论中导出的局部坐标空间的核势和一致性流（即Norfolk模型），研究了双重超精细态μ子俘获反应$μ^- + d \rightarrow n + n + ν_μ$.仅考虑由于$^1S_0$ $nn$散射态的最大贡献。特别注意的是给予估计的理论不确定性，其中四个来源已被确定：（i）模型的依赖性，（ii）手征顺序收敛的弱核电流，（iii）在单核子轴向形状因子的不确定性，以及（iv）采用数值技术来解决绑定和散射$A=2$系统。最后一个不确定性的来源基本上可以忽略不计。已发现$^1S_0$双重态μ子捕获率$Γ^D(^1S_0)$为$Γ^D(^1S_0)=255.8(0.6)(4.4)(2.9)$ s $^{-1}$，其中三个误差来自前三个不确定性来源。$Γ^D(^1S_0)$的本地手性框架内获得的值与以前的计算相比，发现在非常好的协议。
