AI 中文总结
研究利用多种多体方法计算$^{126}$Xe双中微子双电子俘获及$^{134}$Xe双中微子双β衰变的核矩阵元和半衰期，各方法结果考虑不确定性后总体一致，$^{134}$Xe半衰期下限或在下一代实验范围内，$^{126}$Xe半衰期比$^{134}$Xe长一个量级。
AI 中文摘要
我们计算了$^{126}$Xe的双中微子双电子俘获以及$^{134}$Xe的双中微子双β衰变的核矩阵元及相应半衰期。采用了不同多体方法，包括质子 - 中子准粒子随机相位近似、核壳模型、微观相互作用玻色子模型以及重核有效场论。对于两种核素，考虑各方法理论不确定性后，半衰期预测总体一致。有趣的是，所有计算中$^{134}$Xe半衰期预测下限短于$T^{2\nu}_{1/2} \approx 2\times10^{24}$年，可能在下一代实验可及范围内。对于$^{126}$Xe，结果显示其半衰期通常比$^{134}$Xe长一个数量级。
英文摘要
We calculate the nuclear matrix elements and corresponding half-lives for the two-neutrino double-electron capture of $^{126}$Xe and the two-neutrino double-beta decay of $^{134}$Xe. We use different many-body methods: the proton-neutron quasiparticle random-phase approximation, the nuclear shell model, the microscopic interacting boson model, and an effective field theory for heavy nuclei. For both nuclei, all our half-life predictions are generally consistent with each other when including theoretical uncertainties for each method. Interestingly, for all calculations the lower range of the predicted $^{134}$Xe half-life is shorter than $T^{2ν}_{1/2} \approx 2\times10^{24}$\,y, which may be within the reach of next-generation experiments. For $^{126}$Xe, our results typically predict one order of magnitude longer half-lives than those for $^{134}$Xe.
Comments15 pages, 9 figures, appendix included
