论文标题
$^{136} $ XE的两种neutrino $ββ$ decay to the the第一个兴奋$ 0^+$ state in $^{136} $ ba
Two-neutrino $ββ$ decay of $^{136}$Xe to the first excited $0^+$ state in $^{136}$Ba
论文作者
论文摘要
我们将$^{136} $ XE的两种neutrino $β$衰减计算为$^{136} $ ba的第一个兴奋$ 0^+$ state。我们使用不同的多体方法：准粒子随机相近似（QRPA）框架，核壳模型，相互作用的玻色子模型（IBM-2），以及$β$和$ββ$衰减的有效场理论（EFT）。 QRPA表明在当前实验极限的边缘处的衰减速率，但壳模型指向半衰期约两个数量级的半衰期。 IBM-2和EFT的预测位于两者之间，而后者则在领先顺序上提供了系统的不确定性。对核基质元件的运行总和的分析表明，中间状态的贡献之间的微妙取消可以解释不同的理论预测。对于EFT，我们还提出了两个中性$β$衰减的结果，以在其他核中的第一个激发$ 0^+$状态。
We calculate the nuclear matrix element for the two-neutrino $ββ$ decay of $^{136}$Xe into the first excited $0^+$ state of $^{136}$Ba. We use different many-body methods: the quasiparticle random-phase approximation (QRPA) framework, the nuclear shell model, the interacting boson model (IBM-2), and an effective field theory (EFT) for $β$ and $ββ$ decays. While the QRPA suggests a decay rate at the edge of current experimental limits, the shell model points to a half-life about two orders of magnitude longer. The predictions of the IBM-2 and the EFT lie in between, and the latter provides systematic uncertainties at leading order. An analysis of the running sum of the nuclear matrix element indicates that subtle cancellations between the contributions of intermediate states can explain the different theoretical predictions. For the EFT, we also present results for two-neutrino $ββ$ decays to the first excited $0^+$ state in other nuclei.
