Motivated by nonzero neutrino masses and the possibility of new physics discovery, a number of experiments search for neutrinoless double beta decay. While hunting for this hypothetical nuclear process, a significant amount of two-neutrino double beta decay data have become available. Although these events are regarded and studied mostly as the background of neutrinoless double beta decay, they can also be used to probe physics beyond the standard model. In this Letter, we show how the presence of right-handed leptonic currents would affect the energy distribution and angular correlation of the outgoing electrons in two-neutrino double beta decay. Consequently, we estimate constraints imposed by currently available data on the existence of right-handed neutrino interactions without having to assume their nature. In this way, our results complement the bounds coming from the nonobservation of neutrinoless double beta decay as they limit also the exotic interactions of Dirac neutrinos. We perform a detailed calculation of two-neutrino double beta decay under the presence of exotic (axial-) vector currents, and we demonstrate that current experimental searches can be competitive to existing limits.

中文翻译：

---

在两个中微子双Beta衰变中寻找新物理

受非零中微子质量和新物理学发现的可能性的推动，许多实验都在寻找无中微子双β衰变。在寻找这种假设的核过程的同时，大量的两个中微子双β衰变数据已经可用。尽管这些事件大部分被认为是无中微子双β衰变的背景，但它们也可用于探测超出标准模型的物理学。在这封信中，我们显示了右旋轻子电流的存在将如何影响两个中微子双β衰变中输出电子的能量分布和角度相关性。因此，我们估计了当前可用数据对右手中微子相互作用存在的限制，而不必假定它们的性质。通过这种方式，我们的研究结果补充了非中微子双β衰变的非观测边界，因为它们也限制了狄拉克中微子的奇异相互作用。我们在存在奇异（轴向）矢量电流的情况下，对两个中微子双β衰变进行了详细的计算，并且我们证明了当前的实验搜索可以竞争现有的极限。