Systematic decomposition of the neutrinoless double beta decay operator
Systematic decomposition of the neutrinoless double beta decay operator
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DOI：
10.1007/jhep03(2013)055
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发表时间：
2012-12
影响因子：
5.4
通讯作者：
F. Bonnet;M. Hirsch;T. Ota;W. Winter
中科院分区：
文献类型：
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作者：
F. Bonnet;M. Hirsch;T. Ota;W. Winter
我们讨论了九维无中微子双β衰变算符的系统分解，重点讨论了在大型强子对撞机上可以访问的对中微子质量可能有很小贡献的机制。我们首先提供了一个(d=9个树级)完整的无中微子双β衰变图。从这个列表中，人们可以很容易地恢复所有以前讨论过的对无中微子双β衰变过程的贡献，例如著名的质量机制或“奇异”，例如来自左右对称模型的贡献，违反超对称性的R宇称和轻夸克。然而，更有趣的是，我们发现了一些以前的文献中没有讨论过的新的可能性。联系到基于一般洛伦兹不变参数的无中微子双β衰减率的早期工作，这在原则上允许推导出所有可能的贡献的极限。通过一个具体的例子，我们进一步讨论了在大型强子对撞机上可能存在的导致振幅短程部分的介体信号。如果中微子质量的不同测量之间存在张力，例如来自无中微子的双贝塔衰变和宇宙学或单贝塔衰变，对这种贡献的研究将变得特别重要。
We discuss the systematic decomposition of the dimension nine neutrinoless double beta decay operator, focusing on mechanisms with potentially small contributions to neutrino mass, while being accessible at the LHC. We first provide a (d= 9 tree-level) complete list of diagrams for neutrinoless double beta decay. From this list one can easily recover all previously discussed contributions to the neutrinoless double beta decay process, such as the celebrated mass mechanism or “exotics”, such as contributions from left-right symmetric models, R-parity violating supersymmetry and leptoquarks. More interestingly, however, we identify a number of new possibilities which have not been discussed in the literature previously. Contact to earlier works based on a general Lorentz-invariant parametrisation of the neutrinoless double beta decay rate is made, which allows, in principle, to derive limits on all possible contributions. We furthermore discuss possible signals at the LHC for mediators leading to the short-range part of the amplitude with one specific example. The study of such contributions would gain particular importance if there were a tension between different measurements of neutrino mass such as coming from neutrinoless double beta decay and cosmology or single beta decay.