A flavor symmetry for quasi-degenerate neutrinos: Lμ - Lτ
A flavor symmetry for quasi-degenerate neutrinos: Lμ - Lτ
复制标题
准简并中微子的味道对称性：Lμ - Lτ
DOI：
--
复制
发表时间：
2005
影响因子：
4.4
通讯作者：
W. Rodejohann
中科院分区：
文献类型：
--
作者：
S. Choubey;W. Rodejohann
我们考虑了中微子质量矩阵的味道对称性Lμ-Lτ。守恒Lμ-Lτ的最一般中微子质量矩阵预言了具有一个最大混合角和两个零混合角的准简并中微子质量。Lμ-Lτ的存在也可以被中微子混合矩阵的近双极大形式所激发。此外，它还是μτ对称质量矩阵的一个特例。通过在中微子质量矩阵中添加一个小的味盲项和/或应用辐射校正，打破了味道对称性，重现了观察到的中微子振荡现象。在该方案中，既可以容纳正常质量排序，也可以容纳倒置质量排序。对无中微子双β衰变的适度抵消是可望的。可观测值|U E3|2和|1/2-SIN 2θ23|与普通中微子质量标度的四次幂成正比。我们讨论了大气中微子混合是在π/4以上还是在其下面。最后，我们提出了一个基于拉锯机制的模型，它产生一个具有(近似)Lμ-Lτ味道对称性的轻中微子质量矩阵。这是一个最小的模型，只有一个标准的希格斯对偶和三个重的右手中微子。对于软的Lμ-Lτ破缺项，它只需要很小的值就可以再现所分析的现象学上可行的质量纹理。
We consider the flavor symmetry L μ - L τ for the neutrino mass matrix. The most general neutrino mass matrix conserving L μ - L τ predicts quasi-degenerate neutrino masses with one maximal and two zero mixing angles. The presence of L μ - L τ can also be motivated by the near-bimaximal form of the neutrino mixing matrix. Furthermore, it is a special case of μτ symmetric mass matrices. Breaking the flavor symmetry by adding a small flavor-blind term to the neutrino mass matrix and/or by applying radiative corrections is shown to reproduce the observed neutrino oscillation phenomenology. Both the normal and inverted mass ordering can be accommodated within this scheme. Moderate cancellation for neutrinoless double beta decay is expected. The observables |U e3 | 2 and |1/2 - sin 2 θ 23 | are proportional to the inverse of the fourth power of the common neutrino mass scale. We comment on whether the atmospheric neutrino mixing is expected to lie above or below π/4. We finally present a model based on the see-saw mechanism which generates a light neutrino mass matrix with an (approximate) L μ - L τ flavor symmetry. This is a minimal model with just one standard Higgs doublet and three heavy right-handed neutrinos. It needs only small values for the soft L μ - L τ breaking terms to reproduce the phenomenological viable mass textures analyzed.