论文标题
$μ$ - $τ$对称破坏和违反CP的中微子质量矩阵
$μ$-$τ$ symmetry breaking and CP violation in the neutrino mass matrix
论文作者
论文摘要
讨论了中微子质量矩阵中的$μ$ - $τ$交换对称性，并讨论了它的破坏。确切的$μ$ - $τ$对称限制了2-3和1-3中微子混合角度为$θ_{23} =π/4 $和$θ_{13} = 0 $在零订单上。我们声称，$μ$ - $τ$对称性破坏更喜欢违规的大型CP违规，可以实现$θ_{13} $的观察值，并保持$θ_{23} $几乎最大的最大值，尽管是$μ$ - $ $ - $τ$破坏$ breaking breaking breaking can tune $θ_{23} $ casepective caspective。我们从$π/4 $，$θ_{13} $和DIRAC CP相位$δ$之间的$θ_{23} $的偏差之间表现出多种关系，这对于在未来实验中测试$μ$ - $τ$破坏型号很有用。我们还提出了一种混凝土模型，以自发地打破$μ$ - $τ$交换对称性，并且其破裂是由仪表交互介导的，该量规交互在带有$ b-l $和$ b-l $和$l_μ-l_-l_τ$ symmetries的扩展规格模型的框架中辐射。由于中微子质量矩阵中的量规介导的$ $ $ $ - $τ$破裂，人工选择不太可能，而且最大的狄拉克CP相是可取的。
The $μ$-$τ$ exchange symmetry in the neutrino mass matrix and its breaking as a perturbation are discussed. The exact $μ$-$τ$ symmetry restricts the 2-3 and 1-3 neutrino mixing angles as $θ_{23} = π/4$ and $θ_{13} = 0$ at a zeroth order level. We claim that the $μ$-$τ$ symmetry breaking prefers a large CP violation to realize the observed value of $θ_{13}$ and to keep $θ_{23}$ nearly maximal, though an artificial choice of the $μ$-$τ$ breaking can tune $θ_{23}$, irrespective of the CP phase. We exhibit several relations among the deviation of $θ_{23}$ from $π/4$, $θ_{13}$ and Dirac CP phase $δ$, which are useful to test the $μ$-$τ$ breaking models in the near future experiments. We also propose a concrete model to break the $μ$-$τ$ exchange symmetry spontaneously and its breaking is mediated by the gauge interactions radiatively in the framework of the extended gauge model with $B-L$ and $L_μ- L_τ$ symmetries. As a result of the gauge mediated $μ$-$τ$ breaking in the neutrino mass matrix, the artificial choice is unlikely, and a large Dirac CP phase is preferable.
