arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1107.3829hep-phastro-ph.COhep-ex
收藏

A4在分离式跷跷板机构中的香味模型

A4 Flavor Models in Split Seesaw Mechanism

Adisorn Adulpravitchai, Ryo Takahashi

摘要:

额外维度中的跷跷板机制,被称为分裂跷跷板机制,提供了一种自然的方式来实现右手中微子的分裂质谱。它导致一个keV的无菌中微子作为暗物质候选者,两个重右手中微子负责稀薄发生,以解释观察到的宇宙重子不对称性。我们研究模型的基础上$A_4$风味对称性的上下文中的分裂跷跷板机制。指出现有的$A_4$味模型中,大多数的三个右手中微子为$A_4$三重态时,体质量项存在简并问题,从而干扰了右手中微子质谱的分裂机制.然后,我们构造了一个新的$A_4$风味模型工作在分裂跷跷板机制。在该模型中,实验观察到的中微子质量和混合角可以实现从两个I+II型跷跷板贡献。该模型预测了中微子质量矩阵在首阶的$μ-τ$对称性,导致了$θ_{13}$的消失和最大的$θ_{23}$。味对称性$A_4$通过轨道紧化得到的flavon真空排列被破坏。该模型可以与所有的中微子振荡实验,宇宙学讨论的暗物质丰度,leptogenesis,和最近的天体物理数据相一致。

英文摘要:

A seesaw mechanism in an extra-dimension, known as the split seesaw mechanism, provides a natural way to realize a splitting mass spectrum of right-handed neutrinos. It leads to one keV sterile neutrino as a dark matter candidate and two heavy right-handed neutrinos being responsible for leptogenesis to explain the observed baryon asymmetry of the Universe. We study models based on $A_4$ flavor symmetry in the context of the split seesaw mechanism. It is pointed out that most of known $A_4$ flavor models with three right-handed neutrinos being $A_4$ triplet suffer from a degeneracy problem for the bulk mass terms, which disturbs the split mechanism for right-handed neutrino mass spectrum. Then we construct a new $A_4$ flavor model to work in the split seesaw mechanism. In the model, the experimentally observed neutrino masses and mixing angles can be realized from both type I+II seesaw contributions. The model predicts the $μ-τ$ symmetry in the neutrino mass matrix at the leading order, resulting in the vanishing $θ_{13}$ and maximal $θ_{23}$. The flavor symmetry $A_4$ is broken via the flavon vacuum alignment which can be obtained from the orbifold compactification. The model can be consistent with all data of neutrino oscillation experiments, cosmological discussions of dark matter abundance, leptogenesis, and recent astrophysical data.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑