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arXiv 1609.06103hep-phhep-ex
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具有S3对称性和跷跷板相互作用的中微子质量模型

A neutrino mass model with S3 symmetry and see-saw interplay

Soumita Pramanick, Amitava Raychaudhuri

摘要:

我们发展了一个中微子质量和混合的跷跷板模型,具有S3 \times Z3对称性。它涉及I型和II型跷跷板贡献的相互作用,其中前者是次主导的。选择费米子和标量场的S3 \times Z3量子数,使得II型跷跷板产生包含大气质量分裂的质量矩阵,并设置θ_{23} = π/4。没有太阳分裂和θ_{13},而第三混合角可以达到任意值θ_{12}^0。θ_{12}^0的具体选择是有意义的,例如,35.3^ \circ(三双峰)、45.0^ \circ(双峰)、31.7^ \circ(黄金比例)和0^ \circ(无太阳混合)。I型跷跷板的作用是将上述所有因素都推到数据所指示的范围内。该模型导致这些数量之间的新的相互关系,由于它们的共同来源,使其容易证伪。例如,正常(倒置)排序与第一(第二)八分圆中的θ_{23}相关联。CP破坏由右手中微子马约拉纳质量矩阵M_{νR}中的相位控制。在它们不存在的情况下,只有正常的排序是允许的。当M_{νR}是复数时,狄拉克CP相位δ可以很大,即,\sim \pm π/2,也允许倒序。T2 K和NOVA的初步结果支持正常有序和δ \sim -π/2,表明在这个模型中,最轻的中微子质量为0.05 eV或更高。

英文摘要:

We develop a see-saw model for neutrino masses and mixing with an S3\times Z3 symmetry. It involves an interplay of Type-I and Type-II see-saw contributions of which the former is subdominant. The S3 \times Z3 quantum numbers of the fermion and scalar fields are chosen such that the Type-II see-saw generates a mass matrix which incorporates the atmospheric mass splitting and sets θ_{23} = π/4. The solar splitting and θ_{13} are absent, while the third mixing angle can achieve any value, θ_{12}^0. Specific choices of θ_{12}^0 are of interest, e.g., 35.3^\circ (tribimaximal), 45.0^\circ (bimaximal), 31.7^\circ (golden ratio), and 0^\circ (no solar mixing). The role of the Type-I see-saw is to nudge all the above into the range indicated by the data. The model results in novel interrelationships between these quantities due to their common origin, making it readily falsifiable. For example, normal (inverted) ordering is associated with θ_{23} in the first (second) octant. CP-violation is controlled by phases in the right-handed neutrino Majorana mass matrix, M_{νR}. In their absence, only normal ordering is admissible. When M_{νR} is complex the Dirac CP-phase, δ, can be large, i.e., \sim \pm π/2, and inverted ordering is also allowed. The preliminary results from T2K and NOVA which favour normal ordering and δ\sim -π/2 are indicative, in this model, of a lightest neutrino mass of 0.05 eV or more.

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。

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