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arXiv 1702.02877hep-ph
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左右对称模型中自然轻Dirac中微子

Naturally Light Dirac Neutrino in Left-Right Symmetric Model

Debasish Borah, Arnab Dasgupta

摘要:

本文研究了在不需要任何附加对称性的情况下,在左右对称模型(LRSM)中产生微小狄拉克质量中微子的可能性。带电的费米子通过一个普遍的跷跷板机制获得质量,这是由于存在额外的矢量费米子。中微子从带电轻子一样的额外矢量获得一圈狄拉克质量,而不需要任何额外的离散对称性。该模型还可以扩展一个额外的$Z_2$对称性,以便有一个暗生版本的这种情况下预测一个稳定的暗物质的候选人。我们表明,最新的普朗克上限的相对论自由度$N_{\text{eff}}=3.15 \pm 0.23$的有效数量紧密约束的右扇区规范玻色子的质量要重于3.548 TeV。规范玻色子质量的这种约束也影响了右标量二重态暗物质质量的允许值,因为它满足了暗物质遗迹丰度的普朗克约束。我们还讨论了这种情况在带电轻子味破坏和产生可观测的电偶极矩的轻子的可能影响。

英文摘要:

We study the possibility of generating tiny Dirac masses of neutrinos in Left-Right Symmetric Model (LRSM) without requiring the existence of any additional symmetries. The charged fermions acquire masses through a universal seesaw mechanism due to the presence of additional vector like fermions. The neutrinos acquire a one-loop Dirac mass from the same additional vector like charged leptons without requiring any additional discrete symmetries. The model can also be extended by an additional $Z_2$ symmetry in order to have a scotogenic version of this scenario predicting a stable dark matter candidate. We show that the latest Planck upper bound on the effective number of relativistic degrees of freedom $N_{\text{eff}}=3.15 \pm 0.23$ tightly constrains the right sector gauge boson masses to be heavier than 3.548 TeV. This bound on gauge boson mass also affects the allowed values of right scalar doublet dark matter mass from the requirement of satisfying the Planck bound on dark matter relic abundance. We also discuss the possible implications of such a scenario in charged lepton flavour violation and generating observable electric dipole moment of leptons.

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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