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arXiv 1004.5491hep-phastro-ph.COgr-qc
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中微子味混合与宇宙重子不对称性

Flavour Mixing of Neutrinos and Baryon Asymmetry of the Universe

Takehiko Asaka, Hiroyuki Ishida

摘要:

我们研究了$ν$ MSM中的重子生成问题。MSM是由三个右手中微子扩展的最小标准模型,其质量小于弱标度。在这个模型中,宇宙的重子不对称性(BAU)是通过右手中微子之间的味振荡产生的。我们考虑了BAU完全起源于活动中微子混合矩阵中的CP破坏的情况。我们进行分析和数值估计的BAU的产量,并显示如何BAU依赖于混合角和CP违反阶段。发现中微子质量的反层次结构的不对称性比正常层次结构的不对称性得到约4%的抑制因子。然而,指出当$θ_{13}=0$和$θ_{23} = π/4$时,正常层次中的重子生成变得无效,因此倒置层次的情况对于解释目前的BAU变得重要。

英文摘要:

We investigate baryogenesis in the $ν$MSM, which is the Minimal Standard Model (MSM) extended by three right-handed neutrinos with Majorana masses smaller than the weak scale. In this model the baryon asymmetry of the universe (BAU) is generated via flavour oscillation between right-handed neutrinos. We consider the case when BAU is solely originated from the CP violation in the mixing matrix of active neutrinos. We perform analytical and numerical estimations of the yield of BAU, and show how BAU depends on mixing angles and CP violating phases. It is found that the asymmetry in the inverted hierarchy for neutrino masses receives a suppression factor of about 4% comparing with the normal hierarchy case. It is, however, pointed out that, when $θ_{13}=0$ and $θ_{23} = π/4$, baryogenesis in the normal hierarchy becomes ineffective, and hence the inverted hierarchy case becomes significant to account for the present BAU.

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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