arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1807.04282hep-phastro-ph.CO
收藏

一个通向Sub-MeV暗物质的热中微子入口

A Thermal Neutrino Portal to Sub-MeV Dark Matter

Asher Berlin, Nikita Blinov

备注：
46 pages, 10 figures
发表信息：
Phys. Rev. D 99, 095030 (2019)
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

摘要：

在核合成和复合时，比MeV轻的热遗迹对宇宙的能量密度有贡献。对额外辐射自由度的约束通常甚至排除了这种最简单的暗扇区。我们探讨了亚MeV暗区在中微子-光子退耦后与标准模型达到平衡的可能性，这大大削弱了这些约束，并在中微子质量产生的背景下通过轻子数的自发破缺自然产生。获得足够的暗物质丰度，通过引力、物质辐射等同性和中微子质量标度$(m_\text{Pl} / T^\text{MRE})^{1/4} \, m_ν\sim \text{MeV}$的重合，独立地激发了这些模型中的MeV标度。这类设想将通过未来对宇宙微波背景和宇宙物质结构的测量进行决定性的检验。虽然暗区主要与标准模型中微子相互作用，但原则上与核子的大耦合是可能的，从而导致在拟议的低阈值直接检测实验中可观察到的信号。

英文摘要：

Thermal relics lighter than an MeV contribute to the energy density of the universe at the time of nucleosynthesis and recombination. Constraints on extra radiation degrees of freedom typically exclude even the simplest of such dark sectors. We explore the possibility that a sub-MeV dark sector entered equilibrium with the Standard Model after neutrino-photon decoupling, which significantly weakens these constraints and naturally arises in the context of neutrino mass generation through the spontaneous breaking of lepton number. Acquiring an adequate dark matter abundance independently motivates the MeV-scale in these models through the coincidence of gravitational, matter-radiation equality, and neutrino mass scales, $(m_\text{Pl} / T^\text{MRE})^{1/4} \, m_ν\sim \text{MeV}$. This class of scenarios will be decisively tested by future measurements of the cosmic microwave background and matter structure of the universe. While the dark sector dominantly interacts with Standard Model neutrinos, large couplings to nucleons are possible in principle, leading to observable signals at proposed low-threshold direct detection experiments.

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。

↑