标题： 亚兆电子伏特暗流暗物质 显示英文标题

标题： Sub-MeV Dark Sink Dark Matter

摘要： 一个暗沉降器利用暗区相互作用，从暗物质中抽取能量到更轻的暗自由度，即暗辐射。 在这里，我们将包含暗沉降器的暗物质模型扩展到亚兆电子伏特质量。 我们考虑一个暗沉降器模型，其中暗物质在一种轻暗光子下带电，该暗光子与标准模型有动能混合。 对于亚兆电子伏特的暗物质质量，等离子体衰变是将能量传递到暗区的主要机制。 相对于标准的冻结注入宇宙学，再现暗沉降结构中观测到的暗物质密度需要增加暗物质与标准模型的耦合，因此增加了直接探测截面。 这些模型为当前和未来的直接探测实验提供了基准。 考虑到等离子体效应，我们推导出亚兆电子伏特范围内暗沉降器模型的可能暗物质质量和截面范围。 我们提供了代码以重现我们的基准；它可能对其他冻结注入情景有用，包括那些等离子体衰变到暗物质重要的情景。 显示英文摘要

摘要： A Dark Sink uses dark-sector interactions to siphon energy from dark matter to lighter dark degrees of freedom, i.e. dark radiation. Here, we extend dark matter models containing a Dark Sink to sub-MeV masses. We consider a Dark Sink model where the dark matter is charged under a light dark photon that has kinetic mixing with the Standard Model. For sub-MeV dark matter masses, plasmon decays are the dominant mechanism for transferring energy to the dark sector. Relative to a standard freeze-in cosmology, reproducing the observed dark matter density in a Dark Sink structure requires an increase in the dark matter couplings to the Standard Model, and hence increased direct detection cross sections. These models provide benchmarks for current and upcoming direct detection experiments. Accounting for plasmon effects, we derive the range of possible dark matter masses and cross sections for Dark Sink models in the sub-MeV regime. We make code available to reproduce our benchmarks; it may be of use for other freeze-in scenarios, including those where plasmon decays to the dark matter are important.