AI 中文总结
该研究构建双组分暗物质（ALP+暗光子）的冻入模型，通过求解玻尔兹曼方程确定符合511 keV、Hα等约束的参数空间，解释银河系511 keV线并满足遗迹密度要求。
AI 中文摘要
我们研究由类轴子粒子（ALP）和暗光子组成的双组分暗物质的“冻入”场景。暗 sector通过五维ALP-暗光子相互作用与标准模型连接，微小的动力学混合支配暗光子的衰变。通过求解耦合玻尔兹曼方程，我们确定了与观测到的遗迹丰度一致的参数空间。我们发现，对于近简并的暗 sector，暗光子通过动力学混合衰变为正负电子对可解释银河系511 keV线，而五维算符可提供暗光子和ALP粒子产生所需的量，以满足遗迹密度要求。我们进一步将该模型与矮星系的最新Hα观测结果，以及宇宙微波背景、弥散伽马射线、直接探测和对撞机搜寻的约束进行对比。我们确定了可行的参数空间区域，其Ω_DM h²≈0.12，有效标度Λ~10¹⁰-10¹² GeV，暗光子寿命约为10²⁶-10²⁹秒，同时符合观测到的511 keV光子通量、Leo T的Hα约束及所有其他天体物理约束。
英文摘要
We investigate a freeze-in scenario of two component dark matter consisting of an axion-like particle (ALP) and a dark photon. The dark sector connects to the Standard Model through a dimension-five ALP-dark photon interaction, while a small kinetic mixing governs dark photon decays. Solving the coupled Boltzmann equations, we determine the parameter space consistent with the observed relic abundance. We find that, for a nearly degenerate dark sector, dark photon decay into an electron-positron pair through the kinetic mixing explains the Galactic 511 keV line while the dimension five operator can source the necessary production of dark photon and ALP particles to satisfy the relic density. We further confront the model with recent H$α$ observations of dwarf galaxies, together with constraints from the cosmic microwave background, diffuse gamma rays, direct detection and collider searches. We identify viable regions of parameter space yielding $Ω_{\rm DM}h^2\simeq0.12$, with an effective scale $Λ\sim10^{10}$-$10^{12}$ GeV, and dark photon lifetimes of order $10^{26}$-$10^{29}$ s, while remaining consistent with the observed 511 keV photon flux, $Hα$ constraints from Leo T and all other astrophysical constraints.
Comments18 pages, 5 figures
