标题： 天体物理对微电荷原子暗物质的约束 显示英文标题

标题： Astrophysical constraints on millicharged atomic dark matter

摘要： 一些非弹性暗物质模型假设在某种新的$U(1)'$规范对称性下存在束缚态。 如果这种新的暗光子与标准模型光子发生动量混合，那么这些束缚态中的组成粒子可以获得分数电荷。 这种电荷使暗物质介质具有色散性。 我们计算了这种介质的频率依赖折射率，并利用来自天体物理源的频率依赖光到达时间来限制介质中暗原子的性质。 利用蟹状星云脉冲星的光学波长观测数据，我们发现暗（电子）质子的电微电荷小于暗原子质量低于100 keV时的电荷$e$，假设暗精细结构常数为$\boldsymbol{\alpha}=1$。 我们估计，未来对伽马射线暴的宽频带观测可以产生对keV范围内暗原子微电荷的约束，这些约束与现有的对撞机约束相当。 显示英文摘要

摘要： Some models of inelastic dark matter posit the existence of bound states under some new $U(1)'$ gauge symmetry. If this new dark photon kinetically mixes with the standard model photon, then the constituent particles in these bound states can acquire a fractional electric charge. This electric charge renders a dark-matter medium dispersive. We compute this frequency-dependent index of refraction for such a medium and use the frequency-dependent arrival time of light from astrophysical sources to constrain the properties of dark atoms in the medium. Using optical-wavelength observations from the Crab Pulsar, we find the electric millicharge of dark (electrons) protons to be smaller than the electric charge $e$ for dark atom masses below 100 keV, assuming a dark fine structure constant $\boldsymbol{\alpha}=1$. We estimate that future broadband observations of gamma-ray bursts can produce constraints on the millicharge of dark atoms with masses in the keV range that are competitive with existing collider constraints.