Bounds on Velocity-dependent Dark Matter–Proton Scattering from Milky Way Satellite Abundance
Bounds on Velocity-dependent Dark Matter–Proton Scattering from Milky Way Satellite Abundance
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DOI：
10.3847/2041-8213/abd807
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发表时间：
2020-10
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影响因子：
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通讯作者：
Karime Maamari;V. Gluscevic;K. Boddy;E. Nadler;Risa Wechsler
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作者：
Karime Maamari;V. Gluscevic;K. Boddy;E. Nadler;Risa Wechsler
我们使用最新的测量银河系卫星人口从暗能量调查和泛星1推断最严格的天体物理约束到目前为止的速度依赖于暗物质粒子和质子之间的相互作用。我们将动量转移截面建模为相对粒子速度v的幂律，具有自由归一化振幅σ MT = σ 0 v n，以广泛地捕获暗物质-质子散射的非相对论有效理论中产生的相互作用。这种散射导致早期宇宙中重子和暗物质流体之间的动量和热量传递，最终消除了小物理尺度上的结构，并减少了今天矮星系的低质量晕的丰度。从观测结果与冷无碰撞暗物质范式的一致性出发，使用一种依赖于线性微扰理论最稳健预测的新方法，我们推断出对于n = 2、4和6的相互作用模型，σ 0的上限分别为1.4 × 10−23、2.1 × 10−19和1.0 × 10−12 cm 2，暗物质粒子质量为10兆电子伏。这些结果提高了暗物质-质子散射的观测极限的数量级，从而为可行的亚GeV暗物质候选者提供了重要的指导。
We use the latest measurements of the Milky Way satellite population from the Dark Energy Survey and Pan-STARRS1 to infer the most stringent astrophysical bound to date on velocity-dependent interactions between dark matter particles and protons. We model the momentum-transfer cross section as a power law of the relative particle velocity v with a free normalizing amplitude, σ MT = σ 0 v n , to broadly capture the interactions arising within the nonrelativistic effective theory of dark matter–proton scattering. The scattering leads to a momentum and heat transfer between the baryon and dark matter fluids in the early universe, ultimately erasing structure on small physical scales and reducing the abundance of low-mass halos that host dwarf galaxies today. From the consistency of observations with the cold collisionless dark matter paradigm, using a new method that relies on the most robust predictions of the linear perturbation theory, we infer an upper limit on σ 0 of 1.4 × 10−23, 2.1 × 10−19, and 1.0 × 10−12 cm2, for interaction models with n = 2, 4, and 6, respectively, for a dark matter particle mass of 10 MeV. These results improve observational limits on dark matter–proton scattering by orders of magnitude and thus provide an important guide for viable sub-GeV dark matter candidates.