Department of Physics and Astronomy, University of California, Irvine, California 92697, USA.
Phys Rev Lett. 2010 Apr 16;104(15):151301. doi: 10.1103/PhysRevLett.104.151301. Epub 2010 Apr 15.
Dark matter with Sommerfeld-enhanced annihilation has been proposed to explain observed cosmic ray positron excesses in the 10 GeV to TeV energy range. We show that the required enhancement implies thermal relic densities that are too small to be all of dark matter. We also show that the dark matter is sufficiently self-interacting that observations of elliptical galactic dark matter halos exclude large Sommerfeld enhancement for light force carriers. Resonant Sommerfeld enhancement does not modify these conclusions, and the astrophysical boosts required to resolve these discrepancies are disfavored, especially when significant self-interactions suppress halo substructure.
具有 Sommerfeld 增强湮灭的暗物质已被提议用于解释在 10GeV 到 TeV 能区观测到的宇宙射线正电子过剩现象。我们表明，所需的增强意味着热剩余密度太小，无法全部作为暗物质。我们还表明，暗物质具有足够的自相互作用，以至于对椭圆星系暗物质晕的观测排除了轻力载体的大 Sommerfeld 增强。共振 Sommerfeld 增强不会改变这些结论，而且解决这些差异所需的天体物理增强是不利的，尤其是当显著的自相互作用抑制晕的子结构时。
