School of Natural Sciences, Institute for Advanced Study, Einstein Drive, Princeton, New Jersey 08540, USA.
Department of Physics & Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, USA, Department of Physics & Astronomy, University of Hawaii, Honolulu, Hawaii 96822, USA.
Phys Rev Lett. 2018 Aug 24;121(8):081301. doi: 10.1103/PhysRevLett.121.081301.
We present the first cosmological constraint on dark matter scattering with protons in the early Universe for the entire range of dark matter masses between 1 keV and 1 TeV. This constraint is derived from the Planck measurements of the cosmic microwave background (CMB) temperature and polarization anisotropy, and the CMB lensing anisotropy. It improves upon previous CMB constraints by many orders of magnitude, where limits are available, and closes the gap in coverage for low-mass dark matter candidates. We focus on two canonical interaction scenarios: spin-independent and spin-dependent scattering with no velocity dependence. Our results exclude (with 95% confidence) spin-independent interactions with cross sections greater than 5.3×10^{-27} cm^{2} for 1 keV, 3.0×10^{-26} cm^{2} for 1 MeV, 1.7×10^{-25} cm^{2} for 1 GeV, and 1.6×10^{-23} cm^{2} for 1 TeV dark matter mass. Finally, we discuss the implications of this study for dark matter physics and future observations.
我们提出了第一个关于暗物质在早期宇宙中与质子散射的宇宙学限制，涵盖了暗物质质量在 1 keV 到 1 TeV 之间的整个范围。这个限制是从普朗克对宇宙微波背景（CMB）温度和偏振各向异性以及 CMB 引力透镜各向异性的测量中得出的。与之前的 CMB 限制相比，它提高了几个数量级，其中已经有了限制，并且填补了低质量暗物质候选物的覆盖范围的差距。我们关注两种典型的相互作用情景：无速度依赖性的自旋无关和自旋相关散射。我们的结果排除了（在 95%置信水平下）对于 1 keV 的暗物质，其自旋无关相互作用的截面大于 5.3×10^{-27} cm^{2}；对于 1 MeV 的暗物质，其截面大于 3.0×10^{-26} cm^{2}；对于 1 GeV 的暗物质，其截面大于 1.7×10^{-25} cm^{2}；对于 1 TeV 的暗物质，其截面大于 1.6×10^{-23} cm^{2}。最后，我们讨论了这项研究对暗物质物理和未来观测的影响。
