Probing sub-GeV Dark Matter-Baryon Scattering with Cosmological Observables [CEA]

http://arxiv.org/abs/1802.06788


We derive new limits on the elastic scattering cross-section between baryons and dark matter using Cosmic Microwave Background data from the Planck satellite and measurements of the Lyman-alpha forest flux power spectrum from the Sloan Digital Sky Survey. Our analysis addresses generic cross sections of the form $\sigma \propto v^n$, where v is the dark matter-baryon relative velocity, allowing for constraints on the cross section independent of specific particle physics models. We include high-$\ell$ polarization data from Planck in our analysis, significantly improving results for $n\leq-2$ scenarios due to the direct influence of dark matter-baryon scattering on velocity perturbations. We apply a more careful treatment of dark matter thermal evolution than previously done, allowing us to extend our constraints down to dark matter masses of ~MeV. We show in this work that cosmological probes are complementary to current direct detection and astrophysical searches.

Read this paper on arXiv…

W. Xu, C. Dvorkin and A. Chael
Wed, 21 Feb 18
42/58

Comments: 14 pages, 12 figures