Constraints on Dark Matter Interactions with Standard Model Particles from Cosmic Microwave Background Spectral Distortions
Abstract
We propose a new method to constrain elastic scattering between dark matter (DM) and standard model particles in the early Universe. Direct or indirect thermal coupling of nonrelativistic DM with photons leads to a heat sink for the latter. This results in spectral distortions of the cosmic microwave background (CMB), the amplitude of which can be as large as a few times the DM-to-photon-number ratio. We compute CMB spectral distortions due to DM-proton, DM-electron, and DM-photon scattering for generic energy-dependent cross sections and DM mass mχ≳1 keV . Using Far-Infrared Absolute Spectrophotometer measurements, we set constraints on the cross sections for mχ≲0.1 MeV . In particular, for energy-independent scattering we obtain σDM-proton≲10-24 cm2 (keV /mχ)1 /2 , σDM-electron≲10-27 cm2 (keV /mχ)1 /2 , and σDM-photon≲10-39 cm2 (mχ/keV ) . An experiment with the characteristics of the Primordial Inflation Explorer would extend the regime of sensitivity up to masses mχ∼1 GeV .
- Publication:
-
Physical Review Letters
- Pub Date:
- August 2015
- DOI:
- 10.1103/PhysRevLett.115.071304
- arXiv:
- arXiv:1506.04745
- Bibcode:
- 2015PhRvL.115g1304A
- Keywords:
-
- 95.35.+d;
- 14.80.-j;
- 98.70.Vc;
- Dark matter;
- Other particles;
- Background radiations;
- Astrophysics - Cosmology and Nongalactic Astrophysics;
- High Energy Physics - Phenomenology
- E-Print:
- Minor changes. Version accepted for publication in PRL