CMB and 21-cm signals for dark matter with a long-lived excited state
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138 (United States)
- Physics Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States)
- Center for Cosmology and Particle Physics, Department of Physics, New York University, New York, New York 10003 (United States)
Motivated by the eXciting dark matter model of Finkbeiner and Weiner, hypothesized to explain the 511 keV signal in the center of the Milky Way, we consider the cosmic microwave background and 21-cm signatures of models of dark matter with collisional long-lived excited states. We compute the relic excitation fraction from the early Universe for a variety of assumptions about the collisional de-excitation cross section and thermal decoupling. The relic excitation fraction can be as high as 1% for natural regions of parameter space, but could be orders of magnitude smaller. Since the lifetime of the excited state is naturally greater than 10{sup 13} s, we discuss the signatures of such relic excitation on cosmic microwave background and high-z 21-cm observations. Such models have potentially richer astrophysical signals than the traditional weakly interacting massive particle annihilations and decays, and may have observable consequences for future generations of experiments.
- OSTI ID:
- 21250838
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 78, Issue 6; Other Information: DOI: 10.1103/PhysRevD.78.063530; (c) 2008 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
Similar Records
Unveiling the nature of dark matter with high redshift 21 cm line experiments
Exciting dark matter and the INTEGRAL/SPI 511 keV signal