Self-scattering for Dark Matter with an excited state
Self-interacting dark matter scenarios have recently attracted much attention, as a possible means to alleviate the tension between N-body simulations and observations of the dark matter distribution on galactic and sub-galactic scales. The presence of internal structure for the dark matter-for exam...
| Main Authors: | , |
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| Other Authors: | , |
| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing,
2015-09-01T16:22:18Z.
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| Subjects: | |
| Online Access: | Get fulltext |
| Summary: | Self-interacting dark matter scenarios have recently attracted much attention, as a possible means to alleviate the tension between N-body simulations and observations of the dark matter distribution on galactic and sub-galactic scales. The presence of internal structure for the dark matter-for example, a nearly-degenerate state in the spectrum that could decay, or be collisionally excited or de-excited-has also been proposed as a possible means to address these discrepancies. Such internal structure can be a source of interesting signatures in direct and indirect dark matter searches, for example providing a novel explanation for the 3.5 keV line recently observed in galaxies and galaxy clusters. We analyze a simple model of dark matter self-scattering including a nearly-degenerate excited state, and develop an accurate analytic approximation for the elastic and inelastic s-wave cross sections, which is valid outside the perturbative regime provided the particle velocity is sufficiently low (this condition is also required for the s-wave to dominate over higher partial waves). We anticipate our results will be useful in incorporating inelastic self-scattering into N-body simulations, in order to study the quantitative impact of nearly-degenerate states in the dark matter spectrum on galactic structure and dynamics, and in computing the indirect signatures of multi-state dark matter. United States. Dept. of Energy (Cooperative Research Agreement Contract DE-FG02-05ER41360) Cameron and Hayden Lord Foundation (Fellowship) National Science Foundation (U.S.). Graduate Research Fellowship Hertz Foundation (Fellowship) |
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