A lower bound on the mass of dark matter particles
- Institute of Theoretical Physics, ETH Hoenggerberg, CH-8093 Zuerich (Switzerland)
- Ecole Polytechnique Federale de Lausanne, Institute of Theoretical Physics, FSB/ITP/LPPC, BSP 726, CH-1015, Lausanne (Switzerland)
- Department of Astrophysics and Elementary Particles, Bogolyubov Institute for Theoretical Physics, Metrologichna str., 14-B, Kiev 03680 (Ukraine)
We discuss the bounds on the mass of Dark Matter (DM) particles, coming from the analysis of DM phase-space distribution in dwarf spheroidal galaxies (dSphs). After reviewing the existing approaches, we choose two methods to derive such a bound. The first one depends on the information about the current phase space distribution of DM particles only, while the second one uses both the initial and final distributions. We discuss the recent data on dSphs as well as astronomical uncertainties in relevant parameters. As an application, we present lower bounds on the mass of DM particles, coming from various dSphs, using both methods. The model-independent bound holds for any type of fermionic DM. Stronger, model-dependent bounds are quoted for several DM models (thermal relics, non-resonantly and resonantly produced sterile neutrinos, etc.). The latter bounds rely on the assumption that baryonic feedback cannot significantly increase the maximum of a distribution function of DM particles. For the scenario in which all the DM is made of sterile neutrinos produced via non-resonant mixing with the active neutrinos (NRP) this gives m{sub NRP} > 1.7 keV. Combining these results in their most conservative form with the X-ray bounds of DM decay lines, we conclude that the NRP scenario remains allowed in a very narrow parameter window only. This conclusion is independent of the results of the Lyman-{alpha} analysis. The DM model in which sterile neutrinos are resonantly produced in the presence of lepton asymmetry remains viable. Within the minimal neutrino extension of the Standard Model (the {nu}MSM), both mass and the mixing angle of the DM sterile neutrino are bounded from above and below, which suggests the possibility for its experimental search.
- OSTI ID:
- 22156926
- Journal Information:
- Journal of Cosmology and Astroparticle Physics, Vol. 2009, Issue 03; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
- Country of Publication:
- United States
- Language:
- English
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