Gamma-rays from Nearby Clusters: Constraints on Selected Decaying Dark Matter Models
| Autor: | Ke, Jiwei, Luo, Mingxing, Wang, Liucheng, Zhu, Guohuai |
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| Rok vydání: | 2011 |
| Předmět: | |
| Zdroj: | Phys.Lett.B698:44-51,2011 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1016/j.physletb.2011.02.055 |
| Popis: | Recently, the Fermi-LAT collaboration reported upper limits on the GeV gamma-ray flux from nearby clusters of galaxies. Motivated by these limits, we study corresponding constraints on gamma-ray emissions from two specific decaying dark matter models, one via grand unification scale suppressed operators and the other via R-parity violating operators. Both can account for the PAMELA and Fermi-LAT excesses of e^\pm. For GUT decaying dark matter, the gamma-rays from the M49 and Fornax clusters, with energy in the range of 1 to 10 GeV, lead to the most stringent constraints to date. As a result, this dark matter is disfavored with conventional model of e^\pm background. In addition, it is likely that some tension exists between the Fermi-LAT e^\pm excess and the gamma ray constraints for any decaying dark matter model, provided conventional model of e^\pm background is adopted. Nevertheless, the GUT decaying dark matter can still solely account for the PAMELA positron fraction excess without violating the gamma-ray constraints. For the gravitino dark matter model with R-parity violation, cluster observations do not give tight constraints. This is because a different e^\pm background has been adopted which leads to relatively light dark matter mass around 200 GeV. Comment: 17 pages, 4 figures, version to appear in Phys. Lett. B |
| Databáze: | arXiv |
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