PAMELA data and leptonically decaying dark matter
- Institute of Theoretical Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China)
- Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)
- Theoretical Division, Institute of High Energy Physics, Chinese Academy of Sciences, P.O. Box 918-4, Beijing 100049 (China)
Recently PAMELA released their first results on the positron and antiproton ratios. Stimulated by the new data, we studied the cosmic ray propagation models and calculated the secondary positron and antiproton spectra. The low energy positron ratio can be consistent with data in the convection propagation model. Above {approx}10 GeV PAMELA data shows a clear excess on the positron ratio. However, the secondary antiproton is roughly consistent with the data. The positron excess may be evidence of dark matter annihilation or decay. We compare the positron and antiproton spectra with the data by assuming that dark matter annihilates or decays into different final states. The PAMELA data actually excludes quark pairs being the main final states, and disfavors gauge boson final states. Only in the case of leptonic final states can the positron and antiproton spectra be explained simultaneously. We also compare the decaying and annihilating dark matter scenarios which can account for the PAMELA results and find that the decaying dark matter is preferred. Finally, we consider a decaying neutralino dark matter model in the frame of supersymmetry with R-parity violation. The PAMELA data is well fitted with a neutralino mass of 600{approx}2000 GeV and a lifetime of {approx}10{sup 26} seconds. We also demonstrate that a neutralino with mass around 2 TeV can fit PAMELA and ATIC data simultaneously.
- OSTI ID:
- 21259785
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 79, Issue 2; Other Information: DOI: 10.1103/PhysRevD.79.023512; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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