Decaying Dark Matter and the PAMELA Anomaly

By A. Ibarra, D. Tran. 2008

157 citations recorded by the source corpus.

Astrophysical and cosmological observations do not require the dark matter particles to be absolutely stable. If they are indeed unstable, their decay into positrons might occur at a sufficiently large rate to allow the indirect detection of dark matter through an anomalous contribution to the cosmic positron flux. In this paper we discuss the implications of the excess in the positron fraction recently reported by the PAMELA collaboration for the scenario of decaying dark matter. To this end, we have performed a model-independent analysis of possible signatures by studying various decay channels in the case of both a fermionic and a scalar dark matter particle. We find that the steep rise in the positron fraction measured by PAMELA at energies larger than 10 GeV can naturally be accommodated in several realizations of the decaying dark matter scenario. The data point toward a rather heavy dark matter particle, m{sub DM} {approx}> 300 GeV, which preferentially decays directly into first or second generation charged leptons with a lifetime {tau}{sub DM} {approx} 10{sup 26} s.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/38636316c16459a579473c4bd7a96e97e48833eb

Citations in the corpus

• Dark matter annihilations and decays after the AMS-02 positron measurements (2013, unknown): “[8–15]).”