Indirect detection of gravitino dark matter including its three-body decays

Abstract

It was recently pointed out that in supersymmetric scenarios with gravitino dark matter and bilinear R-parity violation, gravitinos with masses below Mw typically decay with a sizable branching ratio into the 3-body final states W^*+lepton and Z^*+neutrino. In this paper we study the indirect detection signatures of gravitino dark matter including such final states. First, we obtain the gamma ray spectrum from gravitino decays, which features a monochromatic contribution from the decay into photon+neutrino and a continuum contribution from the three-body decays. After studying its dependence on supersymmetric parameters, we compute the expected gamma ray fluxes and derive new constraints, from recent FERMI data, on the R-parity breaking parameter and on the gravitino lifetime. Indirect detection via antimatter searches, a new possibility brought about by the three-body final states, is also analyzed. For models compatible with the gamma ray observations, the positron signal is found to be negligible whereas the antiproton one can be significant.

21 pages,16 figures v2: one numerical error corrected, one figure added, main results unchanged

References in corpus (16)

• PYTHIA 6.4 Physics and Manual
• Observation of an anomalous positron abundance in the cosmic radiation
• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Likelihoods and Parameters from the WMAP data
• A new measurement of the antiproton-to-proton flux ratio up to 100 GeV in the cosmic radiation
• The Spectrum of the Isotropic Diffuse Gamma-Ray Emission Derived From First-Year Fermi Large Area Telescope Data
• On possible interpretations of the high energy electron-positron spectrum measured by the Fermi Large Area Telescope
• Decaying Dark Matter can explain the electron/positron excesses
• Minimal Dark Matter predictions for galactic positrons, anti-protons, photons
• Gamma Ray Spectrum from Gravitino Dark Matter Decay
• The galactic antiproton spectrum at high energies: background expectation vs. exotic contributions
• High Energy Cosmic Rays from the Decay of Gravitino Dark Matter
• Gamma-Rays from Decaying Dark Matter
• Antimatter Signatures of Gravitino Dark Matter Decay
• Probing Gravitino Dark Matter with PAMELA and Fermi
• The PAMELA excess from neutralino annihilation in the NMSSM
• New decay modes of gravitino dark matter

Cited by in corpus (3)

• On the Importance of Electroweak Corrections for Majorana Dark Matter Indirect Detection
• T(13) Flavor Symmetry and Decaying Dark Matter
• Gamma-rays from Nearby Clusters: Constraints on Selected Decaying Dark Matter Models