Gamma ray and neutrino flux from the annihilation of neutralino dark matter at the Galactic halo region in the mAMSB model

Abstract

We consider the lightest supersymmetric particle, the neutralino, in a minimal anomaly mediated supersymmetry breaking model to be a possible candidate for weakly interacting massive particles (WIMP) or cold dark matter, and we investigate its direct and indirect detections. The theoretically allowed supersymmetric parametric space for such a model, along with the recent bounds from the LHC, is constrained by the WMAP results for relic densities. The spin-independent and spin-dependent scattering cross sections for dark matter off nucleons are thus constrained from the WMAP results. They are found to be within the allowed regions of different ongoing direct detection experiments. The annihilation of such dark-matter candidates at the Galactic centre produces different standard model particles such as γ-rays and neutrinos. In this work, we calculate the possible fluxes of these γ-rays and neutrinos coming from the direction of the Galactic centre (and its neighbourhood) at terrestrial or satellite-borne detectors. The calculated γ-ray flux is compared with the observational results of the HESS experiment. The neutrino fluxes of different flavours from the Galactic centre and at different locations away from the Galactic centre produced by WIMP annihilation in this model are also obtained for four types of Galactic dark-matter halo profiles. The detection prospects of such νμ coming from the direction of the Galactic centre at the ANTARES under-sea detector are discussed in terms of the muon signal yield from these muon neutrinos. Both the γ-ray and neutrino signals are estimated for four different dark-matter halo profiles.