Dark Matter Signals from Cascade Annihilations
نویسندگان
چکیده
A leading interpretation of the electron/positron excesses seen by PAMELA and ATIC is dark matter annihilation in the galactic halo. Depending on the annihilation channel, the electron/positron signal could be accompanied by a galactic gamma ray or neutrino flux, and the non-detection of such fluxes constrains the couplings and halo properties of dark matter. In this paper, we study the interplay of electron data with gamma ray and neutrino constraints in the context of cascade annihilation models, where dark matter annihilates into light degrees of freedom which in turn decay into leptons in one or more steps. Electron and muon cascades give a reasonable fit to the PAMELA and ATIC data. Compared to direct annihilation, cascade annihilations can soften gamma ray constraints from final state radiation by an order of magnitude. However, if dark matter annihilates primarily into muons, the neutrino constraints are robust regardless of the number of cascade decay steps. We also examine the electron data and gamma ray/neutrino constraints on the recently proposed “axion portal” scenario.
منابع مشابه
Diffuse inverse Compton and synchrotron emission from dark matter annihilations in galactic satellites
Annihilating dark matter particles produce roughly as much power in electrons and positrons as in gamma ray photons. The charged particles lose essentially all of their energy to inverse Compton and synchrotron processes in the galactic environment. We discuss the diffuse signature of dark matter annihilations in satellites of the Milky Way (which may be optically dark with few or no stars), pr...
متن کاملIndirect detection of a subdominant density component of cold dark matter
We examine the detectability through indirect means of weakly interacting dark matter candidates that may constitute not all but only a subdominant component of galactic cold dark matter. We show that the possibility of indirect detection of neutralinos from their annihilations in the Earth and Sun is not severely hampered by decreasing neutralino relic density. Upward-going muon fluxes in unde...
متن کاملObservability of γ Rays from Dark Matter Neutralino Annihilations in the Milky Way Halo
Recent advances in N-body simulations of cold dark matter halos point to a substantial density enhancement near the center. This means that, e.g., the γ ray signals from neutralino dark matter annihilations would be significantly enhanced compared to old estimates based on an isothermal sphere model with large core radius. Another important development concerns new detectors, both spaceand grou...
متن کاملClumpy Neutralino Dark Matter
We investigate the possibility to detect neutralino dark matter in a scenario in which the galactic dark halo is clumpy. We find that under customary assumptions on various astrophysical parameters, the antiproton and continuum γ-ray signals from neutralino annihilation in the halo put the strongest limits on the clumpiness of a neutralino halo. We argue that indirect detection through neutrino...
متن کاملNeutralino Dark Matter and Caustic Ring Signals
We have studied the effects on the gamma-ray flux on Earth by neutralino annihilations in caustic rings of dark matter in the Galactic halo. The caustic ring model by Sikivie has been used where dark matter particles are assumed to possess angular momentum with respect to the Galactic centre. The computer code DarkSUSY was then used to examine the supersymmetric implications on the flux. We con...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2009