Kaluza-Klein Dark Matter After Fermi

摘要: Kaluza-Klein photon in universal extra dimension models is one of the most attractive dark matter candidates as a weakly interacting massive particle. Having a characteristic split spectrum in split universal extra dimension the relic density of Kaluza-Klein photon with 900GeV mass is in good agreement with the observed dark matter amount in our Universe. Interestingly KaluzaKlein photon in the same mass range also provides excellent fits to the recently observed excesses in cosmic electron and positron fluxes. The amount of gamma-ray contributions, mostly from tau decays, can be significant around 300 GeV, thus can be observed or constrained by the forthcoming Fermi-LAT diffuse gamma-ray data.