title: Gamma rays from Kaluza-Klein dark matter.
abstract: A TeV gamma-ray signal from the direction of the Galactic center (GC) has been detected by the HESS experiment. Here, we investigate whether Kaluza-Klein (KK) dark matter annihilations near the GC can be the explanation. Including the contributions from internal bremsstrahlung as well as subsequent decays of quarks and tau leptons, we find a very flat gamma-ray spectrum which drops abruptly at the dark matter particle mass. For a KK mass of about 1 TeV, this gives a good fit to the HESS data below 1 TeV. A similar model, with gauge coupling roughly 3 times as large and a particle mass of about 10 TeV, would give both the correct relic density and a photon spectrum that fits the complete range of data.
authors.affiliation: Department of Physics, Stockholm University, AlbaNova University Center, SE-106 91 Stockholm, Sweden. lbe@physto.se
authors.forename: Lars
authors.initials: L
authors.lastname: Bergström
authors.forename: Torsten
authors.initials: T
authors.lastname: Bringmann
authors.forename: Martin
authors.initials: M
authors.lastname: Eriksson
authors.forename: Michael
authors.initials: M
authors.lastname: Gustafsson