Monoenergetic Gamma-Rays from Non-Minimal Kaluza-Klein Dark Matter Annihilations

Understand

We investigate monoenergetic gamma-ray signatures from annihilations of dark matter comprised of Z^1, the first Kaluza-Klein excitation of the Z boson, in a non-minimal Universal Extra Dimensions model.

• The self-interactions of the non-Abelian Z^1 gauge boson give rise to a large number of contributing Feynman diagrams that do not exist for annihilations of the Abelian gauge boson B^1, which is the standard Kaluza-Klein dark matter candidate.
• We find that the annihilation rate is indeed considerably larger for the Z^1 than for the B^1.
• Even though relic density calculations indicate that the mass of the Z^1 should be larger than the mass of the B^1, the predicted monoenergetic gamma fluxes are of the same order of magnitude.