The PAMELA and ATIC Signals From Kaluza-Klein Dark Matter
  In this letter, we study the possibility that Kaluza-Klein dark matter in a
model with one universal extra dimension is responsible for the recent
observations of the PAMELA and ATIC experiments. In this model, the dark matter
particles annihilate largely to charged leptons, which enables them to produce
a spectrum of cosmic ray electrons and positrons consistent with the PAMELA and
ATIC measurements. To normalize to the observed signal, however, large boost
factors (~10^3) are required. Despite these large boost factors and significant
annihilation to hadronic modes (35%), we find that the constraints from cosmic
ray antiproton measurements can be satisfied. Relic abundance considerations in
this model force us to consider a rather specific range of masses
(approximately 600-900 GeV) which is very similar to the range required to
generate the ATIC spectral feature. The results presented here can also be used
as a benchmark for model-independent constraints on dark matter annihilation to
hadronic modes.
