  We propose a dark matter model with standard model singlet extension of the
universal extra dimension model (sUED) to explain the recent observations of
ATIC, PPB-BETS, PAMELA and DAMA. Other than the standard model fields
propagating in the bulk of a 5-dimensional space, one fermion field and one
scalar field are introduced and both are standard model singlets. The zero mode
of the new fermion is identified as the right-handed neutrino, while its first
KK mode is the lightest KK-odd particle and the dark matter candidate. The
cosmic ray spectra from ATIC and PPB-BETS determine the dark matter particle
mass and hence the fifth dimension compactification scale to be 1.0-1.6 TeV.
The zero mode of the singlet scalar field with a mass below 1 GeV provides an
attractive force between dark matter particles, which allows a Sommerfeld
enhancement to boost the annihilation cross section in the Galactic halo to
explain the PAMELA data. The DAMA annual modulation results are explained by
coupling the same scalar field to the electron via a higher-dimensional
operator. We analyze the model parameter space that can satisfy the dark matter
relic abundance and accommodate all the dark matter detection experiments. We
also consider constraints from the diffuse extragalactic gamma-ray background,
which can be satisfied if the dark matter particle and the first KK-mode of the
scalar field have highly degenerate masses.
