  In the Stueckelberg extension of the Standard Model (StSM), matter in the
hidden sector can act as dark matter. Due to an interplay of mixings produced
by the usual Higgs mechanism and the Stueckelberg mechanism in the neutral
gauge boson sector, the hidden sector matter acquires a milli charge. The
Stueckelberg extension also produces a narrow width Z prime which is detectable
at the Large Hadron Collider. The hidden sector dark matter naturally explains
the PAMELA positron excess by means of a Breit-Wigner enhancement through a Z
prime resonance. We also discuss the origin of milli charge in the context of
the kinetic mixing and the Stueckelberg mixing.
