Hidden Sector Models and Signatures

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.