Hidden Fermion in Stueckelberg Z' Models as Milli-charged Dark Matter

TL;DR

This paper proposes a hidden fermion as a milli-charged dark matter candidate within Stueckelberg Z' models, analyzing its relic density, gamma-ray signals, and collider signatures.

Contribution

It introduces a new dark matter candidate in Stueckelberg Z' models and explores its detection prospects via gamma rays and collider experiments.

Findings

Hidden fermion can account for dark matter relic density.

Gamma-ray flux from annihilation is detectable by future experiments.

Large invisible width of Z' boson at colliders is a key signature.

Abstract

The hidden Stueckelberg Z' model is augmented by a pair of Dirac fermions. If the Z' has a coupling strength comparable to weak scale coupling, one can show that this hidden fermion-antifermion pair could be a milli-charged dark matter candidate with a viable relic density. Monochromatic photon flux coming from the Galactic center due to pair annihilation of these milli-charged particles is calculated and is shown to be within reach of the next generation gamma-ray experiments. Characteristic collider signature of this theoretical endeavor is that the Stueckelberg Z' boson has a large invisible width decaying into the hidden fermion-antifermion pair if kinematically allowed. Singly production of this Z' boson at the LHC and ILC are studied.