The Stueckelberg Extension and Milli Weak and Milli Charge Dark Matter

TL;DR

This paper reviews $U(1)_X$ Stueckelberg extensions of the Standard Model, highlighting the emergence of milli weak and milli charged dark matter, and discusses their implications for relic density and potential string theory origins.

Contribution

It introduces a novel framework combining Stueckelberg mechanisms with the Standard Model, leading to new dark matter types and potential experimental signatures.

Findings

Extra $Z'$ boson with milli weak couplings

Existence of milli weak and milli charged dark matter

WMAP-3 relic density constraints satisfied

Abstract

A overview is given of the recent developments in the $U(1)_X$ Stueckelberg extensions of the Standard Model and of MSSM where all the Standard Model particles are neutral under the $U(1)_X$ but an axion which is absorbed is charged under both $U(1)_X$ and $U(1)_Y$ and acts as the connector field coupling the Standard Model sector with the Stueckelberg sector. Coupled with the usual Higgs mechanism that breaks the $SU(2)_L\times U(1)_Y$ gauge symmetry, this scenario produces mixings in the neutral gauge boson sector generating an extra $Z'$ boson. The couplings of the extra $Z'$ to the Standard Model particles are milli weak but its couplings to the hidden sector matter, defined as matter that couples only to the gauge field of $U(1)_X$, can be of normal electro-weak strength. It is shown that such extensions, aside from the possibility of leading to a sharp $Z' $ resonance, lead to two new types of dark matter: milli weak (or extra weak) and milli charged. An analysis of the relic density shows that the WMAP-3 constraints can be satisfied for either of these scenarios. The types of models discussed could arise as possible field point limit of certain Type IIB orientifold string models.