Predicted Signatures at the LHC from U(1) Extensions of the Standard Model

TL;DR

This paper explores U(1)_X extensions of the Standard Model, focusing on the Stueckelberg mechanism for gauge boson mass generation, predicting narrow Z' signatures at the LHC, and discussing implications for dark matter candidates.

Contribution

It introduces a novel mixing mechanism between U(1)_Y and U(1)_X sectors via the Stueckelberg mechanism, leading to detectable Z' signatures and dark matter candidates.

Findings

Predicts narrow Z' bosons detectable at the LHC

Identifies new dark matter candidates from U(1)_X extensions

Analyzes the role of Fayet-Illiopoulos terms in supersymmetric models

Abstract

We discuss the $U(1)_X$ extensions of the standard model with focus on the Stueckelberg mechanism for mass growth for the extra $U(1)_X$ gauge boson. The assumption of an axionic connector field which carries dual U(1) quantum numbers, i.e., quantum numbers for the hypercharge $U(1)_Y$ and for the hidden sector gauge group $U(1)_X$, allows a non-trivial mixing between the mass growth for the neutral gauge vector bosons in the $SU(2)_L\times U(1)_Y$ sector and the mass growth for the vector boson by the \st mechanism in the $U(1)_X$ sector. This results in an extra $Z'$ which can be very narrow, but still detectable at the Large Hadron Collider (LHC). The $U(1)_X$ extension of the minimal supersymmetric standard model is also considered and the role of the Fayet-Illiopoulos term in such an extension discussed. The $U(1)_X$ extensions of the SM and of the MSSM lead to new candidates for dark matter.