Dirac-Fermionic Dark Matter in $U(1)_X$ Models

TL;DR

This paper analyzes various $U(1)_X$ models with Dirac fermion dark matter, combining collider, direct, and indirect detection constraints to identify viable parameter regions and explore explanations for recent experimental anomalies.

Contribution

It provides a comprehensive analysis of multiple $U(1)_X$ models, including constraints and potential explanations for collider excesses, which is novel in the context of Dirac fermionic dark matter.

Findings

Dark matter masses below ~1 TeV are excluded unless Z'-fermion couplings are suppressed.

Collider constraints exclude Z' masses up to ~3 TeV in several models.

The $U(1)_{d-u}$ model can explain the ATLAS diboson excess.

Abstract

We study a number of $U(1)_X$ models featuring a Dirac fermion dark matter particle. We perform a comprehensive analysis which includes the study of corrections to the muon magnetic moment, dilepton searches with LHC data, as well as direct and indirect dark matter detection constraints. We consider four different coupling structures, namely $U(1)_{B-L}, U(1)_{d-u}, U(1)_{universal}$, and $U(1)_{10+\bar{5}}$, all motivated by compelling extensions to the standard model. We outline the viable and excluded regions of parameter space using a large set of probes. Our key findings are that (i) the combination of direct detection and collider constraints rule out dark matter particle masses lighter than $\sim 1$ TeV, unless rather suppressed Z'-fermion couplings exist, and that (ii) for several of the models under consideration, collider constraints rule out Z' masses up to $\sim 3$ TeV. Lastly, we show that we can accommodate the recent Diboson excess reported by ATLAS collaboration within the $U(1)_{d-u}$ model.