Dark Matter from a Vector Field in the Fundamental Representation of $SU(2)_L$

TL;DR

This paper investigates a vector field in the fundamental representation of $SU(2)_L$ as a dark matter candidate, constraining its parameter space with collider and dark matter search data, and discusses theoretical and phenomenological implications.

Contribution

It introduces a novel $SU(2)_L$ vector field dark matter model with a $Z_2$ symmetry, analyzing its viability and constraints from experimental data.

Findings

A small viable parameter space for the dark matter candidate exists.

Unitarity constraints imply the need for UV completion below 10 TeV.

Predictions differ from inert Two Higgs Doublet Model in mono-jet and related signals.

Abstract

We explore an extension to the Standard Model which incorporates a vector field in the fundamental representation of $SU(2)_L$ as the only non-standard degree of freedom. This kind of field may appear in different scenarios such as Compositness, Gauge-Higgs unification and extradimensional scenarios. We study the model in which a $Z_2$ symmetry is manifest, making the neutral CP-even component of the new vector field a vectorial dark matter candidate. We constraint the parameter space through LEP and LHC data, as well as from current dark matter searches. Additionally, comment on the implications of perturbative unitarity are presented. We find that the model is highly constrained but a small region of the parameter space can provide a viable DM candidate. On the other hand, unitarity demands an UV completion at an scale below 10 TeV. Finally we contrast our predictions on mono-jet, -$Z$, -Higgs production with the ones obtained in the inert Two Higgs Doublet Model.