Dark Matter from a Classically Scale-Invariant $SU(3)_X$

TL;DR

This paper explores a scale-invariant extension of the Standard Model with an additional $SU(3)_X$ gauge symmetry, where dark matter candidates emerge from stable vector bosons, and analyzes their phenomenological viability and detection prospects.

Contribution

It introduces a novel classically scale-invariant model with $SU(3)_X$ symmetry, generating dark matter and electroweak scales via the Coleman-Weinberg mechanism, and thoroughly analyzes dark matter phenomenology.

Findings

Three lightest vector bosons are stable and can be dark matter candidates.

The model's dark matter predictions are consistent with current constraints.

Direct detection prospects are promising for certain parameter regions.

Abstract

In this work we study a classically scale-invariant extension of the Standard Model in which the dark matter and electroweak scales are generated through the Coleman-Weinberg mechanism. The extra $SU(3)_X$ gauge factor gets completely broken by the vacuum expectation values of two scalar triplets. Out of the eight resulting massive vector bosons the three lightest are stable due to an intrinsic $Z_2\times Z_2'$ discrete symmetry and can constitute dark matter candidates. We analyze the phenomenological viability of the predicted multi-Higgs sector imposing theoretical and experimental constraints. We perform a comprehensive analysis of the dark matter predictions of the model solving numerically the set of coupled Boltzmann equations involving all relevant dark matter processes and explore the direct detection prospects of the dark matter candidates.