A 331 WIMPy Dark Radiation Model

TL;DR

This paper proposes a dark radiation model where a small fraction of relativistically produced dark matter particles can mimic extra relativistic species, using a 3-3-1 gauge model consistent with current experimental bounds.

Contribution

It introduces a novel dark radiation scenario within a 3-3-1 gauge model, linking dark matter production to early universe relativistic degrees of freedom.

Findings

Relativistic dark matter can mimic extra neutrino species without conflicting with BBN and CMB constraints.

The model aligns with electroweak precision tests and recent LHC data.

It provides a natural explanation for the number of Standard Model generations.

Abstract

Recent observations suggest that the number of relativistic degrees of freedom in the early universe might exceed what is predicted in the standard cosmological model. If even a small, percent-level fraction of dark matter particles are produced relativistically, they could mimic the effect of an extra realistic species at matter-radiation equality while obeying BBN, CMB and Structure Formation bounds. We show that this scenario is quite naturally realized with a weak-scale dark matter particle and a high-scale ``mother'' particle within a well motivated 3-3-1 gauge model, which is particularly interesting for being consistent with electroweak precision measurements, with recent LHC results, and for offering a convincing explanation for the number of generations in the Standard Model.