Light Dark Matter, Naturalness, and the Radiative Origin of the Electroweak Scale

TL;DR

This paper explores a classically scale-invariant dark sector model where radiative symmetry breaking triggers electroweak symmetry breaking, predicting detectable dark matter and collider signatures consistent with current Higgs measurements.

Contribution

It introduces a novel weakly coupled dark sector model with radiative symmetry breaking that links dark matter properties to electroweak scale stability and predicts observable collider and astrophysical signals.

Findings

Dark fermions account for the correct dark matter relic abundance.

A dark scalar boson with mass < 250 GeV can be detected at the LHC.

Model predicts observable effects on galactic structure and potential collider signatures.

Abstract

We study classically scale invariant models in which the Standard Model Higgs mass term is replaced in the Lagrangian by a Higgs portal coupling to a complex scalar field of a dark sector. We focus on models that are weakly coupled with the quartic scalar couplings nearly vanishing at the Planck scale. The dark sector contains fermions and scalars charged under dark SU(2) x U(1) gauge interactions. Radiative breaking of the dark gauge group triggers electroweak symmetry breaking through the Higgs portal coupling. Requiring both a Higgs boson mass of 125.5 GeV and stability of the Higgs potential up to the Planck scale implies that the radiative breaking of the dark gauge group occurs at the TeV scale. We present a particular model which features a long-range abelian dark force. The dominant dark matter component is neutral dark fermions, with the correct thermal relic abundance, and in reach of future direct detection experiments. The model also has lighter stable dark fermions charged under the dark force, with observable effects on galactic-scale structure. Collider signatures include a dark sector scalar boson with mass < 250 GeV that decays through mixing with the Higgs boson, and can be detected at the LHC. The Higgs boson, as well as the new scalar, may have significant invisible decays into dark sector particles.