Radion Portal Freeze-Out Dark-Matter

TL;DR

This paper proposes a radion portal in extra-dimensional models as a natural mechanism for WIMP dark matter to achieve the observed relic abundance, with specific implications for detection experiments and mass ranges.

Contribution

It introduces a radion portal model with a TeV-scale coupling that explains dark matter relic abundance via resonant annihilation, extending the understanding of dark matter interactions.

Findings

Radion portal can produce correct relic abundance for dark matter up to 1 TeV.

Existing direct detection experiments cannot constrain this model.

Indirect detection excludes dark matter masses between 5 and 80 GeV.

Abstract

We show that, in a consistent model of a stabilized extra-dimensional theory, the radion can serve as a natural portal between ordinary matter and WIMP dark matter. With an effective coupling scale of the Kaluza-Klein theory of 20-100 TeV, the radion portal can produce the observed relic abundance through resonant annihilation for dark matter masses up to a TeV. Existing and planned direct dark matter detection experiments cannot constrain this model. However, indirect detection limits exclude dark matter masses between 5 and 80 GeV, where the radion mediator primarily decays into b-quarks.