Secluded Dark Matter Coupled to a Hidden CFT

TL;DR

This paper extends a secluded dark matter model by incorporating a confining hidden-sector CFT, which naturally explains the small mediator scale and alters the universe's thermal history and detection signals.

Contribution

It introduces a minimal secluded dark matter model with a hidden-sector CFT, providing a natural origin for the mediator scale and exploring its impact on cosmology and phenomenology.

Findings

Hidden-sector confinement generates a small mediator mass.

New annihilation channels affect dark matter relic abundance.

Hidden-sector phase transition influences cosmic-ray signals.

Abstract

Models of secluded dark matter offer a variant on the standard WIMP picture and can modify our expectations for hidden sector phenomenology and detection. In this work we extend a minimal model of secluded dark matter, comprised of a U(1)'-charged dark matter candidate, to include a confining hidden-sector CFT. This provides a technically natural explanation for the hierarchically small mediator-scale, with hidden-sector confinement generating m_{gamma'}>0. Furthermore, the thermal history of the universe can differ markedly from the WIMP picture due to (i) new annihilation channels, (ii) a (potentially) large number of hidden-sector degrees of freedom, and (iii) a hidden-sector phase transition at temperatures T << M_{dm} after freeze out. The mediator allows both the dark matter and the Standard Model to communicate with the CFT, thus modifying the low-energy phenomenology and cosmic-ray signals from the secluded sector.