Vector dark matter in supercooled Higgs portal models

TL;DR

This paper explores hidden sector gauge extensions of the Standard Model, focusing on dark matter and gravitational wave signals from phase transitions, with implications for upcoming detection experiments.

Contribution

It introduces models with radiative symmetry breaking in hidden gauge sectors and analyzes their detectability via direct detection and gravitational waves.

Findings

Dark matter relic density constraints from direct detection.

Gravitational wave signals from electroweak phase transition.

Complementarity of gravitational wave and direct detection experiments.

Abstract

We consider extensions of the Standard Model by a hidden sector consisting of a gauge field coupled with a scalar field. Assuming the absence of dimensionful parameters in the tree level potential, radiative symmetry breaking will make the hidden sector gauge field massive and induce the electroweak scale of the Standard Model. We consider separately dark sector gauge groups $U(1)_{\rm{D}}$ and $SU(2)_{\rm{D}}$, and focus on probing the models with a combination of direct detection experiments and gravitational wave observatories. We find that recent dark matter direct detection results significantly constrain the parameter space of the models where they can account for the observed dark matter relic density via freeze-out. The gravitational wave signals originating from strongly first order electroweak phase transition in these models can be probed in future gravitational wave observatories such as the Laser Interferometer Space Antenna. We show how the projected results compliment direct detection experiments and can help probe parameter space near the neutrino floor of direct detection.