Bridging the $ \mu $Hz gap in the gravitational-wave landscape: unveiling dark baryons

TL;DR

This paper explores gravitational waves in the microhertz range originating from dark sector phase transitions, linking them to dark baryons, TeV-scale physics, and potential collider and GW detections, emphasizing the importance of bridging the dHz gap.

Contribution

It proposes a connection between dHz gravitational waves, dark baryons, and TeV-scale physics, advocating for experimental efforts to detect these signals and explore related models.

Findings

Dark phase transitions can produce dHz GWs.

TeV-scale mechanisms relate dark matter and visible matter densities.

Future GW detectors and colliders are crucial for probing these models.

Abstract

We study gravitational waves (GWs) with frequencies in the $\mu$Hz range, which arise from phase transitions related to dark confinement in the context of dark versions of Quantum Chromodynamics. Based on several compelling motivations, we posit that these theories predict the existence of GeV-mass asymmetric dark baryons, akin to ordinary baryons, with the potential to contribute to dark matter. Furthermore, we emphasize the significance of a particular $\mathcal{O}(\text{TeV})$ scale for multiple reasons. First, to account for the similarity in present-day mass densities between dark matter and visible matter, various TeV-scale mechanisms can elucidate the similarities in both their number densities and masses. Moreover, to address the so-called electroweak hierarchy problem, we consider the introduction of either the Composite Higgs or Supersymmetry at around $\mathcal{O}(\text{TeV})$. These mechanisms lead to intriguing TeV collider signatures and the possibility of detecting mHz GWs in future experiments. In summary, this study provides a strong motivation for advancing GW experiments that can bridge the $\mu$Hz frequency gap in the GW spectrum. Additionally, there is a need for the construction of more powerful particle colliders to explore higher energy regimes. In consideration of the possibility to scrutinize these models from various perspectives, we strongly advocate their further development.