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A<sc>bstract</sc> We argue that the striking similarity between the cosmic abundances of baryons and dark matter, despite their very different astrophysical behavior, strongly motivates the scenario in which dark matter resides within a rich dark sector parallel in structure to that of the standard model. The near cosmic coincidence is then explained by an approximateℤ2exchange symmetry between the two sectors, where dark matter consists of stable dark neutrons, with matter and dark matter asymmetries arising via parallel WIMP baryogenesis mechanisms. Taking a top-down perspective, we point out that an adequateℤ2symmetry necessitates solving the electroweak hierarchy problem in each sector, without our committing to a specific implementation. A higher-dimensional realization in the far UV is presented, in which the hierarchical couplings of the two sectors and the requisiteℤ2-breaking structure arise naturally from extra-dimensional localization and gauge symmetries. We trace the cosmic history, paying attention to potential pitfalls not fully considered in previous literature. Residualℤ2-breaking can very plausibly give rise to the asymmetric reheating of the two sectors, needed to keep the cosmological abundance of relativistic dark particles below tight bounds. We show that, despite the need to keep inter-sector couplings highly suppressed after asymmetric reheating, there can naturally be order-one couplings mediated by TeV scale particles which can allow experimental probes of the dark sector at high energy colliders. Massive mediators can also induce dark matter direct detection signals, but likely at or below the neutrino floor.
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This content will become publicly available on February 1, 2026
Tuning toward the edge of a dark abyss: Implications of a tuning paradigm on the hierarchy between the weak and dark matter scales
It has recently been suggested that tuning toward the boundary of the positivity domain of the scalar potential may explain the separation between the electroweak scale and the unification scale in a grand unified theory. Here, we explore the possibility that the same type of tuning might account for the generation of the electroweak scale from a much lighter dynamically generated scale in a dark sector. We present a model that realizes this idea and provides a proof of principle that the same dark sector can include a viable dark matter candidate.
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- PAR ID:
- 10590940
- Publisher / Repository:
- American Physical Society
- Date Published:
- Journal Name:
- Physical Review D
- Volume:
- 111
- Issue:
- 3
- ISSN:
- 2470-0010
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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