{
  "abstract": "Recent developments in the Swampland program motivate the existence of a mesoscopic Dark Dimension of size $0.1-10~μ$m with bulk Majorana fermions in the $1-10$ keV range. Motivated by this, we derive terrestrial constraints on Majorana bulk neutrinos as a function of the compactification radius. After determining the mass spectrum and mixing structure, we confront the model with Daya Bay neutrino-oscillation data, the KATRIN beta-decay bound, and the KamLAND-Zen neutrinoless double beta decay limit. For the latter, we obtain a closed-form expression for the effective Majorana mass and show that the Kaluza-Klein tower efficiently screens neutrinoless double beta decay when the nuclear momentum exceeds the compactification and Majorana scales. In the Dark-Dimension window, beta decay provides the strongest constraint, pushing the allowed Yukawa couplings down to $\\mathcal{O}(10^{-3})$. Oscillation and neutrinoless double beta decay searches remain complementary, probing smaller and larger Majorana masses, respectively. For completeness, outside the Dark-Dimension assumptions, we investigate how hierarchical Majorana masses can weaken the constraints.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.10668",
  "author_total": 2,
  "authors": [
    {
      "name": "Arturo de Giorgi"
    },
    {
      "name": "Dhruv Pasari"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/3ymj0nxah4hdt.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.10668",
  "fulltext_url": null,
  "id": "3ymj0nxah4hdt",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.10668",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "hep-ex"
    ],
    [
      "arxiv",
      "hep-ph"
    ],
    [
      "arxiv",
      "hep-th"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2609.10668",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-09",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/3ymj0nxah4hdt.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:20:26Z",
      "native_id": "2609.10668",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.10668"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ex",
      "subfield": "high-energy"
    }
  ],
  "title": "The Dark Dimension and Majorana Neutrinos",
  "title_text": "The Dark Dimension and Majorana Neutrinos",
  "type": "preprint",
  "updated_at": "2026-10-30T12:20:26Z",
  "url": "https://research.draconitic.com/paper/3ymj0nxah4hdt",
  "venue": "arXiv",
  "versions": []
}