{
  "abstract": "We propose that the $248\\,\\mathrm{keV}$ nuclear-recoil candidate reported by LUX--ZEPLIN can arise from the endothermic hyperfine excitation of composite dark matter. Rather than requiring two distinct dark-sector particles, the inelasticity of scattering arises from a hyperfine transition between the pseudoscalar and vector states of a single dark hadron. In a PQ-augmented dark QCD framework, the parity-conserving vacuum suppresses dangerous elastic scattering, while axion emission depletes the relic excited-state population. Endothermic excitation near the Galactic kinematic edge then naturally produces a localized high-energy recoil peak. We find that sub-TeV-scale dark matter with a hyperfine splitting of a few hundred keV can yield an order-one event rate in the LZ high-recoil window. This interpretation offers a possible form of dark-matter hyperfine spectroscopy, with complementary tests from dark-photon searches and future recoil-spectrum measurements.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.23477",
  "author_total": 2,
  "authors": [
    {
      "name": "Jie Sheng"
    },
    {
      "name": "Kairui Zhang"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/cqa9xpvqabkfa.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.23477",
  "fulltext_url": null,
  "id": "cqa9xpvqabkfa",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.23477",
  "language": null,
  "licence": "CC0-1.0",
  "licence_label": "CC0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/publicdomain/zero/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "hep-ph"
    ],
    [
      "openalex",
      "3106|Dark Matter and Cosmic Phenomena"
    ]
  ],
  "openalex": "W7214028309",
  "pdf_url": "https://arxiv.org/pdf/2609.23477",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-20",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/cqa9xpvqabkfa.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:23:19Z",
      "native_id": "2609.23477",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.23477"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ph",
      "subfield": "high-energy"
    }
  ],
  "title": "The LUX-ZEPLIN Event as Hyperfine Spectroscopy of Composite Dark Matter",
  "title_text": "The LUX-ZEPLIN Event as Hyperfine Spectroscopy of Composite Dark Matter",
  "type": "preprint",
  "updated_at": "2026-10-30T12:23:19Z",
  "url": "https://research.draconitic.com/paper/cqa9xpvqabkfa",
  "venue": "arXiv",
  "versions": []
}