{
  "abstract": "The LUX-ZEPLIN (LZ) experiment has reported a single nuclear-recoil candidate at $E_R \\simeq 248$keV. LZ interprets it in terms of inelastic dark matter that scatters endothermically from its ground state, $χ_1 N \\to χ_2 N$. In pseudo-Dirac models the excited state $χ_2$ can survive to the present day, and exothermic scattering, $χ_2 N \\to χ_1 N$, is then also open. The published LZ intervals do not describe this case. We rebuild the LZ statistical inference and validate it against the published intervals. We then apply it to a halo that contains a fraction $f$ of $χ_2$. For $f \\gtrsim 10^{-5}$--$10^{-2}$, depending on the mass splitting, the exothermic contribution dominates. For $f=1/2$ the cross section required by the candidate drops by factors of $80$ to $1.6\\times10^4$ for $δ= 250$--$350$~keV, and the kinematic cutoff of the endothermic signal disappears. A benchmark that explains the event with $χ_1$ alone lies a factor of $30$ above the upper limit when half of the halo is $χ_2$.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.35650",
  "author_total": 1,
  "authors": [
    {
      "name": "Vinicius Oliveira"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/ecx3ga6e5dd97.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.35650",
  "fulltext_url": null,
  "id": "ecx3ga6e5dd97",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.35650",
  "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",
      "astro-ph.HE"
    ],
    [
      "arxiv",
      "hep-ph"
    ],
    [
      "openalex",
      "3106|Dark Matter and Cosmic Phenomena"
    ]
  ],
  "openalex": "W7214735299",
  "pdf_url": "https://arxiv.org/pdf/2609.35650",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-28",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/ecx3ga6e5dd97.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:25:12Z",
      "native_id": "2609.35650",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.35650"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.HE",
      "subfield": "high-energy-astrophysics"
    },
    {
      "field": "physics",
      "origin": "arxiv:hep-ph",
      "subfield": "high-energy"
    }
  ],
  "title": "The LZ event with a two-state dark matter halo",
  "title_text": "The LZ event with a two-state dark matter halo",
  "type": "preprint",
  "updated_at": "2026-10-30T12:25:12Z",
  "url": "https://research.draconitic.com/paper/ecx3ga6e5dd97",
  "venue": "arXiv",
  "versions": []
}