{
  "abstract": "The LUX-ZEPLIN experiment has reported one nuclear-recoil event at $248\\pm23_{\\rm stat}\\pm23_{\\rm sys}\\,{\\rm keV}$ in a $2.84\\,{\\rm tonne\\text{-}year}$ exposure, with a local significance of $3.4σ$. Inelastic (endothermic) dark matter is a natural candidate: its kinematic threshold suppresses low-energy recoils and shifts the signal toward higher recoil energies. We perform a model-independent analysis of the LZ data using two sidebands, without specifying an ultraviolet completion, so our results apply broadly to inelastic dark matter with coherent spin-independent nuclear scattering. For each $(m_χ,δ)$ we compute $N_{\\rm low}/N_{\\rm sig}$ and $N_{\\rm hi}/N_{\\rm sig}$---predicted count ratios in the sidebands $[14,225)\\,{\\rm keV}$ and $(271,800]\\,{\\rm keV}$ relative to the signal region $[225,271]\\,{\\rm keV}$. The two ratios vary in opposite directions with $δ$ and are simultaneously optimized at a unique splitting $δ^\\star$. For $m_χ=1\\,{\\rm TeV}$, $δ^\\star=339\\,{\\rm keV}$ with a combined Poisson tension of $\\approx1.9σ$; over $500\\,{\\rm GeV}$--$3\\,{\\rm TeV}$, the tension at $δ^\\star$ rises from $\\lesssim1.3σ$ to $\\approx2.5σ$. Additional suppression arises from the Helm form factor: $|F_{\\rm Xe}^{\\rm Helm}|^2\\simeq3\\times10^{-4}$ at $248\\,{\\rm keV}$, near its second diffraction zero. A dedicated LZ search over $271<E_R<800\\,{\\rm keV}$ would provide a decisive test of inelastic dark matter with $δ\\gtrsim330\\,{\\rm keV}$.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.26698",
  "author_total": 2,
  "authors": [
    {
      "name": "David Delepine"
    },
    {
      "name": "Shaaban Khalil"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/2wpfvj4e1rkz3.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.26698",
  "fulltext_url": null,
  "id": "2wpfvj4e1rkz3",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.26698",
  "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"
    ],
    [
      "openalex",
      "3106|Dark Matter and Cosmic Phenomena"
    ]
  ],
  "openalex": "W7214103756",
  "pdf_url": "https://arxiv.org/pdf/2609.26698",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-22",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/2wpfvj4e1rkz3.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:23:39Z",
      "native_id": "2609.26698",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.26698"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ex",
      "subfield": "high-energy"
    }
  ],
  "title": "Model-Independent Sideband Constraints on Inelastic Dark Matter at the LZ High-Recoil Candidate",
  "title_text": "Model-Independent Sideband Constraints on Inelastic Dark Matter at the LZ High-Recoil Candidate",
  "type": "preprint",
  "updated_at": "2026-10-30T12:23:39Z",
  "url": "https://research.draconitic.com/paper/2wpfvj4e1rkz3",
  "venue": "arXiv",
  "versions": []
}