{
  "abstract": "The LUX-ZEPLIN (LZ) experiment has reported an inelastic nuclear-recoil candidate at $E_{\\rm nr}=248\\pm23_{\\rm stat}\\pm23_{\\rm sys}\\,{\\rm keV}$. We test whether endothermic pseudo-Dirac dark matter coupled to a kinetically mixed dark photon can account for this event while reproducing the observed relic abundance. A five-parameter fit using an energy-only LZ likelihood and a relic-density likelihood favors TeV-scale dark matter with a mass splitting of a few hundred keV, and a GeV-scale mediator. The recoil energy places the splitting near its kinematic ceiling, while secluded annihilation fixes the dark gauge coupling to a good approximation as a function of the dark-matter mass. Representative points predict $\\mathcal{O}(1)$ accepted LZ event candidate and the observed DM relic density. Because the preferred splitting lies below the $e^+e^-$ threshold, the viability of the minimal model depends on the late-time excited-state abundance; a transition dipole can provide additional depletion, and the required light mediator remains testable in accelerator searches.",
  "abstract_shown": true,
  "affiliations": [
    "CSSM and ARC Centre of Excellence for Dark Matter Particle Physics , Department of Physics , Adelaide University , Adelaide 5005 , Australia"
  ],
  "article_type": null,
  "arxiv": "2609.09015",
  "author_total": 5,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Pengxuan Zhu",
      "orcid": "0000-0003-2039-5794"
    },
    {
      "name": "Giovani Dalla Valle Garcia",
      "orcid": "0000-0003-4255-1997"
    },
    {
      "affs": [
        0
      ],
      "name": "X. G. Wang",
      "orcid": "0000-0001-9164-0027"
    },
    {
      "affs": [
        0
      ],
      "name": "Anthony W. Thomas",
      "orcid": "0000-0003-0026-499X"
    },
    {
      "affs": [
        0
      ],
      "name": "Martin J. White"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/e61shadqkw3ge.bib",
  "cited_by": 24,
  "doi": "10.48550/arxiv.2609.09015",
  "fulltext_url": null,
  "id": "e61shadqkw3ge",
  "issns": [
    "2331-8422"
  ],
  "landing_url": "https://arxiv.org/abs/2609.09015",
  "language": "en",
  "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-ph"
    ],
    [
      "openalex",
      "3106|Dark Matter and Cosmic Phenomena"
    ]
  ],
  "openalex": "W7212023224",
  "pdf_url": "https://arxiv.org/pdf/2609.09015",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-08",
  "publisher": "Cornell University",
  "ris": "https://research.draconitic.com/paper/e61shadqkw3ge.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:27:01Z",
      "native_id": "2609.09015",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.09015"
    },
    {
      "first_seen": "2026-11-07T13:20:45Z",
      "native_id": "W7212023224",
      "source": "openalex",
      "url": "https://arxiv.org/abs/2609.09015"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ph",
      "subfield": "high-energy"
    }
  ],
  "title": "Endothermic dark matter with a light dark photon and the LUX-ZEPLIN high-energy nuclear-recoil candidate",
  "title_text": "Endothermic dark matter with a light dark photon and the LUX-ZEPLIN high-energy nuclear-recoil candidate",
  "type": "preprint",
  "updated_at": "2026-11-09T13:21:02Z",
  "url": "https://research.draconitic.com/paper/e61shadqkw3ge",
  "venue": "arXiv",
  "versions": []
}