{
  "abstract": "The recent high-recoil candidate event reported by LUX-ZEPLIN (LZ) motivates dark-matter scenarios with nonstandard kinematics and momentum-dependent interactions. We study a two-state inelastic dark-matter model in which $χ_1$ and $χ_2$ couple off-diagonally to an axion-like particle (ALP) that also couples to gluons and photons. Unlike treatments that assume only one dark-matter state is present today, we track the cosmological evolution of both states. The excited state $χ_2$ is sufficiently long-lived to survive to the present, with its relic fraction determined by the dark-sector conversion process $χ_2χ_2\\leftrightarrowχ_1χ_1$. We find that this fraction depends strongly on the Lorentz structure of the DM--ALP interaction: scalar transition couplings efficiently deplete $χ_2$, favoring endothermic $χ_1 N\\toχ_2 N$ scattering, whereas pseudoscalar transition couplings preserve $f_2\\simeq1/2$, yielding recoil spectra dominated by exothermic $χ_2 N\\toχ_1 N$ down-scattering. Benchmark spectra in all four scenarios can peak near the observed recoil energy of $250\\,\\mathrm{keV}$. Our results demonstrate that the dominant direction of inelastic scattering in direct detection can be dynamically selected by the early-Universe evolution of the dark sector. With additional data, annual modulation measurements could distinguish these scenarios. We further show that the ALP portal can be directly probed at colliders.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.17412",
  "author_total": 5,
  "authors": [
    {
      "name": "Haipeng An"
    },
    {
      "name": "Fei Gao"
    },
    {
      "name": "Jia Liu"
    },
    {
      "name": "Minghao Liu"
    },
    {
      "name": "Changlong Xu"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/77mwfbf0vrmn3.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.17412",
  "fulltext_url": null,
  "id": "77mwfbf0vrmn3",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.17412",
  "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.CO"
    ],
    [
      "arxiv",
      "hep-ex"
    ],
    [
      "arxiv",
      "hep-ph"
    ],
    [
      "openalex",
      "3106|Dark Matter and Cosmic Phenomena"
    ]
  ],
  "openalex": "W7213412101",
  "pdf_url": "https://arxiv.org/pdf/2609.17412",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-15",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/77mwfbf0vrmn3.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:21:41Z",
      "native_id": "2609.17412",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.17412"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.CO",
      "subfield": "cosmology"
    },
    {
      "field": "physics",
      "origin": "arxiv:hep-ex",
      "subfield": "high-energy"
    }
  ],
  "title": "Cosmological Constrained Axion-Portal Inelastic Dark Matter for the LZ Event",
  "title_text": "Cosmological Constrained Axion-Portal Inelastic Dark Matter for the LZ Event",
  "type": "preprint",
  "updated_at": "2026-10-30T12:21:41Z",
  "url": "https://research.draconitic.com/paper/77mwfbf0vrmn3",
  "venue": "arXiv",
  "versions": []
}