{
  "abstract": "A possible gamma-ray excess from the Galactic halo favors dark matter with a mass of several hundred GeV. In previous work, we found that an electroweak scalar doublet is a particularly economical—and nearly uniquely selected—interpretation among simple renormalizable thermal dark-matter models. We point out that its unbroken Z2 symmetry is exactly equivalent to an interchange symmetry between two Higgs doublets, making dark matter the Z2-odd partner of the Standard Model Higgs boson and suggesting that the two doublets may share a common weak-scale origin. We connect this model to the recently reported 248keV nuclear-recoil event in the LUX-ZEPLIN experiment. For dark-matter masses of several hundred GeV, the fixed off-diagonal Z interaction can produce the observed recoil within a narrow, halo-dependent strip near the kinematic boundary, predicting a large annual modulation for a smooth Standard Halo Model. Dedicated solar-capture calculations, however, exclude this Standard-Halo interpretation in the thermal-relic mass range. An enhanced high-velocity tail, potentially associated with the Large Magellanic Cloud, shifts the LZ-preferred splitting upward and may leave marginal compatibility with the solar-neutrino constraint. The solar-neutrino constraint does not affect the identification of inert-doublet dark matter as the Z2 partner of the Standard Model Higgs boson or its possible connection to the Galactic halo excess.",
  "abstract_shown": true,
  "affiliations": [
    "Kavli Institute for the Physics and Mathematics of the Universe (WPI), UTIAS, The University of Tokyo, Kashiwa 277-8583, Japan",
    "Leinweber Institute for Theoretical Physics, Department of Physics, University of California, Berkeley, CA 94720, USA",
    "RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS), RIKEN, Wako 351-0198, Japan",
    "Theoretical Physics Group, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 1,
  "authors": [
    {
      "affs": [
        0,
        1,
        2,
        3
      ],
      "name": "Yasunori Nomura",
      "orcid": "0000-0002-1497-1479"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/0twrjk7e4ay33.bib",
  "cited_by": 42,
  "doi": "10.3390/sym18111777",
  "fulltext_url": null,
  "id": "0twrjk7e4ay33",
  "issns": [
    "2073-8994"
  ],
  "landing_url": "https://doi.org/10.3390/sym18111777",
  "language": "en",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "3106|Dark Matter and Cosmic Phenomena"
    ]
  ],
  "openalex": "W7208794436",
  "pdf_url": null,
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-25",
  "publisher": "Multidisciplinary Digital Publishing Institute",
  "ris": "https://research.draconitic.com/paper/0twrjk7e4ay33.ris",
  "sources": [
    {
      "first_seen": "2026-11-07T13:20:44Z",
      "native_id": "W7208794436",
      "source": "openalex",
      "url": "https://doi.org/10.3390/sym18111777"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "openalex:3106|Dark Matter and Cosmic Phenomena",
      "subfield": "high-energy"
    }
  ],
  "title": "Dark Matter as the Z2 Partner of the Standard Model Higgs Boson",
  "title_text": "Dark Matter as the Z2 Partner of the Standard Model Higgs Boson",
  "type": "peer-reviewed",
  "updated_at": "2026-11-09T13:21:01Z",
  "url": "https://research.draconitic.com/paper/0twrjk7e4ay33",
  "venue": "Symmetry",
  "versions": []
}