{
  "abstract": "The nucleus of thorium-229 ($^{229}$Th) has an exceptionally low-energy isomeric state ($^{229\\mathrm{m}}$Th). Because its excitation energy is close to the energy levels of valence electrons, the lifetime of $^{229\\mathrm{m}}$Th varies substantially depending on its electronic state. Although internal conversion and radiative decay were recently observed, the electronic bridge decay of $^{229\\mathrm{m}}$Th, a higher-order decay process through an electronic transition, has not yet been confirmed. A promising candidate to search for this decay channel is singly charged $^{229\\mathrm{m}}$Th$^+$ in the electronic ground state. Here we produce $^{229\\mathrm{m}}$Th$^+$ by a charge exchange reaction in an ion trap and detect the isomers through measuring the electrons emitted from internal conversion processes. We determined the half-life of $^{229\\mathrm{m}}$Th$^+$ to be 0.46(8) s. Our result differs by several orders of magnitude from the half-lives of internal conversion and radiative decay, indirectly suggesting the existence of the electronic bridge decay of $^{229\\mathrm{m}}$Th. This will enable the direct observation and further investigation of the electronic bridge process, which will contribute to understanding nuclear-electron interactions and accelerating nuclear deexcitation in the operation of a thorium-based nuclear clock.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": "Journal reference: Nat. Phys. 22, 832-837 (2026)",
  "arxiv": "2610.31009",
  "author_total": 9,
  "authors": [
    {
      "name": "Y. Shigekawa"
    },
    {
      "name": "A. Yamaguchi"
    },
    {
      "name": "K. Tokoi"
    },
    {
      "name": "N. Sato"
    },
    {
      "name": "H. Kikunaga"
    },
    {
      "name": "K. Shirasaki"
    },
    {
      "name": "Y. Kasamatsu"
    },
    {
      "name": "M. Wada"
    },
    {
      "name": "H. Haba"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/0ft8x19qjnjmy.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.31009",
  "fulltext_url": null,
  "id": "0ft8x19qjnjmy",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.31009",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "nucl-ex"
    ],
    [
      "arxiv",
      "physics.atom-ph"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2610.31009",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-22",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/0ft8x19qjnjmy.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:34:34Z",
      "native_id": "2610.31009",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.31009"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:physics.atom-ph",
      "subfield": "amo"
    },
    {
      "field": "physics",
      "origin": "arxiv:nucl-ex",
      "subfield": "nuclear"
    }
  ],
  "title": "Lifetime of the singly charged $^{229}$Th nuclear isomer",
  "title_text": "Lifetime of the singly charged ^229Th nuclear isomer",
  "type": "preprint",
  "updated_at": "2026-10-30T12:34:34Z",
  "url": "https://research.draconitic.com/paper/0ft8x19qjnjmy",
  "venue": "arXiv",
  "versions": [
    {
      "doi": "10.1038/s41567-026-03251-1",
      "pid": null,
      "relation": "published-as",
      "title": null,
      "venue": null
    }
  ]
}