{
  "abstract": "Nuclear electric quadrupole moments of unstable isotopes are commonly extracted from laser spectroscopy of the atomic hyperfine structure, where the accuracy is limited to the several-percent level by the available electric-field-gradient (EFG) calculations. In this study, we determine the spectroscopic quadrupole moment of $^{223}$Ra (half-life $t_{1/2} = 11.4$ d) from hyperfine-resolved collinear resonance ionization spectroscopy of the radioactive molecule $^{223}$Ra$^{19}$F. The $X\\,^2Σ^+$ electronic ground state of RaF provides a large axial EFG at the radium nucleus that can be calculated with relativistic coupled-cluster theory to sub-percent accuracy. Together with a three-fold improvement in spectral resolution over previous fast-beam measurements of radioactive molecules, this yields $Q_s = +1.211(7)_\\mathrm{stat}(2)_\\mathrm{syst}(5)_\\mathrm{theo}\\,e\\mathrm{b}$ for $^{223}$Ra with a total uncertainty of 0.73%, approximately three times better than atomic and ionic determinations. This result demonstrates that molecular spectroscopy can provide access to the electromagnetic structure of unstable nuclei with a precision competitive with, and in favorable cases better than, atomic spectroscopy, and may thus be envisioned for studies beyond the limitations of current radioactive-atom experiments.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2611.04696",
  "author_total": 33,
  "authors": [
    {
      "name": "C. M. Fajardo-Zambrano"
    },
    {
      "name": "M. Athanasakis-Kaklamanakis"
    },
    {
      "name": "L. Lalanne"
    },
    {
      "name": "J. R. Reilly"
    },
    {
      "name": "O. Ahmad"
    },
    {
      "name": "M. Au"
    },
    {
      "name": "S. W. Bai"
    },
    {
      "name": "J. Berbalk"
    },
    {
      "name": "C. Bernerd"
    },
    {
      "name": "A. A. Breier"
    },
    {
      "name": "K. Chrysalidis"
    },
    {
      "name": "T. E. Cocolios"
    },
    {
      "name": "R. P. de Groote"
    },
    {
      "name": "K. T. Flanagan"
    },
    {
      "name": "S. Franchoo"
    },
    {
      "name": "R. F. Garcia Ruiz"
    },
    {
      "name": "R. Heinke"
    },
    {
      "name": "P. Imgram"
    },
    {
      "name": "Á. Koszorús"
    },
    {
      "name": "P. Lassègues"
    },
    {
      "name": "J. Lim"
    },
    {
      "name": "Y. C. Liu"
    },
    {
      "name": "K. M. Lynch"
    },
    {
      "name": "A. McGlone"
    },
    {
      "name": "W. C. Mei"
    },
    {
      "name": "G. Neyens"
    },
    {
      "name": "L. Nies"
    },
    {
      "name": "A. Raggio"
    },
    {
      "name": "S. Rothe"
    },
    {
      "name": "B. van den Borne"
    },
    {
      "name": "J. Warbinek"
    },
    {
      "name": "J. Wessolek"
    },
    {
      "name": "X. F. Yang"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/0e9ccf6vpf5sc.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2611.04696",
  "fulltext_url": null,
  "id": "0e9ccf6vpf5sc",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2611.04696",
  "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",
      "nucl-ex"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2611.04696",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-03",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/0e9ccf6vpf5sc.ris",
  "sources": [
    {
      "first_seen": "2026-11-04T15:21:25Z",
      "native_id": "2611.04696",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2611.04696"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:nucl-ex",
      "subfield": "nuclear"
    }
  ],
  "title": "Precise and accurate nuclear electric quadrupole moment of $^{223}$Ra from molecular spectroscopy",
  "title_text": "Precise and accurate nuclear electric quadrupole moment of ^223Ra from molecular spectroscopy",
  "type": "preprint",
  "updated_at": "2026-11-05T15:20:35Z",
  "url": "https://research.draconitic.com/paper/0e9ccf6vpf5sc",
  "venue": "arXiv",
  "versions": []
}