{
  "abstract": "Located at the neutron shell closure $N = 8$, the long-lived radioactive isotope $^{14}$C plays a critical role in geochronology and nuclear structure studies. Despite its widespread use, the nuclear charge radius of $^{14}$C has remained less precisely known compared to its stable counterpart $^{12}$C. Here, we report a high-precision determination of the $^{14}$C charge radius using collinear laser spectroscopy at the COALA setup at TU Darmstadt, improving upon the precision of previous muonic measurements by a factor $5$ and revealing a $1.9σ$ discrepancy of combined uncertainty, indicating a likely underestimated uncertainty in the muonic determination. This measurement challenges state-of-the-art ab initio nuclear theory calculations, including auxiliary field diffusion Monte Carlo, the valence-space in-medium similarity renormalization group, and the no-core shell model, augmented by neural-network techniques. With $^{12}$C and $^{14}$C now forming one of the most precisely characterized even-even isotope pairs, these results also enable improved QED tests.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": "Journal reference: Phys. Rev. Lett. (2026)",
  "arxiv": "2608.17052",
  "author_total": 14,
  "authors": [
    {
      "name": "Kristian König"
    },
    {
      "name": "Patrick Müller"
    },
    {
      "name": "Tobias Gesser"
    },
    {
      "name": "Emily Burbach"
    },
    {
      "name": "Stefano Gandolfi"
    },
    {
      "name": "Matthias Heinz"
    },
    {
      "name": "Phillip Imgram"
    },
    {
      "name": "Alessandro Lovato"
    },
    {
      "name": "Pieter Maris"
    },
    {
      "name": "Takayuki Miyagi"
    },
    {
      "name": "Wilfried Nörtershäuser"
    },
    {
      "name": "Robert Roth"
    },
    {
      "name": "Julien Spahn"
    },
    {
      "name": "Achim Schwenk"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/209th74c88msw.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2608.17052",
  "fulltext_url": null,
  "id": "209th74c88msw",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2608.17052",
  "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",
      "nucl-th"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2608.17052",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-11",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/209th74c88msw.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:21:07Z",
      "native_id": "2608.17052",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2608.17052"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:nucl-ex",
      "subfield": "nuclear"
    }
  ],
  "title": "Accurate Charge Radius Measurement of $^{14}$C Confronts Ab Initio Theory",
  "title_text": "Accurate Charge Radius Measurement of ^14C Confronts Ab Initio Theory",
  "type": "preprint",
  "updated_at": "2026-10-30T12:21:07Z",
  "url": "https://research.draconitic.com/paper/209th74c88msw",
  "venue": "arXiv",
  "versions": [
    {
      "doi": "10.1103/f5s7-1t7w",
      "pid": null,
      "relation": "published-as",
      "title": null,
      "venue": null
    }
  ]
}