{
  "abstract": "We assess the tension between theoretical predictions and the values quoted by the Particle Data Group (PDG) for the partial decay width and branching fraction associated with the radiative charmonium decay $J/ψ\\toγη_c$. A profile scan over the most recent PDG data depending on the branching fraction $\\mathcal{B}(J/ψ\\toγη_c)$ suggests that the correlation between measured branching fractions is compatible with lattice QCD determinations of the partial decay widths $Γ(J/ψ\\toγη_c)$ and $Γ(η_c\\toγγ)$. We propose a theoretically grounded photon line shape for the radiative decay spectrum and a prescription for the extraction of (product) branching fractions involving the magnetic dipole (M1) transition $J/ψ\\toγη_c$. This approach obviates the need to modify the photon energy spectrum line shape using empirical damping functions, as done in the most recent experimental extractions of $\\mathcal{B}(J/ψ\\toγη_c)$ from the photon line shape, thereby eliminating an inherent ambiguity in the determination of the derived observables.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2606.19902",
  "author_total": 2,
  "authors": [
    {
      "name": "Magnus C. Schaaf"
    },
    {
      "name": "Antonio Vairo"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/9g14pvny1yytd.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2606.19902",
  "fulltext_url": null,
  "id": "9g14pvny1yytd",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2606.19902",
  "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",
      "hep-ex"
    ],
    [
      "arxiv",
      "hep-lat"
    ],
    [
      "arxiv",
      "hep-ph"
    ],
    [
      "openalex",
      "3106|Quantum Chromodynamics and Particle Interactions"
    ]
  ],
  "openalex": "W7165378583",
  "pdf_url": "https://arxiv.org/pdf/2606.19902",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-13",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/9g14pvny1yytd.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:29:11Z",
      "native_id": "2606.19902",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2606.19902"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ex",
      "subfield": "high-energy"
    }
  ],
  "title": "Extraction of charmonium branching fractions from $J/ψ\\toγη_c$ radiative decays",
  "title_text": "Extraction of charmonium branching fractions from J/ψ→γη_c radiative decays",
  "type": "preprint",
  "updated_at": "2026-10-30T12:29:11Z",
  "url": "https://research.draconitic.com/paper/9g14pvny1yytd",
  "venue": "arXiv",
  "versions": []
}