{
  "abstract": "Many quarkoniumlike states have been observed above open-flavor thresholds, but their organization and internal structure remain unsettled. We study the isoscalar hidden-charm and hidden-bottom sectors in Born--Oppenheimer effective field theory (BOEFT), between the spin--isospin averaged $S+S$ and $S+P$ thresholds. At leading order, heavy-quark spin decouples, and the quarkonium static potential mixes through string breaking with the lowest tetraquark/open-flavor BO potentials of the same quantum numbers. These potentials are constrained by QCD symmetries, their short- and long-distance behavior, and lattice-QCD data. The only calibrated parameter is the lowest $1^{--}$ adjoint meson mass, fixed from the shallow multiplet associated with the $χ_{c1}(3872)$. Using $T$-matrix, $K$-matrix, and complex-scaling methods, we determine bound states and resonance poles, their masses, pole widths from the included nonstrange $S+S$ channels, normalized pole couplings, and prescription-dependent quarkonium--open-flavor composition measures. The spectrum exhibits a common heavy-quark-spin-symmetry multiplet organization. Most poles are short-distance, predominantly quarkonium resonances. The same equations generate shallow, spatially extended, open-flavor-dominated states with molecular long-distance characteristics. Their binding energies, radii, and small quarkonium components are highly sensitive to the adjoint meson mass, whereas the higher spectrum is more stable. The equations also predict a more compact open-flavor-dominated resonance in the $l = 0$ bottomoniumlike sector, with a dominant $P$-wave open-flavor component. Together with the hybrid levels, the spectrum provides multiplet assignments for most candidates. States not naturally accommodated point to the need for hidden-strange and $S+P$ tetraquark/open-flavor BO sectors and for hybrid--tetraquark and hybrid--quarkonium mixings.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2608.04105",
  "author_total": 5,
  "authors": [
    {
      "name": "Nora Brambilla"
    },
    {
      "name": "Roberto Bruschini"
    },
    {
      "name": "Abhishek Mohapatra"
    },
    {
      "name": "Fang-Zheng Peng"
    },
    {
      "name": "Tommaso Scirpa"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/2b3bckzdt2aft.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2608.04105",
  "fulltext_url": null,
  "id": "2b3bckzdt2aft",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2608.04105",
  "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"
    ],
    [
      "arxiv",
      "nucl-th"
    ],
    [
      "openalex",
      "3106|Quantum Chromodynamics and Particle Interactions"
    ]
  ],
  "openalex": "W7196936282",
  "pdf_url": "https://arxiv.org/pdf/2608.04105",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-04",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/2b3bckzdt2aft.ris",
  "sources": [
    {
      "first_seen": "2026-11-06T18:21:30Z",
      "native_id": "2608.04105",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2608.04105"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ex",
      "subfield": "high-energy"
    },
    {
      "field": "physics",
      "origin": "arxiv:nucl-th",
      "subfield": "nuclear"
    }
  ],
  "title": "Quarkoniumlike states above open-flavor thresholds in Born-Oppenheimer EFT",
  "title_text": "Quarkoniumlike states above open-flavor thresholds in Born-Oppenheimer EFT",
  "type": "preprint",
  "updated_at": "2026-11-09T00:20:34Z",
  "url": "https://research.draconitic.com/paper/2b3bckzdt2aft",
  "venue": "arXiv",
  "versions": []
}