{
  "abstract": "We investigate the near-threshold structure of the exotic tetraquark candidates $χ_{c1}(3872)$ and $T_{cc}^+(3875)$ using the effective-range expansion (ERE) and resonance compositeness relations. From the experimental masses and widths, we extract scattering lengths, effective ranges, and molecular compositeness coefficients within a two-channel framework, with uncertainties propagated through $N=50000$ Monte Carlo samples. We find large negative scattering lengths, $a=-8.49^{+0.93}_{-1.05}$ fm for $χ_{c1}(3872)$ and $a=-14.57^{+1.70}_{-1.66}$ fm for $T_{cc}^+$, and dominant molecular components $X_2>0.95$. The results are robust against variations of compositeness, experimental correlations, and the loop-function subtraction constant. An explicit ERE+CDD-pole analysis finds no physically reasonable bare-state contribution consistent with the observed poles and a natural background. Our results provide strong evidence for predominantly molecular structures of both states and demonstrate the robustness of the ERE approach to near-threshold exotic hadrons.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.08289",
  "author_total": 7,
  "authors": [
    {
      "name": "A. A. Atangana Likéné"
    },
    {
      "name": "A. Franck Rothen"
    },
    {
      "name": "J. M. Ema'a Ema'a"
    },
    {
      "name": "P. Pradyun Hebbar"
    },
    {
      "name": "Saralees Nadarajah"
    },
    {
      "name": "Tobias Golling"
    },
    {
      "name": "G. H. Ben-Bolie"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/7z5fagkes8mn3.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.08289",
  "fulltext_url": null,
  "id": "7z5fagkes8mn3",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.08289",
  "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",
      "hep-ph"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2609.08289",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-08",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/7z5fagkes8mn3.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:19:49Z",
      "native_id": "2609.08289",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.08289"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ph",
      "subfield": "high-energy"
    }
  ],
  "title": "Near-Threshold Dynamics of \\c{hi}c1(3872) and T+cc(3875) States via Effective Range Expansion and Monte Carlo Uncertainty Propagation",
  "title_text": "Near-Threshold Dynamics of \\c{hi}c1(3872) and T+cc(3875) States via Effective Range Expansion and Monte Carlo Uncertainty Propagation",
  "type": "preprint",
  "updated_at": "2026-10-30T12:19:49Z",
  "url": "https://research.draconitic.com/paper/7z5fagkes8mn3",
  "venue": "arXiv",
  "versions": []
}