{
  "abstract": "The nature of the vector charmoniumlike states $ψ(4360)$ and $ψ(4660)$ is controversial, and the existence of the $ψ(4660)$ has been questioned: the BESIII measurement of $e^+e^-\\to Λ_c^+\\barΛ_c^-$ reveals a nearly flat line shape around 4.66 GeV with a nonzero value at threshold, in contrast to the near-threshold enhancement reported earlier by Belle. We address this puzzle in an S-wave coupled-channel framework for $e^+e^-$ annihilation in $\\sqrt{s}\\in [4.0,5.0]~\\mathrm{GeV}$. The formalism includes the open-charm channels $Λ_c^+\\barΛ_c^-$, $Ξ_c^+\\barΞ_c^-$, $Ξ_c^0\\barΞ_c^0$ (via SU(3) symmetry), the inelastic $ψ(2S)π^+π^-$ channel mediated by $σ(500)$ and $f_0(980)$, and the bare $ψ(4360)$ and $ψ(4660)$ as the 4S and 5S excitations. Short-range contact potentials in the heavy-quark limit are used, and the amplitudes follow from solving the Lippmann-Schwinger equation. A combined fit to Belle and BESIII data on $e^+e^-\\to Λ_c^+\\barΛ_c^-$ and $e^+e^-\\to ψ(2S)π^+π^-$ yields two poles, at $(4401.93 \\pm 16.96i)~\\mathrm{MeV}$ and $(4631.39\\pm 62.96i)~\\mathrm{MeV}$, for the $ψ(4360)$ and $ψ(4660)$. Tracing the pole trajectories as the coupling to the bare states is switched off, we show that both poles originate from the bare $4S$ and $5S$ states strongly renormalized by coupled-channel dynamics. In particular, the $ψ(4660)$ emerges as a broad resonance about 58~MeV above the $Λ_c^+\\barΛ_c^-$ threshold; its flat line shape follows from this threshold interplay, providing evidence for its existence. Results are cutoff-robust.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2605.03320",
  "author_total": 3,
  "authors": [
    {
      "name": "Xian-Chen Wang"
    },
    {
      "name": "Quanxing Ye"
    },
    {
      "name": "Qian Wang"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/93vyj7gs1d4ft.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2605.03320",
  "fulltext_url": null,
  "id": "93vyj7gs1d4ft",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2605.03320",
  "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/2605.03320",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-10",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/93vyj7gs1d4ft.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:29:06Z",
      "native_id": "2605.03320",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2605.03320"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ph",
      "subfield": "high-energy"
    }
  ],
  "title": "Does $ψ(4660)$ exist?",
  "title_text": "Does ψ(4660) exist?",
  "type": "preprint",
  "updated_at": "2026-10-30T12:29:06Z",
  "url": "https://research.draconitic.com/paper/93vyj7gs1d4ft",
  "venue": "arXiv",
  "versions": []
}