{
  "abstract": "We discuss mechanisms of $D \\bar{D}$ pair production in $e^+ e^-$ collisions. We consider the $D^0 {\\bar D}^0$-continuum mechanism with the $t/u$-channel $D^*$ vector-meson exchanges, where the $D^* D γ$ coupling constants are derived from the $D^* \\to D γ$ decays. For the $D^+ D^-$ channel, we consider mainly the $D^{\\pm}$ exchanges. We find a relatively large continuum contribution for the $D^0 {\\bar D}^0$ channel and a significantly smaller one for $D^+ D^-$, concluding that the broad bump at $M_{D^0 {\\bar D}^0} = 3.8$ GeV observed by the Belle and BaBar Collaborations has a continuum origin rather than corresponding to the broad $χ_{c0}(3860)$ resonance. We also investigate the resonant production of $D \\bar{D}$ pairs, including $χ_{c0}(3860)$ and $χ_{c2}(3930)$. The $χ_{c2}(3930)$ meson is a good candidate for the first excited $P$-wave charmonium $χ_{c2}(2P)$ state. This resonance can decay into both $D \\bar{D}$ channels; however, its branching fractions are not well known at present. Comparing our model result with $Γ(χ_{c2}(2P) \\to γγ) = 0.544$ keV (corresponding to the Buchmüller-Tye potential) to the BaBar data, we find $B(χ_{c2}(3930) \\to D \\bar{D}) = 0.58 \\pm 0.13$. We present results for differential distributions in several variables for Belle II kinematics. Finally, we shortly mention predictions for the ultraperipheral heavy-ion reaction $Pb Pb \\to Pb Pb D \\bar{D}$ for low invariant mass ($M_{D \\bar{D}} < 4.3$ GeV) at the LHC.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.01420",
  "author_total": 4,
  "authors": [
    {
      "name": "Antoni Szczurek"
    },
    {
      "name": "Izabela Babiarz"
    },
    {
      "name": "Piotr Lebiedowicz"
    },
    {
      "name": "Wolfgang Schäfer"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/bddbxpnd928sx.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.01420",
  "fulltext_url": null,
  "id": "bddbxpnd928sx",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.01420",
  "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-ph"
    ],
    [
      "openalex",
      "3106|Quantum Chromodynamics and Particle Interactions"
    ]
  ],
  "openalex": "W7216358804",
  "pdf_url": "https://arxiv.org/pdf/2610.01420",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-01",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/bddbxpnd928sx.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:26:03Z",
      "native_id": "2610.01420",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.01420"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ex",
      "subfield": "high-energy"
    }
  ],
  "title": "Mechanisms of $D \\bar{D}$ pair production in $e^{+} e^{-} \\to e^{+} e^{-} D \\bar{D}$ and $AA \\to AA D \\bar{D}$ reactions and production of exotic charmonia",
  "title_text": "Mechanisms of D D̅ pair production in e^+ e^− → e^+ e^− D D̅ and AA → AA D D̅ reactions and production of exotic charmonia",
  "type": "preprint",
  "updated_at": "2026-10-30T12:26:03Z",
  "url": "https://research.draconitic.com/paper/bddbxpnd928sx",
  "venue": "arXiv",
  "versions": []
}