{
  "abstract": "Quantum entanglement in $τ^+τ^-$ production provides a direct probe of non-classical spin correlations in a relativistic quantum system, with the $τ$ decay products serving as spin analyzers. We investigate the detector-level feasibility of such measurements in $e^+e^-\\toτ^+τ^-$ at the Super Tau-Charm Facility (STCF) at $\\sqrt{s}=7$ GeV, using the $ρρ$ and $πρ$ decay channels. Signal and dominant background processes are simulated with the full STCF detector and reconstruction framework. Dedicated reconstruction and event-selection procedures yield overall signal efficiencies of approximately $4.5\\%$ and $4.8\\%$, with corresponding purities of about $87.6\\%$ and $93.2\\%$ for the $ρρ$ and $πρ$ channels, respectively. From the reconstructed decay kinematics, the $τ^+τ^-$ spin-density matrix is inferred and the concurrence $C[ρ]$ together with the Bell-sensitive quantity $m_{12}[C]$ are evaluated in a selected fiducial region. For the benchmark requirement $|\\cosθ|<0.2$ and an integrated luminosity of $1~\\mathrm{ab}^{-1}$, the projected relative precision on $C[ρ]$ is about $2.2\\%$ in both channels, while that on $m_{12}[C]$ is approximately $1.4\\%$ for $ρρ$ and $1.5\\%$ for $πρ$, including statistical and detector-resolution uncertainties. The reconstructed $m_{12}[C]$ shows a larger separation from its reference threshold in the $ρρ$ channel, making this topology particularly sensitive to Bell-type spin correlations. These results demonstrate the detector-level feasibility of probing quantum entanglement and non-classical spin correlations in hadronic $τ$ decays at STCF.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.03024",
  "author_total": 6,
  "authors": [
    {
      "name": "Chentao Bao"
    },
    {
      "name": "Xi Tao"
    },
    {
      "name": "Hai Chen"
    },
    {
      "name": "Lailin Xu"
    },
    {
      "name": "Xiaorong Zhou"
    },
    {
      "name": "Mingyi Liu"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/05nmgewq40za3.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.03024",
  "fulltext_url": null,
  "id": "05nmgewq40za3",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.03024",
  "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|Particle physics theoretical and experimental studies"
    ]
  ],
  "openalex": "W7220437087",
  "pdf_url": "https://arxiv.org/pdf/2610.03024",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-02",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/05nmgewq40za3.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:26:45Z",
      "native_id": "2610.03024",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.03024"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ex",
      "subfield": "high-energy"
    }
  ],
  "title": "Entanglement-sensitive observables in $e^+e^- \\to τ^+τ^-$ at STCF: a detector-level feasibility study",
  "title_text": "Entanglement-sensitive observables in e^+e^- → τ^+τ^- at STCF: a detector-level feasibility study",
  "type": "preprint",
  "updated_at": "2026-10-30T12:26:45Z",
  "url": "https://research.draconitic.com/paper/05nmgewq40za3",
  "venue": "arXiv",
  "versions": []
}