{
  "abstract": "Using a sample of $(2712.4 \\pm 14.3) \\times 10^6$ $ψ(3686)$ events collected with the BESIII detector, we perform a partial wave analysis of the decay $ψ(3686)\\toπ^{+}π^{-}η$ with the $π^{+}π^{-}$ invariant mass in the $ρ(770)^0$ mass region, [0.3, 2.2] $\\mathrm{GeV}/c^2$. The cross section line-shape around the $ψ(3686)$ resonance is measured using energy-scan data sets, enabling the estimation of continuum contribution and its interference with the $ψ(3686)$ resonance. The branching fraction of $ψ(3686)\\toρ(770)^0η$ is determined to be $(1.34 \\pm 0.03\\pm0.13) \\times 10^{-5}$. The $ψ(3686)\\to a_{2}(1320)^{\\pm}π^{\\mp}$ decay is observed for the first time with a significance of $35.7σ$, and its partial branching fraction is measured to be $(2.13 \\pm 0.05\\pm0.32) \\times 10^{-5}$. The $η$-$η^{\\prime}$ pseudoscalar mixing angle $θ_P$ is then found to be $(-11.2 \\pm 1.6\\pm3.6)^\\circ$ or $(-19.4\\pm 3.1\\pm5.7)^\\circ$, where the first uncertainty is statistical and the second systematic.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.37182",
  "author_total": 783,
  "authors": [
    {
      "name": "BESIII Collaboration"
    },
    {
      "name": "M. Ablikim"
    },
    {
      "name": "M. N. Achasov"
    },
    {
      "name": "P. Adlarson"
    },
    {
      "name": "X. C. Ai"
    },
    {
      "name": "C. S. Akondi"
    },
    {
      "name": "R. Aliberti"
    },
    {
      "name": "A. Amoroso"
    },
    {
      "name": "Q. An"
    },
    {
      "name": "Y. H. An"
    },
    {
      "name": "M. S. Anderson"
    },
    {
      "name": "Y. Bai"
    },
    {
      "name": "O. Bakina"
    },
    {
      "name": "H. R. Bao"
    },
    {
      "name": "X. L. Bao"
    },
    {
      "name": "M. Barbagiovanni"
    },
    {
      "name": "V. Batozskaya"
    },
    {
      "name": "K. Begzsuren"
    },
    {
      "name": "N. Berger"
    },
    {
      "name": "M. Berlowski"
    },
    {
      "name": "M. B. Bertani"
    },
    {
      "name": "D. Bettoni"
    },
    {
      "name": "F. Bianchi"
    },
    {
      "name": "E. Bianco"
    },
    {
      "name": "A. Bortone"
    },
    {
      "name": "I. Boyko"
    },
    {
      "name": "R. A. Briere"
    },
    {
      "name": "A. Brueggemann"
    },
    {
      "name": "D. Cabiati"
    },
    {
      "name": "H. Cai"
    },
    {
      "name": "M. H. Cai"
    },
    {
      "name": "X. Cai"
    },
    {
      "name": "A. Calcaterra"
    },
    {
      "name": "G. F. Cao"
    },
    {
      "name": "N. Cao"
    },
    {
      "name": "S. A. Cetin"
    },
    {
      "name": "X. Y. Chai"
    },
    {
      "name": "J. F. Chang"
    },
    {
      "name": "T. T. Chang"
    },
    {
      "name": "G. R. Che"
    },
    {
      "name": "Y. Z. Che"
    },
    {
      "name": "C. H. Chen"
    },
    {
      "name": "Chao Chen"
    },
    {
      "name": "G. Chen"
    },
    {
      "name": "H. S. Chen"
    },
    {
      "name": "H. Y. Chen"
    },
    {
      "name": "M. L. Chen"
    },
    {
      "name": "S. J. Chen"
    },
    {
      "name": "S. M. Chen"
    },
    {
      "name": "T. Chen"
    },
    {
      "name": "W. Chen"
    },
    {
      "name": "X. R. Chen"
    },
    {
      "name": "X. T. Chen"
    },
    {
      "name": "X. Y. Chen"
    },
    {
      "name": "Y. B. Chen"
    },
    {
      "name": "Y. Q. Chen"
    },
    {
      "name": "Z. K. Chen"
    },
    {
      "name": "J. Cheng"
    },
    {
      "name": "L. N. Cheng"
    },
    {
      "name": "S. K. Choi"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/0m1r12rq7tenb.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.37182",
  "fulltext_url": null,
  "id": "0m1r12rq7tenb",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.37182",
  "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"
    ],
    [
      "openalex",
      "3106|Quantum Chromodynamics and Particle Interactions"
    ]
  ],
  "openalex": "W7224106403",
  "pdf_url": "https://arxiv.org/pdf/2610.37182",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-27",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/0m1r12rq7tenb.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:35:50Z",
      "native_id": "2610.37182",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.37182"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ex",
      "subfield": "high-energy"
    }
  ],
  "title": "Improved measurement of $ψ(3686)\\to π^+π^- η$",
  "title_text": "Improved measurement of ψ(3686)→ π^+π^- η",
  "type": "preprint",
  "updated_at": "2026-10-30T12:35:50Z",
  "url": "https://research.draconitic.com/paper/0m1r12rq7tenb",
  "venue": "arXiv",
  "versions": []
}