{
  "abstract": "We propose a spin-density-matrix framework for probing anomalous $Wtb$ interactions in top-quark pair production by exploiting the polarizations of the $b$ quark and the $W$ boson and their spin correlations. The $b$-quark spin is analyzed through angular distributions in semileptonic $Λ_b$ decay following fragmentation, while the leptonic $W$ decay serves as a $W$-polarization analyzer. We derive the $bW$ spin density matrix in the presence of anomalous $Wtb$ couplings and show that its polarization and spin-correlation parameters provide linear sensitivity to these couplings. We construct experimentally accessible angular observables associated with these parameters and evaluate their statistical sensitivities. For the HL-LHC at $\\sqrt{s}=14~ \\mathrm{TeV}$ with an integrated luminosity of $3000~ \\mathrm{fb}^{-1}$, the proposed method yields improved constraints on most anomalous $W t b$ couplings, with the sensitivity to $V_R$ enhanced by a factor of 8 and that to $g_L$ by a factor of about 6.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.04971",
  "author_total": 5,
  "authors": [
    {
      "name": "Qi Bi"
    },
    {
      "name": "Zekun Li"
    },
    {
      "name": "Chuntao Liu"
    },
    {
      "name": "Jia Liu"
    },
    {
      "name": "Xiao-Ping Wang"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/9x4ab8q2hr5c8.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.04971",
  "fulltext_url": null,
  "id": "9x4ab8q2hr5c8",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.04971",
  "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",
      "3106|Particle physics theoretical and experimental studies"
    ]
  ],
  "openalex": "W7220708372",
  "pdf_url": "https://arxiv.org/pdf/2610.04971",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-04",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/9x4ab8q2hr5c8.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:27:01Z",
      "native_id": "2610.04971",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.04971"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ph",
      "subfield": "high-energy"
    }
  ],
  "title": "Probing anomalous $Wtb$ couplings through $bW$ spin correlations in top-quark pair production at the HL-LHC",
  "title_text": "Probing anomalous Wtb couplings through bW spin correlations in top-quark pair production at the HL-LHC",
  "type": "preprint",
  "updated_at": "2026-10-30T12:27:01Z",
  "url": "https://research.draconitic.com/paper/9x4ab8q2hr5c8",
  "venue": "arXiv",
  "versions": []
}