{
  "abstract": "We perform an extensive analysis of the quantum correlations carried by the qubit-qubit-qutrit pure state arising in the decay of a massive scalar into a fermion-antifermion pair and a massive gauge boson, $H \\to f \\bar f V$, specialising to the Higgs boson decay $h \\to τ^- τ^+ Z$. Working with the exact tree-level spin state and its systematic expansion around the massless-fermion limit, we obtain analytic control over the entire phase space: the bipartite entanglement measures, the genuine $2 \\otimes 2 \\otimes 3$ entanglement structure (the Miyake classification), as well as the Bell-inequality violations and the non-stabiliserness (magic) are all mapped and reproduced by compact formulas. The bipartite measures exhibit a monogamy-like trade-off between the fermion pair and the fermion-boson pairs. The state is genuinely $2 \\otimes 2 \\otimes 3$ entangled over almost the entire phase space, most strongly in the collinear regions. We derive, for the first time, semi-analytical expressions for the tight $4 \\times 4 \\times 2$ Bell inequalities of the $2 \\otimes 2 \\otimes 3$ system, generalising the optimisation previously available only for three qubits, and find that the local-hidden-variable bound is violated over the entire phase space, reaching within a few per cent of the quantum bound at the upper endpoint of the di-tau mass spectrum. We further extend the stabiliser Rényi entropy and the non-local magic to systems with unequal local dimensions, and show that the near-endpoint state carries almost exactly one bit of non-local magic, which peaks at $\\log_2 \\frac{27}{7} \\simeq 1.95$ in the collinear regions. The differential decay rate concentrates precisely in the most nonclassical region of the phase space.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2607.26122",
  "author_total": 8,
  "authors": [
    {
      "name": "Michał Banacki"
    },
    {
      "name": "Misaki Ohta"
    },
    {
      "name": "Abhyoudai S. Shaleena"
    },
    {
      "name": "Paweł Caban"
    },
    {
      "name": "Michał Eckstein"
    },
    {
      "name": "Kazuki Sakurai"
    },
    {
      "name": "Michael Spannowsky"
    },
    {
      "name": "Paweł Horodecki"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/2var7kraaqnvh.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2607.26122",
  "fulltext_url": null,
  "id": "2var7kraaqnvh",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2607.26122",
  "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-ex"
    ],
    [
      "arxiv",
      "hep-ph"
    ],
    [
      "arxiv",
      "quant-ph"
    ],
    [
      "openalex",
      "3107|Quantum Mechanics and Applications"
    ]
  ],
  "openalex": "W7171835908",
  "pdf_url": "https://arxiv.org/pdf/2607.26122",
  "pmcid": null,
  "pmid": null,
  "published": "2026-07-28",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/2var7kraaqnvh.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:34:04Z",
      "native_id": "2607.26122",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2607.26122"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ex",
      "subfield": "high-energy"
    },
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "Qubit-qubit-qutrit quantum correlations in $H \\to f \\bar f V$",
  "title_text": "Qubit-qubit-qutrit quantum correlations in H → f f̅ V",
  "type": "preprint",
  "updated_at": "2026-10-30T12:34:04Z",
  "url": "https://research.draconitic.com/paper/2var7kraaqnvh",
  "venue": "arXiv",
  "versions": []
}