{
  "abstract": "We investigate the limitations of the two-qutrit quantum tomography in Higgs-boson decays to four charged leptons. At next-to-leading order, the standard reconstruction can yield an operator that is not positive semidefinite, even when radiatively improved spin-analysing powers are used. We trace this failure to the coherent combination of photon- and Z-mediated contributions to the off-shell dilepton system, whose distinct production and decay structures invalidate the assumed universal decay analysers. Nevertheless, the rank-two angular sector remains accessible and perturbatively stable, enabling a robust lower bound on the squared concurrence, and hence a reliable assessment of entanglement beyond leading order.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.25217",
  "author_total": 4,
  "authors": [
    {
      "name": "Morgan Del Gratta"
    },
    {
      "name": "Fabio Maltoni"
    },
    {
      "name": "Davide Pagani"
    },
    {
      "name": "Giovanni Pelliccioli"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/7217ysf0cywjz.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.25217",
  "fulltext_url": null,
  "id": "7217ysf0cywjz",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.25217",
  "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"
    ],
    [
      "openalex",
      "3106|Particle physics theoretical and experimental studies"
    ]
  ],
  "openalex": "W7214070541",
  "pdf_url": "https://arxiv.org/pdf/2609.25217",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-21",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/7217ysf0cywjz.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:23:39Z",
      "native_id": "2609.25217",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.25217"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ex",
      "subfield": "high-energy"
    }
  ],
  "title": "Limitations of quantum tomography in Higgs-boson decays to four leptons",
  "title_text": "Limitations of quantum tomography in Higgs-boson decays to four leptons",
  "type": "preprint",
  "updated_at": "2026-10-30T12:23:39Z",
  "url": "https://research.draconitic.com/paper/7217ysf0cywjz",
  "venue": "arXiv",
  "versions": []
}