{
  "abstract": "This paper has three main aims. First, I review in a pedagogical way the unitarity bounds for form factors in $B$-meson decays, together with the parametrisations most commonly used in phenomenological analyses. These include BGL, BCL, CLN, and the Dispersive Matrix (DM) method. I also clarify the relation between BGL and DM, showing that they are two equivalent implementations of the same unitarity information. Second, I demonstrate that the standard BGL and DM constructions are strictly rigorous only when no subthreshold cuts are present. For $B$-meson decays, this requirement is fulfilled exclusively by the $B\\toπ$ FFs. To treat the generic case, I fully develop the GG parametrisation introduced in a previous paper and show how the same logic extends to a DM-like construction. Third, I perform three novel combined analyses of form factors and obtain predictions over the full semileptonic region. The first analysis concerns the form factors for $B\\toπ$ and $B_s\\to K^{(*)}$, the second those for $B\\to K^{(*)}$ and $B_s\\to ϕ$, and the third those for $B\\to D^{(*)}$ and $B_s\\to D_s^{(*)}$. All numerical results, posterior samples, analysis files, and plots are provided in the supplementary material (https://github.com/gubernari/suppl-unitb).",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2605.26213",
  "author_total": 1,
  "authors": [
    {
      "name": "Nico Gubernari"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/03n2pkd7f3b2k.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2605.26213",
  "fulltext_url": null,
  "id": "03n2pkd7f3b2k",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2605.26213",
  "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": null,
  "pdf_url": "https://arxiv.org/pdf/2605.26213",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-11",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/03n2pkd7f3b2k.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:21:41Z",
      "native_id": "2605.26213",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2605.26213"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ph",
      "subfield": "high-energy"
    }
  ],
  "title": "Unitarity bounds and form-factor predictions for $B$-meson decays",
  "title_text": "Unitarity bounds and form-factor predictions for B-meson decays",
  "type": "preprint",
  "updated_at": "2026-10-30T12:21:41Z",
  "url": "https://research.draconitic.com/paper/03n2pkd7f3b2k",
  "venue": "arXiv",
  "versions": []
}