{
  "abstract": "We know of no microscopic calculation of the semileptonic strangeness-changing 2p2h current. We construct it at tree level for nubar [NN] -> l+ Y N' from vertices of the lowest-order SU(3) chiral Lagrangian: contact, meson-in-flight, baryon-pole and kaon-exchange families, both pn line assignments summed coherently, and decuplet poles with N -> Delta transition form factors and SU(3) route signs. The undressed vector current is the Noether current of the flavour rotation and satisfies the SU(3)-limit Ward identity pointwise. The axial current has a vertex-level kaon-pole completion fixed by the Goldberger-Treiman relation, whose divergence equals (m_s+m_u)P_su by construction; we omit the axial contact operator, its kaon-pole partner, and the remaining inverse-propagator and mass-splitting terms, and the form factors break the vector identity. The flavour routes allow a primary kaon-less Sigma+ n final state from a pp pair that no one-body weak vertex reaches; antisymmetrised, it is 1.13-1.20% of the isolated two-body hyperon rate over the seven charge channels. In a factorised free-pair benchmark, octet baryon poles carry 77% of the Lambda-channel incoherent family sum at 0.6 GeV but 43-58% at 1-5 GeV, where the decuplet carries 26-48%; the line assignments interfere destructively. The isolated two-body current is 0.81-0.87 times as Lambda-rich as the quasi-elastic one at 1-5 GeV (0.67-0.95 across prescriptions); the axial contact operator with its kaon-pole partner at the Lagrangian coefficient lowers this by 2-6%, and a Ward-compatible form-factor dressing changes it by about 4%. A correlation on every meson changes the composition by under 3%; a Landau-Migdal contact on the pions alone leaves kaon exchange unscreened and roughly triples Lambda/Sigma0. The KNY couplings carry the axial N -> Y flavour combinations, so the composition is not the quasi-elastic one rescaled.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.32375",
  "author_total": 1,
  "authors": [
    {
      "name": "Jaroslaw A. Nowak"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/98f067rd9p3n1.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.32375",
  "fulltext_url": null,
  "id": "98f067rd9p3n1",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.32375",
  "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",
      "nucl-th"
    ],
    [
      "openalex",
      "3106|Quantum Chromodynamics and Particle Interactions"
    ]
  ],
  "openalex": "W7223706274",
  "pdf_url": "https://arxiv.org/pdf/2610.32375",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-23",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/98f067rd9p3n1.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:35:15Z",
      "native_id": "2610.32375",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.32375"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:nucl-th",
      "subfield": "nuclear"
    }
  ],
  "title": "Strangeness-changing two-body weak currents from SU(3) chiral dynamics",
  "title_text": "Strangeness-changing two-body weak currents from SU(3) chiral dynamics",
  "type": "preprint",
  "updated_at": "2026-10-30T12:35:15Z",
  "url": "https://research.draconitic.com/paper/98f067rd9p3n1",
  "venue": "arXiv",
  "versions": []
}