{
  "abstract": "We analyze the on-shell content of the local Lorentz covariants of the five-dimensional spin-zero Duffin-Kemmer-Petiau algebra in elastic spin-zero-spin-$1/2$ scattering. The scalar, vector, and tensor structures are reduced explicitly to the two independent amplitudes allowed by the physical parity-conserving process. The two scalar structures are proportional on shell, the genuine nonminimal vector $i[P,β^μ]$ is longitudinal and vanishes after contraction with the conserved fermion vector current, and the projected vectors $Pβ^μ$ and $β^μP$ each reduce to one half of the minimal-vector contribution. The tensor covariants introduce no additional on-shell directions. We discuss the consequences for the four invariant choices used in meson-nucleus optical-potential calculations and show that different nuclear equations can arise only after on-shell-equivalent representatives are promoted to optical operators and iterated beyond the order at which the elementary impulse approximation is fixed. These results provide a systematic basis for distinguishing genuinely independent elementary amplitudes from representation-dependent effects generated by the optical embedding.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.37263",
  "author_total": 1,
  "authors": [
    {
      "name": "Luis B. Castro"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/0ttaftw72g5dk.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.37263",
  "fulltext_url": null,
  "id": "0ttaftw72g5dk",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.37263",
  "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-th"
    ],
    [
      "arxiv",
      "math-ph"
    ],
    [
      "arxiv",
      "math.MP"
    ],
    [
      "arxiv",
      "nucl-th"
    ],
    [
      "openalex",
      "3106|Nuclear physics research studies"
    ]
  ],
  "openalex": "W7224131563",
  "pdf_url": "https://arxiv.org/pdf/2610.37263",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-27",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/0ttaftw72g5dk.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:35:50Z",
      "native_id": "2610.37263",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.37263"
    }
  ],
  "subjects": [
    {
      "field": "mathematics",
      "origin": "arxiv:math-ph",
      "subfield": "mathematical-physics"
    },
    {
      "field": "physics",
      "origin": "arxiv:hep-th",
      "subfield": "high-energy"
    },
    {
      "field": "physics",
      "origin": "arxiv:nucl-th",
      "subfield": "nuclear"
    }
  ],
  "title": "On-shell reduction of spin-zero Duffin-Kemmer-Petiau covariants and implications for the relativistic impulse approximation",
  "title_text": "On-shell reduction of spin-zero Duffin-Kemmer-Petiau covariants and implications for the relativistic impulse approximation",
  "type": "preprint",
  "updated_at": "2026-11-04T15:20:52Z",
  "url": "https://research.draconitic.com/paper/0ttaftw72g5dk",
  "venue": "arXiv",
  "versions": [
    {
      "doi": "10.1016/j.physletb.2026.141112",
      "pid": "7ntnztzs1avz3",
      "relation": "published-as",
      "title": "On-shell reduction of spin-zero Duffin–Kemmer–Petiau covariants and implications for the relativistic impulse approximation",
      "venue": "Physics Letters B"
    }
  ]
}