{
  "abstract": "We study electromagnetic radiative corrections to neutron $β$ decay within chiral perturbation theory extended to include the $Δ(1232)$ resonance as an explicit degree of freedom. Building on a previous analysis performed in the $Δ$-less theory, we identify and compute additional loop contributions with intermediate $Δ$ states at leading and next-to-leading order in the small-scale expansion, and match the results to the pionless effective field theory. We find that the convergence of the chiral expansion significantly improved in the $Δ$-full calculation. The electromagnetic shift in the axial coupling is reduced by $25\\%$ compared to the $Δ$-less result. The correction remains at the percent level and is phenomenologically significant for the comparison between experimental extractions and lattice-QCD determinations of the nucleon axial charge. We also obtain a new $Δ$-induced contribution to the weak magnetism term, which is an order of magnitude smaller than the pion-loop result and negligible for upcoming experiments.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2608.14794",
  "author_total": 3,
  "authors": [
    {
      "name": "Lemonia Gialidi"
    },
    {
      "name": "Emanuele Mereghetti"
    },
    {
      "name": "Jordy de Vries"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/2eft2aarz8431.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2608.14794",
  "fulltext_url": null,
  "id": "2eft2aarz8431",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2608.14794",
  "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-lat"
    ],
    [
      "arxiv",
      "hep-ph"
    ],
    [
      "arxiv",
      "nucl-th"
    ],
    [
      "openalex",
      "3106|Quantum Chromodynamics and Particle Interactions"
    ]
  ],
  "openalex": "W7203694151",
  "pdf_url": "https://arxiv.org/pdf/2608.14794",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-23",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/2eft2aarz8431.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:23:56Z",
      "native_id": "2608.14794",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2608.14794"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-lat",
      "subfield": "high-energy"
    },
    {
      "field": "physics",
      "origin": "arxiv:nucl-th",
      "subfield": "nuclear"
    }
  ],
  "title": "Radiative corrections to neutron $β$ decay with explicit $Δ(1232)$ degrees of freedom",
  "title_text": "Radiative corrections to neutron β decay with explicit Δ(1232) degrees of freedom",
  "type": "preprint",
  "updated_at": "2026-10-30T12:23:56Z",
  "url": "https://research.draconitic.com/paper/2eft2aarz8431",
  "venue": "arXiv",
  "versions": []
}