{
  "abstract": "Precision measurements of nuclear $β$ decay offer a powerful route to tests of physics beyond the Standard Model, but interpreting measurements spectra and correlation observables requires control of subtle nuclear-structure effects. This chapter develops a framework for calculating higher-order corrections--small contributions that can become important at the precision sought in searches for new interactions. After motivating their role in $β$-decay observables (with radiative corrections treated in the accompanying chapter), we introduce the relevant kinematics and multipole expansion of the shape factor, identify the subleading contributions, and present the impulse-approximation multipole operators. We then describe the nuclear many-body methods used to obtain the required states and transition densities, and derive the corresponding operator matrix elements in the harmonic-oscillator basis. Taken together, these ingredients enable systematic calculations of nuclear shape factors beyond the long-wavelength approximation, including higher-order multipoles where needed. By helping distinguish Standard-Model recoil effects from possible signatures of new physics, this framework supports the interpretation of increasingly precise $β$-decay experiments.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.15927",
  "author_total": 2,
  "authors": [
    {
      "name": "Grigor Sargsyan"
    },
    {
      "name": "Ayala Glick-Magid"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/9vhvnj3zdtz84.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.15927",
  "fulltext_url": null,
  "id": "9vhvnj3zdtz84",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.15927",
  "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-ex"
    ],
    [
      "arxiv",
      "nucl-th"
    ],
    [
      "openalex",
      "3106|Nuclear physics research studies"
    ]
  ],
  "openalex": "W7221757120",
  "pdf_url": "https://arxiv.org/pdf/2610.15927",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-11",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/9vhvnj3zdtz84.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:29:06Z",
      "native_id": "2610.15927",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.15927"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:nucl-ex",
      "subfield": "nuclear"
    }
  ],
  "title": "Higher-order corrections to beta decays and nuclear structure",
  "title_text": "Higher-order corrections to beta decays and nuclear structure",
  "type": "preprint",
  "updated_at": "2026-10-30T12:29:06Z",
  "url": "https://research.draconitic.com/paper/9vhvnj3zdtz84",
  "venue": "arXiv",
  "versions": []
}