{
  "abstract": "The strong $CP$ problem remains one of the major open questions in the Standard Model of particle physics. Its best-known solution is the Peccei--Quinn mechanism, which predicts a new pseudoscalar boson, the QCD axion. In recent years, alternative solutions and new perspectives on the foundations of the strong $CP$ problem have also received renewed attention. In this review, we provide a pedagogical account of the underlying physics and summarise the current theoretical and phenomenological status of the problem.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.00620",
  "author_total": 1,
  "authors": [
    {
      "name": "Wen-Yuan Ai"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/6e28wrtjzhk7p.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.00620",
  "fulltext_url": null,
  "id": "6e28wrtjzhk7p",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.00620",
  "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",
      "astro-ph.CO"
    ],
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      "arxiv",
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      "openalex",
      "3106|Particle physics theoretical and experimental studies"
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  "openalex": "W7206213960",
  "pdf_url": "https://arxiv.org/pdf/2609.00620",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-01",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/6e28wrtjzhk7p.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:00Z",
      "native_id": "2609.00620",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.00620"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.CO",
      "subfield": "cosmology"
    },
    {
      "field": "physics",
      "origin": "arxiv:hep-lat",
      "subfield": "high-energy"
    }
  ],
  "title": "Status of the strong $CP$ problem",
  "title_text": "Status of the strong CP problem",
  "type": "preprint",
  "updated_at": "2026-10-30T12:18:00Z",
  "url": "https://research.draconitic.com/paper/6e28wrtjzhk7p",
  "venue": "arXiv",
  "versions": []
}