{
  "abstract": "We investigate the axion--photon--dark photon interaction at the LHC and in gamma-ray line searches. By recasting the CMS mono-photon data, we derive a $95\\%$ CL exclusion reaching $g_{aγ'γ}\\simeq4.8\\times10^{-4}\\ {\\rm GeV}^{-1}$ for dark photon masses $m_{γ'}\\lesssim100$ GeV, with sensitivity extending to $m_{γ'}\\simeq2.3$ TeV, where the effective theory approaches its validity limit. This improves upon the existing LEP mono-photon constraint by a factor of $3$ or more, depending on the dark photon mass. The projected HL-LHC sensitivity improves by a further factor of $\\sim2.7$ and extends the reach to $m_{γ'}\\simeq3$ TeV. The same interaction also induces $s$-wave annihilation of axions into $γγ$. If the axion constitutes dark matter, Fermi-LAT gamma-ray line data become more constraining than the LHC for $m_a\\gtrsim160$ GeV at $m_{γ'}=300$ GeV, where the on-shell collider signal is kinematically suppressed. Combining collider and gamma-ray line constraints excludes a thermal relic axion across the axion mass range considered for this benchmark.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.21989",
  "author_total": 3,
  "authors": [
    {
      "name": "Chuan-Ren Chen"
    },
    {
      "name": "Takaaki Nomura"
    },
    {
      "name": "Van Que Tran"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/8s0nqhebwg4ne.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.21989",
  "fulltext_url": null,
  "id": "8s0nqhebwg4ne",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.21989",
  "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",
      "hep-ph"
    ],
    [
      "openalex",
      "3106|Dark Matter and Cosmic Phenomena"
    ]
  ],
  "openalex": "W7222640084",
  "pdf_url": "https://arxiv.org/pdf/2610.21989",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-15",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/8s0nqhebwg4ne.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:29:50Z",
      "native_id": "2610.21989",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.21989"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ph",
      "subfield": "high-energy"
    }
  ],
  "title": "Probing the Axion--Photon--Dark Photon Interaction with LHC Mono-Photons and Fermi-LAT Gamma-Ray Lines",
  "title_text": "Probing the Axion--Photon--Dark Photon Interaction with LHC Mono-Photons and Fermi-LAT Gamma-Ray Lines",
  "type": "preprint",
  "updated_at": "2026-10-30T12:29:50Z",
  "url": "https://research.draconitic.com/paper/8s0nqhebwg4ne",
  "venue": "arXiv",
  "versions": []
}