{
  "abstract": "We present a Geant4-based simulation study of the sensitivity to a light dark photon, $A'$, using a positron beam incident on a thin liquid-hydrogen target and a high-resolution forward electromagnetic calorimeter for final-state photon reconstruction. This study is motivated by ongoing research and development toward a low-energy positron facility at Jefferson Lab. The proposed search employs the missing-mass technique in the annihilation-in-flight process $e^+e^- \\to γA'$, providing sensitivity to the $A'$ independently of its decay mode. We evaluate the expected backgrounds from standard QED annihilation and bremsstrahlung processes and present the projected sensitivity to the kinetic-mixing parameter $ε^2$ as a function of the $A'$ mass. The experiment with 500~MeV beam will provide the data for $A'$ mass range 7-19 MeV. The projected sensitivity on $ε^2$ is $4\\times10^{-8}$ at $m_{A'}=19$~MeV.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2608.29159",
  "author_total": 3,
  "authors": [
    {
      "name": "Weizhi Xiong"
    },
    {
      "name": "Ashot Gasparian"
    },
    {
      "name": "Bogdan Wojtsekhowski"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/67wj15er41940.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2608.29159",
  "fulltext_url": null,
  "id": "67wj15er41940",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2608.29159",
  "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-ex"
    ],
    [
      "openalex",
      "3106|Particle physics theoretical and experimental studies"
    ]
  ],
  "openalex": "W7204910756",
  "pdf_url": "https://arxiv.org/pdf/2608.29159",
  "pmcid": null,
  "pmid": null,
  "published": "2026-08-29",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/67wj15er41940.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:41Z",
      "native_id": "2608.29159",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2608.29159"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ex",
      "subfield": "high-energy"
    }
  ],
  "title": "Sensitivity of a Missing-Mass Search for a Light Dark Photon with a Positron Beam on a Hydrogen Target",
  "title_text": "Sensitivity of a Missing-Mass Search for a Light Dark Photon with a Positron Beam on a Hydrogen Target",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:41Z",
  "url": "https://research.draconitic.com/paper/67wj15er41940",
  "venue": "arXiv",
  "versions": []
}