{"paper":{"title":"Dark photon searches in the photon channel","license":"http://creativecommons.org/licenses/by/4.0/","headline":"Spectral shape differences in photons from neutral pion decays can probe new regions of dark photon parameter space for invisible decay models.","cross_cats":["hep-ex","nucl-ex"],"primary_cat":"hep-ph","authors_text":"A. Betancur, D. Aristizabal Sierra, J. Velez, K. Pohl","submitted_at":"2026-05-13T15:48:53Z","abstract_excerpt":"Spectral shape differences between photons produced in $\\pi^0\\to\\gamma+\\gamma$ and $\\pi^0\\to\\gamma+A_D$ may provide a new avenue for dark photon searches. Assuming 70 $\\mu$m thick tungsten foils separated by 200 $\\mu$m and a 1 GeV proton beam, we developed a GEANT4 model to estimate photon production and detection including background. Our results demonstrate that multiple campaign runs with a 10-50 $\\mu$A beam could probe previously unexplored regions of parameter space in models where the dark photon has predominantly invisible decays. The results are highly model independent."},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"Our results demonstrate that multiple campaign runs with a 10-50 μA beam could probe previously unexplored regions of parameter space in models where the dark photon has predominantly invisible decays.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The GEANT4 model accurately captures photon production, detection efficiencies, and all relevant backgrounds for the chosen foil thickness, separation, and beam energy without significant unmodeled systematics.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"GEANT4 simulations indicate that photon spectral shape differences from pion decays in a tungsten foil setup could probe new dark photon parameter space with feasible proton beam runs.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Spectral shape differences in photons from neutral pion decays can probe new regions of dark photon parameter space for invisible decay models.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"7968284ecd214cc29dc3d0e97017754160429f4b3248b43601ba5fe2fdd3482a"},"source":{"id":"2605.13696","kind":"arxiv","version":1},"verdict":{"id":"9051294c-0c5d-464d-89b8-33c025c9e6db","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-14T17:49:11.567348Z","strongest_claim":"Our results demonstrate that multiple campaign runs with a 10-50 μA beam could probe previously unexplored regions of parameter space in models where the dark photon has predominantly invisible decays.","one_line_summary":"GEANT4 simulations indicate that photon spectral shape differences from pion decays in a tungsten foil setup could probe new dark photon parameter space with feasible proton beam runs.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The GEANT4 model accurately captures photon production, detection efficiencies, and all relevant backgrounds for the chosen foil thickness, separation, and beam energy without significant unmodeled systematics.","pith_extraction_headline":"Spectral shape differences in photons from neutral pion decays can probe new regions of dark photon parameter space for invisible decay models."},"references":{"count":29,"sample":[{"doi":"","year":2009,"title":"Exploring Portals to a Hidden Sector Through Fixed Targets","work_id":"da85321a-754d-43b1-b430-336b1454d31f","ref_index":1,"cited_arxiv_id":"0906.5614","is_internal_anchor":true},{"doi":"","year":2021,"title":"Dark Scalars and Heavy Neutral Leptons at DarkQuest,","work_id":"ffc389ff-2aae-43d2-bae0-c857215802d7","ref_index":2,"cited_arxiv_id":"","is_internal_anchor":false},{"doi":"","year":2014,"title":"Search for MeV dark photons in a light-shining-through-walls experiment at CERN","work_id":"faea83b7-c2fd-47d5-a3cf-66a83818b59d","ref_index":3,"cited_arxiv_id":"1308.6521","is_internal_anchor":true},{"doi":"","year":null,"title":"Proposal for an Experiment to Search for Light Dark Matter at the SPS","work_id":"dc8032e9-a82c-460c-ba68-c572d304ba7d","ref_index":4,"cited_arxiv_id":"1312.3309","is_internal_anchor":true},{"doi":"","year":2016,"title":"Alekhin et al.,A facility to Search for Hidden Particles at the CERN SPS: the SHiP physics case,Rept","work_id":"d3bcc833-9522-4709-8777-aedb48137b98","ref_index":5,"cited_arxiv_id":"1504.04855","is_internal_anchor":true}],"resolved_work":29,"snapshot_sha256":"fcae367f7ad4401d1666fd8974af7da9b5c42cb46064f254dde2f0ff3697856e","internal_anchors":11},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}