{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"ac741d04a3838eaf4a2c1e56dc3b4698820de854eae0ac17fe7219dfc62f8049","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":["ai:gpt-5.5"],"kind":"seed"},"parents":["32374ef8644e111942e945441cdc3d16ba405fbc4f99d22ad2df20e300814dd3","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"85a388ca0597db0eb80aa8d2bd1744203c574ca886677330c0aa3525f2c39fa9","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":["ai:gpt-5.5"],"external_id":"hep.accelerator-dark-sectors.dark-photon","kind":"well-posed","literature_status":"open","n":"2","parents":[],"plain":"A dark photon would be a heavy cousin of the photon that mixes slightly with ordinary light. It would appear as a narrow bump in electron-positron pair masses or as missing energy.","posed_since":"1986","precise":"Determine whether a $U(1)'$ gauge boson $A'$ with mass $1\\,\\mathrm{MeV}$ to $10\\,\\mathrm{GeV}$ and kinetic mixing $\\epsilon \\sim 10^{-6}\\ \\text{to}\\ 10^{-3}$ exists, in visible ($A' \\to \\ell+ \\ell-$) or invisible decay modes. An answer is a resonance detection or exclusion of the remaining parameter space down to $\\epsilon \\sim 10^{-6}\\ \\text{to}\\ 10^{-5}$.","problem_ref":"32374ef8644e111942e945441cdc3d16ba405fbc4f99d22ad2df20e300814dd3","references":"","settled_by":"Bump hunts and displaced-vertex searches at LHCb, Belle II, HPS, NA64 and future beam dumps (SHiP).","status_note":"","title":"Does a dark photon exist with MeV to GeV mass?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"f965473417954866e09241024a3296007ba11b475edade533a16202415aad604","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"8b9fbe5dd4268665cf046cbe751f4d2fad13ae1ad76fd15d6e3739dd5dbb470f","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"obTj8-DvpBvsmROt1-FOoYaFzkHOsg_PB1iUzNz5xZzBK5Sz8ZXpD9gUbbll33SwrjYCFdel6kuMOha6l9jtDA"},"schema":"pubphys.envelope/1"},"record_hash":"f965473417954866e09241024a3296007ba11b475edade533a16202415aad604","leaf_index":3316}