{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"6fee910af496a1ec60f6a800bd76d8f1c04cd31a80b814fe09f42e0b7fd771c4","created":"2026-10-03T07:18:05Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"958f5468c3a7927bd53e70957a9faa83b49d52aa269d832ad4cbed84e88cd5b3","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"hep.accelerator-dark-sectors.dark-photon","kind":"well-posed","literature_status":"open","n":"1","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 MeV to 10 GeV and kinetic mixing $\\epsilon \\sim 1e-6\\ \\text{to}\\ 1e-3$ 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 $\\epsilon \\sim 1e-6\\ \\text{to}\\ 1e-5$.","problem_ref":null,"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":"09c9143d4a1d1ccd3178fe390a3258b114047adf03da6b4f6f24c823883e4f74"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"32374ef8644e111942e945441cdc3d16ba405fbc4f99d22ad2df20e300814dd3","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"cc39f11f91b048106778121e30b4ada6219aa3083649f103d61aadd702c3f608","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"o6988rm6hPAZIHUDaKve1HUZ5edVHc77xm11epnbGmRdnXg5Rn7BqVZv-2bilSNN9EmWOY7lpuo0c1xjrMUWDw"},"schema":"pubphys.envelope/1"},"record_hash":"32374ef8644e111942e945441cdc3d16ba405fbc4f99d22ad2df20e300814dd3","leaf_index":1522}