{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"5ebb8d485ae936f08c94c1dea2cc5833e818c646ccfd341faebd68a93be52d9a","created":"2026-10-03T07:18:05Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011","e40db54d49b7bbcae272f1539b8bcc9bf6317cdea1fb76b8ba7ab069c56691ac"],"salt":"4ed9f774fa87f0af37ed0859fd411943d310e740cbb169a0b9958861ee7257ba","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"yes-no","assisted_by":[],"external_id":"hep.sterile-neutrino-anomalies.ev-sterile","kind":"well-posed","literature_status":"open","n":"1","parents":[{"note":"","parent_revision":"e40db54d49b7bbcae272f1539b8bcc9bf6317cdea1fb76b8ba7ab069c56691ac","relation":"special_case"}],"plain":"A fourth neutrino that feels no force except gravity, with mass near 1 eV, could explain some anomalies. It would show up as extra appearance and disappearance at short distances.","posed_since":"","precise":"Determine whether a fourth mass state with $\\Delta m^2_{41} \\sim 0.1 \\text{ to } 10\\,\\mathrm{eV}^2$ and mixings |U_e4|, |U_mu4| large enough to produce sin^2(2 theta_mue) ~ 1e-3 exists. An answer is a $5\\,\\sigma$ oscillation signal or exclusion of the region preferred by LSND and gallium in both appearance and disappearance.","problem_ref":null,"references":"","settled_by":"Combined SBN-program oscillation fits with near and far detectors, plus reactor (PROSPECT, STEREO) and atmospheric (IceCube) disappearance limits.","status_note":"Appearance-disappearance tension in global fits and the 2025 MicroBooNE result disfavor the simple 3+1 model.","title":"Does an eV-scale sterile neutrino exist?","topic_ref":"7c3a93300e8710b41f3d7fcb0f1c9a791d835219d51f56a2ebbdc44a8de8988d"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"3cb42522eb6acd43f0f0debf98bbcae131552215be6acdb523466bccb80da689","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"69cc658575b3a14a3dab811e62543d2bc3630955fda7a4496d65eeca89d26f0e","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"9n-nRbzcQliYBKhO1sVaFGKXc-6Vzrw6UBvEYVvZShgtVQ-OqEH4Dsz3X4K6yY82PP1tKKQOnR6Sa5pFBOn4Dw"},"schema":"pubphys.envelope/1"},"record_hash":"3cb42522eb6acd43f0f0debf98bbcae131552215be6acdb523466bccb80da689","leaf_index":1577}