{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"5382ac293dbcdbbda26f1afdc74de3e57c5862d5d58c4836dd79d28b8a05026b","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":["ai:gpt-5.5"],"kind":"seed"},"parents":["99f833884d96384393205516c986a9ec5e2f8d4df855ee94dca113be77b49833","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"c827c0a1702845723b00179f486bacf79a6c4e466ecd7fd5a7abba8e79f14ef4","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":["ai:gpt-5.5"],"external_id":"hep.flavor-puzzle.yukawa-hierarchy","kind":"phenomenon","literature_status":"open","n":"2","parents":[],"plain":"The top quark is about 340000 times heavier than the electron, and quark mixing is small while neutrino mixing is large. No theory predicts these numbers.","posed_since":"","precise":"The SM Yukawa couplings span $y_e \\sim 3 \\times 10^{-6}$ to $y_t \\sim 1$, CKM angles are small ($\\theta_C \\sim 0.23$, $\\mid V_{ub}\\mid$ $\\sim 4 \\times 10^{-3}$) while PMNS angles are large ($\\theta_{12} \\sim 34\\,\\mathrm{deg}$, $\\theta_{23} \\sim 45\\,\\mathrm{deg}$). An answer is a mechanism (Froggatt-Nielsen charges, modular or discrete flavor symmetries, extra-dimensional localization, partial compositeness) that predicts these values with fewer parameters than it explains.","problem_ref":"99f833884d96384393205516c986a9ec5e2f8d4df855ee94dca113be77b49833","references":"","settled_by":"A model with fewer free parameters than observables whose extra predictions (mixing sum rules, flavor-violating rates, new states) are confirmed.","status_note":"","title":"What determines the hierarchy of quark and lepton masses?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"7984ed970a0decf9adecea27605a1a40fdf06d88fdf5317746e2fd62d0c6e66e","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"1bada2386f15c36b46ae02ce4259156d9a47cddb30ce09be0777e41d82e79c49","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"Zy3PQuFqPZMTMwLkHqa_NKK_ifFBFca39nTz1eOhSa3PdiTuRatloTCi70RSxmUHYroNjM3xQK7IwTTFApXbCA"},"schema":"pubphys.envelope/1"},"record_hash":"7984ed970a0decf9adecea27605a1a40fdf06d88fdf5317746e2fd62d0c6e66e","leaf_index":3342}