{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"56bc0ec3071aeab8a3bd69f327c53fee633ecddbb031697f49288207d66fedf2","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":["ai:gpt-5.5"],"kind":"seed"},"parents":["2c909fa6d0ea4bc87ccf2c76e5beb9ee4ef52fe276decce3da9d01b463ae0763","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"9a31fe40033b601a9a07c47a7bc8d489ec3d916714dd5230a3def525315520f8","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":["ai:gpt-5.5"],"external_id":"nuc.precision-anomalies.superallowed-nuclear-corrections","kind":"well-posed","literature_status":"open","n":"2","parents":[],"plain":"Precise decay rates of certain nuclei (superallowed 0+ to 0+ decays) give the strength of the weak coupling between up and down quarks, but only after small nuclear corrections are subtracted. A small deficit that may signal new physics depends on these corrections.","posed_since":"","precise":"Compute the isospin-symmetry-breaking correction $\\delta_{C}$ and the nuclear-structure-dependent radiative correction $\\delta_{\\mathrm{NS}}$ for the best-measured superallowed 0+ -> 0+ transitions (10C to 74Rb) with absolute uncertainty below $10^{-4}$, using ab initio methods with electroweak currents. Answer: corrected Ft values and $V_{ud}$, deciding whether the first-row CKM sum $\\mid V_{ud}\\mid^{2}+\\mid V_{us}\\mid^{2}+\\mid V_{ub}\\mid^{2}$ deviates from 1 (reported deficit of about 2 to 3 standard deviations).","problem_ref":"2c909fa6d0ea4bc87ccf2c76e5beb9ee4ef52fe276decce3da9d01b463ae0763","references":"","settled_by":"Ab initio calculations of $\\delta_C$ and $\\delta_{\\mathrm{NS}}$ for light emitters (10C, 14O) checked against measured isospin-breaking observables, then extended to heavier emitters.","status_note":"$V_{ud} = 0.97373(31)$ from the 2020 Hardy-Towner survey is limited mainly by these nuclear corrections, whose model dependence was under ab initio study as of 2026.","title":"Nuclear-structure corrections in superallowed $\\beta$ decays","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"9001f65e25f8343a0187869478f885c2d1e11664a58829287537f9ed2fe628b2","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"fc9a31721f5c39d271da1f0beec3f1b341f6fa680c04983176a481f55ed202b4","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"OTtrmpSXFZoUyeUXJ3nJXqafbQOni2C3MqrOn0tBZIpzVe7r66ydj_X2OAhlbwQ3UDe4vMpn_h36c2INRj_gDA"},"schema":"pubphys.envelope/1"},"record_hash":"9001f65e25f8343a0187869478f885c2d1e11664a58829287537f9ed2fe628b2","leaf_index":3514}