{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"fc0213196d9af5ba65382caee716c881b17787089801f42658f0c7ceb457bb91","created":"2026-10-03T07:18:07Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"11fcbcfe66f5b638c38a3bc234c13a9002c14a155a30524acdfe31c0aaf9fdc3","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"nuc.precision-anomalies.superallowed-nuclear-corrections","kind":"well-posed","literature_status":"open","n":"1","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 $1e-4$, 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":null,"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":"68930a0e96cfb6023c51ad2da3d1ea500482dc0e5e690cd3ea4398d0ad9ecbec"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"2c909fa6d0ea4bc87ccf2c76e5beb9ee4ef52fe276decce3da9d01b463ae0763","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"bf46fac711dfaa008fd63e2269d551110aebeafa44a10aaff54ba53fd4fe6bb7","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"HjLiSOIIFcyD93Qr_HIYu5lc7g-BTJT70zvw-BdDrLk8wvFTI6sf6UT1pX-RnZ1k8_eQEFwIusH1TFUIhAzbAA"},"schema":"pubphys.envelope/1"},"record_hash":"2c909fa6d0ea4bc87ccf2c76e5beb9ee4ef52fe276decce3da9d01b463ae0763","leaf_index":1787}