An ab initio recipe for taming nuclear-structure dependence of Vud: the ¹⁰C → ¹⁰B superallowed transition

We report the first ab initio calculation of the nuclear-structure-dependent radiative correction δNS to the ¹⁰C → ¹⁰B superallowed transition, computed with the no-core shell model and chiral effective field theory. We obtain δNS = - 0.400 (29)nuc (12)n,el with a $1.7$-times reduction in the nuclear uncertainty when compared to the current literature estimate based on the shell model and Fermi gas picture. This work paves the way for a precise determination of Vud from superallowed beta decays.