An $\textit{ab initio}$ strategy for taming nuclear-structure dependence of $ V_{ud} $ extractions: the $ {}^{10}\mathrm{C} \rightarrow {}^{10}\mathrm{B} $ superallowed transition

We report the first \textit{ab initio} calculation of the nuclear-structure-dependent radiative correction $\delta_{ \mathrm{NS} }$ to the ${}^{10}\mathrm{C} \rightarrow {}^{10}\mathrm{B}$ superallowed transition, computed with the no-core shell model and chiral effective field theory. We obtain $\delta_{ \mathrm{NS} } = - 0.422 (29)_{ \mathrm{nuc} } (12)_{ n,\mathrm{el} }$ with a $1.6$-times reduction in the total 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 $V_{ud}$ from superallowed beta decays within a systematically improvable framework.