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

We report the first $\mathit{\text{ab}}\mathit{\text{initio}}$ calculation of the nuclear-structure-dependent radiative correction ${\delta }_{\mathrm{N}\mathrm{S}}$ to the ${}^{10}\mathrm{C}\to {}^{10}\mathrm{B}$ superallowed transition, computed with the no-core shell model and chiral effective field theory. We obtain ${\delta }_{\mathrm{N}\mathrm{S}}=-0.422(29{)}_{\mathrm{n}\mathrm{u}\mathrm{c}}(12{)}_{n,\mathrm{e}\mathrm{l}}$ 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.