Tests of ab initio nuclear theory via the isobaric multiplet mass equation in T=1 superallowed β decay systems

Precision measurements of superallowed 0+ -> 0+ nuclear β decay currently provide the most precise value of the vector coupling in the weak interaction. The extraction of this quantity from these experiments assume that isospin symmetry is exact, thus requiring that theoretical isospin-symmetry-breaking (ISB) corrections must be applied.

Using ab initio nuclear many body methods based on nuclear interactions from chiral effective field theory, we calculate binding energies of the T=1 superallowed β decay chain and the isobaric multiplet mass equation coefficients. From this we extract ISB corrections to Ft values and compare to experimental data. This should give enough confidence in the ab initio methods to perform precise Standard Model tests of the weak interaction.