Ab initio calculations of ¹⁰C → ¹⁰B super-allowed Fermi transition

Ab initio approaches describe nuclei as nucleons experiencing inter-nucleonic forces, providing a rigorous framework for testing fundamental Standard Model (SM) symmetries. Cabibbo-Kobayashi-Maskawa (CKM) matrix unitarity is a sensitive probe of Beyond SM (BSM) physics. New analysis of Fermi decays reveal a statistical discrepancy with CKM unitarity. Extraction of the largest contributor to unitarity, V_ud, from super-allowed 0⁺ → 0⁺ Fermi transitions requires calculation of the isospin symmetry breaking correction δ_C. Using the No-Core Shell Model with Continuum, with chiral two- and three-nucleon interactions as the sole input, we investigate the ¹⁰C → ¹⁰B super-allowed Fermi decay. We show good description of the 0⁺ ground state for ¹⁰C and, importantly, we present novel structure for ¹⁰B, considered as two charge-exchange mass partitions. The quality of these structure results is encouraging for determination of δ_C, for which we aim to present a preliminary result.