Shape Mixing and Clustering in Nuclei: Probing Physics beyond the Standard Model

Abstract

The ab initio methods in nuclear physics play a major role due to their use of realistic internucleon interactions that grant them predictive capabilities. One of these models -the symmetry-adapted nocore shell model (SA-NCSM) -is capable of reaching the medium-mass region of the chart of the nuclides, by exploiting the emergent symmetries of nuclei, and is therefore well-suited for studying collective correlations and beta decay modes. We apply the SA-NCSM to calculate beta-decay observables essential to probe physics beyond the Standard Model. Our calculations of higher-order recoil terms in the beta decay of 8 Li help to significantly reduce the uncertainties in high-precision experiments that study the vector minus axial vector (V−A) structure of the weak interaction. Furthermore, we calculate neutrinoless double beta decay matrix elements important for determining whether the neutrino is its own antiparticle.