The Role of Approximate Symmetries in Theoretical Predictions for Nuclei

Abstract:  Ab initio methods, for which the only input is the inter-nucleon interaction, play an important role in describing nuclei for which there is limited data, particulalry in regions of the nuclear chart far from stability. However, quantitative predictions are computationally limited by the explosion in scale as the number of nulceons increases. Approximate symmetries of the nucleus can be used to combat this explosion using symmetry adapted approaches. At the same time, these symmetries can be used to gain insight into simple patterns which arise in the spectrum. I will discuss the emergences of two such approximate symmetries, SU(3) and Sp(3,R), associated with nuclear deformations, rotations and giant resonnances and how these symmetries are employed in the ab initio symplectic no-core configuration iteraction framework.