Nuclear physics from an expansion around the unitarity limit

Abstract

Many features of the structure of nuclei can be understood in the unitarity limit, where the two-nucleon S waves have bound states at zero energy. In this limit, the only dimensionful parameter, which is needed for proper renormalization of the relevant effective field theory, is set by the triton binding energy. While the complexity of some many-body systems may stem from a profusion of distinct scales, this one three-body scale is sufficient to generate rich structures already in few-body systems due to the anomalous breaking of continuous to discrete scale invariance. I discuss how the spectra of light nuclei arise from a controlled, perturbative expansion around the unitarity limit. I also present some implications of discrete scale invariance for nuclear matter.