Nuclei may exhibit supersymmetry

Are there any interactions under which bosons and fermions behave similarly? Such a query lies at the heart of the current search for supersymmetry. A supersymmetry might be described somewhat more formally as the invariance of a Hamiltonian under a transformation operator that changes bosons into fermions and vice versa. Although the search is being most hotly pursued by particle and gravitational theorists, the first evidence for a supersymmetry in nature has surfaced in nuclear physics—as manifested in the energy spectra of some complex nuclei. This application of supersymmetry is largely phenomenological, but it has nonetheless intrigued the many theorists interested in the field.