LAUSR

Abstract In this brief review paper I outline the relevance of the single-particle states for the research in nuclear structure. They can be detected and studied by several experimental methods, like direct reactions, inelastic electron scattering, and so on. On the other hand, their properties are directly linked to the structure of nuclei and they can probe different aspects of the correlations that characterizes the nuclear systems. After a short introduction to the link between nuclear structure and properties of single-particle states, the general theoretical framework for the study of single-particle states is presented. The different experimental probes that can be used in detecting the single-particle states are then described, together with the corresponding theoretical methods. Finally, the presentation focuses on the particle-vibration scheme for the study of the single-particle states beyond the mean field level of approximation and some recent progresses in this field are discussed.