Spectroscopy of Exotic Nuclei via Quasi-free Scattering Reactions

In the work presented here we are interested in examining the single-particle strength of nucleons in stable and exotic nuclei and the reduction compared to the independent particle model. The motivation for this work has been the reported reduction of single-particle strengths and in particular the dependency of this reduction as a function of isospin asymmetry expressed in terms of nucleon separation energies. In particular, in (e,e’p) experiments single-particle strengths of the order of 60-70%. In more recent experiments study was extended to exotic nuclei using nuclear knockout reactions. Consistent results with the (e,e’p) experiments were reported for nuclei close to stability but with a strong dependency of the single-particle strength on the proton-neutron asymmetry. The origin of this strong asymmetry is not fully understood and results from transfer reactions do not support this evidence. In this work I will present our results where quasi-free scattering reactions have been extended and used in inverse kinematics with radioactive beams and a hydrogen-rich target. In particular, I will discuss results on the single-particle structure of stable and exotic nuclei along the oxygen isotopic chain from an experiment that was carried out at the R3B/LAND setup at GSI, Germany, and discuss the dependency on neutron/proton separation energy as well as possible dependencies on the reaction theory used for extracting this nuclear structure information.