The tale of tails: Sensitivity of quasi-free reactions on details of the bound-state overlap functions.

It is often stated that one-nucleon knockout in reactions with heavy ion targets are mostly sensitive to the tails of the bound-state wavefunctions. In contrast, (p,2p) and (p,pn) reactions are known to access information on the full overlap functions within the nucleus. We analyze the oxygen isotopic chain and explore the differences between single-particle wave functions generated with potential models, used in the experimental analysis of knockout reactions, and ab initio computations from self-consistent Green's function theory. Contrary to the common belief, we find that not only the tail of the overlap functions, but also information on their internal part are assessed in both reaction mechanisms, which are crucial to yield accurately determined spectroscopic information. The recent revival of (p,2p) reactions, this time in inverse kinematic experiments, will help improve studies of unstable nuclei if combined with a better experimental analysis with inputs from many-body ab initio theories. We suggest that input from state-of-the-art ab initio computations will be fundamental to quantify model dependencies in the analysis of experiments.