New Results On 8B And 23O Ground State Properties

One‐nucleon removal reactions at relativistic energies have been used as spectroscopic tool to obtain information about the ground state properties of 8B and 23O. Using the FRS at GSI, the longitudinal momentum distributions of the emerging fragments after breakup and the one‐nucleon removal cross‐sections were measured. The relative contributions of the remaining fragments (7Be and 22O) in their ground and excited states have been determined from measurements of γ rays in coincidence with the longitudinal momentum distributions. In the 8B case, the experimental breakup data on two different targets (C and Pb) allow a determination of the weight of the 7Be* component in the 8B ground state wave function as (13.3±2.2) %. These results are discussed in the context of a theoretical three‐body model. Preliminary results on 23O indicate a spin and parity assignment of 1/2+ in agreement with shell model predictions.