Coulomb Breakup of Neutron‐Rich Oxygen Isotopes

The ground state structure of the near drip‐line 23O nucleus and neutron‐rich 17,21O isotopes has been investigated at GSI via exclusive measurements of one‐neutron Coulomb breakup reactions with a Pb target using secondary beams of the corresponding projectiles at 400–600 MeV/u. Differential cross sections for electromagnetic dissociation have been measured and compared with the calculated ones in a direct breakup model. The cross section dσ/dE* (excitation energy E*), further differentiated according to the observed (excited) states of the remaining nucleus, provides spectroscopic information on the ground state of these nuclei.