Measurement of Unbound Excited States of 24 O

The unbound excited states of the most neutron-rich oxygen isotope, (24)O (Z = 8, N = 16), have been investigated using the (24)O(p,p')(24)O*-->(23)O+n reaction at RIKEN, where a 63 MeV/neuclon secondary beam of (24)O was produced in a Be production target by the projectile-like fragmentation of a 95 MeV/u (40)Ar primary beam. The first 2(+) excited state was observed in the invariant mass spectrum. This experiment; will give us a deeper understanding of the new magic number at N = 16 in the neutron-rich oxygen isotopes.