Be 8 + Be 8 and C 12 + α breakup states in O 16 populated via the C 13 ( He 4 , 4 α ) n reaction

The C-13(He-4, 4 alpha)n breakup reaction has been studied at beam energies of 27.0, 27.5, and 28.0 MeV. A comparison with previous measurements of the C-12(He-4, Be-8)Be-8 excitation function and C-12(O-16, 4a alpha)C-12 breakup channel suggests the Be-8(gs) + Be-8(gs) decay of O-16 is observed from a possible 2(+) state at 17.3 +/- 0.2 MeV, a 4(+) state at 18.0 +/- 0.2 MeV, a 2(+) or 4(+) state at 19.4 +/- 0.2 MeV, and a 4(+) or 6(+) state at 21.0 +/- 0.2 MeV. The 2(+) or 4(+) assignment for the (19.4 +/- 0.2)-MeV state appears to be supported by the relative cross sections expected for resonant and sequential breakup reactions.