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 $^{13}\mathrm{C}(^{4}\mathrm{He},4\ensuremath{\alpha})n$ breakup reaction has been studied at beam energies of 27.0, 27.5, and 28.0 MeV. A comparison with previous measurements of the $^{12}\mathrm{C}(^{4}\mathrm{He},^{8}\mathrm{Be})^{8}\mathrm{Be}$ excitation function and $^{12}\mathrm{C}(^{16}\mathrm{O},4\ensuremath{\alpha})^{12}\mathrm{C}$ breakup channel suggests the $^{8}\mathrm{Be}_{\mathrm{gs}}+\phantom{\rule{0.16em}{0ex}}^{8}\mathrm{Be}_{\mathrm{gs}}$ decay of $^{16}\mathrm{O}$ is observed from a possible ${2}^{+}$ state at $17.3\ifmmode\pm\else\textpm\fi{}0.2$ MeV, a ${4}^{+}$ state at $18.0\ifmmode\pm\else\textpm\fi{}0.2$ MeV, a ${2}^{+}$ or ${4}^{+}$ state at $19.4\ifmmode\pm\else\textpm\fi{}0.2$ MeV, and a ${4}^{+}$ or ${6}^{+}$ state at $21.0\ifmmode\pm\else\textpm\fi{}0.2$ MeV. The ${2}^{+}$ or ${4}^{+}$ assignment for the ($19.4\ifmmode\pm\else\textpm\fi{}0.2$)-MeV state appears to be supported by the relative cross sections expected for resonant and sequential breakup reactions.