Small angle cross sections for the reactions ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$${(}^{16}$O,α${)\mathrm{}}^{28}$Si and ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$${(}^{16}$O${,}^8$Be${)}^{24}$Mg leading to ground states and first excited states of residual nuclei are reported for $E_{\mathrm{c}.\mathrm{m}.\mathrm{}\mathrm{\sim }12}$ to 20 MeV. Angular distributions are measured for all four exit channels at about forty energies in the neighborhood of resonancelike features. Resonant l values are inferred from both ${\alpha }_0$ and ${}_{}{}^8{}_{}{}^{}$${\mathrm{Be}}_0$ angular distribution and results are compared with other work. The distribution of maxima test shows that cross section maxima in the excitation functions are distributed randomly and that there is a low probability for any resonances in the energy range covered. Statistical model calculations with proper energy level densities and angular momentum conservation reproduce all the general features attributed to heavy-ion resonances.

• Received 11 August 1986

DOI:https://doi.org/10.1103/PhysRevC.34.2144