Coincident detection of $\alpha$ particles is used to measure the differential cross section of the ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$(${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^8{}_{}{}^{}\mathrm{Be}$)${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ reaction for ${\theta }_{\mathrm{c}.\mathrm{m}.\mathrm{}}\simeq 12° \mathrm{to} 68°$ and for each 100 keV interval from $E_{\mathrm{c}.\mathrm{m}.\mathrm{}}=9\mathrm{} \mathrm{to} 20$ MeV. A large number of resonant enhancements is observed in the cross section and the $J^{\pi }$ values of these are unambiguously determined. The energies and widths of some of these resonant structures agree with resonances reported in other exit channels, in particular those which have been interpreted as a quasimolecular collective band in ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}$. Well defined gross structure with $J=8, 10, \mathrm{and} 12$ is observed at $E_{\mathrm{c}.\mathrm{m}.\mathrm{}}\sim 12, 14.5, \mathrm{and} 19$ MeV. NUCLEAR REACTIONS Measured $\frac{d\sigma }{d\Omega }$ for ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$(${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^8{}_{}{}^{}\mathrm{Be}$) at ${\theta }_{\mathrm{c}.\mathrm{m}.\mathrm{}}\simeq 12° \mathrm{to} 68°$ and $E_{\mathrm{c}.\mathrm{m}.\mathrm{}}=9\mathrm{} \mathrm{to} 20$ MeV in 100 keV steps. Determined energy width and dominant $J^{\pi }$ value of resonant enhancements.

• Received 2 October 1975

DOI:https://doi.org/10.1103/PhysRevC.13.1173