The resonant structures in the ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ + ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ system have been studied through the reaction ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$(${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$,${}_{}{}^{16}{}_{}{}^{}\mathrm{O}_{\mathrm{g}.\mathrm{s}.\mathrm{}}^{}{}_{}{}^{}$)${}_{}{}^8{}_{}{}^{}\mathrm{Be}_{\mathrm{g}.\mathrm{s}.\mathrm{}}^{}{}_{}{}^{}$ at $E_{\mathrm{c}.\mathrm{m}.\mathrm{}}=6-11\mathrm{}$ MeV. Excitation functions of the reaction have been measured in 50-keV steps at 14 angles between ${\theta }_{\mathrm{c}.\mathrm{m}.\mathrm{}}\sim 29° \mathrm{and} \sim 90°$. Resonant structures have been found at 5.94, 6.41, 6.68, 7.47, 7.90, 8.10, 8.37, 8.58, 8.88, 9.08, 9.34, 9.56, 9.70, 9.99, 10.29, 10.43, 10.68, and 10.98 MeV. Some of these are new resonances. Their $J^{\pi }$ values have been assigned to be $4^{+}$(5.94 MeV), $2^{+}$(6.41 MeV), $2^{+}$(6.68 MeV), $4^{+}$(7.90 MeV), $2^{+}$ + $4^{+}$(8.10 MeV), $4^{+}$(8.37 MeV), $4^{+}$(8.58 MeV), $6^{+}$(8.88 MeV), $6^{+}$(9.08 MeV), $6^{+}$(9.34 MeV), $6^{+}$(9.56 MeV), $6^{+}$(9.70 MeV), $6^{+}$(9.99 MeV), ($8^{+}$)(10.29 MeV), ($8^{+}$)(10.43 MeV), $8^{+}$(10.68 MeV), and $8^{+}$(10.98 MeV). An interesting relation between this exit channel and the $\alpha$, $\gamma$ exit channels has been found. This may give us important information about the structure of the resonances. Good correspondence has been found with several levels appearing in the reaction ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}({}_{}{}^{16}{}_{}{}^{}\mathrm{O}, \alpha ){}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}_{}^{*}{}_{}{}^{}$. This fact suggests that the resonances in the ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$-${}_{}{}^8{}_{}{}^{}\mathrm{Be}$ channel are true states of ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}$.

NUCLEAR REACTIONS ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$(${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$,${}_{}{}^{16}{}_{}{}^{}\mathrm{O}_{\mathrm{g}.\mathrm{s}.\mathrm{}}^{}{}_{}{}^{}$)${}_{}{}^8{}_{}{}^{}\mathrm{Be}_{\mathrm{g}.\mathrm{s}.\mathrm{}}^{}{}_{}{}^{}$, $E_{\mathrm{c}.\mathrm{m}.\mathrm{}}=6-11\mathrm{}$ MeV; ${\theta }_{\mathrm{c}.\mathrm{m}.\mathrm{}}=29-90\mathrm{}°$; measured $\sigma (\theta , E)$; deduced resonance energies, $J^{\pi }$ values, total widths, partial-width products (${\Gamma }_c·{\Gamma }_0$).

• Received 15 January 1979

DOI:https://doi.org/10.1103/PhysRevC.22.557