An excitation function has been measured for ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ + ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ mutually excited to both first excited states, using $\gamma$ pairs detected in any two of four closely packed 12.5-cm × 12.5-cm NaI detectors. Both $\frac{\overline{W}\left({90}^{\circ }\right)}{\overline{W}\left({180}^{\circ }\right)}$ and $\overline{W}\left({90}^{\circ }\right)+\overline{W}\left({180}^{\circ }\right)$ vary smoothly with bombarding energy, in disagreement with recent predictions of sharp resonant structure.

[NUCLEAR REACTIONS ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}({}_{}{}^{12}{}_{}{}^{}\mathrm{C},{}_{}{}^{12}{}_{}{}^{}\mathrm{C}_{4.44}^{*}{}_{}{}^{}){}_{}{}^{12}{}_{}{}^{}\mathrm{C}_{4.44}^{*}{}_{}{}^{}$, $E=10-15\mathrm{}$ MeV, $\gamma -\gamma$ coin for ${\theta }_{\gamma \gamma }={90}^{\circ } \mathrm{and} {180}^{\circ }$, no sharp resonances observed.]

• Received 9 August 1976

DOI:https://doi.org/10.1103/PhysRevC.16.224