We apply Glauber theory to calculate the cross section for the excitation of the giant dipole resonance ($1^{-}$) in ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ by pions. In the resonance region the cross section ${\sigma }_{\mathrm{GDR}}=1.7\mathrm{}$ mb. It is too small to influence the ratio of the ($\pi ,\pi N$) reaction. This result contradicts previous speculations.

NUCLEAR REACTIONS ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}(\pi ,{\pi }^{\prime }){}_{}{}^{12}{}_{}{}^{}\mathrm{C}_{}^{*}{}_{}{}^{}$, $E=180\mathrm{}$ MeV, calculated $\sigma \mathrm{}\left(E\right)\mathrm{}$ for giant dipole, discussed relevance for ($\pi ,\pi N$) reaction.

• Received 30 March 1976

DOI:https://doi.org/10.1103/PhysRevC.14.1665