Angular correlations between inelastically scattered pions and deexcitation $\gamma$ rays depend upon the spin density matrix of the residual nucleus and thus provide additional information not available in the differential cross sections. The correlation function is calculated for the $0^{+}$ → $2^{+}$ → $0^{+}$ transition in ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ and the resulting symmetry angles are found to be quite similar to those obtained in the adiabatic limit. The model sensitivity is tested for medium energy pions by comparing the Kisslinger potential results with those using a local Laplacian potential. Some differences, especially near cross section minima, are found between the different potential models.

[NUCLEAR REACTIONS ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}(\pi ,{\pi }^{\prime }\gamma )$, $E=30-150\mathrm{}$ MeV; calculated pion-$\gamma$ angular correlation.]

• Received 7 July 1976

DOI:https://doi.org/10.1103/PhysRevC.14.1733