The angular distribution for elastic pion double charge exchange on ${}_{}{}^{18}{}_{}{}^{}\mathrm{O}$ at 164 MeV is studied. Delta motion and delta-nucleus charge exchange interactions are included and found to be important, but the cross section is not satisfactorily reproduced. Some of our results are consistent with the single datum point for the single charge exchange reaction on ${}_{}{}^{18}{}_{}{}^{}\mathrm{O}$.

NUCLEAR REACTIONS Elastic (${\pi }^{+}, {\pi }^{-}$) and (${\pi }^{+}, {\pi }^0$) cross sections calculated and compared with experiment: $E_{\pi }=164\mathrm{}$ MeV.

• Received 30 July 1982

DOI:https://doi.org/10.1103/PhysRevC.27.277