2p→1sPionic Transition

In an attempt to get better agreement between the theoretical predictions and the observed energies and widths of $2p\to 1s$ pion-atomic transitions, we have numerically integrated the Klein-Gordon equation assuming the optical model for the strong interaction potential. We have characterized the interaction by six $s$-wave and four $p$-wave parameters. Using the available data from ${\mathrm{B}}^{10}$ to ${\mathrm{Mg}}^{24}$, we have performed a least-squares fit of the $s$-wave parameters. We find agreement between the observed shifts and our predictions, and the real parts of the $s$-wave parameters agree well with those predicted by Ericson and Ericson. However, our predicted widths vary as much as 50% from the observed widths and we find very poor agreement between the imaginary $s$-wave parameters and Ericson and Ericson's predictions.