Resonant formation of pionic atoms with neutron collisions

We study the n+A(Ab-)n+A reaction, or resonant formation of pionic atoms, with neutron scattering. We evaluate the contribution of the interference of this reaction channel in Ca40 and Pb208 to the elastic scattering amplitude at backward angles. The ratio of signal to the background at 80°is about 10-3, and we estimate that the ratio does not improve at higher angles, hence making this reaction impractical. Our findings have repercussions on a similar reaction now running at the Indiana University Cyclotron Facility.