We relate the $A$-dependent shift of the peak in the $\pi$-nucleus total cross section to geometric and refractive effects. By comparing calculations with and without refractive corrections we show that wave-bending features acting on peripheral partial waves and varying systematically with energy and $A$ are primarily responsible for the shift.

NUCLEAR REACTIONS Scattering theory, $\pi$-nucleus total cross section, $E=100\mathrm{}-200$ MeV.

• Received 11 August 1977

DOI:https://doi.org/10.1103/PhysRevC.16.2306