Pion-nucleus elastic scattering on {sup 12}C, {sup 40}Ca, {sup 90}Zr, and {sup 208}Pb at 400 and 500 MeV

Pion-nucleus elastic scattering at energies above the {Delta}(1232) resonance is studied using both {pi}{sup +} and {pi}{sup {minus}} beams on {sup 12}C, {sup 40}Ca, {sup 90}Zr, and {sup 208}Pb. The present data provide an opportunity to study the interaction of pions with nuclei at energies where second-order corrections to impulse approximation calculations should be small. The results are compared with other data sets at similar energies and with four different first-order impulse approximation calculations. Significant disagreement exists between the calculations and the data from this experiment. {copyright} {ital 1997} {ital The American Physical Society}