π^{-}π^{+}→π^{-}π^{+} interactions below 0.7 GeV from π^{-}p→π^{-}π^{+}n data at 5 GeV/c

Magnetostrictive spark chambers were used with a large-aperture magnet spectrometer to study the reaction π−p→π−π+n at 5.0 GeV/c at Argonne National Laboratory. Differential cross sections for this reaction were measured in the region of low nucleon momentum transfer. Extrapolation techniques were used to obtain cross sections and phase shifts for the reaction π−π+→π−π+ in the region of dipion mass less than 0.7 GeV. Effects of the interference between the strong π−π+ amplitude and the Coulomb amplitude off the mass shell were investigated and were found to be small.