Real Parts of Amplitudes and Polarization ofπNCharge-Exchange Scattering

Using fixed-$t$ dispersion relations, low-energy phase shifts (or $s$-channel resonances), and the imaginary parts of the $s$-channel helicity amplitudes of analyses at 6 GeV, we determine the real parts, the differential cross sections, and the polarizations for ${\pi }^{-}p\to {\pi }^{0}n$ at several energies. The approach is parameter-free and almost model-independent, and leads to results in agreement with experiment and with amplitude analyses.