On charge-exchange reaction in meson-nucleon scattering at large angles

π+-p scattering and exchange process at high energies and fixed angles are considered within the Logunov-Tavkhelidze quasipotential approach. Experimental data are analysed following the hypothesis on the presence of the phase shift between isotopic amplitudes. It is shown that the latter may be chosen equal 90 deg C, thus providing a good description of the data on π+-p scattering and charge exchange reaction. The relation obtained for the corresponding cross sections is in a good agreement with an experiment. (S.V.G.)