Effective range analysis of low-energy nucleon-antinucleon interactions

An effective range expansion is developed for the Nanti N system incorporating annihilation, charge-exchange and Coulomb interaction. By fitting the LEAR data on elastic scattering and charge-exchange differential cross sections the Nanti N scattering lengths and effective ranges are obtained. These solutions reproduce also the data on antiprotonic hydrogen, antineutron-proton total and annihilation cross sections and the behaviour of the forward amplitude real-to-imaginary ratio. (orig.)