Unitary multichannel sidewise dispersion calculation of the nucleon anomalous magnetic moments

In sidewise dispersion calculations of the anomalous magnetic moments of the nucleon, the intermediate πN strong states involved are the S11 and P11, both of which are highly inelastic at low energies. These inelastic effects have not previously been included in a systematic manner consistent with unitarity in order to ensure a real absorptive part. We present a multichannel ND-1 formalism for the strong scattering and photoproduction which gives a unitary result for the anomalous moments. The strong form factor is given simply in terms of D-1. Explicit calculations demonstrate that contributions to the dispersion integrals far beyond W∼1500 MeV will be necessary in determining μ. © 1974 The American Physical Society.