A previously developed relativistic, separable potential model of the pion-nucleon system will be extended to higher energies and to a larger number of coupled channels, including a photon-nucleon channel. An exchange model will be developed as an alternative to the separable potential model. These models will be used to calculate meson-baryon scattering and production processes, properties of the baryon resonances, and meson photoproduction from nucleons. Previously developed one boson exchange models of the two-nucleon system will be extended by including other exchange processes, and by allowing for coupling to nucleon delta and delta-delta states. Inclusion of this coupling will make it possible to account for inelastic processes. Various schemes for calculating the electromagnetic form factors of the deuteron will be investigated, with particular attention paid to the restrictions imposed by relativity and gauge invariance. Calculations on the three-nucleon system will be carried out using invariant three-nucleon mass operators constructed from two-nucleon mass operators. Such calculations lead to results for the three-nucleon bound states and scattering amplitudes which satisfy the requirements of relativity, and therefore make it possible to study relativistic effects in the three-nucleon system.
