Unified description of hadronic and electromagnetic reactions of the two-nucleon system

Studies of the two-nucleon system are essential for a profound understanding of nuclear structure and for the exploration of the limits of the effective description of atomic nuclei in terms of nucleons, mesons and isobars. In the present work, a unified description of hadronic and electromagnetic reactions on the two-nucleon system is developed in the framework of a coupled-channel N N / N Δ -approach which is based on one general Hamiltonian and which treats the pion exchange in the hadronic baryon–baryon interaction as well as in the meson exchange currents in the exact retarded manner. Unitarity and gauge invariance are at least approximately fulfilled. Several hadronic and electromagnetic reactions in the two-nucleon sector are discussed and the role of the deuteron as an effective neutron target is considered.