ON THE FIELD-THEORETICAL APPROACH TO THE NUCLEON-NUCLEON-SCATTERING PROBLEM IN THE LOW-ENERGY REGION

A relativistic dime-dimensional Lippmann-Schwinger-type equation for t he NN scattering matrix is derived from the field-theoretical Low equa tion. The potential of the latter nonlinear integral equation uniquely determines the potential of the suggested Lippmann-Schwinger-type equ ation and consists of two parts. The first part, calculated with the u se of the simplest phenomenological meson-nucleon Lagrangians, reprodu ces the one-boson-exchange (OBE) NN potential. The second part of the potential of the Low equation is defined by the on-mass-shell meson-ex change terms and is a non-Hermitian operator. The numerical calculatio n carried out in the framework of the OBE model of NN interactions has demonstrated that the on-mass-shell meson-exchange terms give an esse ntial contribution to the NN phase shifts, whereas the contribution fr om the non-Hermitian part of the potential can safely be neglected.