ON THE DISPERSION-RELATION TREATMENT OF THE LOW ENERGY PION-NUCLEON SCATTERING
π介子和核子在低能的散射

The relation between the subtracted dispersion relations for the low energy pion-nucleon scattering and the usual Lagrangian formulation under the renormalization treatment is discussed in the present paper. It is shown that the subtraction actually represents the renormalization of the interaction constants. Using the subtracted dispersion relations we have treated the problem of the S-wave pion nucleon scattering. Our result shows that the interaction between the pion and the nucleon should be of the pseudo-vector type rather than the pseudo-scalar type.