The vector and tensor exchange contributions to πN → πN

Using fixed-t dispersion relations together with experimental data on π^?p → π⁰n we determine the real and imaginary parts of the s-channel helicity amplitudes (SHA) of the vector (?) exchange contribution to πN → πN. The results are in good agreement with amplitude analyses. We also make comparison with finite-energy sum-rules (FESR) and discuss certain implications. Furthermore, on the basis of two-component duality and FESR we calculate the tensor (f) contribution. The t-structure of the resulting SHA is compared with independent information on hadronic tensor exchanges.