In the first part of the talk, I discussed the nature of the effective theory that describes the properties of the pion-nucleon-interaction at low energies, using the static model as a starting point. In the second part, I then pointed out that the infrared singularities occurring in the pi-N scattering amplitude are stronger and of a more complex structure than those encountered in pi-pi scattering. A formulation of the effective theory that properly accounts for these was described and the results obtained thereby were illustrated with a few examples.
Categories: hep-ph