Direct calculation of the K-matrix for pion electro-production in the   Delta channel
  We present a method to calculate directly the K-matrices for the pion electro-production processes in the framework of chiral quark models which allows for a clean separation of the resonant amplitudes from the background. The method is applied to the calculation of the multipole amplitudes M_{1+}, E_{1+}, and S_{1+} in the Delta channel within the Cloudy Bag Model. A good overall description is found in a broad energy range. 
P. Alberto, L. Amoreira, M. Fiolhais, B. Golli, S. Sirca