Axial Excitation of the Delta in Chiral Quark Models
  We discuss electro-magnetic and weak axial N-Delta transition amplitudes in the linear sigma-model and the Cloudy-Bag Model as typical representatives of chiral quark models. We show that good qualitative understanding of the transition can be obtained in models which, in addition to the pion cloud, incorporate a fluctuating sigma-field inside the baryon. 
S. Sirca, L. Amoreira, M. Fiolhais, B. Golli