The microscopic structure of $pi NN$, $pi NDelta$ and $piDeltaDelta$ vertices in a hybrid constituent quark model

We present a microscopic description of the strong $pi NN$, $pi NDelta$ and $piDeltaDelta$ vertices. Our starting point is a constituent-quark model supplemented by an additional $3qpi$ non-valence component. In the spirit of chiral constituent-quark models, quarks are allowed to emit and reabsorb a pion. This multichannel system is treated in a relativistically invariant way within the framework of point-form quantum mechanics. Starting with a common $SU(6)$ spin-flavor-symmetric wave function for $N$ and $Delta$, we calculate the strength of the $pi NN$, $pi NDelta$ and $piDeltaDelta$ couplings and the corresponding vertex form factors. Our results are in accordance with phenomenological fits of these quantities that have been obtained within purely hadronic multichannel models for baryon resonances.