Transition form factors and helicity amplitudes for electroexcitation of negative- and positive parity nucleon resonances in a light-front quark model

A workable basis of quark configurations $s^3$, $s^2p$ and $sp^2$ at light front has been constructed to describe the high-$Q^2$ behavior of transition form factors and helicity amplitudes in the electroproduction of the lightest nucleon resonances, $N_{1/2^-}(1535)$ and $N_{1/2^+}(1440)$. High-quality data of the CLAS Collaboration are described in the framework of a model which takes into account mixing of the quark configurations and the hadron-molecular states. The model allows for a rough estimate of the quark core weight in the wave function of the resonance in a comparison with high momentum transfer data on resonance electroproduction.