ELECTROMAGNETIC N-]N-STAR-(1535) TRANSITION IN THE RELATIVISTIC CONSTITUENT-QUARK MODEL

We study a light-cone model of the nucleon and the S11(1535) resonance which provides a relativistic generalization of the constituent-quark model in the nonperturbative low-Q2 regime. The two parameters of the model, namely, the size parameter ± and the constituent-quark mass mq300 MeV, are fixed by the axial form factor. We find good agreement for the electromagnetic form factors of the nucleon up to Q21-2 GeV2. All static properties of the nucleon, except for the neutron charge radius, are reproduced within 10%. In addition, we show that the electromagnetic current of the nucleon is conserved. The S11(1535) transition amplitudes, where gauge invariance is achieved by including a three-body current, are calculated from a constraint-free form-factor set. They are in reasonable agreement with the available photo- and electroproduction data. © 1990 The American Physical Society.