Electromagnetic transition form factors of the Roper resonance in baryon chiral perturbation theory

摘要

We consider the electromagnetic transition form factors of the Roper resonance in the framework of an effective field theory of pions, nucleons and delta and Roper resonances as explicit degrees of freedom. We fit two free parameters to experimental data for the N(1440) photon decay helicity amplitudes A(1/2) taken from PDG and make predictions for the Q(2) dependence of these amplitudes. We also estimate the contributions of the delta resonances.