File:PhysRevC.100.035204.pdf

English: We investigate the formation of resonances in the P33 partial wave with emphasis on possible emergence of dynamically generated quasibound states as a consequence of a strong p-wave pion attractive interaction in this partial wave, as well as their possible interaction with the genuine quark excited states. By using the Laurent-Pietarinen expansion we follow the evolution of the S-matrix poles in the complex energy plane as a function of the interaction strength. Already without introducing a genuine quark resonant state, two physically interesting resonances emerge with pole masses around 1200 and 1400 MeV, with dominant πN and πΔ components, respectively. The added genuine resonant state in the (1s)3 quark configuration mixes with the lower dynamically generated resonance forming the physical Δ(1232) resonance, and pushes the second dynamical resonance to around 1500 MeV, which allows it to be identified with the Δ(1600) resonance. Adding a second resonant state with one quark promoted to the 2s orbit generates another pole whose evolution remains well separated from the lower two poles. We calculate the helicity amplitudes at the pole and suggest that their Q2 dependence could be a decisive test to discriminate between different models of the Δ(1600) resonance.