Disentangling the dynamical origin of P11 Nucleon Resonances

We show that two almost degenerate poles near the $piDelta$ threshold and the next higher mass pole in the $P_{11}$ partial wave of $pi N$ scattering evolve from a single bare state through its coupling with $pi N$, $eta N$ and $pipi N$ reaction channels. This finding provides new information on understanding the dynamical origins of the Roper $N^*(1440)$ and $N^*(1710)$ resonances listed by Particle Data Group. Our results for the resonance poles in other $pi N$ partial waves are also presented.