Disentangling the dynamical origin of P11 Nucleon Resonances

TL;DR

This paper investigates the dynamical origins of P11 nucleon resonances, revealing that two near-degenerate poles emerge from a single bare state through interactions with multiple reaction channels, shedding light on the nature of Roper resonances.

Contribution

It demonstrates that P11 resonances originate from a single bare state coupling with various channels, providing new insights into their dynamical formation.

Findings

Two nearly degenerate poles arise from a single bare state.

Resonance poles are influenced by coupling with multiple reaction channels.

Results offer new understanding of Roper N*(1440) and N*(1710) origins.

Abstract

We show that two almost degenerate poles near the $\pi\Delta$ 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 $\pi\pi N$ 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.