Regge phenomenology of the $N^*$ and $\Delta^*$ poles

TL;DR

This paper applies Regge phenomenology to analyze the structure of $N^*$ and $\Delta^*$ baryon poles, using pole extractions from scattering data to understand their internal quark configurations.

Contribution

It introduces a method to incorporate pole widths into Regge trajectory analysis, providing new insights into baryon structure from scattering data.

Findings

Most states align with a compact three-quark model

Regge trajectories help distinguish internal baryon structures

Inclusion of imaginary parts improves trajectory consistency

Abstract

We use Regge phenomenology to study the structure of the poles of the $N^*$ and $\Delta^*$ spectrum. We employ the available pole extractions from partial wave analysis of meson scattering and photoproduction data. We assess the importance of the imaginary part of the poles (widths) to obtain a consistent determination of the parameters of the Regge trajectory. We compare the several pole extractions and show how Regge phenomenology can be used to gain insight in the internal structure of baryons. We find that the majority of the states in the parent Regge trajectories are compatible with a mostly compact three-quark state picture.