Regge phenomenology of theN*andΔ*poles

A Pilloni,G Fox,I V Danilkin,A P Szczepaniak,A Jackura,V Mathieu,J A Silva-Castro,M Albaladejo,J Nys,Joint Physics Analysis Center ,C Fernández-Ramírez

doi:10.1103/physrevd.99.034003

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.

Highlights

The baryon spectrum is one of the main tools for investigation of the nonperturbative QCD phenomena
The value of st should be compatible with its interpretation as an effective threshold in the resonance region. This is used as the criterion to select the physically meaningful minimum if several local minima appear in the fits
The systematic errors associated with model dependence in the amplitude analyses are not considered in the pole extractions, we take the differences among models as an indication of such uncertainties

Summary

Introduction

The baryon spectrum is one of the main tools for investigation of the nonperturbative QCD phenomena. The goal of baryon spectroscopy is to understand the origin and structure of resonances, e.g., to establish if a given resonance can be classified as compact three quark (3q) state, as predicted by the quark model or that it has other hadronic components.

Objectives

Results

Conclusion