Understanding the nature of baryon resonances

Author:

Derek B. Leinweber, Curtis D. Abell, Liam C. Hockley, Waseem Kamleh, Zhan-Wei Liu, Finn M. Stokes, Anthony W. Thomas, Jia-Jun Wu

Keyword:

High Energy Physics - Lattice, High Energy Physics - Lattice (hep-lat), High Energy Physics - Phenomenology (hep-ph), Nuclear Theory (nucl-th)

journal:

ADP-24-01/T1240

date:

2024-01-10 00:00:00

Abstract

This presentation opens with a brief review of lattice QCD calculations showing the $2s$ radial excitation of the nucleon sits at approximately 2 GeV, well above the Roper resonance position. We then proceed to reconcile this observation with experimental scattering data. While the idea of dressing quark-model states in a coupled-channel analysis to describe scattering data has been around for decades, it's now possible to bring these descriptions to the finite-volume of lattice QCD for confrontation with lattice-QCD calculations. This combination of lattice QCD and experiment demands that we reconsider our preconceived notions about the quark-model and its excitation spectrum. We close with a discussion of an unanticipated resolution to the missing baryon resonances problem.

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