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Understanding the structure of nucleon excitations from their wavefunctions

Jackson A. Mickley1, Waseem Kamleh1, Derek B. Leinweber1, and Finn M. Stokes1,2

  • 1Centre for the Subatomic Structure of Matter, Department of Physics, Adelaide University, South Australia 5005, Australia
  • 2Jülich Supercomputing Centre, Institute for Advanced Simulation, Forschungszentrum Jülich, Jülich D-52425, Germany

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Phys. Rev. D 114, 034519 – Published 24 August, 2026

DOI: https://doi.org/10.1103/fyd3-cqj1

Abstract

Relativistic wavefunctions of nucleon excitations are scrutinized to understand their node structure and the underlying role of local interpolating fields in generating the nucleon spectrum. In addressing quark model perspectives, approximately 4000 propagators are employed on the heaviest PACS-CS ensemble at mπ≃702  MeV. We examine the ground and four lowest-lying excited states at zero momentum for both positive- and negative-parity spectra, where the proton’s d-quark wavefunction is calculated about the two u quarks at the origin. This is achieved using two local interpolating fields that each carry the quantum numbers of the nucleon but with differing spin-flavor structures, one of which vanishes in the nonrelativistic limit. We find that two distinct types of wavefunction nodes are manifest: “superposition nodes” formed through a linear combination of interpolating fields and novel “built-in nodes” that are fundamentally built in to the s-wave Dirac components of an individual interpolating field. These are investigated qualitatively through visualizations in the form of both volume and surface renderings and quantitatively by the calculation of radial wavefunctions. Combined, these findings build a comprehensive picture of the single-particle nucleon spectrum and how its properties derive from fundamental lattice operators.

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Phys. Rev. D 114, 034519– Published 24 August, 2026
  • Received 15 April 2026
  • Accepted 22 July 2026
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