Structure of Nucleon Excited States from Lattice QCD

Quantum Chromodynamics (QCD) describes the interactions between elementary quarks and gluons as they compose the nucleons at the heart of atomic structure. The interactions give rise to complexity that can only be examined via numerical simulations on supercomputers. This work provides an introduction to the numerical simulations of lattice QCD and establishes new formalisms relevant to understanding the structure of nucleons and their excited states. The research opens with an examination of the non-trivial QCD vacuum and the emergence of centre domains. The focus then turns to establishing a novel Parity-Expanded Variational Analysis (PEVA) technique solving the important problem of isolating baryon states moving with finite momentum. This seminal work provides a foundation for future calculations of baryon properties. Implementation of the PEVA formalism discloses important systematic errors in conventional calculations and reveals the structure of nucleon excited states from the first principles of QCD for the first time.

Nominated as an outstanding Ph.D. thesis by the The University of Adelaide, Adelaide, Australia South Australian nominee for the 2018 Bragg Gold Medal for Excellence in Physics First presentation of a groundbreaking technique in lattice QCD calculations of baryon properties Awarded the Intel Student Fellowship at LATTICE 2016 for outstanding research accomplishments in the field of Lattice QCD

Auteur
Finn Stokes completed their BSc (High Performance Computational Physics) (Honours) at The University of Adelaide in 2012, with an Honours thesis focusing on visualisations of structures that form in the quantum fluctuations of gluon fields in empty space. They continued at U. Adelaide to study for their PhD in the Special Research Centre for the Subatomic Structure of Matter, investigating the structure of protons and neutrons, and their excited states. Finn is currently a member of the nuclear and particle physics research group of the Institute for Advanced Simulation at the Jülich Supercomputing Centre.

Contenu
Introduction.- Background.- Centre Clusters in the Yang-Mills Vacuum.- Parity Expanded Variational Analysis.- Form Factors of the Proton and Neutron.- Elastic Form Factors of Nucleon Excitations.- Conclusion.- Bibliography.- Index.