The GDH sum rule and extension to photoproduction off neutron targets in the Jülich-Bonn model
The GDH sum rule and extension to photoproduction off neutron targets in the Jülich-Bonn model
Main document (9.4MB)Art der Hochschulschrift
DissertationPrüfungsdatum
24.07.2026Datum der Veröffentlichung
03.08.2026Erstgutachter
Hanhart, ChristophZweitgutachter
Meißner, Ulf-G.Metadaten
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Inhalt
In this thesis, the light baryon spectrum of nucleon and delta resonances is stud- ied up to center-of-mass energies of 2.5 GeV. In this energy region, the strong interaction is non-perturbative and other methods are required. For this purpose, the Jülich-Bonn dynamical coupled-channel framework is employed. The model uses hadrons as the relevant degrees of freedom and the interaction is constructed from an effective Lagrangian. Furthermore, s-channel diagrams are included as genuine resonance states. The Lippmann-Schwinger scattering equation preserves analyticity, which is essential for a reliable extraction of resonance properties.
The Jülich-Bonn model was originally developed for pion-induced reactions such as πN → πN, ηN, KΛ and KΣ. It was later extended in a phenomenological way to include the photoproduction processes γp → π0p, π+n, K0Λ+, K0Σ+ and K+Σ0.
In this thesis, we present an updated fit result with new photoproduction data for the processes γp → π0p, π+n and ηp. So far, only photoproduction reactions with proton targets were analysed in this framework. One of the main achievements of this thesis is the extension of the framework to photoproduction off neutron targets, allowing for a simultaneous description of γn → π0n and π−p, in addition to the reactions listed above.
Another important aspect of this thesis is the Gerasimov-Drell-Hearn (GDH) sum rule, which follows from fundamental principles of quantum field theory and provides access to the spin structure of the nucleon. Using the Jülich-Bonn framework, the contributions of individual reaction channels to the GDH sum rule are determined. These contributions are calculated for photoproduction processes on both proton and neutron targets, providing new insights into the spin-dependent structure of the nucleon.
This thesis is structured as follows: Chapter 1 gives a short introduction to the Standard Model, the strong interaction, and light baryon spectroscopy. Chapter 2 presents the theoretical foundations relevant to this work. In Chapter 3, the Jülich- Bonn dynamical coupled-channel framework is described. In Chapter 4, the fit results of a recently published analysis with new photoproduction data is presented. The extension of the Jülich-Bonn model to photoproduction with neutron targets and the fit to the data base for the final-states π0n and π−p is presented in Chapter 5. Finally, Chapter 6 presents and discusses the contributions of the individual channels to the GDH sum rule, based on the fits performed in Chapters 4 and 5.
The Jülich-Bonn model was originally developed for pion-induced reactions such as πN → πN, ηN, KΛ and KΣ. It was later extended in a phenomenological way to include the photoproduction processes γp → π0p, π+n, K0Λ+, K0Σ+ and K+Σ0.
In this thesis, we present an updated fit result with new photoproduction data for the processes γp → π0p, π+n and ηp. So far, only photoproduction reactions with proton targets were analysed in this framework. One of the main achievements of this thesis is the extension of the framework to photoproduction off neutron targets, allowing for a simultaneous description of γn → π0n and π−p, in addition to the reactions listed above.
Another important aspect of this thesis is the Gerasimov-Drell-Hearn (GDH) sum rule, which follows from fundamental principles of quantum field theory and provides access to the spin structure of the nucleon. Using the Jülich-Bonn framework, the contributions of individual reaction channels to the GDH sum rule are determined. These contributions are calculated for photoproduction processes on both proton and neutron targets, providing new insights into the spin-dependent structure of the nucleon.
This thesis is structured as follows: Chapter 1 gives a short introduction to the Standard Model, the strong interaction, and light baryon spectroscopy. Chapter 2 presents the theoretical foundations relevant to this work. In Chapter 3, the Jülich- Bonn dynamical coupled-channel framework is described. In Chapter 4, the fit results of a recently published analysis with new photoproduction data is presented. The extension of the Jülich-Bonn model to photoproduction with neutron targets and the fit to the data base for the final-states π0n and π−p is presented in Chapter 5. Finally, Chapter 6 presents and discusses the contributions of the individual channels to the GDH sum rule, based on the fits performed in Chapters 4 and 5.
Klassifikation (DDC)
530 PhysikSchneider, Carolin: The GDH sum rule and extension to photoproduction off neutron targets in the Jülich-Bonn model. - Bonn, 2026. - Dissertation, Rheinische Friedrich-Wilhelms-Universität Bonn.
Online-Ausgabe in bonndoc: https://nbn-resolving.org/urn:nbn:de:hbz:5-91537
Online-Ausgabe in bonndoc: https://nbn-resolving.org/urn:nbn:de:hbz:5-91537
@phdthesis{handle:20.500.11811/14342,
urn: https://nbn-resolving.org/urn:nbn:de:hbz:5-91537,
author = {{Carolin Schneider}},
title = {The GDH sum rule and extension to photoproduction off neutron targets in the Jülich-Bonn model},
school = {Rheinische Friedrich-Wilhelms-Universität Bonn},
year = 2026,
month = aug,
note = {In this thesis, the light baryon spectrum of nucleon and delta resonances is stud- ied up to center-of-mass energies of 2.5 GeV. In this energy region, the strong interaction is non-perturbative and other methods are required. For this purpose, the Jülich-Bonn dynamical coupled-channel framework is employed. The model uses hadrons as the relevant degrees of freedom and the interaction is constructed from an effective Lagrangian. Furthermore, s-channel diagrams are included as genuine resonance states. The Lippmann-Schwinger scattering equation preserves analyticity, which is essential for a reliable extraction of resonance properties.
The Jülich-Bonn model was originally developed for pion-induced reactions such as πN → πN, ηN, KΛ and KΣ. It was later extended in a phenomenological way to include the photoproduction processes γp → π0p, π+n, K0Λ+, K0Σ+ and K+Σ0.
In this thesis, we present an updated fit result with new photoproduction data for the processes γp → π0p, π+n and ηp. So far, only photoproduction reactions with proton targets were analysed in this framework. One of the main achievements of this thesis is the extension of the framework to photoproduction off neutron targets, allowing for a simultaneous description of γn → π0n and π−p, in addition to the reactions listed above.
Another important aspect of this thesis is the Gerasimov-Drell-Hearn (GDH) sum rule, which follows from fundamental principles of quantum field theory and provides access to the spin structure of the nucleon. Using the Jülich-Bonn framework, the contributions of individual reaction channels to the GDH sum rule are determined. These contributions are calculated for photoproduction processes on both proton and neutron targets, providing new insights into the spin-dependent structure of the nucleon.
This thesis is structured as follows: Chapter 1 gives a short introduction to the Standard Model, the strong interaction, and light baryon spectroscopy. Chapter 2 presents the theoretical foundations relevant to this work. In Chapter 3, the Jülich- Bonn dynamical coupled-channel framework is described. In Chapter 4, the fit results of a recently published analysis with new photoproduction data is presented. The extension of the Jülich-Bonn model to photoproduction with neutron targets and the fit to the data base for the final-states π0n and π−p is presented in Chapter 5. Finally, Chapter 6 presents and discusses the contributions of the individual channels to the GDH sum rule, based on the fits performed in Chapters 4 and 5.},
url = {https://hdl.handle.net/20.500.11811/14342}
}
urn: https://nbn-resolving.org/urn:nbn:de:hbz:5-91537,
author = {{Carolin Schneider}},
title = {The GDH sum rule and extension to photoproduction off neutron targets in the Jülich-Bonn model},
school = {Rheinische Friedrich-Wilhelms-Universität Bonn},
year = 2026,
month = aug,
note = {In this thesis, the light baryon spectrum of nucleon and delta resonances is stud- ied up to center-of-mass energies of 2.5 GeV. In this energy region, the strong interaction is non-perturbative and other methods are required. For this purpose, the Jülich-Bonn dynamical coupled-channel framework is employed. The model uses hadrons as the relevant degrees of freedom and the interaction is constructed from an effective Lagrangian. Furthermore, s-channel diagrams are included as genuine resonance states. The Lippmann-Schwinger scattering equation preserves analyticity, which is essential for a reliable extraction of resonance properties.
The Jülich-Bonn model was originally developed for pion-induced reactions such as πN → πN, ηN, KΛ and KΣ. It was later extended in a phenomenological way to include the photoproduction processes γp → π0p, π+n, K0Λ+, K0Σ+ and K+Σ0.
In this thesis, we present an updated fit result with new photoproduction data for the processes γp → π0p, π+n and ηp. So far, only photoproduction reactions with proton targets were analysed in this framework. One of the main achievements of this thesis is the extension of the framework to photoproduction off neutron targets, allowing for a simultaneous description of γn → π0n and π−p, in addition to the reactions listed above.
Another important aspect of this thesis is the Gerasimov-Drell-Hearn (GDH) sum rule, which follows from fundamental principles of quantum field theory and provides access to the spin structure of the nucleon. Using the Jülich-Bonn framework, the contributions of individual reaction channels to the GDH sum rule are determined. These contributions are calculated for photoproduction processes on both proton and neutron targets, providing new insights into the spin-dependent structure of the nucleon.
This thesis is structured as follows: Chapter 1 gives a short introduction to the Standard Model, the strong interaction, and light baryon spectroscopy. Chapter 2 presents the theoretical foundations relevant to this work. In Chapter 3, the Jülich- Bonn dynamical coupled-channel framework is described. In Chapter 4, the fit results of a recently published analysis with new photoproduction data is presented. The extension of the Jülich-Bonn model to photoproduction with neutron targets and the fit to the data base for the final-states π0n and π−p is presented in Chapter 5. Finally, Chapter 6 presents and discusses the contributions of the individual channels to the GDH sum rule, based on the fits performed in Chapters 4 and 5.},
url = {https://hdl.handle.net/20.500.11811/14342}
}
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