Dissertation
The z-expansion: applications in particle decay and scattering processes
University of Iowa
Doctor of Philosophy (PhD), University of Iowa
Spring 2023
DOI: 10.25820/etd.007039
Abstract
The z-expansion is an exciting mathematical tool that has been used to study a variety of different particle decay and scattering events over the last few decades. The decay rates and scattering cross sections are functions of objects called form factors, which can be described by the z-expansion. The z-expansion is only a function of the particle momentum transfer. I will show its application in two independent investigations: in the vector form factor that appears in B meson decays and in the axial form factor that appears in neutrino-nucleon scattering.
For B meson decays, we investigate two different parameterizations of the vector form factor that both use the z-expansion. By fitting these parameterizations to experimental data collected by the Belle collaboration, we are able to determine the goodness of the fit and the self-consistency of each parameterization with differing numbers of free parameters. This will be useful for future lattice QCD simulations that only have manageable uncertainties in a small range of momentum transfer values.
For neutrino scattering, we investigate the historical dipole ansatz for the axial form factor which does not involve the z-expansion and the more modern description of the axial form factor with the z-expansion. By using the results of external z-expansion fits, we are able to determine a quantitative description of how the uncertainties in the axial form factor propagates into the scattering cross section. This will be useful for future neutrino oscillation experiments which require extremely high precision cross section calculations.
Details
- Title: Subtitle
- The z-expansion: applications in particle decay and scattering processes
- Creators
- Daniel Simons
- Contributors
- Yannick Meurice (Advisor)Jane Nachtman (Committee Member)Wayne Polyzou (Committee Member)Vincent Rodgers (Committee Member)Michael Wagman (Committee Member)
- Resource Type
- Dissertation
- Degree Awarded
- Doctor of Philosophy (PhD), University of Iowa
- Degree in
- Physics
- Date degree season
- Spring 2023
- Publisher
- University of Iowa
- DOI
- 10.25820/etd.007039
- Number of pages
- x, 166 pages
- Copyright
- Copyright 2023 Daniel Simons
- Grants
- High Energy Experimental and Theoretical Physics Research at the University of Iowa, DE-SC0010113, United States Department of Energy (United States, Washington) - DOE
- Language
- English
- Date submitted
- 04/24/2023
- Date approved
- 05/08/2023
- Description illustrations
- tables, graphs
- Description bibliographic
- Includes bibliographical references (pages 156-166).
- Public Abstract (ETD)
- The next generation of experimental particle physics requires high precision calculations beyond what is currently achievable. The z-expansion is an exciting mathematical technique that has been growing in usage over the last few decades, and it can be used to describe the interactions of subatomic particles at the precision level that is required of these new experiments. This work is split into two investigations towards independent physics processes, one particle decaying into other smaller particles and the collision of two particles. By investigating the decay process with several models and experimental data, we are able to determine the best model to describe the data. And by investigating the collisions of two particles with various models and experimental data, we are able to determine how precise the input for our calculations need to be in order to achieve an output with a given precision.
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984428939702771
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