Download the full-sized PDF of Study of leptonic systems and loop calculation  techniquesDownload the full-sized PDF



Permanent link (DOI):


Export to: EndNote  |  Zotero  |  Mendeley


This file is in the following communities:

Graduate Studies and Research, Faculty of


This file is in the following collections:

Theses and Dissertations

Study of leptonic systems and loop calculation techniques Open Access


Other title
muon decay asymmetry
magnetic moment
dimensional regularization
Type of item
Degree grantor
University of Alberta
Author or creator
Liang, Yi
Supervisor and department
Andrzej Czarnecki (Physics)
Examining committee member and department
Alexander Penin (Physics)
Kevin Beach (Physics)
Vadim A. Kravchinsky (Physics)
Davood Rafiei (Computing Science)
Andrzej Czarnecki (Physics)
Department of Physics

Date accepted
Graduation date
Doctor of Philosophy
Degree level
Proper handling of divergent integrals is presented, first with the example of the photon-photon scattering. The classic result of this process was questioned, because the necessity of regularization in the classic calculation was not clear. This challenge has its counterpart. The standard result for the decay of the Higgs boson into two photons was also questioned for a similar reason. We have verified the classic result of the photon-photon scattering, and have confirmed the necessity of regularization. The need to implement the regularization procedure in the calculation of the Higgs decay process is tested with multiple calculational approaches. We find once again the standard result to be correct. We numerically study properties of leptonic systems. The first system is the positronium ion, a three-body system consisting of two electrons and a positron. The gyromagnetic factor of the positronium ion is determined with first relativistic corrections. We calculate the modified g -factor of this system for the first time. Our final topic is the computation of the spin asymmetry of the muon decay in perturbative QED. We point out that at the alpha squared level the asymmetry requires a careful definition due to multi-lepton final states and suggest to use familiar QCD techniques to define it in an infra-red safe way. We find that the TWIST measurement of the asymmetry is in excellent agreement with the Standard Model.
Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission.
Citation for previous publication

File Details

Date Uploaded
Date Modified
Audit Status
Audits have not yet been run on this file.
File format: pdf (PDF/A)
Mime type: application/pdf
File size: 4304887
Last modified: 2015:10:12 16:13:26-06:00
Filename: Liang_Yi_201405_PhD.pdf
Original checksum: 7574bb9e8de3ca98a0fba1c5c6b61047
Activity of users you follow
User Activity Date