Authors:	Chao, En-Hung
Title:	Hadronic light-by-light scattering contribution to the anomalous magnetic moment of the muon from Lattice Quantum Chromodynamics
Online publication date:	14-Feb-2022
Year of first publication:	2022
Language:	english
Abstract:	The anomalous magnetic moment of the muon, $a_\mu$, provides a stringent test for the Standard Model of particle physics, as it is so far one of the most precisely measured quantities. On the theory side, the Standard Model prediction has reached the same level of precision as experiment. However, a long-standing discrepancy between the Standard Model theory prediction and the experimental result exists. In order for the tension to potentially reach the critical level of five standard deviations, it is essential to further reduce the errors. The uncertainty on the theory side is dominated by the hadronic contributions. The main purpose of this thesis is to calculate the Hadronic Light-by-Light scattering contribution $\ahlbl$, which makes one of the single largest contributions to the error budget of the Standard Model prediction. The calculation is based on Lattice Quantum Chromodynamics (LQCD), a Monte-Carlo based technique that gives access to non-perturbative hadronic physics from first-principles. In particular, we adopt a position-space formalism which handles the Quantum Electrodynamics (QED) effects semi-analytically in the continuum and infinite-volume. In this thesis, along with additional unpublished material, I present the results of a series of publications related to our determination of $\ahlbl$. I discuss several techniques that have been applied to our $\ahlbl$ calculations in order to have better control over different artifacts introduced by the simulations. After showing how our position-space method can be applied, by considering as an example the scalar-meson contribution to $\ahlbl$, and how one estimates the finite-size effects under our formalism with several models, I explain how to make the connection between different calculable contributions in LQCD and low-energy effective models. With all the building blocks introduced, the analyses leading to our published results are reviewed at the end of this thesis.
DDC:	530 Physik 530 Physics
Institution:	Johannes Gutenberg-Universität Mainz
Department:	FB 08 Physik, Mathematik u. Informatik
Place:	Mainz
ROR:	https://ror.org/023b0x485
DOI:	http://doi.org/10.25358/openscience-6720
URN:	urn:nbn:de:hebis:77-openscience-4047c3b5-eb36-4765-8d9a-af16f8bfb90d9
Version:	Original work
Publication type:	Dissertation
License:	In Copyright
Information on rights of use:	http://rightsstatements.org/vocab/InC/1.0/
Extent:	xii, 176 Seiten
Appears in collections:	JGU-Publikationen