High energy physics: from quantum field theory to Higgs coupling measurement

This document summarizes work in theoretical and experimental high-energy physics completed as part of the author’s doctoral studies, while providing context and motivation for these projects. Beginning with an overview of the relevant backgrounds, the motivation for this doctoral research is explored by discussing the current state of particle physics and many unanswered questions in this field. Emphasis is placed on providing broad context to readers outside of the particle physics community. Theoretical work from early PhD studies is briefly summarized, exploring the continuity of scalar quantum fields and studying a novel toy field theory with intriguing nonlinear wave solutions. The discussion then turns to the experimental side of particle physics, covering relevant conceptual material and experimental techniques. The author’s research in collaboration with the CMS experiment is presented, detailing the motivation and methodology. This project produces a measurement of the strength of interaction between the top quark and Higgs boson, obtaining a Yukawa coupling of Yt = 1.16+0.24-0.35 relative to the standard model value.