Probing Undiscovered Particles with Theory and Data-Driven Tools

Abstract

The Standard Model has been precisely tested by a plethora of experiments and has proved extremely successful at describing the fundamental interactions of subatomic particles. Despite this, there are numerous exciting questions motivating the existence of additional physics beyond the Standard Model. In this dissertation, we study a variety of theoretical and data-driven tools for discovering this physics. For theoretical tools, we explore various effective field theories, including those describing: axions mixing with other axions or non-compact scalars, axion interactions with magnetic monopoles, axion strings interacting with massive fermions, CP violating Higgs portal dark matter, scalar triplet and singlet-doublet models as solutions to the CDF-II W mass anomaly, and modifications to Froggatt-Nielsen models for explaining the hierarchy between different flavors of Standard Model Yukawa couplings. Additionally, we investigate machine learning based data-driven tools for precision Top-quark mass measurement and for anomaly detection.