Searches for supersymmetry in the vector boson fusion topology with the ATLAS detector

The Standard Model of particle physics attempts to describe the most fundamental aspects of our world. It has generated a vast number of successful predictions and offers immense explanatory power as to why and how the fundamental interactions observed in nature proceed the way they do. At the same time, there exist deep mysteries about our world and inconsistencies within the Standard Model itself that cannot be ignored. Supersymmetry is an extension to the Standard Model proposed to resolve some of these problems. A search for supersymmetric particles called electroweakinos within the vector boson fusion topology is presented using the full Run-2 dataset collected by the ATLAS experiment at CERN. Generation of the signal model hypothesis, modeling and estimation of backgrounds, development of powerful discriminating variables, and statistical interpretation of the results are detailed. No excess above the Standard Model prediction is found. Model independent limits on generic new physics scenarios are performed, with the most stringent limit having a visible cross-section of 0.017 fb. Model dependent limits placed on electroweakino production exclude neutralino masses below 60 GeV. This constitutes the first signature based search of its kind at ATLAS and lays the groundwork for future work, which may include searches for light scalar states, which solve the strong-CP problem and bulk gravitons, which incorporate gravity into the Standard Model.