Abstracts Physics

Two leptons, jets, and missing transverse momentum in ATLAS: yet more non-evidence for supersymmetry

by Rupert Tombs

Searching for new phenomena is an essential endeavour of experimental physics, and is helped by guidance from plausible theoretical predictions. This thesis presents such a search for signals of high-energy protons scattering to massive resonances with dramatic decays, which are predicted by supersymmetric models. No new phenomena appear in the results, so they support the Standard Model in its continuing successful extrapolation to describe the most extreme behaviours of proton collisions. Supersymmetry as a concept is not falsified by this lack of new phenomena, nor by the many similar observations. But it is also not confirmed. Data are best interpreted with an understanding of their origins, so we begin by describing the theoretical and experimental background to our search. Our results also depend strongly on the interpretation of data by conventional analysis procedures, whose properties and explanations are not obvious. To explain these procedures, we also discuss their historical context and the basic theory of data analysis.