A robustness study of signal strength upper limits based on simplified model spectra of supersymmetry

This thesis investigates the robustness of r-values and exclusion ranges derived from weighted sums of simplified supersymmetric models used in a recent analysis by the CMS collaboration [CMS Collaboration, Physics Letters B $\mathbf{842}$ (2023)], evaluating whether a set of more comprehensive supersymmetric models yield significantly different r-values and exclusion ranges. Weighted sums of simplified, single process models are often used to emulate more complete models. We calculated the r-values and exclusion ranges for a set of models which had similar constraints, but were more physically motivated[A. Canepa, T. Han, and X. Wang, Fermilab Technical Publications (2020)]. We found that the r-values calculated by the CMS Collaboration were lower than those from the more comprehensive models for three out of four models, and the range of excluded parameters calculated by the CMS collaboration were wider than those from the alternative models. While further study is required to make a definitive conclusion on the efficacy of reinterpreting simplified models to approximate a physically complete model, the results found suggest that the predictions made using weighted sums of simplified models may not accurately approximate the results for a more physically complete model.