A search for supersymmetry with the CMS detector in the single-lepton final state using the sum of masses of large-radius jets

A search for supersymmetry with the CMS detector in the single-lepton final state using the sum of masses of large-radius jets by Ryan Edward Heller The discovery of the Higgs boson casts new urgency to an old question: the Higgs mass hierarchy problem. Supersymmetry can provide an elegant and natural solution to the hierarchy problem, and would result in many new particles accessible at the TeV scale probed by the LHC. This dissertation describes a search for a classic natural supersymmetry signature, gluino mediated top squark production. The search is performed in the single-leptonfinal state, relying on the large missing energy and high jet and b-flavor jet multiplicitiesto separate the gluino signal from the Standard Model backgrounds. The backgroundmeasurement is centered around the variable MJ, the sum of masses of large radius jets.The search uses a sample of proton-proton collisions at center of mass energy 13 TeVrecorded by the CMS detector, corresponding to an integrated luminosity of 35.9 fb−1 .The observed yields in the signal regions are consistent with the expected Standard Modelbackgrounds, and the results are interpreted in the context of simplified models of gluinopair production. Scenarios with gluino masses up to approximately 1.9 TeV are excludedat 95% confidence level for neutralino masses less than 1 TeV. This negative result joinsa substantial body of evidence disfavoring supersymmetry realized near the electroweakscale.