Celik, Ali (2018-05). Measurement of the Standard Model Processes for Supersymmetry Search in Low Momentum Single-Electron Events in the Vector Boson Fusion Topology at the LHC. Doctoral Dissertation.
Thesis
The yield of events with two jets, a single low-momentum electron, and large missing transverse momentum in the vector boson fusion (VBF) topology is measured in proton-proton collisions at center-of-mass energy of 13 TeV. The data corresponds to a total integrated luminosity of 35.86 fb?1 collected in 2016 by the CMS detector at CERN's Large Hadron Collider. The event selection requirements with electron's transverse momentum of 10 GeV to 40 GeV are optimized for the production of charginos (??+-1) and next-to-lightest neutralinos (??02) in supersymmetry (SUSY) compressed mass-spectra scenarios where the mass difference (?M) between ??+-1 and lightest neutralino (??01) is small. The masses of sleptons (I) are assumed to be between ??+-1 and ??01. The measurements in the VBF topology in various control regions are performed for the first time at hadron collider experiments, and the observed events are consistent with expectations by the Standard Model (SM) processes. The results are used to predict the SM event yields in the signal region in a blind analysis, and to set limits on the SUSY production in the VBF topology. Expected lower limits at 95% CL on the ??+-1 /??02 mass are reported for various ?M values in a scenario, where the branching fraction of I -> l + ??01 is 1/3 for each lepton flavour. The expected limits will be compared with observed limits in the next phase of the blind analysis.
