Search for Boosted Top-Antitop Quark Resonances in Muon+Jets Events at 13 TeV Proton-Proton Collisions
thesisposted on 31.10.2017, 00:00 by Irving Daniel Sandoval Gonzalez
Numerous extensions of the Standard Model (SM) predict the existence of new interactions with enhanced couplings to the top quark. The associated massive new particle described by these theories could be observed as a top-antitop quark resonance. In this work, I present a search for such resonances using data recorded in 2016 with the CMS detector in proton-proton collisions at a center-of-mass energy of 13 TeV at the LHC, corresponding to an integrated luminosity of 35.9 fb−1 . This search is performed in events containing one muon, at least two jets and missing transverse energy in the final state. The analysis is optimized for events where the top quarks have a large Lorentz-boost by using jet substructure variables and boosted decision trees to suppress sources of irreducible background. The results show that the SM background predictions are in agreement with the observed data. Thus, 95% Confidence Level upper limits on the production cross section times branching fraction of selected benchmark models are set.