Search for heavy ZZ resonances in the llvv channel using proton-proton collisions at s = 13 TeV with the ATLAS detector at the LHC

<p>This thesis provides a description of the search for new resonances in event signatures consisting of two Z bosons, where one Z boson decays to a opposite-sign same-flavour lepton pair ll (l = electron or muon), while the other Z boson decays to neutrinos which are experimentally quantified...

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Bibliographic Details
Main Author: Petrov, M
Other Authors: Bortoletto, D
Format: Thesis
Published: 2018
Description
Summary:<p>This thesis provides a description of the search for new resonances in event signatures consisting of two Z bosons, where one Z boson decays to a opposite-sign same-flavour lepton pair ll (l = electron or muon), while the other Z boson decays to neutrinos which are experimentally quantified by a large missing transverse momentum. The description of the search includes the analysis selection criteria, the background estimation and the exclusion limits on the production of new physics. The analysis is divided into two signal regions, based on the resonant production mode i.e. gluon-gluon fusion or vector boson fusion. The result of the H-&gt;ZZ-&gt;llvv search is combined with the result from the H-&gt;ZZ-&gt;4l analysis to arrive at better constrains of heavy Higgs boson production and to set exclusion limits on two higgs doublet models. Additionally, upper limits are derived for spin-2 Kaluza-Klein graviton resonances for masses between 600 GeV and 2 TeV in the context of the Randall-Sundrum model. The analysis search uses data gathered from proton-proton collisions at a center-of-mass energy of 13 TeV, corresponding to a total integrated luminosity of 36.1 fb-1 collected by the ATLAS detector during the 2015+2016 data runs at the Large Hadron Collider. No statistically significant excess over the background prediction is found in the 2015+2016 data.</p>