Search For A Supersymmetric Partner To The Top Quark Using A Multivariate Analysis Technique

Download or read book Search for a Supersymmetric Partner to the Top Quark Using a Multivariate Analysis Technique written by Smita Darmora and published by . This book was released on 2015 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: Supersymmetry (SUSY) is an extension to the Standard Model (SM) which introduces supersymmetric partners of the known fermions and bosons. Top squark (stop) searches are a natural extension of inclusive SUSY searches at the Large Hadron Collider (LHC). If SUSY solves the naturalness problem, the stop should be light enough to cancel the top loop contribution to the Higgs mass parameter. The 3rd generation squarks may be the rst SUSY particles to be discovered at the LHC. The stop can decay into a variety of nal states, depending, amongst other factors, on the hierarchy of the mass eigenstates formed from the linear superposition of the SUSY partners of the Higgs boson and electroweak gauge bosons. In this study the relevant mass eigenstates are the lightest chargino (X ±/1) and the neutralino (X 0/1). A search is presented for a heavy SUSY top partner decaying to a lepton, neutrino and the lightest supersymmetric particle (X 0/1) , via a b-quark and a chargino (X ±/1) in events with two leptons in the nal state. The analysis targets searches for a SUSY top partner by means of a Multivariate Analysis Technique, used to discriminate between the stop signal and the background with a learning algorithm based on Monte Carlo generated signal and background samples. The analysis uses data corresponding to 20.3 fb−1 of integrated luminosity at root s = 8 TeV, collected by the ATLAS experiment at the LHC in 2012.