Study of a Multivariate Technique for the Search of Single Top-Quark Production with $\sqrt s =$ 8 TeV in the CMS experiment at CERN

The analysis reported in the third chapter is on the collision data collected at 8 TeV in the CMS detector with a luminosity of 19.3 fb􀀀1, focused on muonic decay of the top quark in the s-channel topology. The rst section of this chapter is about the event selection used in the analysis while in the second section, the control samples and backgrounds are explained. The third section is about the systematic uncertainties. The fourth section gives a detailed explaination of the analysis using a multivariate technique called the Boosted Decision Trees (BDT) by choosing the most discriminating variables via a feedback loop. The results of the analysis are given in the last section.