Study of the Higgs boson decay to two muons with the CMS detector at LHC

This thesis describes a study of the muon selection for the search of the Standard Model Higgs boson decay to two muons with the CMS detector at LHC. Data collected during the 2017 run have been analyzed, corresponding to an integrated luminosity of 41.6 1/fb. Three strategies, built upon different selection criteria and muon momentum requirements, are tested. The agreement between data and Monte Carlo distributions for the most relevant kinematic variables is found to be good. The efficiency of muon identification and isolation has been measured with real data, and corrections to the Monte Carlo estimates (so-called “scale factors”) have been determined as a function of muon transverse momentum and pseudorapidity. The statistical significance obtained by the three selections has been estimated using simulated signal and background samples, in order to establish the best compromise between efficiency and purity. The so-called \textit{medium} muon selection with loose isolation cuts and a transverse momentum cut at 10 GeV is found to achieve the best significance.