Search for H→cc at CMS in VBF production with Run-3 data

The Higgs boson discovery represents a milestone in particle physics and the ATLAS and CMS experiments at CERN have dedicated a great effort to the investigation of its properties. However, the Higgs boson couplings to second generation quarks and first generation fermions are still statistically out of reach at the present experiments. The measurement of the Higgs boson coupling with charm quarks is one of the highest priority goals of the CMS physics program, as it could provide valuable insights on new physics. In this thesis, for the first time, the search for the Higgs boson decay into a charm quark-antiquark pair in VBF production at the CMS experiment is performed. Data collected during the 2023 of the Run-3 of the LHC proton-proton collision program are investigated. This search is particularly challenging because of the small branching ratio of the Higgs boson decay into charm quarks and the overwhelming QCD multijet background. The final result of this study is an upper limit at 95% confidence level on the Higgs production cross section times its decay branching ratio.