Anomalous couplings of the Higgs boson in the WW decay channel with the CMS experiment at the LHC

The thesis herein constitutes a comprehensive investigation of anomalous couplings between the Higgs boson (H) and the bosons W, Z, and g, including the effects of Charge-Parity (CP) violation in the context of the direct searches of anomalous couplings. The study employs various Higgs production mechanisms, such as gluon-gluon fusion, vector boson fusion, and the associated production with a W or Z boson, focusing on the Higgs boson decay to a pair of W bosons in the different flavor dilepton (e$\mu$) final state. The data analyzed was collected by the CMS detector at the LHC from 2016 to 2018, with a center-of-mass energy of 13 TeV and an integrated luminosity of 138 fb$^{-1}$. To increase sensitivity to anomalous effects at the production vertex, the kinematic information from associated jets in the Higgs production was combined using matrix element techniques. The study also utilized Monte Carlo simulation and matrix-element reweighting to model all kinematic features in the production and decay of the Higgs boson, along with a full simulation of detector effects. The analysis resulted in a simultaneous measurement of four Higgs boson couplings to electroweak vector bosons within the framework of a standard model effective field theory. The measured values were found to be consistent with the standard model expectations for the Higgs boson, and constraints were set on the fractional contribution of the anomalous couplings to the Higgs boson cross-section. These results significantly surpass the precision and coverage of the last H to WW anomalous coupling analysis. Additionally, a hardware analysis is included, focusing on the Drift Tubes Phase-2 upgrades of the CMS detector to accommodate higher luminosities expected for future operations. Through precision measurements and advanced analysis techniques, this research contributes to our understanding of the fundamental nature of the universe, seeking to uncover new physics phenomena beyond the standard model.