Measurement of the properties of the Higgs boson in CMS experiment at the LHC

Since the groundbreaking discovery of the Higgs boson (H) in 2012, the primary focus of the experiments conducted at the Large Hadron Collider (LHC) has been to accurately measure its properties. This essential physics program is driven by two key objectives: firstly, to validate the description of generation of mass as in the standard, and secondly, to utilize the measured properties of the H to explore the new physics phenomena, beyond the standard model physics. Towards this end this thesis describes essentially two analyses of current interest and high importance, carried out using the Run-2 p-p collision data collected by the CMS experiment at the LHC. The first study concerns the search for the non-resonant H pair produced through Vector Boson Fusion (VBF) mode in two photons and two b-jets final state. The constraints on the anomalous coupling of a pair of H with a pair of gauge bosons was determined for the first time by the CMS collaboration. Further, a projection study of the feasibility of the non-resonant H pair production in the context of the High luminosity LHC is also presented. In the second study the measurement of H through VBF production and subsequent decays to two b-quarks is carried out for the first time using Run-2 data from CMS. Though this study has used CMS datasets of 2016 and 2018, the derived signal strength is comparable with the analysis carried out by the ATLAS collaboration, using full dataset of Run-2. This CMS analysis also reported the first observation of the VBF production of followed by decay to b-quark pair, in a hadron collider. Finally, two detector performance related studies are reported regarding a) the performance check of the missing transverse energy filters, and, b) the estimation of the resolution and the response of the missing transverse energy in the events containing photons along with the jets.