Studies for the CMS detector and a preliminary analysis of Higgs boson decay to charm quark-antiquark pair in the vector boson fusion process

	Abstract: In the first part of this talk, three studies related to the CMS detector at the Large Hadron Collider will be presented. These studies include investigations of the performance of the missing transverse energy filters for various data sets, the development of data quality monitoring plots for the identification of tau leptons, and the derivation of working points for isolation criteria for the electron at the trigger level. These contributions aim to improve the quality and efficiency of the recorded data from the CMS experiment. In the second half, the status of our analysis for the measurement of Higgs boson coupling to the charm quark-antiquark pair will be discussed. This analysis uses the vector boson fusion production mode. We shall present the performance of a classifier based on a Message-Passing Neural Network for rejecting backgrounds.