Cms Dark Matter Physics Analysis and Research and Development of the Future Detector Sifcc(3/3)

Various astrophysical observations indicate that more than 80% of the matter in the universe is dark matter. However, we know nothing about the detailed feature of dark matter. Unraveling the nature of dark matter is one of the most important targets of particle physics today. A popular dark matter candidate is weakly interacting massive particle (WIMP). This document proposes to look for WIMP dark matter produced at large hadron collider (LHC) using the Run II and Run III data collected by the Compact Muon Solenoid experiment (CMS). The searches for dark matter will be performed in three physics analyses: mono-h, the visible decays of DM-SM mediator into b quarks, extension of mono-X with long-lived intermediate particles. In addition, this document proposes to study the performance of the detector SiFCC for future 100 TeV pp colliders. The detector performance will be evaluated using jet energy resolution, substructure variables, and timing information; these variables are typically used to reduce background in the dark matter searches.