CMS endcap tracker for the High-Luminosity LHC and search for Higgs pair production

The Large Hadron Collider (LHC) at CERN is the greatest particle accelerator that has been in operation for more than a decade and has been immensely successful in validating the SM – while the biggest success of it being the discovery of the Higgs boson. A major upgrade was designed to maximize the physics reach of the LHC for the second half of its lifetime that would lead to an increase in luminosity by a factor often, compared to its original design value, called the High Luminosity LHC (HL-LHC) Upgrade. This thesis investigates and reports on efforts for the realization of this upgrade on two fronts; it first focuses on the upgrade of the CMS detector, mainly of the Strip Tracker Detector's; these efforts include commissioning a new cleanroom and developing a control system, making the services design as well as developing quality assurance procedures and tests. The second half of this dissertation reports on yet another upgrade effort, a prospective analysis searching for a Higgs pair (HH) in an attempt to prove the physics reach of the proposed upgrade. The analysis of choice has been decided to be HH as self-interaction of the Higgs boson is a great portal that enables us to obtain a deeper understanding of the spontaneous symmetry breaking. In summary, this dissertation is devoted to the HL-LHC upgrade, describing the upgrade studies on detector level and outlining the expected performance.