Impact of newly planned detectors on improvingsearch for physics in modern colliders

Particle colliders provide an opportunity to search for heavy particles believed to exist in the first moments of the beginning of the Universe after the big bang. Not only this but many phenomena that can be observed in colliders can help to improve our understanding of the origin of mass, matter and structure of our Universe. The Large Hadron Collider is the world's highest energy collider. It is designed to reach a very high center of mass energies and high luminosities to search for new physics or do precise measurements of Standard Model processes in phase spaces that could not be probed before. Although the LHC to discover Higgs particles still some physics program that could be pursued by a next-energy frontier collider with sufficient luminosity. These would include: understanding the mechanism behind mass generation, the Higgs mechanism and the role of the Higgs boson in the electroweak symmetry breaking; answering the question of whether the Higgs boson is a fundamental or composite particle; searching for, and possibly discovering, supersymmetric or other exotic particles, which could be part of the Universe's dark matter; and hunting for signs of extra space time dimensions and quantum gravity. The Large Hadron Collider accelerator is foreseen to undergo an upgrade which will lead to a phase of increased collision luminosity. Operated under the foreseen conditions, the current CMS (Compact Muon Solenoid) tracking system would suffer from inefficiencies and data loss due to radiation damage and incompatibility of the read-out electronics. Therefore, for the High Luminosity LHC era, a major upgrade is planned for the CMS experiment. The current tracking system of CMS will be replaced with an entirely new system. The upgraded tracking detector will, for the first time, contribute to the trigger decision by providing trigger information to the first-level trigger system of CMS. This will be achieved using the so-called pT -modules, a novel module design with trigger capabilities and on-board momentum discrimination. Within this context we have studied in this thesis the production of pp → W⁺Z, with subsequent decays W+ → ℓ+ νe and Z → ℓ+ ℓ− in the High-Luminosity Large Hadron Collider within the framework of the Standard Model. We have explored the impact of the planned detector upgrades on precision measurements and the sensitivity to Beyond Standard Model physics. Using insights from simulations, this thesis highlights the role of advanced detectors in improving the reconstruction, reducing the uncertainties, and extending the discovery reach in vector boson interactions. The results of the thesis can motivate search for this production process at the High-Luminosity Large Hadron Collider once the collider is constructed. In turn this will help to understand the physics of the Standard Model and the electroweak sector.