Measurement of the Higgs Boson Pair Production in the WWZZ Decay Channel and Development of MTD Control and Safety Systems in the CMS Experiment

The Thesis describes the development and implementation of the 𝐻𝐻 → 𝑊 𝑊∗𝑍𝑍∗ → 4𝑙 analysis, using a dataset of 200 fb⁻¹ collected by the Compact Muon Solenoid (CMS) detector over five years. The observed (expected) 95 % confidence level upper limit of 142.3 (176.8) times the theory value is set for the Higgs boson pair cross section. Additionally, the work on the Minimum ionising particle Timing Detector (MTD) control system is detailed. The technical solutions discussed in this study contribute to the continuity of high-precision measurements of Higgs boson physics at CMS.