Measurement of $K^+ \to \pi^+ \mu^+ \mu^−$ Decay Form Factor and Evaluation of Muon Veto and Charged Hodoscope Efficiencies at NA62 Experiment at CERN

The main focus of the presented thesis is the measurement of form factor parameters and branching fraction of a rare kaon decay $K^+ \to \pi^+ \mu^+ \mu^- (K_{\pi\mu\mu})$ at the NA62 experiment, using a sub-sample of data collected in 2017. In addition to the main $K_{\pi\mu\mu}$ analysis, efficiency evaluation studies for sub-detectors MUV3 and CHOD carried out by the author are summarized in the thesis. The measured efficiencies were monitored during the NA62 data taking in 2016–2018 using the developed tools.