• slope
• ratio
• pi0
• NA62
• kaon
• form
• experiment
• factor
• decays
• branching
• dalitz

The present work has been carried on within the NA62 experiment, the current CERN research program for testing the Standard Model (SM) through the study of the rare kaon decays. It deals with the study of two kaon decays: K->pipi0ee, K->pipi0(pi0->eeg).
After an introduction to the NA62 experiment and its sub-detectors, which are employed in the analysis, the simulation and the Reconstruction software packages are brief described.
The K->pipi0ee decay is discussed in the second chapter: the theoretical motivations are given and since it is a new discovered kaon decay channel, it has been studied from the point of view of its perspectives in the NA62 experiment. This means that the study is focused on the determination of estimate of the result which might be obtained with the final collectable signal sample. Two kinds of signal selection are described, both performed on the available simulation of the signal decay mode.
The K->pipi0(pi0->eeg) has been studied to measure the quantities linked to the pi0 Dalitz decay: the Transition Form Factor slope (TFF) and the Branching Ratio (BR). The TFF is linked with the computation of the magnetic moment of the muon, while its BR enters in other Branching Ratio computations as the main source of error.
After an introduction to the relevant quantities of this decay, the perspectives in NA62 are presented with a rough signal selection applied on data. The result is promising with an expected signal statistics that overcomes the one of the previous experiments.
The signal selection was tuned through the simulation of the signal and background events and problems linked with a part of the NA62 data sample are discussed.
With the final selected samples the TFF slope and BR is measured, trying to solve problems linked to the trigger efficiency of the experiment.