Study of the tracking efficiency for $D^0$ decays into $K\pi \pi \pi$ and $K\pi$

This report describes the work I have done during my eight week period as a summer student at CERN. The project was consisted in the study and simulation of two different hadronic final states, four-body and two-body, for the decay of neutral D meson measuring the tracking efficiency. We used data collected by the CMS experiment in 2016 and Monte Carlo technique to perform the simulations.