Charm decays with photons in the final state and trigger counter efficiencies study

This thesis presents a study done on the strong decay of the D0* meson using data taken with the FOCUS spectrometer at Fermi National Laboratory Accelerator at Batavia, IL. FOCUS is a fixed target experiment designed to study photo-production of charmed states. The D0* branching ratio is measured to understand D meson decays with photons in the final state. The work done in the calibration and simulation of the trigger counter efficiencies for the HxV and OH detectors that form part of the first level trigger of the spectrometer is also presented.