Improving the Description of Lateral Shower Profiles in the FoCal Detector Prototype

Abstract

To get a better understanding of the fundamental laws and particles of the universe, a forward electromagnetic calorimeter (FoCal) is proposed for ALICE at CERN. A prototype detector has been build and is currently being analysed. This thesis focusses on finding an analytical description of the lateral hit density profiles of the prototype, obtained by measurements of the 50 GeV SPS beam at CERN. Unfortunatly, uncertainties of the hit densities from earlier analysis were lost and new uncertainties have been calculated, assuming pure Poisson fluctuations of the number of hits with a constant mean value per event. The new uncertainties are overestimated with the current approach, leading to difficulty in interpreting the fit results. From earlier analysis a power law function was deemed best fit for the profiles and in this thesis four adjustments are applied for new fits. The results are compared by looking at chisquare values of the fits. All adjusted functions seem to perform better than the original and the function, with added polynomial inside the power, performs best. Comparison between the results of the overestimated uncertainties and results obtained with underestimated uncertainties, shows similar behaviour of the fits. This could imply the functions are good to describe the data.