Charged multiplicity measurement for simulated pp events in the Compact Muon Solenoid (CMS) detector

Abstract

In this thesis, I studied the effectiveness of a method for measuring the charged multiplicity of proton-proton collisions in the Compact Muon Solenoid (CMS) experiment at LHC energies ... This technique involves counting reconstructed hits in the innermost layer of the pixel tracker. By using the relationship between pseudorapidity and deposited charge of the hits, we can distinguish between signal and background. We calculate a transformation function as the division of the average Monte Carlo track distribution by the average reconstructed hit distribution. By applying this transformation to the reconstructed hit distributions on an event-by-event basis, we can collect information about minimum bias events. This method gives us access to low PT particles which cannot be reconstructed in charged multiplicity methods using tracklets. A description of the method is given, followed by preliminary results: reconstructed Neh distributions for ... distribution.