Monte-Carlo-Simulations for tt+X-Events at the CMS-Experiment

The objective of this thesis is to investigate the degree to which Delphes is usable as a substitution for GEANT, specifically in the case of tt+X events. This is done by attempting to produce simulated data using Delphes which is as close as possible to existing simulations made using GEANT. In the first part, the used simulation tools are reviewed and a workflow which isolates the effect of varying the detector level simulation is devised. In the latter part, deviations between the GEANT-based results and the Delphes-based results are investigated, and an attempt is made to determine their origin and to mitigate them by adjusting the Delphes configuartion. By comparing the deviation between Delphes and GEANT across simulations of different parton level processes (ttbb, ttH and ttZ), the universality of the findings is gauged.

A repository with relevant code and configuration files exists under https://gitlab.etp.kit.edu/cn-cms/ttx-delphes/.