First of all I wish to thank my thesis advisors, Mehdi Jazayeri at the Vienna Technical University and Sergio Cittolin at CERN for the time they sacrificed in helping me with this work. I owe also a great debt to Paris Sphicas for his co-supervision. I am grateful that Eva Kühn volunteered to be my second supervisor in Vienna and helped me without bureaucratic hurdles to be able to follow her lectures from distance. This dissertation has been made possible by the generous support of the Austrian government to the doctoral student programme at the European Laboratory for Particle Physics in Geneva. I am grateful to all members of the CMS collaboration, especially the ones at CERN for their support and help in all scientific questions. Thanks go to Lynda Haughney at CERN/Prevessin for making this work readable.