Signal Classification Techniques for Searches and Measurements at the LHC

This thesis focuses on three different examples of techniques designed to extract signal from background in the highly polluted by QCD environment of the proton-proton collisions at the Large Hadron Collider. The first is an attempt at quark-gluon tagging with the help of a simplified version of the shower deconstruction approximation to the likelihood ratio. We find that it outperforms some frontrunners in the field for a large variety of jet definitions and constraints, assuming topocluster-like objects instead of hadrons as seeds. The second search is tasked with identifying boosted W bosons, emitted from high virtuality quarks, thereby measuring the effects of Sudakov logarithmic enhancement under different assumptions of the systematic uncertainty. Finally, we examine the LHC's capability to measure and constrain the strength of the ttH (H->bb) channel in an extensive search of various modestly boosted phase space regions. Under optimistic assumptions about the missing energy reconstruction in b-tagged jets and the handling of the systematic uncertainty, we are able to exclude deviations on the order of 20% from the SM expectation.