Searches for heavy resonances in all-jet final states with top quarks using jet substructure techniques with the CMS Experiment

While the Standard Model is very successful in describing subnuclear phenomena, it is not acomplete theory of particle physics. Several new theories have been developed to address itsissues. Many extensions of the Standard Model predict the existence of high-mass resonances.In some cases these resonances have an enhanced coupling to third generation quarks or toa hypothetical new generation of heavy non-chiral quarks. This thesis describes two searchesfor new phenomena compatible with these theories, in particular a search is presented forresonant top-antitop production, and the first search for heavy resonances decaying to a topquark and a heavy top quark partner T is shown.The searches target the all-jets decay channels and use data collected by the CMS Experiment at the CERN LHC between 2012 and 2015 at a center-of-mass energy of 8 TeV and13 TeV. Due to the high mass of the resonances considered, the final state particles have ahigh Lorentz-boost. To reconstruct the hadronic decay of the top quarks and W bosons, jetsubstructure techniques such as top quark and W boson tagging algorithms, and boosted bjet identification are employed. These algorithms are studied with a particular focus on theirvalidation and performance assessment.No signs of physics beyond the Standard Model are observed, but stringent limits areplaced on the production of heavy resonances decaying to top-antitop quark pairs or a topquark and a heavy T quark.