This thesis presents innovative contributions to the CMS experiment in the new trigger system for the restart of the LHC collisions in Run II, as well as original analysis methods and important results that led to official publications of the Collaboration. The author's novel reconstruction algorithms, deployed on the Field-Programmable Gate Arrays of the new CMS trigger architecture, have brought a gain of over a factor 2 in efficiency for the identification of tau leptons, with a very significant impact on important H boson measurements, such as its decays to tau lepton pairs and the search for H boson pair production. He also describes a novel analysis of HH bb tautau, a high priority physics topic in a difficult channel. The original strategy, optimisation of event categories, and the control of the background have made the result one of the most sensitive concerning the self-coupling of the Higgs boson among all possible channels at the LHC.

Auteur
After completing his studies in Physics at the University of Milano-Bicocca in Italy, Luca Cadamuro obtained his PhD from the Laboratoire Leprince-Ringuet at the École Polytechnique in France. He is currently a Postdoctoral Research Associate at the University of Florida and a Distinguished Research Fellow at Fermilab LPC. A member of the CMS Collaboration, his research activities and interests include electroweak symmetry breaking and Higgs boson physics, and the development of algorithms for current and future upgrades of the trigger of the experiment.

Contenu
Preamble.- Introduction to Higgs Boson Pair Production.- Experimental Apparatus.- The L1 Trigger.- Event Selection and Categorization.- Modelling of Physics Processes.- Results on HH bb + .- Future prospects for HH searches.- Conclusions.- Appendix.