New physics for the large hadron collider: new minimal models of composite higgs
The discovery of the Higgs boson at CERN marks the beginning of a new era in particle physics. After an impressive forty-year search that has ended making Europe the undisputed leader in particle physics, the finding of the long-sought particle offers us the unique possibility of start testing the origin of the electroweak symmetry breaking. In particular, this means that we could be closer than ever to understand some extremely important unsolved puzzles in particle physics, like the large hierarchy between the electroweak and the Planck scales or the origin of fermion masses. Models of composite Higgs are certainly among the best motivated and attractive scenarios trying to address these issues. They also occupy a prominent place in the forefront of theoretical physics, being the object of study of a large community of particle physicists. In this proposal I present an innovative and compelling scenario within this framework where composite leptons, motivated by minimal implementations of leptons featuring a seesaw mechanism of type-III, can partially or fully replace the usual role of the top quark as a trigger of electroweak symmetry breaking without including any anomalously light partner. The presence of custodial symmetry, customary in realistic incarnations of composite Higgs models, ensures that the required sizable degree of compositeness of the right-handed charged leptons is in complete agreement with electroweak precision measurements. These new scenarios offer a beautiful bridge between flavor, neutrino physics and Higgs physics. Throughout this proposal I develop the main objectives and goals of the research proposed, namely, the precise study of lepton flavor constraints in realistic holographic realizations of these models, the study of their implications on Higgs physics, the possible constraints coming from loop corrections to precision observables, their experimental probes at the LHC as well as the possible relation with Dark Matter.