Browsing by Author "Aalto-Setälä, Laura"

In this work the connection between neutrino mass mechanisms and leptonic CP violation at collider experiments is studied. These subjects are connected on a fundamental level: the neutrino mass models dictate the form of the neutrino mass matrix; leptonic CP violation is expressed in the neutrino mass matrix by the Dirac and Majorana phases. The mass of neutrinos has been a subject of intensive study since the discovery of neutrino oscillation in the 1990s. This was the first, and still the only, observation that could not be explained by the standard model of particle physics. Neutrino mass mechanisms provide a way to extend the symmetry group of the standard model so that the neutrino masses are included. In addition to the tree-level seesaw mechanisms, four higher energy models, namely the minimal left-right symmetric model, the Littlest Higgs model, an SU(5) with an adjoint fermion, and the Altarelli-Feruglio model are reviewed. The first three extend the symmetry group of the standard model by a continuous symmetry, whereas the last extends it with a discrete flavor symmetry. It is possible that the seesaw mediators responsible for neutrino masses are within the energy reach of the LHC. Then the parameters of the neutrino mass matrix could be probed at collider experiments. One could determine the existence of the Dirac and Majorana phases by studying their effects on observable quantities of the channels including the seesaw mediators. These effects are reviewed in this work. The non-zero values of the phases would still not determine the existence of leptonic CP violation: generally, a CP odd phase can lead into CP even processes. It is concluded that the discovery potential of the Majorana phases is quite promising at the studied processes. For the Dirac phase, the effects are more subtle and its value will probably be determined at other experiments.