Running of Neutrino Parameters in Extra Dimensions

In recent years, extra-dimensional models have received new attention as possible extensions to the Standard Model (SM). In this thesis, we study a six-dimensional model with universal extra dimensions (UEDs). The extra dimensions are compactified, and all fields in the SM can probe them. From our four-dimensional point of view, we perceive them as towers of heavy particles, corresponding to the SM fields. In this thesis, we discuss the six-dimensional UED model together with an effective neutrino mass operator. We determine the renormalization group equations (RGEs) relevant to determine the renormalization group running of neutrino parameters. The RGEs are solved numerically and we thus determine the energy-dependence of the lepton mixing angles, the neutrino masses, and the gauge couplings in this model. We find that the mixing angle θ12, the neutrino masses and the gauge couplings exhibit significant running. The running has a power-law dependence, as it is boosted by contributions from the extra dimensions. The model is of particular interest, since it gives predictions at energies obtained in the Large Hadron Collider (LHC). The experiment have already provided restrictions of the size on the extra dimensions, and will hopefully enlighten us further regarding their existence.