Michaela Elisabeth Albrecht

Two Approaches Towards the Flavour Puzzle: Dynamical Minimal Flavour Violation and Warped Extra Dimensions Michaela Elisabeth Albrecht

The experimental findings that the quark masses andmixing angles in the Standard Model are so muchdifferent is considered to be unnatural because they originate from a single mechanism - the Higgs mechanism. This is known as the quark flavour puzzle and in this thesis we discuss two approaches to resolve it. Incorporating the concept of minimal flavour violation, we promote the Yukawaentries to dynamical spurion fields in an effectivefield theory. Their vacuum expectation valuessequentially break the maximal flavour symmetry ofthe Standard Model and generate the hierarchy of the quark masses and mixing angles. In Randall-Sundrum models the five-dimensional quarkmass matrices render the effective four-dimensionalYukawa matrices hierarchical by a different quarklocalisation in the extra dimension. In both models we focus on possible flavour-changingneutral currents that are constrained by experiment.