Phenomenology of Discrete Flavour Symmetries

Understand

The flavour puzzle is an open problem both in the Standard Model and in its possible supersymmetric or grand unified extensions.

• In this thesis, we discuss possible explanations of the origin of fermion mass hierarchies and mixings by the use of non-Abelian discrete flavour symmetries.
• We present a T'- and an S4-based realisations in which the spontaneous breaking of the symmetry produces realistic fermion mass hierarchies, the quark mixing matrix comparable to the Wolfenstein parametrisation and the lepton mixing matrix close to the so-called tribimaximal pattern.
• We also present an alternative S4-based flavour model which naturally leads to the weak complementarity relation with a relatively large lepton reactor angle.