Fermion masses and symmetry breaking of a U(2) flavour symmetry
  We show how a specific sequential breaking pattern of a U(2) flavour symmetry occurs automatically in a broad framework. The relative orientation in U(2) space of the spurion fields that breaks the U(2) symmetry is uniquely fixed, thus determining the form of the fermion mass matrices in a predictive way. 
Riccardo Barbieri, Leonardo Giusti, Lawrence J. Hall, Andrea Romanino