Flavour symmetries and Kähler operators

Any supersymmetric mechanism to solve the flavour puzzle would generate mixing both in the superpotential Yukawa couplings and in the Kähler potential. In this paper we study, in a model independent way, the impact of the nontrivial structure of the Kähler potential on the physical mixing matrix, after kinetic terms are canonically normalized. We undertake this analysis both for the quark sector and the neutrino sector. For the quark sector, and in view of the experimental values for the masses and mixing angles, we find that the effects of canonical normalization are subdominant. On the other hand, for the leptonic sector we obtain different conclusions depending on the spectrum of neutrinos. In the hierarchical case we obtain similar conclusions as in the quark sector, whereas in the degenerate and inversely hierarchical case, important changes in the mixing angles could be expected.