  We present a model of quark and lepton masses and mixings based on A4 family
symmetry, a discrete subgroup of an SO(3) flavour symmetry, together with
Pati-Salam unification. It accommodates tri-bimaximal neutrino mixing via
constrained sequential dominance with a particularly simple vacuum alignment
mechanism emerging through the effective D-term contributions to the scalar
potential.

High Energy Physics - Phenomenology