Tribimaximal neutrino mixing from a supersymmetric model with A4 family symmetry

In the supersymmetric seesaw model of neutrino masses, augmented by the non-Abelian discrete tetrahedral symmetry A(4), a specific pattern of neutrino mixing is automatically generated if one of the three heavy singlet neutrino superfields acquires a nonzero vacuum expectation value. This pattern turns out to be exactly that of tribimaximal mixing, i.e. sin(2)theta(23)=1/2, sin(2)theta(12)=1/3, and sin(2)theta(13)=0, in good agreement with data.