Tribimaximal mixing, leptogenesis, and θ13

We show that seesaw models based on flavor symmetries (such as A(4) and Z(7) x Z(3)) which produce exact tribimaximal neutrino mixing also imply a vanishing leptogenesis asymmetry. We show that higher order symmetry breaking corrections in these models can give a non-zero leptogenesis asymmetry and generically also give deviations from tribimaximal mixing and a non-zero theta(13) greater than or similar to 10(-2.) (c) 2008 Elsevier B.V. All rights reserved.