Minimal modification to the tri-bimaximal neutrino mixing

Current experimental data on neutrino oscillations are consistent with the tri-bimaximal mixing. If future experimental data will determine a non-zero V-e3 and/or find CP violations in neutrino oscillations, there is the need to modify the mixing pattern. We find that a simple neutrino mass matrix, resulting from A(4) family symmetry breaking with residual Z(3) and Z(2) discrete symmetries respectively for the Higgs sectors generating the charged lepton and neutrino mass matrices, can satisfy the required modifications. We assume that the so-called sequestering problem could be solved. The neutrino mass matrix is minimally modified with just one additional complex parameter compared with the one producing the tri-bimaximal mixing. One interesting feature of this minimal modification is that V-alpha 2 is still equal to 1/root 3, for alpha = e, mu, tau. The CP violating Jarlskog factor J has a simple form (vertical bar J vertical bar = vertical bar Ve1Ve3 vertical bar/2 root 3 for real neutrino mass matrix). We also discuss how this mixing matrix can be tested experimentally. (c) 2006 Elsevier B.V. All rights reserved.