  Compared to the other neutrino mixing angles \theta_{13} is small. The solar
mass splitting is about two orders smaller than the atmospheric splitting. We
show that it is possible that both are perturbative effects on a more symmetric
structure. The perturbation also affects the solar mixing angle and can make
alternate mixing patterns such as tribimaximal, bimaximal, or other variants
equally viable. For real perturbations this can be accomplished only for normal
mass ordering and with the lightest neutrino mass less than 10^{-2} eV. Both
mass orderings can be accommodated by going over to complex perturbations
provided the lightest neutrino is heavier. The CP-phase in the lepton sector
that emerges distinguishes between different mixing models.

High Energy Physics - Phenomenology;High Energy Physics - Experiment