Paper detail

The T2K Indication of Relatively Large theta_13 and a Natural Perturbation to the Democratic Neutrino Mixing Pattern

The T2K Collaboration has recently reported a remarkable indication of the ν_μ-> ν_e oscillation which is consistent with a relatively large value of θ_{13} in the three-flavor neutrino mixing scheme. We show that it is possible to account for such a result of θ_{13} by introducing a natural perturbation to the democratic neutrino mixing pattern, without or with CP violation. A testable correlation between θ_{13} and θ_{23} is predicted in this ansatz. We also discuss the Wolfenstein-like parametrization of neutrino mixing, and comment on other possibilities of generating sufficiently large θ_{13} at the electroweak scale.