Obtaining nonvanishing 𝜃13 with constrained neutrino Yukawa matrix and implications for flavor model buildings

Abstract

Assuming a diagonal Majorana neutrino mass matrix, we investigate the neutrino Yukawa textures which lead to a non-zero reactor mixing angle θ 13 . The neutrino effective coupling matrix κ ef f is pre-diagonalized by a constant mixing pattern V ν with a vanishing θ ν 13 . The resulting pre-diagonal symmetrical matrix κ is set to be four texture zeros with two types of off-diagonal elements nonzero, which is κ 13 and κ 23 , respectively. With the expectation of simple textures we thoroughly classify the linear combinations, α i , β i and γ i of Yukawa elements λ ij in a same row, according to the values vanishing or not. Each set of the classifications can lead to a Yukawa texture which may have implications for the discrete flavor model buildings. We also present a model based on A 4 according to one set of the constraints on the three combinations with a specific choice of a coefficient in Yukawa texture. *