Bi-pair neutrino mixing

A new type of neutrino mixing named bi-pair neutrino mixing is proposed to describe the current neutrino mixing pattern with a vanishing reactor mixing angle and is determined by a mixing matrix with two pairs of identical magnitudes of matrix elements. As a result, we predict sin2θ12=1−1/2(≈0.293) for the solar neutrino mixing and either sin2θ23=tan2θ12 or cos2θ23=tan2θ12 for the atmospheric neutrino mixing. We determine flavor structure of a mass matrix M, leading to diagonal masses of m1,2,3, and find that |Mμμ−Mee/t122|:|Mμτ|:|Mττ−Mee/t122|=t232:|t23|:1 for the normal mass hierarchy if m1=0, where tij=tanθij (i,j=1,2,3) and Mij (i,j=e,μ,τ) stand for flavor neutrino masses. For the inverted mass hierarchy, the bi-pair mixing scheme turns out to satisfy the strong scaling ansatz requiring that |Mμμ|:|Mμτ|:|Mττ|=1:|t23|:t232 if m3=0.