Partial µ −τ symmetry from kinetic normalization

Abstract

 We consider models with broken μ-τ permutation symmetry through higher dimensional operators renor-
malizing the lepton kinetic terms in the action. We study the consequences on the structure of the neutrino
mass matrix and find in particular that the allowed region for the lightest mass in the normal hierar-
chy plotted as a function of the atmospheric mixing element |Vμ3| is very restricted with the atmospheric
mixing angle θ23 to lie in the second octant. On the other hand, the corresponding allowed region in the
inverted hierarchy regime is less restrictive.