# Deviation from Tetra-Maximal Neutrino Mixing Above the GUT scale

Research paper by Bipin Singh Koranga, P. Gaira

Indexed on: 03 Aug '10Published on: 03 Aug '10Published in: International Journal of Theoretical Physics

#### Abstract

We consider non-renormalizable interaction term as perturbation of the conventional neutrino mass matrix. We assume that the neutrino masses and mixing arise through physics at a scale intermediate between Planck scale and the electroweak breaking scale. We also assume that, just above the electroweak breaking scale, neutrino masses are nearly degenerate and their mixing is tetra-maximal. Quantum gravity (Planck scale effects) lead to an effective SU(2)L×U(1) invariant dimension-5 Lagrangian involving neutrino and Higgs fields. On electroweak symmetry breaking, this operator gives rise to correction to the above masses and mixing. These additional term can be consider as a perturbation to the Tetra-maximal mass matrix. The nature of gravitational interaction demands that the element of this perturbation matrix should be independent of flavor indices. We compute the deviation of three neutrino mixing angles due to Planck scale effects. We find that there is no change in θ13 and θ23 but change in solar mixing angle θ12 is suppress by 3.0°.