Large Changes of Atmospheric Mixing Angle $\theta_{23}$ with Four Flavor Mixing from Planck Scale Effects

TL;DR

This paper investigates how Planck scale effects can significantly alter the atmospheric neutrino mixing angle $ heta_{23}$ in a four-flavor neutrino model, especially for degenerate neutrino masses, with implications for physics beyond the GUT scale.

Contribution

It introduces a detailed analysis of Planck scale effects on four-flavor neutrino mixing, highlighting large changes in $ heta_{23}$ for degenerate neutrino masses, which is a novel insight.

Findings

Planck scale effects significantly modify $ heta_{23}$ in four-flavor neutrino mixing.

Degenerate neutrino masses are more susceptible to Planck scale induced changes.

Certain mixing angles remain unchanged above the GUT scale.

Abstract

We consider the effects of Planck scale on four flavour neutrino mixings. The gravational interaction at $M_{x}=M_{\rm planck}$, we find that for degenerate neurino mass order, the Planck scale effects changes the mixing angle $\theta'_{23}$, $\theta'_{12}$ values and $\theta'_{13}$, $\theta'_{14}$, $\theta'_{34}$, $\theta'_{24}$ are unchanged above the GUT scale. In this paper, we study neutrino mixing in four flavor above the GUT scale.