Generalized Friedberg-Lee model for CP violation in neutrino physics

TL;DR

This paper introduces a generalized Friedberg-Lee model for Dirac neutrinos that incorporates CP violation, resulting in specific constraints on neutrino mixing angles and CP phase consistent with experimental data.

Contribution

It develops a non-hermitian, symmetric, magic neutrino mass matrix model with real eigenvalues, extending the Friedberg-Lee framework to include CP violation effects.

Findings

Inverted neutrino mass hierarchy with m3=0.

Predicted mixing angles: θ12≈35-36°, θ13≈7-11°, θ23=45°.

CP violation parameter J≈0.027-0.044.

Abstract

We propose a phenomenological model of Dirac neutrino mass operator based on the Fridberg-Lee (FL) neutrino mass model to include CP violation. By considering the most general set of complex coefficients, and imposing the condition that the mass eigenvalues are real, we find a neutrino mass matrix which is non-hermitian, symmetric and magic. In particular, we find that the requirement of obtaining real mass eigenvalues by transferring the residual phases to the mass eigenstates self-consistently, dictates the following relationship between the imaginary part of the mass matrix elements $B$ and the parameters of the FL model: $B=\pm\sqrt{3/4(a-b_{r})^{2}\sin^{2}2\theta_{13}\cos^{2}\theta_{12}}$. We obtain inverted neutrino mass hierarchy, $m_{3}=0$. Making a correspondence between our model and the experimental data produces stringent conditions on the parameters as follows: $35.06^{\circ}\lesssim\theta_{12}\lesssim36.27^{\circ}$, $\theta_{23}= 45^{\circ}$, $7.27^{\circ}\lesssim\theta_{13}\lesssim11.09^{\circ}$, and $82.03^{\circ}\lesssim\delta\lesssim85.37^{\circ}$. We get mildly broken $\mu-\tau$ symmetry, which reduces the resultant neutrino mixing pattern from tribimaximal (TBM) to trimaximal (TM). The CP violation as measured by the Jarlskog parameter is restricted by $0.027\lesssim J\lesssim0.044$.