English

Equal Majorana Phases from a Minimal and Predictive Neutrino Texture

High Energy Physics - Phenomenology 2026-04-30 v4

Abstract

We propose a new, minimal Majorana neutrino mass matrix texture and study its predictions within a partial tri-bimaximal (TBM) mixing scheme, where sinθ12=1/3\sin\theta_{12} = 1/\sqrt{3} and sinθ23=1/2\sin\theta_{23} = 1/\sqrt{2}, with θ13\theta_{13} and δ\delta treated as free parameters. The texture forbids θ13=0\theta_{13} = 0 and does not correspond to a μτ\mu-\tau symmetric structure. As a notable feature, the texture predicts the equality of the Majorana phases. In addition, we find that the predictions show distinct behavior depending on the sign of a single real texture parameter. The texture is realized through a hybrid framework of one Type-I seesaw and two Type-II seesaw mechanisms under an extended symmetry group, SU(2)LU(1)YA4Z10Z7SU(2)_L \otimes U(1)_Y \otimes A_4 \otimes Z_{10} \otimes Z_{7} with properly chosen model parameters. The texture is seen to favor the normal hierarchy for neutrino masses.

Keywords

Cite

@article{arxiv.2303.02358,
  title  = {Equal Majorana Phases from a Minimal and Predictive Neutrino Texture},
  author = {Sagar Tirtha Goswami and Pralay Chakraborty and Subhankar Roy},
  journal= {arXiv preprint arXiv:2303.02358},
  year   = {2026}
}