Dirac neutrino mass models with a modular $S^{}_4$ symmetry

TL;DR

This paper explores Dirac neutrino mass models using a modular $S_4$ symmetry, demonstrating how to generate realistic lepton masses and mixing patterns consistent with current neutrino oscillation data.

Contribution

It introduces a novel approach to model Dirac neutrinos with modular symmetry, including the suppression of Majorana terms and detailed analysis of model classes.

Findings

Ten out of twelve models fit current neutrino data

Models accommodate various charged-lepton sector weights

Renormalization effects are thoroughly analyzed

Abstract

In this paper, we investigate lepton mass spectra, flavor mixing and CP violation with a modular $S^{}_4$ symmetry under the assumption that neutrinos are Dirac fermions. We find that the Majorana mass term can be forbidden by adjusting the weight of the right-handed neutrino superfields. We study the scenarios where modular forms in the neutrino sector take the lowest non-trivial weight two, while those in the charged-lepton sector vary from two to six. The corrections from renormalization-group running effects to our model have also been discussed in detail. We totally obtain twelve different classes of models and find that ten of them can accommodate current neutrino oscillation data.