$S_4$ symmetric four-generation models for charged leptons

TL;DR

This paper develops $S_4$ symmetric four-generation models for charged leptons, ensuring consistency with observed masses and predicting a fourth-generation lepton mass of 556 GeV.

Contribution

It constructs new four-generation charged lepton models with exact $S_4$ symmetry, differing from previous models by including additional symmetries.

Findings

Model is consistent with observed charged lepton masses.

Predicts the fourth-generation charged lepton mass as 556 GeV.

Demonstrates the viability of $S_4$ symmetry in multi-generation models.

Abstract

We propose $S_4$ symmetric four-generation models for charged leptons. Although an $S_4$ symmetric four-generation model has been already proposed, there are some additional symmetries in the model. We construct four-generation models for charged leptons with only requirement of exact $S_4$ symmetry. It turned out that at least one of the models is consistent with observations of charged lepton masses and predicts the mass of the charged lepton of the fourth generation to be 556 GeV.