Lμ−Lτ effects to quarks and leptons from flavor unification

Paul H Frampton,Sin Kyu Kang,Soonkeon Nam,Jihn E Kim

doi:10.1103/physrevd.102.013005

Abstract

In the family grand unification models (fGUTs), we propose that gauge U(1)'s beyond the minimal GUT gauge group are family gauge symmetries. For the symmetry $L_\mu-L_\tau$, i.e. $Q_{2}-Q_{3}$ in our case, to be useful for the LHC anomaly, we discuss an SU(9) fGUT and also present an example in Georgi's SU(11) fGUT.

Highlights

In the family grand unification theory (GUT) models, we propose that gauge U(1)’s beyond the minimal GUT gauge group are family gauge symmetries
The most interesting problem remaining in the Standard Model (SM) is the flavor or family problem
The family problem forces the symmetry of all of the massless chiral fields surviving below the grand unification theory (GUT) scale MGUT or the Planck scale MP

Summary

INTRODUCTION

The most interesting problem remaining in the Standard Model (SM) is the flavor or family problem. The mixings of six flavors of quark allow a CP violating phase which is successful in agreeing precisely with data on CP violation in K and B decays, yet the correct derivation of baryogenesis which itself needs CP violation and the tiny ratio η 1⁄4 ðΔnB=nγÞ ≃ 9 × 10−11 remains challenging, especially as to whether the CP violation known in quark flavor mixing can suffice to explain the matter-antimatter asymmetry of the Universe. These are merely two examples of cosmological applications of flavor theory. Within family GUT models, Lμ − Lτ symmetry can affect the prediction of RH phenomenology since the quantum number Lμ − Lτ applies to the quark members in the same family

GRAND UNIFICATION OF FAMILIES

Changing chirality

Δ10 þ ð3y