Three sterile neutrinos in E6

TL;DR

This paper explores how the E6 grand unified group naturally includes three sterile neutrinos within its fundamental representation, discussing their mixing patterns and potential experimental implications.

Contribution

It demonstrates that E6 models inherently contain three sterile neutrino candidates and analyzes their mixing and experimental consequences.

Findings

E6's 27-plet includes three sterile neutrino candidates

Mixing patterns of sterile neutrinos are characterized

Potential experimental signatures are discussed

Abstract

Candidates for unfication of the electroweak and strong interactions include the grand unified groups SU(5), SO(10), and the exceptional group E6. The 27-dimensional fundamental representation of E6 contains exotic fermions, including weak isosinglet quarks of charge -1/3, vector-like weak isodoublet leptons, and neutral leptons which are singlets under both left-handed and right-handed SU(2). These last are candidates for light "sterile" neutrinos, hinted at by some recent short-baseline neutrino experiments. In order to accommodate three families of quarks and charged leptons, an E6 model must contain three 27-plets, each of which contains a sterile neutrino candidate n. The mixing pattern within a 27-plet is described, and experimental consequences are discussed.