Searching for signatures of $E_{\rm 6}$

TL;DR

This paper explores the $E_6$ grand unified theory, discussing its predictions of new particles and their implications for collider searches and neutrino physics, with updated analysis and bounds on particle masses.

Contribution

It updates and extends previous discussions on $E_6$ features, linking them to current collider searches and neutrino mass patterns, and discusses gauge unification near $10^{16}$ GeV.

Findings

Potential for extra $Z$ bosons and vector-like fermions

Bounds on masses of beyond Standard Model particles

Gauge unification near $10^{16}$ GeV with TeV-scale scalars

Abstract

The grand unified group $E_6$~is a predictive scheme for physics beyond the standard model (SM). It offers the possibility of extra $Z$ bosons, new vector-like fermions, sterile neutrinos, and neutral scalars in addition to the SM Higgs boson. Some previous discussions of these features are updated and extended. Their relevance to present searches at the CERN Large Hadron Collider and in patterns of neutrino masses is noted. Addition of a small set of scalar bosons at the TeV scale permits gauge unification near a scale of $10^{16}$ GeV, and leads to bounds on masses of particles beyond those in the standard model.