Exotic fermions inE6and the anomalous magnetic moments of leptons

Abstract

The mixing between the exotic fermions and the usual fermions (in ${\mathrm{E}}_6$ theories) can lead to flavor-changing neutral currents. Such couplings can produce new and potentially large contributions to the anomalous magnetic moments of the electron and muon. We analyze these possibilities and comment on other processes (such as μ→eγ) which can be used to constrain ${\mathrm{E}}_6$ theories.