O(18) revived: Splitting the spinor

Abstract

We propose an O(18) theory which is perturbatively unifiable and which accounts for the absence of right-handed families in the low-energy world. The theory predicts a fourth left-handed family as well as four right-handed families at energies near the weak scale. It also implies the existence of eight light neutrinos, all of which contribute to the width of the Z 0. Cosmological arguments suggest that four of these neutrinos should have masses between 2 and 35 GeV, and that the other four should be much lighter. They also suggest the existence of a doubly charged scalar φ ++ and a singly charged scalar φ +. Dramatic signatures include the production of four right-handed charged leptons and eight right-handed quarks, Z 0 → v′ R + v′ R → v R γ +_ v R γ , and e +e − → φ ++ + φ −−. The lightest right-handed charged quark should be surprinsingly long-lived (τ⪸10 −2 sec) for a particle of mass ≅ 100 GeV.