Abstract
The ‘‘universal seesaw mechanism,’’ which accounts for ,u,d≪, predicts . Combined with an axial-vector symmetry principle, this mechanism allows for the coeexistence of heavy (≲) families without appeal to a hierarchy in Yukawa couplings and without introduction of additional mass scales. It then follows that (i) the physical right-handed heavy (light) ordinary fermions are mostly SU(2 singlets (doublets), (ii) there is no analogous neutrino mass hierarchy, and (iii) sets the Peccei-Quinn mass scale.
- Received 25 January 1988
DOI:https://doi.org/10.1103/PhysRevLett.60.1813
©1988 American Physical Society