See-saw masses for quarks and leptons

An ambidextrous electroweak interaction model with SU(2${)}_{\mathrm{L}}$×SU(2${)}_{\mathrm{R}}$×U(1) gauge symmetry is described in which the conventional quarks and leptons are accompanied by a set of new fermions that transform as singlets of SU(2${)}_{\mathrm{L}}$ and SU(2${)}_{\mathrm{R}}$. Only two doublets of Higgs scalars are introduced to break the gauge symmetry SU(2${)}_{\mathrm{L}}$×SU(2${)}_{\mathrm{R}}$×U(1) to U(1) of electromagnetism. The masses of all known quarks and leptons result from the Gell-Mann, Ramond, and Slansky ‘‘see-saw mechanism’’ between the conventional fermions and the new ‘‘singlet’’ fermions. The definition of the Fermi coupling constant and neutrino neutral-current interactions are identical to those of the standard SU(2${)}_{\mathrm{L}}$×U(1) model. The singlet fermion masses lie in the 100-GeV to 1-TeV range to be probed by the oncoming accelerators of the 1990s.