Conventional quarks and leptons of any one generation are assigned to the chiral-color representations of strong- and electroweak-interactions symmetry ${\mathrm{SU}\mathrm{}\left(3\right)\mathrm{}}_L\otimes {\mathrm{SU}\mathrm{}\left(3\right)\mathrm{}}_R\otimes {\mathrm{SU}\mathrm{}\left(2\right)\mathrm{}}_L\otimes {\mathrm{U}\mathrm{}\left(1\right)\mathrm{}}_Y$. The anomalies are canceled by addition of exotic quarks and leptons that are all singlets under the weak-interactions group ${\mathrm{SU}\mathrm{}\left(2\right)\mathrm{}}_L$. The model requires only two Higgs representations to break the gauge symmetry and to give masses to all the quarks and leptons. All quarks and leptons acquire masses through the seesaw mechanism of Gell-Mann, Ramond, and Slansky.

• Received 28 January 1988

DOI:https://doi.org/10.1103/PhysRevLett.60.2003