A gauge-theory model of weak and electromagnetic interactions is proposed. The symmetry group is SU(3)×U(1) and the fermions are all placed in triplets (or antitriplets) and singlets. The theory is vectorlike and hence anomaly-free. Discrete symmetries are imposed to avoid unwanted mixings and to appropriately restrict the Higgs potential. The details of fermion and boson mass generation are given. The couplings and masses of the two massive neutral flavor-preserving gauge bosons are determined by fitting the neutral-current data; agreement is excellent. We also analyze the predictions for multimuon production in neutrino scattering as a function of lepton and hadron masses. Finally we examine the limits on such processes as $K_L\to {\mu }^{+}{\mu }^{-}$, $\mu \to e\gamma$, etc.

• Received 8 August 1977

DOI:https://doi.org/10.1103/PhysRevD.17.1402