Written October 1997 by K.S. Babu, C. Kolda, and J. MarchRussell (IAS/Princeton). Any electrically charged gauge boson outside of the Standard Model is generically denoted

(IAS/Princeton). Any electrically charged gauge boson outside of the Standard Model is generically denoted W 0. A W 0 always couples to two diierent avors of fermions, similar to the W boson. In particular, if a W 0 couples quarks to leptons it is a leptoquark gauge boson. The most attractive candidate for W 0 is the W R gauge boson associated with the left-right symmetric models 1]. These models seek to provide a spontaneous origin for parity violation in weak interactions. Here the gauge group is extended to SU(3) C SU(2) L SU(2) R U(1) B{L with the Standard Model hypercharge identiied as Y = T 3R + (B{L)=2, T 3R being the third component of SU(2) R. The fermions transform under the gauge group in a left-right symmetric fashion: q L for leptons. Note that the model requires the introduction of right-handed neutrinos, which can facilitate the seesaw mechanism for explaining the smallness of the ordinary neutrino masses. A Higgs bidoublet (1; 2; 2; 0) is usually employed to generate quark and lepton masses and to participate in the electroweak symmetry breaking. Under left-right (or parity) After spontaneous symmetry breaking, the two W bosons of the model, W L and W R , will mix. The physical mass eigenstates are denoted as