Phenomenology of quark-lepton-symmetric models

Quark-lepton-symmetric models are a new class of gauge theories which unify the quarks and leptons. In these models the gauge group of the standard model is extended to include a "color" group for the leptons, and consequently the quarks and leptons can then be related by a $Z_2$ discrete quark-lepton symmetry. The phenomenological implications of these theories are explored. Two varieties are analyzed, one being the simplest quark-lepton-symmetric model, and the other also containing conventional left-right symmetry. Each theory has a $Z^{\prime }$ boson, whose masses are constrained at 90% C.L. to be greater than 700 and 650 GeV, respectively. Phenomenological constraints from rare decays are also examined. An examination of the phenomenological implications of the extended fermion spectrum is given.