Weak gauge bosons above or straddling the standard-model masses in an SU(2)×U(1)×SU(2)′ gauge model

We present a natural SU(2)×{}U(1)×{}SU(2){'} gauge model with low-energy predictions identical to those of the standard model, but which allows all gauge-boson masses to be above or straddling their standard values. We discuss the Higgs structure and its relationship to the naturalness of the model. Current measurements of the e⁺e^-→μ⁺μ^- cross section set upper limits on the lightest W and Z masses of 89 and 116 GeV, respectively; from data on e⁺e^-→hadrons, the corresponding limits M_W₁<87 and M_Z₁<108 GeV are deduced. Some high-energy predictions for the model are explored. The model is extended to U(1)×SU(2)N with all possible SU(2)×{}U(1) Higgs doublets and SU(2)×{}SU(2) Higgs quartets.