On the role of the Higgs mechanism in present electroweak precision tests

Based on the observables MW, Γl, anti s2W(M2Z), we evaluate the parameters Δx, Δy and ε at one-loop level within an electroweak massive vector-boson theory, which does not employ the Higgs mechanism. The theoretical results are consistent with the experimental ones on Δx, Δy, ε. The theoretical prediction for Δy coincides with the standard-model one (apart from numerically irrelevant terms which vanish for MH → ∞). Non-renormalizability only affects Δx and ε, which differ from the standard-model results by the replacement log MH → log Λ for a heavy Higgs mass, MH (where Λ denotes an effective UV cut-off). (orig.)