WALKING TECHNICOLOR AND ELECTROWEAK RADIATIVE-CORRECTIONS

We examine the effect of walking technicolor dynamics on the electroweak S-parameter and contrast it with the effect of QCD-like technicolor dynamics. Our main tools are the operator product expansion for the high-momentum behavior of the electroweak gauge boson vacuum polarizations and the analyticity of these polarizations which relate their low and high momentum behaviors. We show that whereas in large QCD-like technicolor models S is large and positive, in walking technicolor models a negative contribution is emphasized, related to the large anomalous dimension of the technifermion condensate. Thus in walking technicolor S is determined by a large cancellation of two competing effects. This may result in much smaller values of S than in QCD-like technicolor, although considerable uncertainties are involved. We conclude that it is impossible to rule out walking technicolor based on the present experimental limits on S and the present theoretical technology.