WEAK DELTA-I = 1/2 RULE AND THE DYNAMICAL HIGGS MECHANISM

We show that the weak ΔI=12 rule, mW2mZ2=cos2θ, in an SUL(2)â-U(1) gauge model can be obtained from a dynamical Higgs mechanism. This is independent of weak isospin breaking in the fermion mass spectrum. A consequence of this mechanism is a sum rule which implies the existence of heavy quarks or leptons with ultraviolet masses comparable to the W and Z weak boson masses, ∼30-100 GeV. © 1979 The American Physical Society.