Implications of mt and Rb on Ztt couplings in standard ETC models

In standard ETC models the sideways and diagonal ETC interactions contribute to δRb with opposite signs. The aim of this article is to study the implications of the CDF value for mt and the LEP value for Rb on ztt couplings where the LH sideways and diagonal ETC effects interfere constructively. We find that for mt = 175 GeV, δRb = 0.0022 and ms2 = md2, Fvt and Fat are modified by 19% and 7% respectively from their SM values. The constrains implied by these deviations on diagonal ETC scenarios and the feasibility of probing them at NLC through polarization and angular distribution studies in e+e− → tt are also considered.