Nonoblique Corrections in Technicolor Theories Revisited
  In extended technicolor (ETC) theories, while the sideways ETC boson exchange decreases the width $\Gamma_b \equiv \Gamma (Z\rightarrow b \bar{b})$, the flavor-diagonal ETC boson exchange tends to increase it, and the ETC-corrected $R_b \equiv \Gamma_b / \Gamma_{\mbox{\footnotesize had}}$ value could agree with recent measurements. The $\tau$ asymmetry parameter may also increase in a way consistent with experiment. The weak-interaction $\rho$ parameter receives a correction from diagonal ETC exchange which is just barely acceptable by experiments. 
Guo-Hong Wu