Nonoblique Corrections in Technicolor Theories Revisited

Abstract

In extended technicolor (ETC) theories, while the sideways ETC boson exchange decreases the width ${\Gamma }_b\equiv \Gamma (Z\to b\bar{b})$, the flavor-diagonal ETC boson exchange tends to increase it, and the ETC-corrected $R_b\equiv {\Gamma }_b/{\Gamma }_{\text{mbox}had}$ 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.

Comments: importance of the rho parameter constraint included, version appeared in PRL 74 4137 (1995)