Remarks on flavor-changing neutral currents in walking technicolor.

Abstract

We point out that since the running coupling $\overline{\ensuremath{\alpha}}({q}^{2})$ in walking technicolor (WTC) can be rather strong at the extended technicolor (ETC) scale ${q}^{2}\ensuremath{\sim}{\ensuremath{\Lambda}}_{\mathrm{ETC}}^{2}$, the standard consideration of flavor-changing neutral currents (FCNCs) in WTC based on the lowest order in perturbation theory in $\ensuremath{\alpha}$ is not fully conclusive. We reanalyze this problem and conclude that FCNCs can indeed be suppressed in WTC if ETC interactions are chosen in an appropriate way. The crucial point is that the factor of enhancement of the masses of pseudo Goldstone bosons in WTC is just that which is sufficient to suppress FCNCs. FCNCs in the so-called strong ETC are also briefly discussed.