In the light case of the noncommuting extended technicolor model the heavy gauge bosons can have a mass less than or of the order of 1 TeV and hence they could be directly produced at foreseeable colliders. Even below their kinematic production threshold they are expected to produce significant deviations from the standard model (SM) predictions to various distributions of production cross sections and asymmetries that could be measured with high precision at the NLC. In this work we study the latter effects due to the heavy neutral $Z_H$ boson in the process $e^{+}{e}^{-}\to t\overline{t}.$ We find that even for $M_{Z_H}=1500\mathrm{}\mathrm{GeV}$ the deviations from the SM, particularly in ${\sigma }_L$ and $A_{\mathrm{LR}},$ are large enough to be measurable at NLC500.

• Received 19 December 1996

DOI:https://doi.org/10.1103/PhysRevD.56.402