The Vertex Corrections in Technicolor Model without Exact Custodial Symmetry

Abstract

We discuss the effects of isospin breaking which appear in the vertex corrections for $Zb \bar{b}$, $Zτ^+τ^-$ and $Wντ$ in a one-family technicolor model without exact custodial symmetry. By means of the effective lagrangian approach we compute the vertex corrections for $Zb\bar{b}$, $Zττ$ and $Wτν$ taking account of the contributions from technivectormesons. If the isospin symmetry in technilepton sector is not exact, technivectormesons contribute to the vertex correction for $Zττ$ but such contributions to the correction for $Wτν$ are absent. If the difference is measured, it is the evidence of the isospin breaking.