CPviolation in semileptonic top quark decays in the Weinberg model

We show that the charged Higgs sector in Weinberg’s model for CP violation can cause a large CP violation effect in t→bτ${\nu }_{\mathrm{\tau }}$. The asymmetry in the partial rate is dominated by contributions such as Z(and γ)-${\mathit{H}}^{+}$ box diagrams interfering with a (near-resonance) W tree diagram. But far more significant are the asymmetries in the partially integrated rates and in the energy between the ${\mathrm{\tau }}^{+}$ and the ${\mathrm{\tau }}^{\mathrm{-}}$. These stem from (near-resonance) W-tree–${\mathit{H}}^{+}$-tree interference.