CPviolatingZtt¯andγtt¯couplings at a futuree+e−collider

The effect of new operators that give rise to $\mathrm{CP}$-violating couplings of the type $\mathrm{Zt}\overline{t}$ and $\gamma t\overline{t}$ are examined at future electron positron linear colliders (FLC). The impact of these $\mathrm{CP}$ violating interactions over standard model predictions was studied for the process $e^{+}{e}^{-}\to t\overline{t}$ with the subsequent decays $\overrightarrow{t}{\mathrm{bl}}^{+}{\nu }_l$ and $\overline{t}\to \overline{b}{l}^{-}{\overline{\nu }}_l,$ called the dilepton mode, and $\overrightarrow{t}{\mathrm{bl}}^{+}{\nu }_l$ and $\overline{t}\to \overline{b}\overline{q}{q}^{\prime }$ or $\overrightarrow{t}\mathrm{bq}{q}^{\prime }$ and $\overline{t}\to \overline{b}{l}^{-}{\overline{\nu }}_l,$ called the single lepton mode, where the final leptons are $l^{\pm }{=e}^{\pm }$ or ${\mu }^{\pm },$ and the final quarks are ${q(q}^{\prime })=u(d)\mathrm{}$ or $c\left(s\right).$ A polarized electron beam and $\mathrm{CP}$ observables and asymmetries are used to impose bounds on the anomalous couplings.