Extracting anomalous gluon–top-quark effective couplings at the supercolliders

Production of tt¯ by gluon fusion fullowed by t→${\mathit{bW}}^{+}$, t¯→${\mathit{bW}}^{\mathrm{-}}$, and ${\mathit{W}}^{\pm }$→${\mathit{e}}^{\pm }$ ${\nu }_{\mathit{e}}$(ν${\mathrm{¯}}_{\mathit{e}}$) is studied to extract the CP-violating chromoelectric dipole moment form factor of the top quark. The fact that the spin of the top quark, in its rest frame, is in the direction of the ${\mathit{e}}^{+}$ momentum facilitates the analysis. Expressions for the differential cross section and decays are given. We find that the Superconducting Super Collider or Large Hadron Collider, it is possible to put a limit of ${10}^{\mathrm{-}20}$ ${\mathit{g}}_{\mathit{s}}$-to ${10}^{\mathrm{-}19}$ ${\mathit{g}}_{\mathit{s}}$ cm on these effective couplings through the use of ‘‘optimal observables.’’ Naive observables such as simple triple product correlations are typically an order of magnitude less effective.