Energy spectrum of secondary leptons in e+e− → tt̄: Non-standard interactions and CP violation Original Research Article

The process of top-quark pair production at future high-energy e+e− linear colliders has been investigated as a possible test of physics beyond the Standard Model. Non-standard interactions have been assumed both for the production and for the subsequent decay of the top quarks. The energy spectrum of the single lepton ℓ± and the energy correlation of ℓ+ and ℓ− emerging from the process e+e− → tt → ℓ±X/ℓ+ℓ−X are calculated. The energy-spectrum asymmetry of ℓ+ and ℓ− is considered as a measure of CP violation. An optimal method to determine whether CP violation occurs in the production or in the decay processes is proposed.