EFFECTS OF NONSTANDARD INTERACTIONS FOR THE ENERGY SPECTRUM OF SECONDARY LEPTONS IN $e^+ e^-\to t\bar t$

Abstract

The process of top-quark pair production followed by semileptonic decays at future high-energy e+ e- linear colliders is investigated as a possible test of physics beyond the Standard Model. Assuming the most general nonstandard forms for [Formula: see text], [Formula: see text] and Wtb couplings, the energy spectrum of the single lepton ℓ± and the energy correlation of ℓ+ and ℓ- emerging from the process [Formula: see text] are calculated. Expected precision of the nonstandard-parameter determination is estimated adopting the recently-proposed optimal method.