Unique heavy lepton signature at $e^+e^-$ linear collider with polarized beams

TL;DR

This paper investigates how polarized beams at the ILC can uniquely identify heavy lepton effects in e+e- collisions, distinguishing them from other new physics scenarios through polarization asymmetries and W boson polarization analysis.

Contribution

It introduces a method using beam and W boson polarization asymmetries to distinguish heavy lepton effects from other new physics at the ILC.

Findings

Polarized beams significantly enhance detection sensitivity.

Double polarization asymmetry helps uniquely identify heavy leptons.

W boson polarization analysis improves model discrimination.

Abstract

We explore the effects of neutrino and electron mixing with exotic heavy leptons in the process e^+e^-\to W^+W^- within E_6 models. We examine the possibility of uniquely distinguishing and identifying such effects of heavy neutral lepton exchange from Z-Z' mixing within the same class of models and also from analogous ones due to competitor models with anomalous trilinear gauge couplings (AGC) that can lead to very similar experimental signatures at the e^+e^- International Linear Collider (ILC) for \sqrt{s}=350, 500 GeV and 1 TeV. Such clear identification of the model is possible by using a certain double polarization asymmetry. The availability of both beams being polarized plays a crucial role in identifying such exotic-lepton admixture. In addition, the sensitivity of the ILC for probing exotic-lepton admixture is substantially enhanced when the polarization of the produced W^\pm bosons is considered.