Probing heavy charged fermions at $e^+e^-$ collider using the Optimal Observable Technique

TL;DR

This paper investigates how to precisely measure the couplings of heavy charged leptons at an $e^+e^-$ collider using the optimal observable technique, including a UV-complete model with dark matter and supersymmetric analogs.

Contribution

It introduces the application of the optimal observable technique to measure heavy lepton couplings at future colliders, and explores a UV-complete model with dark matter and supersymmetric parallels.

Findings

Determined the statistical accuracy for coupling measurements.

Analyzed effects of heavy leptons in a UV-complete model.

Compared results to chargino production in supersymmetry.

Abstract

In this work we study the production of color-neutral and singly-charged heavy leptons at the proposed International Linear Collider. We use the optimal observable technique to determine the statistical accuracy to which the coupling of such fermions to the $Z$ gauge boson (vector, axial or chiral) can be measured. We also consider a UV-complete model that contains these particles as well as a dark matter candidate, and consider some observable effects involving both; the correspondence to chargino production in supersymmetric models with heavy sleptons is briefly discussed.