Searching for vector-like leptons decaying into an electron and missing transverse energy in e$^{+}$e$^{-}$ collisions with $\sqrt{s} = 240$ GeV at the FCC-ee

TL;DR

This paper investigates the potential to detect vector-like leptons decaying into electrons and missing energy at the FCC-ee, setting exclusion limits if no new physics is observed.

Contribution

It introduces a novel analysis method for vector-like leptons in electron-positron collisions at 240 GeV using Monte Carlo simulations.

Findings

Establishes 95% CL exclusion limits on vector-like lepton mass.

Analyzes the sensitivity of FCC-ee to lepton portal dark matter signals.

Provides a benchmark scenario for future searches.

Abstract

This analysis delves into the lepton portal dark matter by utilizing Monte Carlo simulated samples from electron-positron collisions at the Future Circular Collider (FCC-ee), operating at a center of mass energy of 240 GeV and an integrated luminosity of 10.8 ab$^{-1}$. The study explores a specific benchmark scenario in which dark matter is represented as a scalar particle produced as a byproduct of a vector-like lepton. The key signal signature features missing transverse energy alongside dilepton events. Should new physics not be detected, this study establishes 95\% confidence level exclusion limits on the mass of the vector-like leptons and the Yukawa coupling.