Investigating vector-like leptons decaying into an electron and missing transverse energy in e$^{+}$ e$^{-}$ collisions with $\sqrt{s} = 500$ GeV at the ILC

Abstract: This analysis focuses on probing the lepton portal dark matter using Monte Carlo simulated samples from electron-positron collisions at the International Linear Collider (ILC) of 500 GeV center of mass energy with an integrated luminosity of 1000 fb$<sup>{-1}$. The study examines a benchmark scenario where the dark matter is a scalar particle produced as a daughter particle of the vector-like lepton. The signal topology consists of missing transverse energy and dilepton. If no new physics is discovered,the study sets 95\% confidence level exclusion limits on the mass of vector-like leptons.