Eur. Phys. J. C (2025) 85: 1429
https://doi.org/10.1140/epjc/s10052-025-15178-7

Regular Article - Theoretical Physics

Probing vector-like leptons at 3 TeV CLIC using fat jet signatures

¹ School of Physics and Electronic Engineering, Xinxiang University, 453003, Xinxiang, China
² School of Electro-Mechanical Engineering, Zhongyuan Institute of Science and Technology, 461000, Xuchang, China
³ Henan Institute of Science and Technology, 453003, Xinxiang, China
⁴ Department of Physics, Henan Normal University, 453007, Xinxiang, China

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Received: 23 June 2025
Accepted: 1 December 2025
Published online: 16 December 2025

Abstract

We present a comprehensive study of isosinglet vector-like lepton $({\tau }^{\prime \pm })$ pair production at the 3 TeV Compact Linear Collider (CLIC) within a simplified effective field theory framework. Our analysis incorporates full simulations of initial state radiation, beamstrahlung, and beam polarization effects. Focusing on the dominant decay channels ${\tau }^{\prime \pm }\to W^{\pm }{\nu }_{\tau },$$Z{\tau }^{\pm },$ and $h{\tau }^{\pm }$ with subsequent hadronic decays, we demonstrate that the TeV-scale masses of vector-like leptons generate strongly boosted W,  Z,  and Higgs bosons, yielding distinctive experimental signatures as collimated fat jets. Through detailed detector-level simulations, we establish the $2\sigma$ exclusion limits and $5\sigma$ discovery potential for VLLs, mapping their dependence on both the VLL mass and integrated luminosity. The analysis further evaluates the sensitivity to the branching ratio $\text{BR}({\tau }^{\prime }\to W{\nu }_{\tau })$ as a function of ${\tau }^{\prime }$ mass for four benchmark integrated luminosities: 100, 300, 500, and 1000 ${\text{fb}}^{-1}.$