A Comparative Study of Z$^{\prime}$ mediated Charged Lepton Flavor Violation at future lepton colliders

TL;DR

This paper evaluates the potential of future lepton colliders to detect Z' mediated charged lepton flavor violation, showing significant improvements over current experimental limits through detailed simulations.

Contribution

It provides a comparative analysis of CLFV search sensitivities at various future colliders using Monte Carlo simulations and assesses their potential to surpass existing bounds.

Findings

Future colliders can significantly improve sensitivity to Z' mediated CLFV.

Tau-related CLFV couplings will be constrained more tightly.

Comparative analysis with current limits highlights the potential for discovery.

Abstract

Charged lepton flavor violation (CLFV) represents a transition between charged leptons of different generations that violates lepton flavor conservation, which is a clear signature of possible new physics beyond the standard model. By exploiting a typical example model of extra Z$^{\prime}$ gauge boson, we perform a detailed comparative study on CLFV searches at several future lepton colliders, including a 240 GeV electron-positron collider and a TeV scale muon collider. Based on detailed signal and background Monte-Carlo studies with fast detector simulations, we derive the potentials in searching for Z$^{\prime}$ mediated CLFV couplings with $e\mu$, $e\tau$ and $\mu\tau$ of different future colliders. The results are compared with the current limits set by either low-energy experiments or the high-energy LHC experiments. We find that the sensitivity of the $\tau$ related CLFV coupling strength at future lepton colliders will be significantly improved comparing with the current best constraints.