Leptophilic Dark Matter in Lepton Interactions at LEP and ILC

TL;DR

This paper uses precise LEP data to set competitive limits on leptophilic dark matter through four-lepton contact interactions and projects that future ILC data could provide even stronger constraints at TeV scales.

Contribution

It provides a model-independent analysis of leptophilic dark matter constraints using LEP data and forecasts the potential of ILC to improve these limits.

Findings

LEP data constrains leptophilic dark matter effectively.

ILC could surpass current limits at TeV energies.

Limits depend on mediator coupling strength.

Abstract

Dark matter particles that couple primarily to leptons are only weakly constrained by data from direct detection experiments and the LHC. However, models of this kind necessarily generate effective four-lepton contact interactions at the tree- or one-loop-level, which can be probed in $e^+e^-$ collisions. In this work, precise data from LEP is used to derive limits on leptophilic dark matter in a model-independent framework. The bounds turn out to be competitive with, and in some cases exceed, limits from mono-photon events. We also extrapolate our results to ILC energies and luminosities. We show that ILC data for contact interactions may be able to set the strongest limits on TeV-scale leptophilic dark matter for couplings $g\gtrsim 1$ of the mediators.