The leptophilic dark matter with $Z'$ interaction: from indirect searches to future $e^+ e^-$ collider searches

Understand

We investigate the scenario where the dark matter only interacts with the charged leptons in the standard model via a neutral vector mediator $Z'$.

• Such a scenario with a 430 GeV dark matter can fit the recent positron fluxes observed by the AMS-02 Collaborations, with the reasonable boost factors.
• We study the possibility of searching such leptophilic $Z'$ via its lepton final states and invisible decay modes at the future electron-positron colliders, such as the International Linear Collider (ILC) and the Compact Linear Collider (CLIC).
• We find that for the benchmark models with $Z'$ mass from 1.0 TeV to 1.5 TeV, the searches for the invisible decays of $Z'\to \bar \chi \chi$ is easily achieved at the CLIC 1.5 TeV runs via the mono-photon process.