Leptophilic Dark Matter with $Z'$ interactions

TL;DR

This paper explores a leptophilic dark matter model mediated by a $Z'$ boson, analyzing constraints from relic density, direct detection, and collider experiments, revealing significant limitations despite no direct quark interactions.

Contribution

It introduces a simple leptophilic $Z'$-mediated dark matter model and provides a comprehensive analysis of experimental constraints and future discovery prospects.

Findings

Leptophilic DM can be constrained by current experiments.

Relic density and collider data restrict the parameter space.

Future LHC searches have potential to discover or further limit the model.

Abstract

We consider a scenario where dark matter (DM) interacts exclusively with Standard Model (SM) leptons at tree level. Due to the absence of tree-level couplings to quarks, the constraints on leptophilic dark matter arising from direct detection and hadron collider experiments are weaker than those for a generic WIMP. We study a simple model in which interactions of DM with SM leptons are mediated by a leptophilic $Z'$ boson, and determine constraints on this scenario arising from relic density, direct detection, and other experiments. We then determine current LHC limits and project the future discovery reach. We show that, despite the absence of direct interactions with quarks, this scenario can be strongly constrained.