Characterising Dark Matter Interacting with Extra Charged Leptons

Abstract

In the context of a simplified leptophilic Dark Matter (DM) scenario where the mediator is a new charged fermion carrying leptonic quantum number and the DM candidate is either scalar or vector, the complementarity of different bounds is analysed. In this framework, the extra lepton and DM are odd under a $\mathbb Z_2$ symmetry, hence the leptonic mediator can only interact with the DM state and Standard Model (SM) leptons of various flavours. We show that there is the possibility to characterise the DM spin (scalar or vector), as well as the nature of the mediator, through a combined analysis of cosmological, flavour and collider data. We present an explicit numerical analysis for a set of benchmarks points of the viable parameter space of our scenario.