New leptons with exotic decays: collider limits and dark matter complementarity

TL;DR

This paper analyzes collider constraints on new vector-like leptons with exotic decays, including into dark photons, and explores their role in dark matter production, providing a comprehensive framework for future searches.

Contribution

It introduces a model-independent approach to collider limits on leptons with exotic decays and discusses their connection to dark matter via dark photons.

Findings

Collider limits are extended to arbitrary decay branching ratios.

Exotic decays into dark photons can account for dark matter relic abundance.

Complementarity between collider searches and dark matter experiments is demonstrated.

Abstract

We describe current and future hadron collider limits on new vector-like leptons with exotic decays. We consider the possibility that, besides standard decays, the new leptons can also decay into a Standard Model charged lepton and a stable particle like a dark photon. To increase their applicability, our results are given in terms of arbitrary branching ratios in the different decay channels. In the case that the dark photon is stable at cosmological scales we discuss the interplay between the dark photon and the vector-like lepton in generating the observed dark matter relic abundance and the complementarity of collider searches and dark matter phenomenology.