# Lepton-Trijet and Displaced Vertex Searches for Heavy Neutrinos at Future Electron-Proton Colliders

## TL;DR

This paper explores the potential of future electron-proton colliders to detect heavy neutrinos through lepton-flavour violating and displaced vertex signatures, showing superior sensitivity for neutrino masses around a few hundred GeV.

## Contribution

It introduces the analysis of lepton-trijet and displaced vertex signatures for heavy neutrino detection at ep colliders, highlighting their effectiveness over other methods.

## Key findings

- LFV lepton-trijet signature offers the best sensitivity for heavy neutrino masses around a few hundred GeV.
- ep colliders provide a clean environment ideal for heavy neutrino searches.
- Analysis at the reconstructed level demonstrates promising detection prospects.

## Abstract

Electron proton (ep) colliders could provide particle collisions at TeV energies with large data rates while maintaining the clean and pile~up-free environment of lepton colliders, which makes them very attractive for heavy neutrino searches. Heavy (mainly sterile) neutrinos with masses around the electroweak scale are proposed in low scale seesaw models for neutrino mass generation. In this paper, we analyse two of the most promising signatures of heavy neutrinos at ep colliders, the lepton-flavour violating (LFV) lepton-trijet signature and the displaced vertex signature. In the considered benchmark model, we find that for heavy neutrino masses around a few hundred GeV, the LFV lepton-trijet signature at ep colliders yields the best sensitivity of all currently discussed heavy neutrino signatures (analysed at the reconstructed level) up to now.