Search for Heavy Right-Handed Neutrinos at the LHC and Beyond in the Same-Sign Same-Flavor Leptons Final State

TL;DR

This paper investigates the LHC's potential to discover heavy Majorana neutrinos through same-sign leptons, comparing production modes and proposing optimized search strategies for current and future colliders.

Contribution

It provides a comprehensive analysis of heavy neutrino detection prospects at the LHC and a 100 TeV collider, including new search strategies for different production mechanisms.

Findings

Resonant production dominates at lower energies.

Gauge boson fusion becomes significant at higher energies.

Proposed strategies improve discovery potential.

Abstract

In this study we explore the LHC's Run II potential to the discovery of heavy Majorana neutrinos, with luminosities between $30$ and $3000$ fb$^{-1}$ in the $l^{\pm}l^{\pm}j~j$ final state. Given that there exist many models for neutrino mass generation, even within the Type I seesaw framework, we use a simplified model approach and study two simple extensions to the Standard Model, one with a single heavy Majorana neutrino, singlet under the Standard Model gauge group, and a limiting case of the left-right symmetric model. We then extend the analysis to a future hadron collider running at $100$ TeV center of mass energies. This extrapolation in energy allows us to study the relative importance of the resonant production versus gauge boson fusion processes in the study of Majorana neutrinos at hadron colliders. We analyze and propose different search strategies designed to maximize the discovery potential in either the resonant production or the gauge boson fusion modes.