Lepton Number Violation: Seesaw Models and Their Collider Tests

TL;DR

This paper reviews Seesaw models for neutrino mass generation, emphasizing their lepton number violating signatures and collider testability, providing updated predictions and analysis strategies for current and future high-energy experiments.

Contribution

It offers a comprehensive review of Seesaw scenarios, including new predictions, analysis channels, and collider strategies for detecting lepton number violation.

Findings

Identification of new production and decay channels for Seesaw particles

Updated coverage of parameter space at colliders

Availability of Monte Carlo tools for collider studies

Abstract

The Majorana nature of neutrinos is strongly motivated from the theoretical and phenomenological point of view. A plethora of neutrino mass models, known collectively as Seesaw models, exist that could generate both a viable neutrino mass spectrum and mixing pattern. They can also lead to rich, new phenomenology, including lepton number non-conservation as well as new particles, that may be observable at collider experiments. It is therefore vital to search for such new phenomena and the mass scale associated with neutrino mass generation at high energy colliders. In this review, we consider a number of representative Seesaw scenarios as phenomenological benchmarks, including the characteristic Type I, II, and III Seesaw mechanisms, their extensions and hybridizations, as well as radiative constructions. We present new and updated predictions for analyses featuring lepton number violation and expected coverage in the theory parameter space at current and future colliders. We emphasize new production and decay channels, their phenomenological relevance and treatment across different facilities in $e^+e^-$, $e^-p$ and $pp$ collisions, as well as the available Monte Carlo tools available for studying Seesaw partners in collider environments.