Low energy processes to distinguish among seesaw models

TL;DR

This paper compares three seesaw models using effective field theory, focusing on low-energy processes that can distinguish them, especially when lepton number violation occurs at low energy scales.

Contribution

It introduces a method to differentiate seesaw models via dimension-six operators and explores scenarios with large dimension-six effects and small neutrino masses without fine-tuning.

Findings

Distinct dimension-six operator signatures for each seesaw model

Possibility of large low-energy effects with small neutrino masses

Unique phenomenological features of fermionic triplet seesaw

Abstract

We consider the three basic seesaw scenarios (with fermionic singlets, scalar triplets or fermionic triplets) and discuss their phenomenology, aside from neutrino masses. We use the effective field theory approach and compare the dimension-six operators characteristic of these models. We discuss the possibility of having large dimension-six operators and small dimension-five (small neutrino masses) without any fine-tuning, if the lepton number is violated at a low energy scale. Finally, we discuss some peculiarities of the phenomenology of the fermionic triplet seesaw model.