Are Neutrinos Their Own Antiparticles?

TL;DR

This paper discusses the concept of Majorana neutrinos, their potential to be their own antiparticles, and how neutrinoless double beta decay could confirm their Majorana nature, highlighting the significance of neutrino masses.

Contribution

It clarifies the relationship between Majorana neutrinos and their masses, and introduces a toy model illustrating the conditions for neutrinoless double beta decay.

Findings

Majorana masses make neutrinos distinctive particles

Neutrinoless double beta decay indicates nonzero neutrino masses

Both right-handed and left-handed currents are involved in the decay

Abstract

We explain the relationship between Majorana neutrinos, which are their own antiparticles, and Majorana neutrino masses. We point out that Majorana masses would make the neutrinos very distinctive particles, and explain why many theorists strongly suspect that neutrinos do have Majorana masses. The promising approach to confirming this suspicion is to seek neutrinoless double beta decay. We introduce a toy model that illustrates why this decay requires nonzero neutrino masses, even when there are both right-handed and left-handed weak currents.