# Distinguishing between Dirac and Majorana neutrinos in the presence of general interactions

## TL;DR

This paper explores how neutrino-electron scattering can differentiate Dirac from Majorana neutrinos by identifying unique observable regions, analyzing experimental data, and discussing future testing prospects.

## Contribution

It derives general conditions for distinguishing neutrino types considering all Lorentz-invariant interactions and applies them to experimental data.

## Key findings

- Certain parameter regions are exclusive to Dirac neutrinos.
- Current experimental data are consistent with both neutrino types.
- Future experiments could improve discrimination capabilities.

## Abstract

We revisit the possibility of distinguishing between Dirac and Majorana neutrinos via neutrino-electron elastic scattering in the presence of all possible Lorentz-invariant interactions. Defining proper observables, certain regions of the parameter space can only be reached for Dirac neutrinos, but never for Majorana neutrinos, thus providing an alternative method to differentiate these two possibilities. We first derive analytically and numerically the most general conditions that would allow to distinguish Dirac from Majorana neutrinos, both in the relativistic and non-relativistic cases. Then, we apply these conditions to data on $\nu_\mu$-$e$ and $\bar{\nu}_e$-$e$ scatterings, from the CHARM-II and TEXONO experiments, and find that they are consistent with both types of neutrinos. Finally, we comment on future prospects of this kind of tests.