Scattering processes could distinguish Majorana from Dirac neutrinos

TL;DR

This paper demonstrates that considering neutrino polarization evolution reveals clear differences between Majorana and Dirac neutrino scattering on electrons, which could be observable in astrophysical environments or with polarized targets.

Contribution

It introduces a novel approach by analyzing neutrino polarization evolution, highlighting potential observable differences between Majorana and Dirac neutrinos in scattering processes.

Findings

Polarization evolution causes distinguishable effects in neutrino scattering.

Differences are significant even at high neutrino energies with polarized electrons.

Astrophysical magnetic fields can induce measurable polarization changes.

Abstract

It is well known that Majorana neutrinos have a pure axial neutral current interaction while Dirac neutrinos have the standard vector-axial interaction. In spite of this crucial difference, usually Dirac neutrino processes differ from Majorana processes by a term proportional to the neutrino mass, resulting in almost unmeasurable observations of this difference. In the present work we show that once the neutrino polarization evolution is considered, there are clear differences between Dirac and Majorana scattering on electrons. The change of polarization can be achieved in astrophysical environments with strong magnetic fields. Furthermore, we show that in the case of unpolarized neutrino scattering onto polarized electrons, this difference can be relevant even for large values of the neutrino energy.