A potential test of the CP properties and Majorana nature of neutrinos

TL;DR

This paper explores how future solar neutrino experiments could detect CP properties and the Majorana nature of neutrinos by analyzing azimuthal asymmetries in neutrino-electron scattering, sensitive to neutrino dipole moments.

Contribution

It proposes a novel method to test neutrino CP properties and Majorana nature using azimuthal asymmetries in solar neutrino scattering data from upcoming experiments.

Findings

Future experiments like Hellaz can detect azimuthal asymmetries.

Sensitivity to neutrino dipole moments can reveal CP properties.

Potential to distinguish Majorana from Dirac neutrinos.

Abstract

The scattering of solar neutrinos on electrons may reveal their CP properties, which are particularly sensitive to their Majorana nature. The cross section is sensitive to the neutrino dipole moments through an interference of electro-magnetic and weak amplitudes. We show how future solar neutrino experiments with good angular resolution and low energy threshold, such as Hellaz, can be sensitive to the resulting azimuthal asymmetries in event number, and could therefore provide valuable information on the CP properties and the nature of the neutrinos, provided the solar magnetic field direction is fixed.