# CP Violation in Antineutrino-Electron Elastic Scattering

## TL;DR

This paper proposes a method to detect CP violation in antineutrino-electron elastic scattering by measuring azimuthal asymmetries, which could indicate exotic antineutrino states and involves analyzing interference effects between standard and exotic couplings.

## Contribution

It introduces a novel approach to identify CP-violating effects in antineutrino-electron scattering through azimuthal asymmetry measurements and explores the relation between antineutrino and neutrino scattering cross sections.

## Key findings

- Azimuthal asymmetry can reveal CP violation in antineutrino-electron scattering.
- Differential cross section for antineutrino scattering relates to neutrino scattering via specific substitutions.
- Potential evidence for exotic antineutrino states through interference effects.

## Abstract

Elastic scattering of transversely polarized electron antineutrino beam off unpolarized electrons can be used to detect the CP-violating effects by measuring the azimuthal asymmetry of recoil electrons caused by the interference terms between the standard vector $c_{V}^{L}$, axial $c_{A}^{L}$ couplings of left-chirality antineutrinos and exotic scalar $c_{S}^{R}$ coupling of right-chirality ones in the differential cross section. It would be a positive evidence for the existence of the exotic antineutrino states. Moreover, we also show that the differential cross section for the $\overline{\nu} e^- $ scattering can be obtained from the one for the $\nu e$ scattering, if one makes the substitution $c_{T}^{R} \to -c_{T}^{R}$, $c_{A}^{L} \to -c_{A}^{L}$, ${\bf q}\to -{\bf q}$, ${\boldmath $\hat{\eta}_{\nu}$}\to -{\boldmath $\hat{\eta}_{\nu}$}$.