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.

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 $\hat{\eta}_{\nu}$}$.