Neutrinos Polarimetry in Muon Decay

TL;DR

This paper investigates the polarization of electron antineutrinos emitted in muon decay, revealing potential effects from nonstandard Lorentz structures in weak interactions through detailed spectral and angular analysis.

Contribution

It provides the first calculation of antineutrino polarization in muon decay considering nonstandard S, T Lorentz sectors using empirical coupling parameters.

Findings

Transverse neutrino polarization component identified.

Spectral shape and angular distribution computed.

Implications for nonstandard weak interaction sectors.

Abstract

We consider massive Dirac electron antineutrino to be observed in the muon decay, $\mu^{-} \rightarrow e^- +\bar{\nu}_{e} + \nu_{\mu}$, at rest in the LAB reference frame. A computation of $\bar{\nu}_{e}$ differential direct spectral shape and angular distribution was performed. This has resulted in transverse component of the neutrino polarization emerging from the nonstandard S, T sector of the Lorentz structure in the Fermi leptonic charged weak interaction. The calculation is based on empirical values of the coupling parameters.