Tests of Lorentz symmetry in single beta decay

TL;DR

This paper explores how low-energy single beta decay experiments can detect potential Lorentz symmetry violations, providing a complementary approach to high-energy tests and identifying specific experimental signatures.

Contribution

It introduces new experimental signatures of Lorentz violation in beta decay that are not observable in neutrino oscillations, expanding the methods for testing fundamental symmetries.

Findings

Identification of Lorentz violation signatures in polarized and unpolarized neutron decay

Proposal of spectral endpoint measurements as probes for Lorentz violation

Complementary role of low-energy beta decay experiments in symmetry tests

Abstract

Low-energy experiments studying single beta decay can serve as sensitive probes of Lorentz invariance that can complement interferometric searches for deviations from this spacetime symmetry. Experimental signatures of a dimension-three operator for Lorentz violation that are unobservable in neutrino oscillations are described for the decay the polarized and unpolarized neutrons as well as for measurements of the spectral endpoint in beta decay.