Constraints on Space-Time Torsion from Hughes-Drever Experiments

TL;DR

This paper uses Hughes-Drever experiments to set the tightest constraints on space-time torsion, specifically on axial torsion, by analyzing atomic energy level effects related to spin couplings.

Contribution

It reanalyzes existing Hughes-Drever experiments to derive new, stringent bounds on space-time torsion coupling, improving previous constraints.

Findings

Tightest constraint on axial torsion: K ≤ 1.5 × 10^{-15} m^{-1}

Reanalysis of experiments on anisotropy of mass and spin couplings

Space-time torsion effects on atomic energy levels are highly constrained

Abstract

The coupling of space-time torsion to the Dirac equation leads to effects on the energy levels of atoms which can be tested by Hughes-Drever type experiments. Reanalysis of these experiments carried out for testing the anisotropy of mass and anomalous spin couplings can lead to the till now tightest constraint on the axial torsion by $K \leq 1.5 . 10^{-15} m^{-1}$.