Longitudinal Atomic Beam Spin Echo Experiments: A possible way to study Parity Violation in Hydrogen

TL;DR

This paper explores using longitudinal atomic beam spin echo experiments with hydrogen to detect parity violation through geometrical phases, supported by in-beam spin rotation measurements and theoretical calculations.

Contribution

It proposes a novel experimental approach to observe parity-violating geometrical phases in hydrogen using lABSE techniques, combining experimental data and theoretical analysis.

Findings

In-beam spin rotation measurements agree with theoretical predictions.

Metastable 2S states show potential signatures of parity violation.

The method could enable future detection of P-violation in hydrogen.

Abstract

We discuss the propagation of hydrogen atoms in static electric and magnetic fields in a longitudinal atomic beam spin echo (lABSE) apparatus. Depending on the choice of the external fields the atoms may acquire both dynamical and geometrical quantum mechanical phases. As an example of the former, we show first in-beam spin rotation measurements on atomic hydrogen, which are in excellent agreement with theory. Additional calculations of the behaviour of the metastable 2S states of hydrogen reveal that the geometrical phases may exhibit the signature of parity-(P-)violation. This invites for possible future lABSE experiments, focusing on P-violating geometrical phases in the lightest of all atoms.