Observation of a Large Atomic Parity Violation Effect in Ytterbium

TL;DR

This paper reports the first observation of a large atomic parity violation effect in ytterbium, significantly exceeding previous measurements in cesium, and confirms theoretical predictions, paving the way for future fundamental physics experiments.

Contribution

It presents the first experimental measurement of a large atomic parity violation effect in ytterbium, aligning with theoretical expectations and enabling new research avenues.

Findings

Parity-violating amplitude in ytterbium is two orders of magnitude larger than in cesium.

The observed amplitude matches theoretical predictions.

This measurement enables future studies of neutron skins and anapole moments.

Abstract

Atomic parity violation has been observed in the 6s^2 1S0 - 5d6s 3D1 408-nm forbidden transition of ytterbium. The parity-violating amplitude is found to be two orders of magnitude larger than in cesium, where the most precise experiments to date have been performed. This is in accordance with theoretical predictions and constitutes the largest atomic parity-violating amplitude yet observed. This also opens the way to future measurements of neutron skins and anapole moments by comparing parity-violating amplitudes for various isotopes and hyperfine components of the transition.