Demonstration of a Sensitive Method to Measure Nuclear Spin-Dependent Parity Violation

TL;DR

This paper demonstrates a highly sensitive method for measuring nuclear spin-dependent parity violation in diatomic molecules, surpassing previous atomic PV measurements and capable of detecting effects across various nuclei.

Contribution

The authors introduce a novel measurement technique using diatomic molecules that significantly improves sensitivity to NSD-PV effects, with systematic errors well-controlled.

Findings

Sensitivity surpasses previous atomic PV measurements

Systematic errors are suppressed to the level of statistical sensitivity

Measured the matrix element W with uncertainty less than 0.7 Hz

Abstract

Nuclear spin-dependent parity violation (NSD-PV) effects in atoms and molecules arise from $Z^0$ boson exchange between electrons and the nucleus, and from the magnetic interaction between electrons and the parity-violating nuclear anapole moment. We demonstrate measurements of NSD-PV that use an enhancement of the effect in diatomic molecules, here using the test system $^{138}$Ba$^{19}$F. Our sensitivity surpasses that of any previous atomic PV measurement. We show that systematic errors can be suppressed to at least the level of the present statistical sensitivity. We measure the matrix element, $W$, of the NSD-PV interaction with total uncertainty $\delta W/(2\pi)<0.7$ Hz, for each of two configurations where $W$ must have different signs. This sensitivity would be sufficient to measure NSD-PV effects of the size anticipated across a wide range of nuclei.