Measuring Nuclear Spin Dependent Parity Violation With Molecules: Experimental Methods and Analysis of Systematic Errors

TL;DR

This paper demonstrates a highly sensitive experimental method to measure nuclear spin-dependent parity violation effects in molecules, surpassing previous atomic measurements, and effectively suppressing systematic errors.

Contribution

It introduces an improved experimental approach using ${^{138} ext{Ba}^{19} ext{F}}$ molecules to measure NSD-PV effects with unprecedented sensitivity and systematic error control.

Findings

Achieved measurement sensitivity with uncertainty <0.7 Hz for the matrix element W.

Suppressed systematic errors to at least the level of statistical sensitivity.

Demonstrated potential to measure NSD-PV effects across various nuclei.

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. It has been proposed to study NSD-PV effects using an enhancement of the observable effect in diatomic molecules [D. DeMille $\textit{et al.}$, Phys. Rev. Lett. $\textbf{100}$, 023003 (2008)]. Here, we demonstrate measurements of this type with sensitivity surpassing that of any previous atomic PV measurement, using the test system ${^{138}\mathrm{Ba^{19}F}}$. We show that systematic errors associated with our technique can be suppressed to at least the level of the present statistical sensitivity. With $\sim\!170$ hours of data, we measure the matrix element, $W$, of the NSD-PV interaction with 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.