The nuclear anapole moment interaction in BaF from relativistic coupled cluster theory

TL;DR

This paper reports high-accuracy relativistic coupled cluster calculations of the nuclear anapole moment interaction in BaF, providing a recommended value for the P-odd interaction coefficient to aid experimental measurements.

Contribution

The study offers the first high-precision relativistic coupled cluster calculation of the $W_A$ coefficient for BaF, including analysis of computational parameters and an estimated uncertainty.

Findings

Calculated $W_A$ coefficient: 147.7 Hz

Uncertainty estimated at 1.5%

Analysis of basis set, relativistic, and correlation effects

Abstract

We present high accuracy relativistic coupled cluster calculations of the P-odd interaction coefficient $W_A$ describing the nuclear anapole moment effect on the molecular electronic structure. The molecule under study, BaF, is considered a promising candidate for the measurement of the nuclear anapole moment, and the preparation for the experiment is now underway [Altunas et al., Phys. Rev. Lett. 120, 142501 (2018)]. Influence of various computational parameters (size of the basis set, treatment of relativistic effects, and treatment of electron correlation) on the calculated $W_A$ coefficient is investigated and a recommended value of 147.7 Hz with an estimated uncertainty of 1.5% is proposed.