# Relativistic coupled-cluster analysis of parity nonconserving amplitudes and related properties of the $6s ~ ^2S_{1/2} - 5d ~ ^2D_{3/2;5/2}$ transitions in $^{133}$Cs

## TL;DR

This paper uses a relativistic coupled-cluster method to calculate parity nonconserving amplitudes in cesium, providing detailed theoretical predictions for experimental tests of fundamental symmetries.

## Contribution

It presents the first comprehensive RCC-based calculations of PNC amplitudes and related properties for specific cesium transitions, including both NSI and NSD effects, with correlation, Breit, and QED corrections.

## Key findings

- Calculated $E1_{PNC}$ amplitudes for $^{133}$Cs transitions.
- Assessed the impact of correlation, Breit, and QED effects.
- Suggested experimental schemes for measuring these amplitudes.

## Abstract

We present the results of our calculations of the parity nonconserving electric dipole amplitudes ($E1_{PNC}$) for the $6s ~ ^2S_{1/2} - 5d ~ ^2D_{3/2;5/2}$ transitions of $^{133}$Cs employing a relativistic coupled-cluster (RCC) method. $E1_{PNC}$ values for the nuclear spin independent (NSI) and nuclear spin dependent (NSD) parity non-conservation (PNC) effects for different hyperfine levels of the $6s ~ ^2S_{1/2} - 5d ~ ^2D_{3/2}$ transition and only due to the NSD PNC interaction Hamiltonian for all possible hyperfine levels of the $6s ~ ^2S_{1/2} - 5d ~ ^2D_{5/2}$ transition are given. We have also performed calculations of several properties that are relevant for assessing the reliability of the calculations of the amplitudes of the above mentioned transitions. We highlight the importance of correlation effects by giving the results of both the Dirac-Fock (DF) and RCC contributions. Approximate contributions to these properties from the Breit and quantum electrodynamics (QED) interactions have also been evaluated. Plausible experimental schemes to measure these transition amplitudes by light shift techniques and interference involving induced Stark shifts are outlined.