Relativistic multi-reference Fock-space coupled-cluster calculation of the forbidden $6s^2^1 S_0 \longrightarrow 6s5d^3 D_1$ magnetic-dipole transition in ytterbium

TL;DR

This paper presents highly accurate relativistic multi-reference Fock-space coupled-cluster calculations of forbidden transitions in ytterbium, aiding fundamental physics tests beyond the standard model.

Contribution

The study provides the most precise theoretical transition matrix elements for ytterbium, improving the accuracy of parity non-conservation measurements and beyond-standard-model physics searches.

Findings

Computed magnetic-dipole transition amplitude ($1.34\times10^{-4}\mu_{B}$) matches experimental value ($1.33\times10^{-4}\mu_{B}$).

Calculated transition matrix elements are in good agreement with previous estimates.

Results will help determine parity non-conserving amplitudes in ytterbium.

Abstract

We report the forbidden $6s^{2} ^{1}S_{0}\longrightarrow6s5d ^{3}D_{1}$ magnetic-dipole transition amplitude computed using multi-reference Fock-space coupled-cluster theory. Our computed transition matrix element ($1.34\times10^{-4}\mu_{B}$) is in excellent agreement with the experimental value ($1.33\times10^{-4}$ $\mu_{B}$). This value in combination with other known quantities will be helpful to determine the parity non-conserving amplitude for the $6s^{2} ^{1}S_{0}\longrightarrow6s5d ^{3}D_{1}$ transition in atomic Yb. To our knowledge our calculation is the most accurate to date and can be very important in the search of physics beyond the standard model. We further report the $6s6p ^{3}P_{0}\longrightarrow6s6p ^{1}P_{1}$ and $6s5d ^{3}D_{1}\longrightarrow6s6p ^{3}P_{0}$ transition matrix elements which are also in good agreement with the earlier theoretical estimates.