Atomic parity violation in highly charged $^{40,48}$Ca and $^{208}$Pb ions

TL;DR

This paper calculates parity-violation-induced E1 amplitudes in highly charged ions of calcium and lead, considering nuclear effects and potential new physics, to aid in searches for physics beyond the standard model.

Contribution

It provides detailed calculations of parity-violation amplitudes in specific ions, including neutron skin effects and new Z' boson interactions, highlighting their impact on new physics searches.

Findings

Neutron-skin effects are negligible in calcium isotopes for Z' searches.

Significant neutron-skin and Z' effects are found in lead isotopes.

Results support using calcium ions for cleaner new physics investigations.

Abstract

We calculate parity-violation-induced E1 amplitudes for the $1s\rightarrow 2s$ and $1s^2 2s\rightarrow 1s^2 3s$ transitions in H- and Li-like ions of $^{40}$Ca, $^{48}$Ca, and $^{208}$Pb. In our analysis, we account for neutron skin effects and nuclear uncertainties for each nucleus. We consider the spin-independent weak-interaction contribution of the $Z^0$ boson described by standard model, as well as the effects of a hypothetical new $Z'$ boson of varying mass. We conclude that the neutron-skin corrections in the $^{40,48}$Ca isotope pair can mostly be neglected when considering $Z'$ boson effects, which is an advantage for the search for new parity-violating physics. On the other hand, both the neutron skin effect and the sensitivity to hypothetical $Z'$ interactions in $^{208}$Pb is shown to be significant.