Atoms through the looking glass – a relativistic challenge

Abstract

Abstract:The search for weak-interaction induced atomic parity non-conservation, initiated in the 70s, challenges both theory and experiment. Since the weak interaction is very short-range, the atomic effects increase rapidly with nuclear charge, as ¢ ¡. The focus has thus been on heavy atoms, where relativistic effects are essential, and nuclear size must be taken into account. The generalization of atomic many-body methods to relativistic systems involved both computational and formal difficulties, incorporating methods developed in quantum electrodynamics. Twenty years ago, the ability was emerging to treat atomic pair correlation in a relativistic framework. The application to many-electron systems opened for comparison with many atomic properties, such as isotope shifts, hyperfine structure and hyperfine anomalies, which reflect nuclear properties. In addition, the search for simultaneous violation of both parity and time reversal symmetry involves different types of effects, including nuclear "Schiff moments". Comparison between computed and experimental results for highly charged hydrogen-like systems provides a test of the theoretical and numerical treatment of the electron-nucleus interaction and of the description of nuclear distributions.

Isotope shifts inNe20,22: Precision measurements and global analysis in the framework of intermediate coupling

“…The RIS of levels (denoted L) is easier to interpret, from the perspective of atomic theory, than that of lines [35,61,62]. Moreover, due to the fact that there are many more lines than levels, recalculating the line IS from level IS results in a substantial increase in precision.…”

Testing QED and atomic-nuclear interactions with high-Zions

“…This sensitivity expresses itself as a noticeable perturbation of the standard hyperfine splitting. A complete description of the electron-nuclear interaction and of the nuclear distributions is not only a prerequisite for QED measurements, as our discussion has already shown, but also for the interpretation of atomic parity non-conservation experiments induced by the weak interaction, as detailed in the review by Mårtensson-Pendrill [61].…”