The research develops a new, broadly applicable, method for precision calculation of properties of atomic systems with more than one valence electron. This method combines the all-order approach currently used in precision calculations of properties of monovalent atoms with the configuration interaction (CI) approach that is applicable for many-electron systems. The main goal of this research is to improve the theoretical understanding of parity nonconservation (PNC) in heavy atoms.
The goal of this research was to develop theoretical methods to study fundamental interactions with atomic systems (for example, Ra+ and Tl). We developed methods to study atoms which can be used to test the present theory of electroweak interactions called the standard model and to search for new effects that will signify new physics not yet discovered. Our research will allow to analyze past or current experiments and to direct future experimental searches. There are several current experiments aimed at the study of weak interaction in atoms. Our work on the calculation of parity nonconserving amplitude in Ra+ ion will allow to test the predictions of the standard model when the experiments are completed. In another part of the project, we have resolved the discrepancy between calculated values of the enhancement factor for the electric-dipole moment of Tl. Search for permanent electric-dipole moment of atoms and elementary particles is aimed at discovering new physics beyond effects predicted by the standard model. Study of fundamental symmetries requires accurate knowledge of atomic properties, and new methods needed to be developed. In this project, we have combined two different approaches to develop a new method capable of accurate calculation of relevant properties which represents a significant advance in the methodology of high-precision atomic structure calculations. We have also applied the methods developed in this project to calculate various atomic properties. For some systems that we considered in this project, no high-precision values of these atomic properties previously existed. We were able to make accurate predictions for a number of atomic properties of many different systems. Knowledge of atomic properties is useful for variety of modern applications in physics and technology including the development of better atomic clocks. Graduate students were directly involved in the forefront research under this grant and presented their research at the scientific meetings.
