Weak and Electromagnetic Radiative Corrections in Atomic Physics

University Of Notre Dame, Notre Dame IN

Investigators

Abstract

Quantum Electrodynamics (QED) has been a very active field in recent years. Two theoretical techniques, S-matrix theory and effective field theory, allow the systematic treatment of many-electron systems, with the former being most useful for highly charged ions and the latter for neutral, few-electon atoms. Given the success of the theory, another important direction the field is going in is the use of the high precision of both experiment and QED theory to make atoms testing grounds for non-QED physics. The most striking use has been parity nonconservation (PNC) in heavy atoms, and another important use is in nuclear physics. A first major focus of this research will be in the fine structure of helium as a way of determining the fine structure constant. The extreme complexity of the electron g-2 approach, recently shown by an error found in Kinoshita?s calculations, indicates the value of an alternative approach. Independent checks of a recent calculation of Pachucki are proposed. A second focus will involve research on highly charged ions, continuing a long standing collaboration with K.T. Cheng of Lawrence Livermore National Laboratory. Completion of calculations of the spectra of sodiumlike ions along with extension to copperlike ions is proposed. Hyperfine splitting in highly charged ions will also be studied. A third research area is recoil corrections. The treatment of recoil in a highly relativistic system has been treated only by one other group. G. Adkins and I have been working on an independent approach to the problem, and continuation of this research is proposed. Another use of recoil techniques is in the treatment of photon-Z boson exchange diagrams, which have a binding singularity that has not yet been evaluated in a Bethe-Salpeter framework. A final goal, with broader impact, is writing a textbook on bound state quantum field theory. Most of the techniques used in the research described above have not yet been well described in textbook form, and doing this, along with giving a much needed update of Bethe and Salpeter's monograph, is the intention of this work.