1. Bound electron g-2 Journal Club January 2007 Andrzej Czarnecki University of Alberta based on Karshenboim, PLA 266, 380 (2000)

2. Outline How to compute the energy shift due to the B-field? Connection between Dirac and Schrödinger wave functions Theoretical prediction and why it’s useful

3. B-field as perturbation How are these two descriptions related?

4. Dirac  Schrödinger We get g b from this comparison:

5. Example: p 2 (neglect V-E) The spin-dependent part gives:

6. Complete correction

7. Main new result in that paper: effect of short-range perturbations of the Coulomb potential For a perturbation the change of the g-factor is

8. From Werth Electron mass from bound-electron g-2 Motion in a Penning trap:

9. Electron mass from bound-electron g-2 Pachucki, AC, Jentschura, Yerokhin, 2005

10. Electron mass: two-loop bound-state effect Using the Mainz group measurements of ν L / ν C we get The free-electron mass determination, van Dyck, Farnham, Schwinberg 1995