Noriaki Watanabe (Nagoya):

Electron g-2

Abstract:

The fine structure constant is determined by several methods using electromagnetic observables. The electron g-2 is the best observable for determing it. The uncertainty in the fine structure constant is 20 times smaller than for the next most precise independent method. However, through a new experiment, it can be expected that the uncertainty of the independent method could be almost the same as the best one. The values of the fine structure constant determined by 2 independent methods should be consistent. Confirmation of this will be the most stingent test of QED. We need to know QED contributions at 5 loop level completely to give the test a precise meaning. In this talk, I will explain the status of the calculations.