Tests of QED with Positronium

本研究的重点是新的和持续的实验测试量子电动力学（QED）和相对论束缚态形式在正电子-电子系统正电子（Ps）。Ps是这种测试的一个有吸引力的原子，因为它是纯轻子，因为电子和正电子是反粒子，因此湮灭对Ps的实能级和虚能级的独特影响可以高精度地测试。近年来，QED理论的精度已经超过了实验的精度，如何相应提高实验的精度和理论的对抗是当前的挑战。一项新的三重态衰变率测量将在2001年初达到200ppm的不确定度；目前的实验将把它推到60 ppm的水平。

The major emphasis of this research is new and continuing experimental tests of quantum electrodynamics (QED) and relativistic bound-state formalism in the positron-electron system positronium (Ps). Ps is an attractive atom for such tests because it is purely leptonic and because the electron and the positron are antiparticles, and thus the unique effects of annihilation on the real and imaginary energy levels of Ps can be tested to high precision. In the past few years, the precision of QED theory has overtaken that of experiment, and the challenge now is to improve the experimental precision correspondingly and to confront theory. A new measurement of the triplet decay rate will achieve 200 ppm uncertainty early in 2001; the present experiment will push this to a level of 60 ppm.