Higher Order Corrections to Positronium Energy Levels and Decay Rates

正电子是研究束缚态量子场论的理想实验室。目前的工作集中在计算低能级正电子的能量和衰减率。关于自旋三重态的衰减率，理论和更早的实验是不一致的。最近对这一比率的实验测量与理论吻合得多。对正电子衰减率的O(A2)修正的计算将检验早期的结果，并有助于解决目前实验与理论之间的分歧。

Positronium is an ideal laboratory to study bound state quantum field theory. The present work focuses on the calculation of the energies and decay rates of the low-lying levels of positronium. Theory and older experiments are in disagreement on the spin-triplet decay rate. A more recent experimental measurement of this rate is in much better agreement with theory. The calculation of the O(a2) correction to the orthopositronium decay rate will check the earlier result and help resolve the current diagreement between experiment and theory.