Order alpha(2) corrections to the decay rate of orthopositronium

Phys Rev Lett. 2000 May 29;84(22):5086-9. doi: 10.1103/PhysRevLett.84.5086.

Abstract

Order alpha(2) corrections to the decay rate of orthopositronium are calculated in the framework of nonrelativistic QED. The resulting contribution is found to be in significant disagreement with one set of experimental measurements, though another experiment is in agreement with theory.