O(alpha(2)Gamma,alpha(3)Gamma) binding effects in orthopositronium decay -art. no. 111301

We present a new, simplified analysis of the low-energy electron-positron i nteraction, and use the resulting effective theory to calculate the binding effects that contribute to the decay rate Gamma of orthopositronium throug h O(alpha (3)1n alpha Gamma). We express the total decay rate in terms of t he annihilation rate for a free electron and positron at threshold, which h as just recently been computed to sufficient precision. Our O(alpha (2)Gamm a) result corrects errors in a previous analysis.