O(α²Γ,α³Γ) binding effects in orthopositronium decay

We present a new, simplified analysis of the low-energy electron-positron interaction, and use the resulting effective theory to calculate the binding effects that contribute to the decay rate Γ of orthopositronium through O(α³ln αΓ). We express the total decay rate in terms of the annihilation rate for a free electron and positron at threshold, which has just recently been computed to sufficient precision. Our O(α²Γ) result corrects errors in a previous analysis.