Orthopositronium decay form factors and two-photon correlations

Abstract

We give results for the orthopositronium decay form factors through one-loop order. We use the form factors to calculate momentum correlations of the final-state photons $\ensuremath{\langle}{k}_{Ai}{k}_{Bj}\ensuremath{\rangle}$ and $\ensuremath{\langle}{\mathrm{k\ifmmode \hat{}\else \^{}\fi{}}}_{Ai}{\mathrm{k\ifmmode \hat{}\else \^{}\fi{}}}_{Bj}\ensuremath{\rangle}$, including one-loop corrections, for ensembles of initial orthopositronium atoms having arbitrary polarization.