Abstract
Theories of the two-photon couplings of -wave positronium and systems are reviewed and a relationship is found between field-theoretic calculations of and the vector-meson-dominance model for both heavy- and light-quark systems. Relativistic corrections to the two-photon decay rates are evaluated and are found to be very important for the light-quark system. We find that the widely quoted ratio of between the widths of heavy-quark scalar and tensor mesons is significantly modified in the light- sector. We find however that the helicity-zero amplitude for the coupling of tensor mesons, which vanishes in the nonrelativistic limit, remains small for light quarks, in accord with experimental observation.
- Received 20 August 1990
DOI:https://doi.org/10.1103/PhysRevD.43.2161
©1991 American Physical Society