THE ORTHOPOSITRONIUM DECAY PUZZLE AND PRIMORDIAL NUCLEOSYNTHESIS
arXiv:hep-ph/9505443 · doi:10.1016/0370-2693(95)00797-O
Abstract
The discrepancy between the experimental decay rate of orthopositronium (o-Ps) and the QED theoretical prediction can be solved by invoking decays of o-Ps into exotic particles with branching ratios of the order of 10^{-3}. We show that considerations based on primordial nucleosynthesis and effective Lagrangians place a very stringent upper bound: B = Gamma(o-Ps -> ``exotic'' + ...)/Gamma(o-Ps) <= 2 x 10^{-15}, ruling out the exotic decay solution to the puzzle.
11 pages, LaTeX file, 1 figure in a compressed uuencoded additional file. Full postscript file available at ftp://ftp.ifae.es/preprint/ft/uabft366.ps