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 ∼ 10-3. We show that considerations based on primordial nucleosynthesis and effective Lagrangians place a very stringent upper bound: B ≡ Γ (o-Ps → "exotic" + ...) Γ(o-Ps) ≤ 2 × 10-15, ruling out the exotic decay solution to the puzzle. © 1995.
|Journal||Physics Letters B|
|Publication status||Published - 17 Aug 1995|