Quantum mechanics versus local realism and a recent EPR experiment on K0K̄0

The interest of the Orsay Einstein-Podolsky-Rosen experiments of the eighties was limited by a loophole due to the photomultipliersʹ low detection efficiency. This limitation can be overcome in the case of neutral kaon pairs for which the detection efficiency is high. We show that for such pairs produced in the state JPC=1−− the prediction of local realism differ from those of standard quantum theory by 30% or more. A natural extension of a recent experiment on antiproton annihilations at rest into kaon pairs [CPLEAR Collaboration, A. Apostolakis et al., Phys. Lett. B 422 (1998) 339] could lead to a decisive step forward in this matter.