COMPLETE-POSITIVITY AND THE K-(K)OVER-BAR SYSTEM

Models that provide experimentally testable violations of ordinary qua ntum mechanics have been recently proposed. These models are based on non-unitary time evolutions of density matrices that are generated by linear positive maps, We discuss the consequences of imposing a strong er condition on those maps, known as complete positivity. It turns out that experimental data on tile neutral kaon system giving upper bound s to the parameters characterizing positive maps, also give bounds to those determining completely positive ones.