Completely positive dynamical maps and the neutral kaon system Original Research Article

The evolution of quantum irreversible processes can be effectively described using dynamical semigroups. They involve non-unitary time evolutions of density matrices that are generated by completely positive maps. In the case of the neutral kaon system such an approach leads to a modification of the standard Weisskopf-Wigner evolution, characterized by six phenomenological parameters. Bounds on the magnitude of these parameters could be given using available experimental data. In this respect, it is remarkable that the condition of complete positivity might be put to a precise test in future more refined experiments.