  Employing an effective formalism for decaying system we are able to
investigate Heisenberg's uncertainty relation for observables measured at
accelerator facilities. In particular we investigate the neutral K--meson
system and show that, firstly, due to the time evolution an uncertainty between
strangeness measurements at different times is introduced and, secondly, due to
the imbalance of matter and antimatter (CP violation) an uncertainty in the
evolution of the eigenstates of the effective Hamiltonian of the system.
Consequently, the existence of CP violation is linked to uncertainties of
observables, i.e. the outcomes cannot be predicted even in principle to
arbitrary precisions.

High Energy Physics - Phenomenology;Quantum Physics