B. C. Hiesmayr

Also in particle physics basic questions of quantum mechanics can be raised and
the peculiar behaviour of entanglement can be investigated, which is the basic
ingredient for the future technologies such as quantum information and quantum
communication.
A Bell inequality -- analogous to the entangled photon system -- can be
derived, however, the inequality is not violated because of the ``unfortunate’’
constants in these systems. However, these entangled meson-antimeson systems
offer other properties -- not analogous to other known spin-1/2 systems --
which open new insights, e.g. that the violation of the CP symmetry is related
to entanglement.
Another approach to study entanglement is via decoherence models. New data from
the B-meson factory of the KEKB collider in Japan (BELLE detector) or the new
data from the K-meson factory of the DAPHNE maschine in Italy can be used to
get upper bounds on decoherence and to test/exclude different decoherence
models.
Surprisingly, it turns out, that the parameter extracted from the experiments
are in simple connections to mathematical and theoretical concepts which in
this way are directly confronted with experimental data.