Entanglement, fluctuations and discrete symmetries in particle decays

Pairs of pseudoscalar neutral mesons from decays of vector resonances are studied as bipartite systems in the framework of density operator. Time-dependent quantum entanglement is quantified in terms of the entanglement entropy and these dependences are demonstrated on data on correlated pairs of K and B mesons, as measured by the KLOE and Belle experiments . Another interesting characteristics of such bipartite systems are moments of the CP distributions. These moments are directly measurable and they appear to be very sensitive to the initial degree of entanglement of a pair.