Testing quantum mechanics in the neutral kaon system at a φ-factory

In this paper the possibility of performing a Bell-type test of quantum mechanics in the neutral kaon system at a φ-factory is discussed. It is shown that a Bell inequality can be formulated for this system using a formalism based on a kaon quasispin picture and taking into account CP violation. Tiny violations of this inequality by quantum mechanics could be experimentally tested at a high luminosity φ-factory, by exploiting either coherent K_S- K_L regeneration in a thin regenerator, or single kaon quasispin oscillations in vacuum. The high precision detector of an experiment at a φ-factory, addressing direct CP violation in neutral kaon decays, could successfully perform such a test.