A generalized bell inequality and decoherence for the K-0(K)over-bar(0) system

First, a generalized Bell-inequality for different times and for different quasi-spin states is developed. We focus on special quasi-spin eigenstates and times. The inequality based on a local realistic theory is violated by the CP-violating parameter tl] if the quantum theory is used to recalculate the probabilities. Next, the quantum mechanical probabilities are modified by the decoherence approach, which enables the initial state to factorize spontaneously. In this way we get a lower Limit for the decoherence paramet er I, which measures the degree of decoherence. This result is compared wit h the experimental value [2, 3] of the decoherence parameter zeta deduced f rom the data of the CPLEAR experiment [4].