An experiment testing a possible gravitational contribution to CP violation in the neutral kaon system

An indirect experimental test of the gravitational interaction of antimatter can be performed by measuring the branching fraction of the CP violating decay of K_L in a low gravity environment, either in Earth orbit or on the moon. The Standard Model explains some of the CP violation through the pure phase in the CKM matrix, however ample room remains for CP violation contributions from other interactions and forces in the mixing of the neutral K and B mesons. Gravitation is a good candidate for such a contribution. We present new simulation results showing that the lower gravitational strength in space may change the level of CP violation such that a 5 sigma discrimination may be obtained by measuring the K_L produced by the cosmic proton flux on a dedicated detector within a relatively short time frame.