The existence of the effect was proven in 1964 when James Cronin and Val Fitch demonstrated that the neutral K meson decayed a fraction of the time into only two pi mesons instead of three.
As described by Sakharov, the asymmetry due to this phenomenon in the first seconds of the big bang may explain the observed matter-antimatter ratio in the universe. Theoretical attempts to explain this phenomenon via the Kobayashi-Maskawa model and the super-weak model were motivated by the behavior of charged K mesons. The existence of the effect was proven in 1964 when James Cronin and Val Fitch demonstrated that the neutral K meson decayed a fraction of the time into only two pi mesons instead of three. FTP, name this phenomenon which occurs when certain conservation laws are violated.
As described by Sakharov, the asymmetry due to this phenomenon in the first seconds of the big bang may explain the observed matter-antimatter ratio in the universe.
CP violation (or charge-conjunction parity violation)