Physicists were again surprised when in 1964, James Cronin and Val Fitch provided clear evidence in kaon decays that CP symmetry could be broken too, winning them the 1980 Nobel Prize in Physics.
Os físicos foron sorprendidos de novo cando en 1964 James Cronin e Val Fitch achegaron evidencias claras nunha desintegración dun kaón, que a simetría CP podía ser rota tamén, recibindo o premio Nobel de física de 1980.