Jim Cronin
Val Fitch
In experiments at the Alternating Gradient Synchrotron at the Department of Energy's Brookhaven National Laboratory, physicists Jim Cronin and Val Fitch discovered in 1964 that matter and antimatter do not always behave symmetrically, as scientists had believed. Instead, Cronin and Fitch found a slight difference in the behavior of the subatomic particles called kaons, and their antiparticles, antikaons. This small but critical difference, known as CP violation, between the behavior of matter and antimatter, may account for the existence of our asymmetric universe, made only of matter.