When was the first antiproton discovered?

The antiproton was discovered in 1955 at the University of California, Berkeley, by Emilio Segrè and Owen Chamberlain. It was the first known antiparticle of the proton and gave strong support to the idea that every particle may have an antimatter counterpart. The discovery earned the 1959 Nobel Prize in Physics. Antiprotons later became important in studies of antimatter, particle accelerators, and fundamental symmetries.