Born: 10 July 1920, San Francisco, CA, USA
Died: 28 February 2006, Berkeley, CA, USA
Affiliation at the time of the award: University of California, Berkeley, CA, USA
Prize motivation: "for their discovery of the antiproton."
Prize share: 1/2
The matter around us has a kind of mirror image - antimatter. A particle and its antiparticle have an opposite electrical charge, among other things. The electron's antiparticle positron was the first to be discovered. With high concentrations of energy, a pair of particles and antiparticles can be created, but when a particle and an antiparticle meet, both are annihilated and their mass is converted into radiation. In a 1955 experiment with a powerful particle accelerator, Owen Chamberlain and Emilio Segrè confirmed the existence of the proton's antiparticle, the antiproton.