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Cronin, James Watson

Cronin, James Watson, 1931–2016, American nuclear physicist, b. Chicago, Ph.D. Univ. of Chicago, 1955. Cronin and co-researcher Val Logsdon Fitch were awarded the 1980 Nobel Prize in Physics for a 1964 experiment conducted at Brookhaven National Laboratory, Long Island, N.Y., that proved that certain subatomic reactions do not adhere to fundamental symmetry principles. Specifically, they showed, by examining the decay of K-mesons, that a reaction run in reverse does not merely retrace the path of the original reaction, which showed that the reactions of subatomic particles are not indifferent to time. Their discovery of what is known as the Fitch-Cronin effect also helped explain why matter-antimatter collisions in the aftermath of the big bang did not destroy all matter in the universe (see also cosmology ). With Alan A. Watson he later (1992) proposed a project to study high-energy cosmic rays that became the Pierre Auger Observatory, Mendoza prov., Argentina. After working at Brookhaven and then Princeton (from 1958), Cronin spent most of his career (from 1971; emeritus from 1997) at the Univ. of Chicago.

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