James Cronin

Facts

James Watson Cronin

Photo from the Nobel Foundation archive.

James Watson Cronin
The Nobel Prize in Physics 1980

Born: 29 September 1931, Chicago, IL, USA

Died: 25 August 2016, St. Paul, MN, USA

Affiliation at the time of the award: University of Chicago, Chicago, IL, USA

Prize motivation: "for the discovery of violations of fundamental symmetry principles in the decay of neutral K-mesons."

Prize share: 1/2

Work

For a long time, physicists assumed that various symmetries characterized nature. In a kind of "mirror world" where right and left were reversed and matter was replaced by antimatter, the same physical laws would apply, they posited. The left-right symmetry had already been proven violated when, in 1964, James Cronin and Val Fitch discovered that the matter-antimatter symmetry is violated when the neutral K-meson decays. Their experiment also proved that symmetry does not apply during time reversal: reactions going backward in time are not identical to those going forward.

To cite this section
MLA style: James Cronin – Facts. NobelPrize.org. Nobel Media AB 2018. Thu. 13 Dec 2018. <https://www.nobelprize.org/prizes/physics/1980/cronin/facts/>

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