Nobel Prizes and Laureates

Nobel Prizes and Laureates

The Nobel Prize in Physics 1980
James Cronin, Val Fitch

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Val Fitch - Facts

Val Logsdon Fitch

Val Logsdon Fitch

Born: 10 March 1923, Merriman, NE, USA

Died: 5 February 2015, Princeton, NJ, USA

Affiliation at the time of the award: Princeton University, Princeton, NJ, USA

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

Field: particle physics

Prize share: 1/2


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, Val Fitch and James Cronin 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.

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