Neutrino

:Neutrino is also an operating system. See QNX.

History

The neutrino was first postulated in 1931 by Wolfgang Pauli to explain the energy spectrum of beta decays, the decay of a neutron into a proton and an electron. Pauli theorized that an undetected particle was carrying away the observed difference between the energy and angular momentum of the initial and final particles. Because of their "ghostly" properties, the first experimental detection of neutrinos had to wait until about 25 years after they were first discussed. In 1956 Clyde Cowan, Frederick Reines, F. B. Harrison, H. W. Kruse, and A. D. McGuire published the article "Detection of the Free Neutrino: a Confirmation" in Science (see neutrino experiment), a result that was rewarded with the 1995 Nobel Prize.

Related Topics:
1931 - Wolfgang Pauli - Beta decay - Proton - Energy - Angular momentum - Clyde Cowan - Frederick Reines - Science - Neutrino experiment - 1995 Nobel Prize

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The name neutrino was coined by Enrico Fermi - who developed the first theory describing neutrino interactions - as a word play on neutrone, the Italian name of the neutron. (Neutrone in Italian means big and neutral, and neutrino means small and neutral.)

Related Topics:
Enrico Fermi - Italian - Neutron

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In 1962 Leon M. Lederman, Melvin Schwartz and Jack Steinberger showed that more than one type of neutrino exists by first detecting interactions of the muon neutrino. When a third type of lepton, the tau, was discovered in 1975 at the Stanford Linear Accelerator, it too was expected to have an associated neutrino. First evidence for this third neutrino type came from the observation of missing energy and momentum in tau decays analogous to the beta decay that had led to the discovery of the neutrino in the first place. The first detection of actual tau neutrino interactions was announced in summer of 2000 by the DONUT collaborationhttp://www-donut.fnal.gov/ at Fermilab, making it the latest particle of the Standard Model to have been directly observed.

Related Topics:
Leon M. Lederman - Melvin Schwartz - Jack Steinberger - Muon - Tau - Stanford Linear Accelerator - DONUT - Fermilab - Standard Model

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The difficulty in detecting neutrinos was illustrated by Richard Feynmann. He said "All you have to do is imagine something that does practically nothing. You can use your son-in-law as a prototype."

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