Research News - The Nobel Prize in Physics 2002 for the Observation of Cosmic Neutrinos - Resonance

The first half of the Nobel Prize in physics for 2002 has been shared by Raymond Davis, Jr. and Masatoshi Koshiba for their observations of cosmic neutrinos. On two earlier occasions, Nobel Prizes have been awarded for discovery of neutrinos from controlled experiments: in 1988 to Leon M Lederman, Melvin Schwartz and Jack Steinberger for the discovery of the muon type neutrino and the neutrino beam method, and in 1995 to Frederick Reines for the discovery of the electron type neutrino (discovered jointly with the by then deceased Clyde L Cowan, Jr.), who shared the prize with Martin Perl for his discovery of the tau lepton. Neutrinos are particles that participate only in the weak interactions, apart from participating in the gravitational interactions. The existence of the electron type neutrino was postuled in 1930 by Wolfgang Pauli in order to account for energy and angular momentum conservation in nuclear beta decay. They do not carry electric charge and the so-called color charge of the strong interactions. With the discovery of the muon in the 1940’s and the tau lepton in the 1970’s, heavier cousins of the electron, the electron type neutrino found cousins in the muon type and tau type neutrinos.

Address for Correspondence

B Ananthanarayan,
Centre for Theoretical Studies,
Indian Institute of Science,
Bangalore 560 012, India.
Email: anat@cts.iisc.ernet.in