Pauli and the neutrino

4 December 2002

On 4 December 1930, Austrain theorist Wolfgang Pauli (pictured here in 1933) wrote a famous letter in which he dared to hypothesise the existence of new particle - the particle now known as the neutrino. Pauli proposed the new particle to explain why energy seemed to go missing in the form of radioactivity known as beta-decay. The neutrino would took away energy but without being detected, as it has no electric charge and a very small mass. It was to be another 26 years before Fred Reines and Clyde Cowan claimed the first detection of Pauli's "undetectable" particle. Pauli himself went on to receive the Nobel prize for physics in 1945, not for his idea of the neutrino but for his famous "exclusion principle".

Credit: CERN Pauli Archive