# Nicola Cabibbo: Wikis

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# Encyclopedia

Nicola Cabibbo

Born 10 April 1935
Rome, Italy
Nationality Italian
Fields Particle physics
Institutions Italian National Institute of Nuclear Physics
Known for Cabibbo angle

Nicola Cabibbo (born 10 April 1935) is an Italian physicist, best known for his work on the weak interaction. He was also the president of the Italian National Institute of Nuclear Physics from 1983 to 1992, and since 1993 he has been the president of the Pontifical Academy of Sciences. He was born in Rome.

## Work

The Cabibbo angle represents the rotation of the mass eigenstate vector space formed by the mass eigenstates $\scriptstyle{| d \rangle , \ | s \rangle}$ into the weak eigenstate vector space formed by the weak eigenstates $\scriptstyle{| d^\prime \rangle , \ | s^\prime \rangle}$. The rotation angle is θC = 13.04°.

Cabibbo's major work on the weak interaction originated from a need to explain two observed phenomena:

Cabibbo solved the first issue by postulating weak universality, which involves a similarity in the weak interaction coupling strength between different generations of particles. He solved the second issue with a mixing angle θC (now called the Cabibbo angle), between the down and strange quarks. Modern measurements show that θC = 13.04°.

Before the discovery of the third generation of quarks, Cabibbo's work was extended by Makoto Kobayashi and Toshihide Maskawa to the Cabibbo–Kobayashi–Maskawa matrix. In 2008, Kobayashi and Maskawa shared one half of the Nobel Prize in Physics for their work. Some physicists had bitter feelings that the Nobel Prize committee failed to reward Cabibbo for his part.[1] Asked for a reaction on the prize, Cabibbo preferred to give no comment. According to sources close to him, he was very embittered.[2]

Recent work on evaluating the importance of scientific papers using Google's PageRank algorithm identifies Cabibbo's paper "Unitary symmetry and leptonic decays"[3] as the top ranked out of 353,268 articles on physics published since 1893.[4] The same research shows that most of the authors of the top-ranked papers are also Nobel Prize winners, which makes Cabibbo's exclusion seem all the more curious.

More recently, Cabibbo has been researching applications of supercomputers to address problems in modern physics with the experiments APE 100 and APE 1000.

Cabibbo has supported attempts to rehabilitate executed Italian pantheist philosopher Giordano Bruno, citing the apologies on Galileo Galilei as a possible model to correct the historical wrongs done by the Church.[5]

## References

1. ^ Valerie Jamieson (7 October 2008). "Physics Nobel snubs key researcher". New Scientist. Retrieved 2009-11-06.
2. ^   (Italian)
3. ^ Nicola Cabibbo (1963). "Unitary symmetry and leptonic decays". Physical Review Letters 10: 531–533.
4. ^ "How Google’s PageRank predicts Nobel Prize winners". 21 January 2009. Retrieved 2009-11-06.
5. ^   (French)

# Quotes

Up to date as of January 14, 2010

### From Wikiquote

Nicola Cabibbo (born ) is an Italian physicist, best known for work on the weak nuclear interaction. He was also the president of the Italian National Institute of Nuclear Physics from 1983 to 1992, and since 1993 he is the president of the Pontifical Academy of Sciences.

## Sourced

• Science that abdicates its cultural values risks being perceived as an extension of technology, an instrument in the hands of political or economic power. Humanity that disavows science risks falling into the hands of superstition.
• Address to the Holy Father, in The cultural values of science, The Pontifical Academy of Sciences, Scripta Varia 105 (8-11 November 2002), page xiv[1]
• Science is incapable of supplying answers to ultimate questions about why things exist and what their purpose is.
• interview by John L. Allen, Jr. on July 18, 2005, National Catholic Reporter (July 21, 2005)[2]