Nicola Cabibbo (10 April 1935 – 16 August 2010) was an Italian physicist best known for his work on the weak interaction, particularly his introduction of the Cabibbo angle. Interested in science from a young age, he studied physics at the Sapienza University of Rome, graduating in 1958 with a thesis completed under Bruno Touschek.
Early life and education
Nicola Cabibbo was born on 10 April 1935 in Rome, Italy to Silician parents; his father, Emanuele, was a lawyer and his mother was a housewife.[1] He was interested in mathematics, physics and astronomy from an early age, and built his own radios.[2] Despite growing up during World War II, his elementary school education ran uninterrupted, and he subsequently attended the Liceo Torquato Tasso.[2][3] There, a textbook titled What Is Mathematics? sparked Cabibbo's interest in pursuing scientific studies.[3]
In 1963, while working at CERN, Cabibbo found the solution to the puzzle of the weak decays of strange particles, formulating what came to be known as Cabibbo universality. In 1967 Nicola settled back in Rome where he taught theoretical physics and created a large school. He was president of the INFN from 1983 to 1992, during which time the Gran Sasso Laboratory was inaugurated. He was also president of the Italian energy agency, ENEA, from 1993 to 1998, and was president of the Pontifical Academy of Sciences from 1993 until his death.[6] In 2004, Cabibbo spent a year at CERN as guest professor, joining the NA48/2 collaboration.[7]
Research
The Cabibbo angle represents the rotation of the masseigenstatevector space formed by the mass eigenstates into the weak eigenstate vector space formed by the weak eigenstates . The rotation angle is θC = 13.04°.Nicola Cabibbo and Makoto Kobayashi
Cabibbo's major work on the weak interaction originated from a need to explain two observed phenomena:
The transitions with change in strangeness had amplitudes equal to one fourth of those with no change in strangeness.
Cabibbo addressed these issues, following Murray Gell-Mann and Maurice Lévy, by postulating weak universality, which involves a similarity in the weak interaction coupling strength between different generations of particles. He addressed the second issue with a mixing angleθC (now[8] 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, this 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 vital part.[9][10][11] Asked for a reaction on the prize, Cabibbo preferred to give no comment. According to sources close to him, however, he was embittered.[12]
Later, Cabibbo researched applications of supercomputers to address problems in modern physics with the experiments APE 100 and APE 1000.
Cabibbo supported attempts to rehabilitate executed Italian philosopher Giordano Bruno, citing the apologies on Galileo Galilei as a possible model to correct the historical wrongs done by the Church.[13]
^Giorgio Salvini, director of the Frascati laboratories at the time, thought it was necessary to have a theoretical research group to support the laboratories' experimental activities.[2]
