James Cronin

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James Cronin (2006)

James Watson Cronin (born September 29, 1931 in Chicago , Illinois , † August 25, 2016 in Saint Paul , Minnesota ) was an American physicist and Nobel Prize winner. He received the 1980 Nobel Prize with Val Fitch for discovering CP violation .

Life

Cronin graduated from Southern Methodist University in 1951 and went to the University of Chicago for further training , where he received his PhD in 1955 . He then worked at the Brookhaven National Laboratory . From 1958 to 1971 he was at Princeton University and then became a professor at the University of Chicago.

Cronin worked on the decay of hyperons and the creation of muons . He determined the total effective cross section of the pion - proton scattering and perfected the spark chamber , which he was the first physicist to use to detect particles by photographing the spark traces.

The subject of current research in particle physics is the Cronin effect . It describes a modification of the proton scattering (more generally of hadrons) on nuclei compared to what one would expect if one considers the nucleus as a set of independent nucleons and is caused by the scattering of the quarks of the proton (the hadrons) on those of the nuclei . The effect was discovered in the late 1970s and manifests itself in an accumulation in the spectrum of the scattered particles at medium transverse impulses (from 1 to 2 GeV for protons) with a corresponding attenuation at lower transverse impulses.

In 1980, Cronin and Val Fitch received the Nobel Prize in Physics “for the discovery of violations of fundamental symmetry principles in the decay of neutral K mesons ”, that is, the discovery of CP violation, published in 1964 (with also James H. Christenson and René Turlay ) . The experiment for this was carried out in 1964 at Brookhaven National Laboratory.

In 1982, while on a sabbatical at CERN , he led a small team to make the best direct measurement of the lifetime of the π0 .

He later worked on research into cosmic rays at the Pierre Auger Observatory .

In 1962 he became a Sloan Research Fellow and in 1963 a Fellow of the American Physical Society . Since 1967 he has been a member of the American Academy of Arts and Sciences , since 1970 of the National Academy of Sciences and since 1999 of the American Philosophical Society . In 2003 he was admitted to the Russian Academy of Sciences as a foreign member and in 2007 to the Royal Society .

literature

Web links

Commons : James Cronin  - collection of images, videos and audio files

Individual evidence

  1. ^ Nobel laureate James Cronin dies at 84 . Physics World , August 26, 2016, accessed August 26, 2016.
  2. ↑ For example: J.-P. Blaizot, F. Gelis, R. Venugopalan: High energy pA collisions in the color glass condensate approach I. Gluon production and the Cronin effect . In: Nucl. Phys. A , Volume, 743 2004, pp. 13-56, arxiv : hep-ph / 0402256
  3. ^ JH Christenson, J. Cronin, V. Fitch, R. Turlay: Evidence for the decay of the meson . In: Phys. Rev. Lett. , Volume 13, 1964, pp. 138-140
  4. ^ Alan Watson: Obituaries - October 14, 2016: James Cronin 1931-2016 . CERN Courier. Retrieved July 24, 2019.
  5. ^ American Academy of Arts and Sciences. Book of Members . (PDF) accessed on April 2, 2016
  6. ^ Member History: James Watson Cronin. American Philosophical Society, accessed July 2, 2018 .
personal data
SURNAME Cronin, James
ALTERNATIVE NAMES Cronin, James W .; Cronin, James Watson (full name)
BRIEF DESCRIPTION American physicist
DATE OF BIRTH September 29, 1931
PLACE OF BIRTH Chicago , Illinois
DATE OF DEATH August 25, 2016
Place of death Saint Paul , Minnesota