James Cronin

For the founder of Monkey World, see Jim Cronin.

James Watson Cronin
Cronin at the 2010 Lindau Nobel Laureate Meeting
Born	(1931-09-29) 29 September 1931 Chicago, Illinois, USA
Nationality	United States
Alma mater	Southern Methodist University University of Chicago (Ph.D.)
Known for	Nuclear physics
Awards	Nobel Prize in Physics John Price Wetherill Medal National Medal of Science
Scientific career
Fields	Physics
Institutions	University of Chicago

James Watson Cronin (born September 29, 1931) is an American nuclear physicist.

Cronin was born in Chicago, Illinois and attended Southern Methodist University in Dallas, Texas. Cronin and co-researcher Val Logsdon Fitch were awarded the 1980 Nobel Prize in Physics for a 1964 experiment that proved that certain subatomic reactions do not adhere to fundamental symmetry principles. Specifically, they proved, by examining the decay of kaons, that a reaction run in reverse does not merely retrace the path of the original reaction, which showed that the interactions of subatomic particles are not indifferent to time. Thus the phenomenon of CP violation was discovered.

Cronin received the Ernest Orlando Lawrence Award in 1976 for major experimental contributions to particle physics including fundamental work on weak interactions culminating in the discovery of asymmetry under time reversal. In 1999, he was awarded the National Medal of Science.

Cronin is Professor Emeritus at the University of Chicago and a spokesperson emeritus for the Auger project. Cronin is a member of the Board of Sponsors of The Bulletin of the Atomic Scientists

Biography

James Cronin was born on September 29, 1931 in Chicago, Illinois, where his father, James Farley Cronin, was a graduate student of classical languages at the University of Chicago. After his father had obtained his doctorate the family first moved to Alabama, and later in 1939 to Dallas, Texas, where his father became a professor of Latin and Greek at Southern Methodist University. After high school Cronin stayed in Dallas and obtained an undergraduate degree at Southern Methodist University in physics and mathematics in 1951.

For graduate school Cronin moved back to Illinois to attend the University of Chicago. His teachers there included Nobel Prize laureates Enrico Fermi, Maria Mayer, and Murray Gell-Mann. He wrote his thesis on experimental nuclear physics under super vision of Samuel K. Allison. While in graduate school he also met his wife, Annette Martin, who he married in 1954.

After obtaining his doctorate in 1955, Cronin joined the group of Rodney Cool and Oreste Piccioni at Brookhaven National Laboratory, where the new Cosmotron particle accelerator had just been completed. Here he started to study parity violation in the decay of hyperon particles. During this time he also met Val Fitch, who brought him to Princeton University in 1958. Together they studied the decays of neutral K mesons, in which they discovered CP violation in 1964. This discovery earned the duo the 1980 Nobel Prize in Physics.

After the discovery, Cronin spent a year in France at the Centre d'Etudes Nucleaires at Saclay. After returning to Princeton he continued studying the neutral CP violating decay modes of the long lived neutral K meson. In 1971, he moved back to the University of Chicago to become a full professor. This was attractive for him because of a new 400 GeV particle accelerator being build at nearby Fermilab.

Personal Life

Cronin is married to Annette Martin. They have three children: Two daughters, Cathryn and Emily, and a son, Daniel.

Publications

• Banner, M.; Cronin, J. W.; Liu, J. K.; & J. E. Pilcher. "Measurement of the Branching Ratio K{sub L} → γ γ ∕ K{sub L} → 3π{sup 0}", Palmer Physical Laboratory, Princeton University, United States Department of Energy (through predecessor agency the Atomic Energy Commission), (August 12, 1968).

• Banner, M.; Cronin, J. W.; Liu, J. K.; & J. E. Pilcher. "Measurement of the Branching Ratio K{sub L} → 2π{sup 0} ∕ K{sub L} → 3π{sup 0}", Palmer Physical Laboratory, Princeton University, United States Department of Energy (through predecessor agency the Atomic Energy Commission), (August 14, 1968).

• Cronin, J. W.; Frisch, H. J.; Shochet, M. J.; Boymond, J. P.; Mermod, R.; Piroue, P. A.; & R. L. Sumner. "Atomic Number Dependence of Hadron Production at Large Transverse Momentum in 300 GeV Proton--Nucleus Collisions", Enrico Fermi Institute, University of Chicago, Joseph Henry Laboratories, Princeton University, United States Department of Energy (through predecessor agency the Atomic Energy Commission), National Science Foundation, (July 15, 1974).

• Brun, T. O.; Carpenter, J. M.; Krohn, V. E.; Ringo, G. R.; Cronin, J. W.; Dombeck, T. W.; Lynn, J. W.; & S. A. Werner. "Measurement of Ultracold Neutrons Produced by Using Doppler-shifted Bragg Reflection at a Pulsed-neutron Source", Argonne National Laboratory, University of Chicago, University of Maryland, College Park, University of Missouri, United States Department of Energy, (1979).

• Cronin, J. W.; Deshpande, N. G.; Kane, G. L.; Luth, V. C.; Odian, A. C.; Machacek, M. E.; Paige, F.; Schmidt, M. P.; Slaughter, J.; & G. H. Trilling. "Report of the Working Group on CP Violation and Rare Decays", University of Chicago, University of Oregon, University of Michigan, Stanford Linear Accelerator Center (SLAC), Northeastern University, Brookhaven National Laboratory (BNL), United States Department of Energy, (October 1984).

External links

• Biography and Bibliographic Resources, from the Office of Scientific and Technical Information, United States Department of Energy
• Cronin's Nobel lecture on CP Symmetry Violation
• James Watson Cronin at Nobel-winners.com
• James Cronin at nobelprize.org
• the discovery of violations of fundamental symmetry principles in the decay of neutral K-mesons.
• Short biography at the University of Chicago