James Watson Cronin (September 29, 1931 – August 25, 2016) was an American
particle physicist.
Cronin and co-researcher
Val Logsdon Fitch
Val Logsdon Fitch (March 10, 1923 – February 5, 2015) was an American nuclear physicist who, with co-researcher James Cronin, was awarded the 1980 Nobel Prize in Physics for a 1964 experiment using the Alternating Gradient Synchrotron at B ...
were awarded the 1980
Nobel Prize in Physics
The Nobel Prize in Physics () is an annual award given by the Royal Swedish Academy of Sciences for those who have made the most outstanding contributions to mankind in the field of physics. It is one of the five Nobel Prizes established by the ...
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 particle
In physics, a subatomic particle is a particle smaller than an atom. According to the Standard Model of particle physics, a subatomic particle can be either a composite particle, which is composed of other particles (for example, a baryon, lik ...
s are not invariant under time reversal. 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
The National Medal of Science is an honor bestowed by the President of the United States to individuals in science and engineering who have made important contributions to the advancement of knowledge in the fields of behavioral science, behavior ...
.
Cronin was
Professor
Professor (commonly abbreviated as Prof.) is an Academy, academic rank at university, universities and other tertiary education, post-secondary education and research institutions in most countries. Literally, ''professor'' derives from Latin ...
Emeritus
''Emeritus/Emerita'' () is an honorary title granted to someone who retires from a position of distinction, most commonly an academic faculty position, but is allowed to continue using the previous title, as in "professor emeritus".
In some c ...
at the
University of Chicago
The University of Chicago (UChicago, Chicago, or UChi) is a Private university, private research university in Chicago, Illinois, United States. Its main campus is in the Hyde Park, Chicago, Hyde Park neighborhood on Chicago's South Side, Chic ...
winning the prestigious Quantrell Award and a spokesperson emeritus for the
Auger project. He was a member of the Board of Sponsors of the
Bulletin of the Atomic Scientists.
Education and early life
James Cronin was born in
Chicago
Chicago is the List of municipalities in Illinois, most populous city in the U.S. state of Illinois and in the Midwestern United States. With a population of 2,746,388, as of the 2020 United States census, 2020 census, it is the List of Unite ...
on September 29, 1931. His father, James Farley Cronin, was a graduate student of classical languages at the
University of Chicago
The University of Chicago (UChicago, Chicago, or UChi) is a Private university, private research university in Chicago, Illinois, United States. Its main campus is in the Hyde Park, Chicago, Hyde Park neighborhood on Chicago's South Side, Chic ...
. After his father had obtained his doctorate the family first moved to Alabama, and later in 1939 to
Dallas
Dallas () is a city in the U.S. state of Texas and the most populous city in the Dallas–Fort Worth metroplex, the List of Texas metropolitan areas, most populous metropolitan area in Texas and the Metropolitan statistical area, fourth-most ...
,
Texas
Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...
, where his father became a professor of Latin and Greek at
Southern Methodist University
Southern Methodist University (SMU) is a Private university, private research university in Dallas, Texas, United States, with a satellite campus in Taos County, New Mexico. SMU was founded on April 17, 1911, by the Methodist Episcopal Church, ...
. After high school Cronin stayed in Dallas and obtained an undergraduate degree at SMU in physics and mathematics in 1951.
He is of Irish descent, with his Irish ancestors immigrating from County Cork, Ireland.
For graduate school Cronin moved back to Illinois to attend the University of Chicago. His teachers there included
Nobel Prize laureates
Enrico Fermi
Enrico Fermi (; 29 September 1901 – 28 November 1954) was an Italian and naturalized American physicist, renowned for being the creator of the world's first artificial nuclear reactor, the Chicago Pile-1, and a member of the Manhattan Project ...
,
Maria Mayer,
Murray Gell-Mann
Murray Gell-Mann (; September 15, 1929 – May 24, 2019) was an American theoretical physicist who played a preeminent role in the development of the theory of elementary particles. Gell-Mann introduced the concept of quarks as the funda ...
and
Subrahmanyan Chandrasekhar
Subrahmanyan Chandrasekhar (; 19 October 1910 – 21 August 1995) was an Indian Americans, Indian-American theoretical physicist who made significant contributions to the scientific knowledge about the structure of stars, stellar evolution and ...
. He wrote his thesis on experimental nuclear physics under supervision of
Samuel K. Allison.
Research and career
After obtaining his doctorate in 1955, Cronin joined the group of
Rodney L. Cool and
Oreste Piccioni
Oreste Piccioni (October 24, 1915 – April 13, 2002) was an Italian-American physicist who made important contributions to elementary particle physics. He is the co-discoverer of the antineutron.
Biography
He was a graduate student of En ...
at
Brookhaven National Laboratory
Brookhaven National Laboratory (BNL) is a United States Department of Energy national laboratories, United States Department of Energy national laboratory located in Upton, New York, a hamlet of the Brookhaven, New York, Town of Brookhaven. It w ...
, where the new
Cosmotron
The Cosmotron was a particle accelerator, specifically a proton synchrotron, at Brookhaven National Laboratory. Its construction was approved by the U.S. Atomic Energy Commission in 1948, reaching its full energy in 1953, and continuing to run ...
particle accelerator
A particle accelerator is a machine that uses electromagnetic fields to propel electric charge, charged particles to very high speeds and energies to contain them in well-defined particle beam, beams. Small accelerators are used for fundamental ...
had just been completed. There he started to study
parity violation
In physics, a parity transformation (also called parity inversion) is the flip in the sign of ''one'' spatial coordinate. In three dimensions, it can also refer to the simultaneous flip in the sign of all three spatial coordinates (a point ref ...
in the decay of
hyperon
In particle physics, a hyperon is any baryon containing one or more strange quarks, but no charm, bottom, or top quarks. This form of matter may exist in a stable form within the core of some neutron stars. Hyperons are sometimes generically re ...
particles. During that time he also met
Val Fitch, who brought him to
Princeton University
Princeton University is a private university, private Ivy League research university in Princeton, New Jersey, United States. Founded in 1746 in Elizabeth, New Jersey, Elizabeth as the College of New Jersey, Princeton is the List of Colonial ...
in Fall 1958. After Cosmotron underwent magnet failure, Cronin and the Brookhaven group moved to
Bevatron
The Bevatron was a particle accelerator — specifically, a Weak focusing, weak-focusing proton synchrotron — located at Lawrence Berkeley National Laboratory, U.S., which began operations in 1954. The antiproton was discovered there in ...
at the
University of California, Berkeley
The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California), is a Public university, public Land-grant university, land-grant research university in Berkeley, California, United States. Founded in 1868 and named after t ...
during the first half of 1958. Cronin and Fitch 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
The Nobel Prize in Physics () is an annual award given by the Royal Swedish Academy of Sciences for those who have made the most outstanding contributions to mankind in the field of physics. It is one of the five Nobel Prizes established by the ...
.
After the discovery, Cronin spent a year in
France
France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...
at the
Centre d'Études Nucléaires 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 built at nearby
Fermilab
Fermi National Accelerator Laboratory (Fermilab), located in Batavia, Illinois, near Chicago, is a United States Department of Energy United States Department of Energy National Labs, national laboratory specializing in high-energy particle phys ...
.
When he moved to Chicago, he began a long series of experiments on particle production at high transverse momentum. With physicist Pierre Piroue and colleagues we learned about many things. These are summarized in Physical Review D, vol 19, page 764 (1977). Following these experiments Cronin took a sabbatical at
CERN
The European Organization for Nuclear Research, known as CERN (; ; ), is an intergovernmental organization that operates the largest particle physics laboratory in the world. Established in 1954, it is based in Meyrin, western suburb of Gene ...
in 1982–83, where he performed an experiment to measure of the lifetime of the
neutral pion
In particle physics, a pion (, ) or pi meson, denoted with the Greek letter pi (), is any of three subatomic particles: , , and . Each pion consists of a quark and an antiquark and is therefore a meson. Pions are the lightest mesons and, more g ...
(Physics Letters vol 158 B page 81, 1985). He then switched to the study of cosmic rays. The first was a series of measurements looking for point sources of cosmic rays. No sources were found. A summary of the measurements was published in Physical Review D vol 55 page 1714 (1997). In 1998 he joined the faculty at the
University of Utah
The University of Utah (the U, U of U, or simply Utah) is a public university, public research university in Salt Lake City, Utah, United States. It was established in 1850 as the University of Deseret (Book of Mormon), Deseret by the General A ...
on a half-time basis to work on
ultra-high-energy cosmic ray
In astroparticle physics, an ultra-high-energy cosmic ray (UHECR) is a cosmic ray with an energy greater than 1 EeV (1018 electronvolts, approximately 0.16 joules), far beyond both the rest mass and energies typical of other cosmic ray part ...
physics and to jumpstart the
Pierre Auger Observatory
The Pierre Auger Observatory is an international cosmic ray observatory in Argentina designed to detect ultra-high-energy cosmic rays: sub-atomic particles traveling nearly at the speed of light and each with energies beyond . In Earth's atmosphe ...
project. His appointment was to last five years, but he left after a year to continue gathering international support for the Observatory with
Alan Watson[ and Murat Boratav.
Cronin is one of the 20 American recipients of the Nobel Prize in Physics to sign a letter addressed to President ]George W. Bush
George Walker Bush (born July 6, 1946) is an American politician and businessman who was the 43rd president of the United States from 2001 to 2009. A member of the Bush family and the Republican Party (United States), Republican Party, he i ...
in May 2008, urging him to "reverse the damage done to basic science research in the Fiscal Year 2008 Omnibus Appropriations Bill" by requesting additional emergency funding for the Department of Energy's Office of Science, the National Science Foundation
The U.S. National Science Foundation (NSF) is an Independent agencies of the United States government#Examples of independent agencies, independent agency of the Federal government of the United States, United States federal government that su ...
, and the National Institute of Standards and Technology
The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into Outline of p ...
.
Publications
*Banner, M.; Cronin, J. W.; Liu, J. K.; & J. E. Pilcher
"Measurement of the Branching Ratio K → γ γ / K → 3π"
Palmer Physical Laboratory, Princeton University
Princeton University is a private university, private Ivy League research university in Princeton, New Jersey, United States. Founded in 1746 in Elizabeth, New Jersey, Elizabeth as the College of New Jersey, Princeton is the List of Colonial ...
, United States Department of Energy
The United States Department of Energy (DOE) is an executive department of the U.S. federal government that oversees U.S. national energy policy and energy production, the research and development of nuclear power, the military's nuclear w ...
(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 → 2π / K → 3π"
Palmer Physical Laboratory, Princeton University
Princeton University is a private university, private Ivy League research university in Princeton, New Jersey, United States. Founded in 1746 in Elizabeth, New Jersey, Elizabeth as the College of New Jersey, Princeton is the List of Colonial ...
, United States Department of Energy
The United States Department of Energy (DOE) is an executive department of the U.S. federal government that oversees U.S. national energy policy and energy production, the research and development of nuclear power, the military's nuclear w ...
(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
The University of Chicago (UChicago, Chicago, or UChi) is a Private university, private research university in Chicago, Illinois, United States. Its main campus is in the Hyde Park, Chicago, Hyde Park neighborhood on Chicago's South Side, Chic ...
, Joseph Henry Laboratories, Princeton University
Princeton University is a private university, private Ivy League research university in Princeton, New Jersey, United States. Founded in 1746 in Elizabeth, New Jersey, Elizabeth as the College of New Jersey, Princeton is the List of Colonial ...
, United States Department of Energy
The United States Department of Energy (DOE) is an executive department of the U.S. federal government that oversees U.S. national energy policy and energy production, the research and development of nuclear power, the military's nuclear w ...
(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
Argonne National Laboratory is a Federally funded research and development centers, federally funded research and development center in Lemont, Illinois, Lemont, Illinois, United States. Founded in 1946, the laboratory is owned by the United Sta ...
, University of Chicago
The University of Chicago (UChicago, Chicago, or UChi) is a Private university, private research university in Chicago, Illinois, United States. Its main campus is in the Hyde Park, Chicago, Hyde Park neighborhood on Chicago's South Side, Chic ...
, University of Maryland, College Park
The University of Maryland, College Park (University of Maryland, UMD, or simply Maryland) is a public university, public Land-grant university, land-grant research university in College Park, Maryland, United States. Founded in 1856, UMD i ...
, University of Missouri
The University of Missouri (Mizzou or MU) is a public university, public Land-grant university, land-grant research university in Columbia, Missouri, United States. It is Missouri's largest university and the flagship of the four-campus Univers ...
, United States Department of Energy
The United States Department of Energy (DOE) is an executive department of the U.S. federal government that oversees U.S. national energy policy and energy production, the research and development of nuclear power, the military's nuclear w ...
, (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
The University of Chicago (UChicago, Chicago, or UChi) is a Private university, private research university in Chicago, Illinois, United States. Its main campus is in the Hyde Park, Chicago, Hyde Park neighborhood on Chicago's South Side, Chic ...
, University of Oregon
The University of Oregon (UO, U of O or Oregon) is a Public university, public research university in Eugene, Oregon, United States. Founded in 1876, the university is organized into nine colleges and schools and offers 420 undergraduate and gra ...
, University of Michigan
The University of Michigan (U-M, U of M, or Michigan) is a public university, public research university in Ann Arbor, Michigan, United States. Founded in 1817, it is the oldest institution of higher education in the state. The University of Mi ...
, Stanford Linear Accelerator Center
SLAC National Accelerator Laboratory, originally named the Stanford Linear Accelerator Center,
is a Federally funded research and development centers, federally funded research and development center in Menlo Park, California, Menlo Park, Ca ...
(SLAC), Northeastern University
Northeastern University (NU or NEU) is a private university, private research university with its main campus in Boston, Massachusetts, United States. It was founded by the Boston Young Men's Christian Association in 1898 as an all-male instit ...
, Brookhaven National Laboratory
Brookhaven National Laboratory (BNL) is a United States Department of Energy national laboratories, United States Department of Energy national laboratory located in Upton, New York, a hamlet of the Brookhaven, New York, Town of Brookhaven. It w ...
(BNL), United States Department of Energy
The United States Department of Energy (DOE) is an executive department of the U.S. federal government that oversees U.S. national energy policy and energy production, the research and development of nuclear power, the military's nuclear w ...
, (October 1984).
* Abraham J., Cronin J. W. et al., Observation of suppression of the Flux of Cosmic Rays above 4x10**19 eV., Phys Rev Letters vol 101, p 061101, (2008).
Personal life
While in graduate school he also met his wife, Annette Martin, whom he married in 1954. She was the Director of Special Events at the University of Chicago. They have three children: two daughters, Cathryn (b. 1955) and Emily (b. 1959), and a son, Daniel (b. 1971). In June 2005 Annette Martin died of complications of Parkinson's disease. She was 71.
In November 2006 he married Carol Champlin.
In May 2011 his daughter Cathryn Cranston died of leukemia at age 54.
Cronin died on August 25, 2016, at the age of 84.
References
External links
* including the Nobel Lecture, December 8, 1980 ''CP Symmetry Violation – The Search for Its Origin''
James Watson Cronin
on Nobel-winners.com
* ttps://web.archive.org/web/20081012072551/http://physics.uchicago.edu/research/areas/astro_cosmo_x.html#Cronin Short biography at the University of Chicago*
{{DEFAULTSORT:Cronin, James Watson
1931 births
2016 deaths
University of Chicago alumni
American Nobel laureates
American nuclear physicists
People associated with CERN
Foreign members of the Royal Society
Foreign members of the Russian Academy of Sciences
Members of the United States National Academy of Sciences
National Medal of Science laureates
Nobel laureates in Physics
University of Chicago faculty
Weak interaction physicists
Sloan Research Fellows
University of Utah faculty
Fellows of the American Physical Society