Murray Gell-Mann

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Murray Gell-Mann (2007)
Murray Gell-Mann at Harvard University (2005)

Murray Gell-Mann (born September 15, 1929 in New York , NY , USA , † May 24, 2019 in Santa Fe , New Mexico ) was an American physicist . In 1969 he received the Nobel Prize in Physics “for his contributions and discoveries relating to the classification of elementary particles and their interactions ”.

life and work

After graduating from school in 1944, Gell-Mann studied physics at Yale University until 1948 , and in 1951 received his doctorate from the Massachusetts Institute of Technology (MIT) under Victor Weisskopf . From 1956 until his retirement in 1993 he was a professor at the California Institute of Technology (Caltech).

Gell-Mann made fundamental contributions to the theory and classification of strongly interacting particles ( hadrons ) early on . In 1953 he introduced the quantum number " Strangeness " to classify hadrons. With Abraham Pais , he investigated the K meson system, a prime example of a quantum mechanical two-state system . But he also made significant contributions in other areas of quantum field theory and elementary particle physics . For example, he introduced the renormalization group with Francis Low in 1954 . In another work with Low, he examined what was later called the Bethe-Salpeter equation . With Richard Feynman he published a new formulation of the weak interaction ( VA theory ) in 1958 .

With Keith Brueckner he investigated the many-particle problem of the electron gas and with Marvin Leonard Goldberger the general quantum mechanical scattering theory. With Walter Thirring and Goldberger he introduced dispersion relations. In a work with Maurice Lévy he examined the “chiral model” (PCAC (partially conserved axial vector current), Goldberger-Treiman relation). These models express the chiral symmetry of the strong interaction and served as phenomenological models to describe it (relationships between masses and coupling constants, etc.) from the 1960s onwards.

Gell-Mann and independently of him Juval Ne'eman proposed a phenomenological model for the classification of hadrons in 1961, which he initially named " Eightfold Way " according to the noble eightfold path in Buddhism , since the number 8 plays a central role in the model. In 1964, Gell-Mann and independently George Zweig developed the Quark model from it. At that time only three quark flavors (up, down, strange) were known, today three more are known, but they have a much higher mass and therefore could not be discovered in the experiments of the 1960s. The corresponding symmetry group for three quark flavors is the SU (3) group and the generators of the SU (3), which are similar to the Pauli matrices, are called Gell-Mann matrices .

In Physics Volume 1, 1964, p. 63 (The symmetry group of vector and axial vector currents) and Physical Review Volume 125, 1962, p. 1067 he introduced “current algebras” in connection with his work on the Quark model (literally " Algebra of Currents "), which were very popular in the 1960s.

In 1972 he and Harald Fritzsch introduced the color degree of freedom of the quarks, and in a joint work with Heinrich Leutwyler , full quantum chromodynamics was introduced.

Gell-Mann spent some time at CERN in the 1960s and returned in the late 1970s when he lectured on the great union of the various forces in nature.

In the late 1970s and 1980s he was a. a. involved in the development of Grand Unified Theories (GUT). Among other things, he investigated with Pierre Ramond and Richard Slansky the possibilities of embedding the color group in GUTs and developed the “Seesaw” mechanism for mass production. He also participated in the development of supergravity , Kaluza-Klein and string theory . In the 1990s he took part in the expansion of the “ decoherent histories ” interpretation of quantum mechanics (with James Hartle ). From 1993 he worked at the Santa Fe Institute , which he co-founded in 1984 , where he dealt with complex adaptive systems and generally with the emergence of complex phenomena from simple laws. He reported on this in his popular science book The Quark and the Jaguar and most recently dealt with cooperative approaches in economics .

Gell-Mann was a member of the Committee for the Scientific Investigation of Claims of the Paranormal . In 1959 he was the first recipient of the Dannie Heineman Prize .

His PhD students include Kenneth Wilson , Barton Zwiebach, and Sidney Coleman .

He died at his Santa Fe home on May 24, 2019 at the age of 89.

Awards (selection)

In addition, Gell-Mann received the Ernest Orlando Lawrence Prize , the Benjamin Franklin Medal , and numerous honorary doctorates from the Universities of Cambridge , Columbia , Oxford , Chicago , Florida , Yale and others.

Works

  • Gell-Mann and Ne'eman (Eds.): The Eightfold Way. 1964 (textbook on the Eightfold Way ).
  • The curd and the jaguar. Piper, Munich 1994, ISBN 3-492-22296-X (popular science book).
  • Selected papers. World Scientific, 2010.

literature

See also

Web links

Commons : Murray Gell-Mann  - Collection of Images, Videos and Audio Files

Footnotes and sources

  1. ↑ That is the correct spelling of the name, but it was also often quoted as Gellmann.
  2. ↑ George Johnson: Murray Gell-Mann, Who Peered at Particles and Saw the Universe, Dies at 89. In: nytimes.com. The New York Times, May 24, 2019, accessed May 24, 2019 .
  3. ↑ Isotopic spin and new unstable particles. In: Physical Review. Volume 92, 1953, p. 833.
  4. ↑ Physical Review. Volume 97, 1955, p. 1387.
  5. ↑ Quantum Electrodynamics at Small Distances. In: Physical Review. Volume 95, 1954, p. 1300.
  6. ^ Bound states in quantum field theory. In: Physical Review. Volume 84, 1951, p. 350.
  7. ^ Theory of the Fermi interaction. In: Physical Review. Volume 109, 1958, p. 193. This theory was also independently developed by George Sudarshan and Robert Marshak around the same time.
  8. ^ Correlation energy of an electron gas at high density. In: Physical Review. Volume 106, 1957, pp. 364, 369.
  9. ^ Formal theory of scattering. In: Physical Review. Volume 91, 1955, p. 398
  10. ↑ Use of causality conditions in quantum theory. In: Physical Review. Volume 95, 1954, p. 1612.
  11. ^ The axial vector current in beta decay. In: Nuovo Cimento. Volume 16, 1960, p. 705.
  12. ↑ This corresponds to the number of particles in a special representation of the symmetry group SU (3) (SU for special unitary group ), that is the group of unitary (3 × 3) matrices with determinant 1. Baryons like protons and neutrons consist of three Quarks, mesons made up of two (a quark and an anti-quark).
  13. ↑ A schematic model of baryon and meson. In: Physics Letters B. Volume 8, 1964, p. 214. The name was taken by Gell-Mann from the book Finnegans Wake by James Joyce ("Three quarks for Muster Mark"), where, according to Arno Schmidt, it reproduces a gull's cry onomatopoeically, which rhymes with König Marke. In addition to linguistic interests, Gell-Mann also has ornithological interests.
  14. ↑ According to Harald Fritzsch : Das absolut Unveränderliche, TB, 2007, p. 99, James Joyce heard the word while passing through the market in Freiburg im Breisgau when market women offered their dairy products.
  15. ↑ Quarks. Developments in the quark theory of hadrons. In: Acta physica austriaca. Suppl. 9, 1972, p. 733.
    Light cone current algebra, pi decay and e + e - annihilation. In: Fritzsch and W. Bardeen (eds.): Scale and conformal symmetry in hadron physics. 1973, p. 139.
    However, the degree of color freedom was used in models by Yōichirō Nambu , Han and Greenberg as early as the mid-1960s .
  16. ↑ Fritzsch, Gell-Mann and Leutwyler: Advantages of the color octet gluon picture. In: Physics Letters B. Volume 47, 1973, p. 365.
  17. ^ Fritzsch and Gell-Mann: Current algebra. Quarks and what else? In: 16th International Conference High energy physics. CERN 1972, Volume 2, p. 135.
  18. ↑ CERN pays tribute to Murray Gell-Mann ( English ) CERN . Retrieved July 24, 2019.
  19. ^ Reviews of modern physics. Volume 50, 1979, p. 721.
  20. ↑ In: van Nieuwenhuizen and Freedman (eds.): Supergravity. 1979.
  21. ↑ Ole Peters, Murray Gell-Mann: Evaluating gambles using dynamics. In: chaos. An Interdisciplinary Journal of Nonlinear Science. 26, 023103 (2016). AIP Publishing, February 2, 2016, accessed January 8, 2020 .
  22. ↑ Murray Gell-Mann passes away at 89. In: santafe.edu. Santa Fe Institute, May 24, 2019, accessed May 24, 2019 .
  23. ^ Member History: Murray Gell-Mann. (No longer available online.) In: search.AmPhilSoc.org. American Philosophical Society, formerly the original ; accessed on August 17, 2018 (English, with biography).  ( Page no longer available , search in web archives )@1@ 2Template: Dead Link / search.amphilsoc.org
  24. ↑ Murray Gell-Mann passes away at 89. In: santafe.edu. Santa Fe Institute, May 24, 2019, accessed May 24, 2019 .
personal data
SURNAME Gell-man, Murray
BRIEF DESCRIPTION American physicist
DATE OF BIRTH September 15, 1929
PLACE OF BIRTH New York City
DATE OF DEATH May 24, 2019
Place of death Santa Fe , New Mexico