Murray Gell-Mann (Gell-Mann), Murray( The American physicist, Nobel Prize in Physics, 1969)
Comments for Murray Gell-Mann (Gell-Mann), Murray
Biography Murray Gell-Mann (Gell-Mann), Murray
genus. September 15, 1929
American physicist Murray Gell-Mann was born in New York and was the youngest son of immigrants from Austria, Arthur and Pauline (Rayhshtayn) Gell-Mann. At the age of fifteen, G.-M. enrolled at Yale University, graduating in 1948. with a bachelor of arts degree. The following years he spent in graduate school at MIT, where in 1951. received his doctorate in physics. After a year's stay at the Princeton Institute for Basic Research (New Jersey), G.-M. joined the University of Chicago with Enrico Fermi, first teacher (1952 ... 1953), then assistant professor (1953 ... 1954) and Associate Professor (1954 ... 1955).
In 50-ies. physics of elementary particles (the main area of scientific interest G.-M.) was in the formative stage. The principal means of experimental research in the department of physics were boosters, 'slingshot' particle beam in a fixed target: the collision of incident particles with the target source of new particles. With the help of accelerators experimenters managed to get several new types of elementary particles, besides the already known protons, neutrons and electrons. Theoretical physicists have tried to find a scheme that would classify all the new particles.
Scientists have discovered particles with the unusual (strange) behavior. The rate of birth of such particles as a result of some of the clashes showed that their behavior is determined by the strong interaction, which is characterized by speed. Strong, weak, electromagnetic and gravitational interactions are comprised of four fundamental interactions that underlie all phenomena. However, strange particles decayed unusually long time, that it would be impossible if their behavior is determined by the strong interaction. The decay rate of strange particles, seems to point to the fact that this process is determined by a much weaker interaction.
In addressing this daunting task, and focused H.-M. The starting point of his theories, he chose the concept, known as charge independence. Its essence is a definite group of particles, which accentuates their similarities. For example, despite the fact that the proton and neutron are different electric charge (a proton has a charge of +1, the neutron - 0) in all other respects they are identical. Consequently, they are the two varieties of the same type of particles called nucleons, with an average charge, or center of charge, equal to 1 / 2. It is often said that the proton and neutron form a doublet. Other particles may also be included in a similar doublets or in groups of three particles, called triplets, or in the 'group', consisting of only one particle - singlets. General name of the group consisting of any number of particles - multiplet.
All attempts to group the strange particles similarly failed. In formulating its scheme of their grouping, GA-M. found that the average charge of their multiplets differs from 1 / 2 (the average charge of the nucleons). He came to the conclusion that this difference may be a fundamental property of strange particles, and proposed to introduce a new quantum property called strangeness. For reasons of algebraic nature of the strangeness of a particle is equal to twice the difference between the average charge of the multiplet and the average charge of the nucleons +1 / 2. GA-M. showed that strangeness is conserved in all reactions involving a strong interaction. In other words, the total strangeness of all particles to the strong interaction should be absolutely equal to the total strangeness of all particles after the interaction. Saving strangeness explains why the decay of such particles can not be determined by the strong interaction. In a collision of some other, not strange, strange particles are particles pairs. Thus the strangeness of a single particle compensates the strangeness of another. For example, if one particle in the pair is the strangeness of +1, the strangeness of the other is -1. That is why the total strangeness of strange particles, both before and after the collision is equal to 0. After the birth of strange particles scatter. Isolated strange particle can not decay due to the strong interaction, if the products of its decay must be a particle with zero strangeness, since such a collapse would prejudice the conservation of strangeness. GA-M. showed that the electromagnetic interaction (the characteristic time of which entered into between the ages of strong and weak interactions) also retains the strangeness. Thus, strange particles, born, survived until the collapse determined the weak interaction, which does not preserve the strangeness. His idea of GM-M. published in 1953
In 1955, Mr.. GA-M. became an adjunct professor at the Faculty of California Institute of Technology, in the next year he was full professor and in 1967. became an honorary professor's office, established in memory of Robert E. Millikan.
In 1961. GA-M. found that the system of multiplets, he proposed to describe the strange particles can be included in a much more general theoretical framework that enabled him to group all strongly interacting particles in the 'family'. His scheme of GA-M. called the eightfold way (by analogy with the eight attributes of the righteous lives of Buddhism), as some particles were grouped into families, numbering eight members. His proposed classification scheme of particles is also known as SU (3) symmetry. Soon, regardless of GA-M. similar classification of the particles suggested an Israeli physicist Yuval Ne'eman.
Eightfold Path G.-M. often compared to the periodic system of chemical elements DI. Mendeleev, in which the chemical elements with similar properties are grouped into families. Like Mendeleev, who left in the periodic table, some empty cells, predicting the properties of yet unknown elements, GA-M. left vacancies in some families of particles, suggesting some particles with the right set of properties to fill 'vacuum'. G. M-Theory. received partial confirmation in 1964, after the discovery of the so-called omega-minus-shperona, whose existence was predicted by them.
In 1963, while as a visiting professor at the Massachusetts Institute of Technology, G.-M. found that the detailed structure of the Eightfold Path can be explained by assuming that each particle participating in the strong interaction, consists of a triplet of particles with a charge constituting a fractional portion of the electric charge of the proton. The same opening came and American physicist George Zweig, who worked at the European Center for Nuclear Research. GA-M. called a particle with fractional charge quarks, borrowing a word from the novel by James Joyce's' Finnegans Wake '(' Three quarks for Mr. Mark! "). Quarks can have a charge of +2 / 3 or -1 / 3. There are also antiquarks with charges of -2 / 3 or 1 / 3. Neutron, which has no electric charge, consists of a single quark with charge +2 / 3 and two quarks of charge -1 / 3. Proton, which has charge +1, consists of two quarks with charges of +2 / 3 and one quark with charge -1 / 3. Quarks with the same charge may be different other properties, ie. There are several types of quarks with the same charge. Different combinations of quarks allow us to describe all strongly interacting particles.
In 1969. GA-M. was awarded the Nobel Prize in Physics "for his discoveries concerning the classification of elementary particles and their interactions'. Speaking at the award ceremony, Ivar Waller of the Royal Swedish Academy of Sciences noted that GM-M. 'for more than a decade, is considered the leading scientist in the field theory of elementary particles'. According to Waller, the methods proposed by G.-M., 'are among the most powerful tools for further research on elementary particle physics'.
Among other contributions GA-M. in theoretical physics should be noted his suggested together with Richard II. Feynman concept of 'current' weak interactions and the subsequent development of 'current algebra'.
In 1955, Mr.. GA-M. married J. Margaret Dawe, who was an archaeologist. They had a son and a daughter. The wife of G.-M. died in 1981. GA-M. enjoyed watching the birds, loves walking, traveling to places untouched by civilization. In 1969. GA-M. helped organize a program of environmental research, funded by the National Academy of Sciences. He is interested in historical linguistics.
GA-M. Danny Heineman awarded the American Physical Society (1959), Prize-winning physicist Ernest Orlando Lawrence Atomic Energy Commission, United States (1966), medals Franklinovskogo Franklin Institute (1967) and medals of John J. Carty, National Academy of Sciences USA (1968). He is a member of the American Academy of Arts and Sciences and a foreign member of the Royal Society of London. In 1959, Mr.. GA-M. was awarded an honorary degree from Yale University.