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Marry Gell-mann

Picture of Marry Gell-mann

Date of Birth: 09/15/1929

Age: 87

Place of birth: New York

Citizenship: United States

Background

In 50-ies. elementary particle physics (the main area of ??scientific interests G.-M.) was in its formative stages. The main means of experimental studies in the department of physics were boosters, "shoot" a beam of particles in a fixed target: the collision of the incident particle with a target creates new particles. Using accelerators experimenters managed to get a few new types of elementary particles, in addition to the already known of protons, neutrons and electrons. Theoretical physicists have tried to find some scheme that would allow to classify all the new particles.

Scientists have discovered particles with an unusual (strange) behavior. The rate of particle production as a result of some clashes showed that their behavior is determined by the strong interaction, which is characterized by speed. Strong, weak, electromagnetic and gravitational interactions form the four fundamental interactions that underlie all phenomena. However, the strange particles decayed unusually long time that it would not be possible if the behavior was determined by the strong interaction. The rate of decay of strange particles, seems to point to the fact that this process is determined much more by the weak interaction.

In addressing this daunting task and focused G.-M. The starting point of his constructions, he chose the concept, known as charge independence. Its essence is a certain group of particles, emphasizing their similarities. For example, despite the fact that the proton and neutron different electric charge (proton has a charge of +1, neutron - 0), in all other respects they are identical. Consequently, they can be considered in two varieties of the same type of particles called nucleons having an average charge or the charge center equal to 1/2. We say that the proton and neutron form a doublet. Other particles may also be incorporated into doublets or similar in the three groups of particles known as triplets or "group" consisting of only a single particle - singlets. The common name of the group consisting of any number of particles - m.

All attempts to group the strange particles in the same way failed. Developing his scheme of categories, G.-M. I found that the average charge of the multiplets differ from 1/2 (the average charge of 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 strangeness of a particle is equal to twice the difference between the average charge of the multiplet and medium nucleon charge +1/2. G.-M. It showed that strangeness is conserved in all reactions, which involve strong interaction. In other words, the total strangeness of the particles to the strong interaction must be absolutely equal to the total strangeness of the particles after the interaction. The conservation of strangeness explains why the collapse of such particles can not be determined by the strong interaction. In a collision of some other, not strange, strange particles particles are produced in pairs. In this oddity of a single particle compensates another oddity. For example, if one particle in the pair has one oddity, the strangeness of the other is equal to -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 disintegrate as a result of the strong interaction, if the products of its decay must be a particle with zero strangeness, as such a decay would violate conservation of strangeness. G.-M. It showed that electromagnetic interference (characteristic time which acts concluded between the ages of strong and weak interactions) also keeps an oddity. Thus, strange particles, born, survive until the collapse determined the weak interaction that does not conserve strangeness. His ideas G.-M. He published in 1953

In 1955 G.-M. He became an associate professor at the Faculty at Caltech; next year onuzhe full professor, and in 1967 won an honorary professorial post, established in memory of Robert A. Millikan.

In 1961 G.-M. I found that multiplets system, he proposed to describe the strange particles can be incorporated into a much more general theoretical framework that allowed him to group all strongly interacting particles in the "family." His scheme G.-M. He called the Eightfold Path (by analogy with the eight attributes of the righteous lives in Buddhism) because some particles are grouped into families, numbering eight members. His proposed classification scheme particles also known as SU (3) symmetry. Soon regardless G.-M. similar particle classification proposed Israeli physicist Yuval Ne`eman.

Eightfold Path G.-M. often compared to the periodic table of chemical elements DI Mendeleyev, in which chemical elements with similar properties are grouped into families. Like Mendeleev, who left in the periodic table are some empty cells, predicting the properties of yet unknown elements G.-M. left vacancies in some families of particles, assuming any particles with the right set of features need to fill "the void." Theory G.-M. He 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. I 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 equal to the fractional part of the electric charge of the proton. The same came to the opening, and the American physicist George Zweig, who worked at the European Nuclear Research Center. G.-M. called particles with fractional charge quarks, borrowed the word from the novel by James Joyce`s "Finnegans Wake" ( "Three quarks for Mr. Brand!"). Quarks may have a charge +2/3 or -1/3. There are also charges antikvarkis -2/3 or +1/3. A neutron has no electrical charge, consists of one quark with a charge of +2/3 and two-quark with a charge of -1/3. Proton, which has charge +1, consists of two quarks with charges +2/3 and one quark with a charge of -1/3. Quarks are one and the same charge may differ in other properties, ie, There are several types of quark with the same charge. Different combinations of quarks allow to describe all strongly interacting particles.

In 1969 G.-M. He was awarded the Nobel Prize in Physics "for their discoveries concerning the classification of elementary particles and their interactions." Speaking at the award ceremony, Ivar Waller of the Royal Swedish Academy of Sciences said that G.-M. "For more than a decade, it is considered a leading scientist in the field theory of elementary particles." According to Waller, the methods proposed G.-M., "are among the most powerful tools for further research in elementary particle physics."

Among other contributions G.-M. in theoretical physics should be noted proposed jointly with Richard P. Feynman, the term "current" weak interactions and the subsequent development of the "current algebra."

In 1955 G.-M. married John. Margaret Dow, who was an archaeologist. They had a son and a daughter. G.-M. wife died in 1981 G.-M. He enjoyed watching the birds, enjoy walking, traveling to places untouched by civilization. In 1969 G.-M. He helped to organize a program of environmental studies, financed by the US National Academy of Sciences. Interested in it and historical linguistics.

G.-M. Danny Heineman awarded the American Physical Society (1959), Prize in Physics Ernest Lawrence of the United States Commission on Nuclear Energy (1966), Franklin Medal Franklin Institute (1967) and John J. medals. 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 G.-M. He was awarded an honorary degree from Yale University.