Gell-Mann

M. Gell-Mann (California Institute of Technology, Pasadena) contributions and discoveries concerning the classification of elementary particles and their interactions. 

Gell-Mann, M., and Brueckner, K. A., Phys. Rev. 106, 364, Correlation energy of an electron gas at high density/ ... 

Quark model of hadrons (Gell-Mann, Zweig). 

Here both, ta and Aa> are the antisymmetric generators of 87/(3), i.e., the antisymmetric Gell-Mann matrices (A, A e 2,5,7 ), acting in flavor and color space, respectively. In the two-flavor color superconducting phase (2SC) where only the light quarks are involved in the condensation, the flavor index in Eq. (1) is restricted to A = 2. In this case it is always possible, without loss of generality, to perform a color rotation such that the 2SC phase is described by s22 / 0 and saa = 0 if (A, A ) (2,2). 

Dothan, Y., Gell-Mann, M., and Ne eman, Y. (1965), Series of Hadron Energy Levels as Representations of Non-Compact Groups, Phys. Lett. 17, 148. 

Gell-Mann began his career in physics when more and more new particles were being discovered. In the early part of his career, he made some important contributions to the field of particle physics. But it was only somewhat later that he began to ponder the problem of making some sense of the multitude of particles that were then known. 

The eightfold-way theory had its first success when Gell-Mann used it to predict the existence of an as-yet-undiscovered particle, just as Mendeleev had predicted the existence of undiscovered evidence. Gell-Mann called the hypothetical particle the omega-minus (it had a negative charge). In 1964 experimentalists found the particle and confirmed that it had exactly the mass Gell-Mann said it would have. 

When Gell-Mann and Zweig proposed their theories, quarks had never been observed in nature, so many physicists were skeptical of their existence. Their skepticism deepened when extensive experimental searches failed to turn up any evidence of free quarks in nature. The quark theory seemed to work, but the doubters viewed... 

By then the quest had passed from the hands of the chemists into those of the physicists, who made a series of discoveries that were eerily like those that had been made in chemistry. Physicists discovered new particles until the number of known particles grew beyond reason. Then, like their predecessor Mendeleev, Gell-Mann and Ne eman discovered a hidden order. Like Bohr, who had probed the workings of the atom, Gell-Mann and Zweig theorized about the inner mechanisms of mesons and baryons, introducing the concept of the quark. 

Gell-Mann, Murray. The Quark and the Jaguar. New York W. H. Freeman, 1994. Gell-Mann writes of his two main scientific interests, particle physics and the sciences of complexity. 

Within 1 year, at the Cosmotron, Fowler et al.66 discovered a new phenomenon, the associated production in the same collision of two different strange particles for example, a A0 and a K°. These observations were in agreement with Pais approach and prompted its full development in 1954 Gell-Mann and Pais and, independently, Nishijima67 were able to define the new quantum number, called strangeness, and, from a detailed analysis of the already rich harvest of new processes, to assign its value to all known particles. 

A further step of fundamental importance was made in 1961 by Gell-Mann and Ne eman who proposed a classification scheme based on the Sophus Lie group of symmetry SU(3)70 for the more than 100 particles endowed with strong interactions (hadrons). 

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