Memories of Murray and the Quark Model

Life at Caltech with Murray Gell-Mann in the early 1960's is remembered. Our different paths to quarks, leading to different views of their reality, are described.Comment: Talk presented at the "Conference in Honor of Murray Gell-Mann's 80th Birthday," Nanyang Technical University, Singapore, February 24,2010. 18 pages, 4 figure

Origins of the Quark Model

An intellectual history of the quark model prior to February 1964 is presented. Aspects of this history are best summarized by a parable: Man asked God for a riddle, and God obliged: "What is green, hangs from a tree, and sings?" This, of course, was a very difficult question. So man asked God for the answer, and God replied: "A herring!" "A herring? But why is it green?" "Because I painted it green." "But why does it hang from a tree?" "Because I put it there. " "And why does it sing?" "If it didn't sing you would have guessed it was a herring.

K-leptonic decay and partially conserved currents

An operational definition for the partial conservation of the strangeness-changing vector current is given and applied to leptonic K+ and K20 decay. The K* resonance is explicitly included in the calculation and quantitative agreement with experiment is obtained. A detailed comparison with the K+ data of Brown et al. and Dobbs et al. is given. Because of rapid variations of a form factor, it is found that the data of these two groups are not in contradiction. From the K20 experiment of Luers et al., I=1/2 and 3/2 currents are seen to exist. Λβ decay is briefly considered. It is found that an explanation for the slowness of K leptonic decay and the vector part of Λβ decay may be connected with the partial conservation of the strangeness-changing vector current

Introduction to the chemistry of fractionally charged atoms: Electronegativity

The behavior of massive fractionally charged particles in matter is governed by the laws of chemistry if electromagnetic interactions dominate at atomic distances. Chemical properties of such "quark atoms" can be predicted by interpolating isoelectronic sequences. The properties of quark atoms lie between those of a neutral atom and an ion. Electronegativity helps in the qualitative understanding of quark chemistry. Electronegativities, together with ionization potentials and electron affinities, are computed for the quark elements. The concepts of chemical analogy and isomorphism are introduced. Analogies based on shell structure and electronegativity are established. Many quark elements cannot be compared to a single ordinary element. They are chemical chimeras. An understanding of quark chemistry is essential for the design and interpretation of quark-search experiments. The impact of chemical reactions on quark impurities in matter can be monitored by observing the behavior of more abundant isomorphic control elements. Contrary to common belief, the chemical differences between a quark element and its ordinary counterpart are substantial

The Symmetries of Nature

The study of the symmetries of nature has fascinated scientists for eons. The application of the formal mathematical description of symmetries during the last century has produced many breakthroughs in our understanding of the substructure of matter. In this talk, a number of these advances are discussed, and the important role that George Sudarshan played in their development is emphasize

Model for the hadrons

A particle spectrum in the low-mass region is obtained from the spin structure of the dominant Regge exchange. Since we work in the low-energy region, diffraction is negligible and resonances dominate the scattering.(1) Our calculational procedure exploits the fact that the dominant Regge exchange forces certain helicity amplitudes to vanish in the forward or backward directions

Migration trajectories of ‘highly skilled’middling transnationals: Singaporean transmigrants in London

10.1002/psp.569Population, Space and Place171116-12