Quark

The three quarks are the positive quark, p, the negative quark, n, and the strange quark, k. (Note that we use p and n for the quarks, p and n for the nucleons.) All three are fermions, with spin h p has electric charge 4-f, and n and k have charge —i. The antiquarks p, h, and X have charges —f, and +5, respectively. Each quark has baryon number +5 (each antiquark—i) k has xenicity 1 and k has xenicity —1. 

The failure so far to observe any single quarks among the products of high-energy reactions indicates that they have very large mass, several thousand MeV. The effective mass of k in diquarks is about 145 MeV greater than that of n and p that of n is about 4 MeV greater than that of p. 

Let us consider the diquarks with baryon number 0 —that is, the compounds of a quark and an antiquark. The most stable diquarks are expected to be those in which both particles are in a Is orbital, as they move about their common center of mass. The quarks and antiquarks are different particles hence the Pauli exclusion principle does not forbid-parallel spins for a quark and its antiquark, and a I5- diquark can have resultant spin 0 or resultant spin 1. The mesons tt, and tt are ph, pp, (or nn), and pn, respectively, and various other mesons are similarly represented. The proton is represented by p-n and the neutron by pn-. The strange quark k (and its antiparticle k) are found in the mesons and baryons with xenicity different from zero. 

The nature of the strange quark is not as yet understood. One possibility is that k bears the same structural relation to n that the muon bears to the electron this relation, however, is also not yet clear. 

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Tracing the historical development of quantum physics, the author describes the baffling and seemingly lawless world of leptons, hadrons, gluons and quarks and provides a lucid and exciting guide for the layman to the world of infinitesimal particles. 

E. D. Commins and P. H. Bucksbaum, Weak Interactions oJEeptons and Quarks, Cambridge University Press, Cambridge, U.K., 1983, p. 389. 

J. I. Friedman and H. W. Kendall (Massachusetts Institute of Technology) and R. E. Taylor (Stanford) pioneering investigations concerning deep elastic scattering of electrons on protons and bound neutrons, of essential importance for the development of the quark model in particle physics. 

Quark, m. curd, curds trash, quarkartig, quarkig, a. curd-like, curdy. 

Speise-dl, n. edible oil specif., olive oil. -ordnung, /. diet, regimen, -pilz, to. edible fungus, -pumpe, /. feed pump, -quark, to. cottage cheese. 

As far as is known, ordinary matter is made of tiny building blocks called elementary particles. For example, an atom is made up of a nucleus surrounded by one or more electrons. As far as scientists have been able to determine, the electrons are elementary particles, not made of anything simpler. Fdowever, an atomic nucleus is not clcmcntai y, but is a composite particle made up of simpler particles called protons and neutrons. (The lightest nucleus is the nucleus of ordinai y hydrogen, which consists of only a single proton.) Today, physicists believe that even protons and neutrons are not elementai y but are composite particles made up of still simpler building blocks called quarks. 

At the present time, quarks are believed to be elementary particles. All the particles in an atom, whether elementary or not, are particles of matter and possess mass. Electrons, protons, and neutrons can also exist outside of atoms. 

Other aspects of the traditional view of the electron continue to come into question. Experiments carried out in Germany this year suggest that the electron may not be fundamental after all. Instead, it may possess a substructure consisting of lepto quarks. One cannot help but speculate whether there may come a point when the electron itself, which has been the cause of so many celebrations this year, might also turn out to be not so real. 

Glashow, Sheldon L. From alchemy to quarks the study of physics as a liberal art. Pacific Grove (CA) Brooks/Cole Pub, 1994. xxvi, 692 p. ISBN 0534166563... 

Xn an entiraly different wetter. X have been reading and thinking about the proton and quarks. The 9en r l wey how Nobel Prises have been given seems to be far from proper, but 1 obviously hava no influence. The second point is that the whole discussion of quarks and gluons is a little unconvincing. I hava even triad soma improvement on the way to look at the problem. I hava nothing really to report, but t continue to worry. 

The Km and Vj1iax of the Michaelis-Menten equation are actually made up of sums and products of little k s. You only have to look in most biochemistry texts to see a description of the derivation of the Michaelis-Menten equation in terms of little k s. The little k s are like quarks and leptons—you ve heard the names, but you re not quite sure what they are and even less sure about how they work. There s a section later (actually last) in the book if you haven t heard or can t remember about rate constants. 

Phillips believed he had found such an instance in Occult Chemistry—and that it even provided evidence that quarks were not fundamental particles. Yet in this boundary skirmish between physics and parapsychology over the subatomic world, Phillips, Smith, and Besant and Leadbeater ultimately will not persuade the scientific world. The boundaries between occultism and... 

Alex Keller s The Infancy of Atomic Physics Hercules in His Cradle (1983) is one of the finest such studies. Emilio Segre s From X-Rays to Quarks Modern Physicists and Their Discoveries (1980) is another excellent history, one that also focuses on the personalities of the physicists. 

Phillips notes in the preface to ESP of Quarks and Superstrings (1999) that... 

Phillips, Stephen M. 1980. Extra-Sensory Perception of Quarks. Wheaton Theosophical Publishing House. 

Segre, Emilio. 1980. From X-Rays to Quarks Modern Physicists and Their Discoveries. Berkeley The University of California Press. 

It led to a prediction that the number of different sorts of neutrino (equivalent in standard particle physics to the number of families of quarks and leptons) is less than 4 and probably no more than 3. This prediction was subsequently confirmed (subject to slight reservations about differences between effective numbers of neutrino species in the laboratory and in the early Universe) by measurements of the width or lifetime of the Z° boson at CERN in 1990. 

H. Reeves, in F. Sanchez, M. Collados and R. Rebolo (eds.), Observational and Physical Cosmology, Cambridge University Press 1990, p. 73, includes a description of the physics of the quark-hadron phase transition. 

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

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