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Technicolor: status and prospects

Description: Technicolor models are briefly reviewed, and a number of promising signatures at hadron colliders are described. Low-scale technicolor should be discoverable in Run 11 of the Fermilab Tevatron; failing that, it would be hard to miss at the LHC. While technicolor models may be unfashionable, it is important to search for their signatures; we do not know how nature has chosen to break electroweak symmetry.
Date: September 1, 1997
Creator: Womersley, J.
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Matrix membranes and integrability

Description: This is a pedagogical digest of results reported in Curtright, Fairlie, {ampersand} Zachos 1997, and an explicit implementation of Euler`s construction for the solution of the Poisson Bracket dual Nahm equation. But it does not cover 9 and 10-dimensional systems, and subsequent progress on them Fairlie 1997. Cubic interactions are considered in 3 and 7 space dimensions, respectively, for bosonic membranes in Poisson Bracket form. Their symmetries and vacuum configurations are explored. Their associated first order equations are transformed to Nahm`s equations, and are hence seen to be integrable, for the 3-dimensional case, by virtue of the explicit Lax pair provided. Most constructions introduced also apply to matrix commutator or Moyal Bracket analogs.
Date: June 1, 1997
Creator: Zachos, C.; Fairlie, D. & Curtright, T.
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Topcolor and the First Muon Collider

Description: We describe a class of models of electroweak symmetry breaking that involve strong dynamics and top quark condensation. A new scheme based upon a seesaw mechanism appears particularly promising. Various implications for the first-stage muon collider are discussed.
Date: April 1, 1998
Creator: Hill, C.T.
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Photoproduction of hybrid mesons

Description: In this contribution the author discusses prospects for photoproducing hybrid mesons at CEBAF, based on recent model results and experimental indications of possible hybrids. One excellent opportunity appears to be a search for I = 1, J{sup PC} = 2{sup +{minus}} ``b{sub 2}{sup o}`` hybrids in (a{sub 2}{pi}){sup o} through diffraction photoproduction. Other notable possibilities accessible through {pi}{sup +}; {pi}{sub J}{sup +}(1770) in f{sub 2}{pi}{sup +} and (b{sub 1}{pi}){sup +}; {pi}{sup +}(1800) in f{sub 0}{pi}{sup +}, f{sub 2}{pi}{sup =}, {rho}{sup +}{omega} and ({rho}{pi}){sup +}; a{sub 1} in f{sub 1}{pi}{sup +} and f{sub 2}{pi}{sup +}; and {omega} in ({rho}{pi}){sup o}, {omega}{eta} and K{sub 1}K.
Date: November 1, 1998
Creator: Barnes, T.
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Modeling pollutant transport using a meshless-lagrangian particle model

Description: A combined meshless-Lagrangian particle transport model is used to predict pollutant transport over irregular terrain. The numerical model for initializing the velocity field is based on a meshless approach utilizing multiquadrics established by Kansa. The Lagrangian particle transport technique uses a random walk procedure to depict the advection and dispersion of pollutants over any type of surface, including street and city canyons
Date: January 1, 2002
Creator: Carrington, D. B. (David B.) & Pepper, D. W. (Darrell W.)
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RECURSION RELATIONS AND SIMPLIFIED EXPRESSIONS FOR THE 6-j SYMBOLS

Description: It is shown that the 144 symmetry properties of the 6-j symbols which were discovered by Regge can be displayed with a 4 x 4 array that is invariant to the ordering of three of the rows and all columns. The elements of the array are linear combinations of the quantum numbers. In addition, it is shown that a large set of three-term recursion relations exist. The recursion relations are used to deduce simplified expressions for the 6-j symbois in special cases. (auth)
Date: May 16, 1963
Creator: Zerby, C.D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department

THE SYSTEMATICS OF BARYON AND MESON STATES

Description: Present information on established and possible baryons and mesons, its derivation, and its organization on the basis of unitary symmetry are discussed. Some questions of particular interest in connection with the last point are considered. 35 references. (D.C.W.)
Date: January 1, 1963
Creator: Dalitz, R H
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Are partons confined tachyons?

Description: The author notes that if hadrons are gravitationally stabilized ``black holes``, as discrete physics suggests, it is possible that partons, and in particular quarks, could be modeled as tachyons, i.e. particles having v{sup 2} > c{sup 2}, without conflict with the observational fact that neither quarks nor tachyons have appeared as ``free particles``. Some consequences of this model are explored.
Date: March 1, 1996
Creator: Noyes, H.P.
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Quasi-degenerate neutrinos from an abelian family symmetry

Description: The authors show that models with an abelian family symmetry which accounts for the observed hierarchies of masses and mixings in the quark sector may also accommodate quasi-degeneracies in the neutrino mass spectrum. Such approximate degeneracies are, in this context, associated with large mixing angles. The parameters of this class of models are constrained. The authors discuss their phenomenological implications for present and foreseen neutrino experiments.
Date: December 31, 1996
Creator: Binetruy, P.; Lavignac, S.; Petcov, S. & Ramond, P.
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Partner: UNT Libraries Government Documents Department

Electroproduction of light quark baryons

Description: The status of electromagnetic excitation of light quark (u, d) baryon states is reviewed and confronted with results of calculations within the framework of microscopic models of the baryon structure and the photon - baryon coupling. Prospects for a qualitative improvement of their knowledge in this sector using photon and electron beams at the new, intermediate energy continuous wave (CW) electron machines are discussed.
Date: April 1, 1992
Creator: Burkert, V.
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Unified description of kaon electroweak form factors

Description: A calculation of the semileptonic decays of the kaon (K{sub l3}) is presented. The results are direct predictions of a covariant model of the pion and kaon introduced earlier by Ito, Buck, Gross. The weak form factors for K{sub l3} are predicted with absolutely no parameter adjustments of the model. The authors obtained for the form factor parameters: f{sub {minus}}(q{sup 2}=m{sub l}{sup 2})/f{sub +}(q{sup 2}=m{sub l}{sup 2})={minus}0.28 and {lambda}{sub +}= 0.028, both within experimental error bars. Connections of this approach to heavy quark symmetry will also be discussed.
Date: June 1, 1996
Creator: Afanasev, A. & Buck, W.
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Form factors of kaon semileptonic decays

Description: A calculation of the semi-leptonic decays of the kaon (K{sub 13}) is presented. The results are direct predictions of a covariant model of the pion and kaon introduced earlier by Ito, Buck, and Gross. The weak form factors for K{sub 13} are predicted with absolutely no parameter adjustments of the model. The authors obtained for the form factor parameters: f{sub {minus}}(q{sup 2} = m{sub 1}{sup 2})/f{sub +}(q{sup 2} = m{sub 1}{sup 2}) = 0.28 and {lambda}{sub +} = 0.028, both within experimental error bars. Connections of this approach to heavy quark symmetry is also discussed.
Date: July 1, 1996
Creator: Afanasev, Andrei & Buck, W.W.
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Quark-antiquark bound states in the relativistic spectator formalism

Description: The quark-antiquark bound states are discussed using the relativistic spectator (Gross) equations. A relativistic covariant framework for analyzing confined bound states is developed. The relativistic linear potential developed in an earlier work is proven to give vanishing meson {r_arrow} q + {anti q} decay amplitudes, as required by confinement. The regularization of the singularities in the linear potential that are associated with nonzero energy transfers (i.e. q{sup 2} = 0, q{sup {mu}} {ne} 0) is improved. Quark mass functions that build chiral symmetry into the theory and explain the connection between the current quark and constituent quark masses are introduced. The formalism is applied to the description of pions and kaons with reasonable results.
Date: November 1, 1999
Creator: Savkli, Cetin & Gross, Franz
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Goldstone pion and other mesons

Description: A covariant wave equation for q{anti q} interactions with an interaction kernel composed of the sum of constant vector and linear scalar confining interactions is solved for states with two quarks with identical mass. The model includes an NJL-like mechanism which links the dynamical breaking of chiral symmetry to the spontaneous generation of quark mass and the appearance of a low mass Goldstone pion. A novel feature of this approach is that it automatically explains the small mass of the pion even though the linear potential is a scalar interaction in Dirac space, and hence breaks chiral symmetry. Solutions for mesons composed of light quarks ({pi},{rho}, and low lying excited states) and heavy quarks ({rho}{sub c}, J/{Psi}, and low lying excited states) are presented and discussed.
Date: January 1, 1994
Creator: Gross, F. & Milana, J.
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Strong dynamics at the muon collider: Working group report

Description: New strong dynamics at the energy scale {approx} 1 TeV is an attractive and elegant theoretical ansatz for the origin of electroweak symmetry breaking. We review here, the theoretical models for strong dynamics, particularly, technicolor theories and their low energy signatures. We emphasize that the fantastic beam energy resolution ({sigma}{sub E}/E {approximately} 10{sup -4}) expected at the first muon collider ({radical}s=100-500 GeV) allows the possibility of resolving some extraordinarily narrow technihadron resonances and, Higgs-like techniscalars produced in the s-channel. Investigating indirect probes for strong dynamics such as search for muon compositeness, we find that the muon colliders provide unparalleled reaches. A big muon collider ({radical}s=3-4 TeV) would be a remarkable facility to study heavy technicolor particles such as the topcolor Z`, to probe the dynamics underlying fermion masses and mixings and to fully explore the strongly interacting electroweak sector.
Date: March 1, 1998
Creator: Bhat, P. C. & Eichten, E.
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Quark and proton spin structure in the Instanton Liquid Model of QCD

Description: Within an instanton based model of QCD the authors address the important question of how much of the proton spin is carried by the spins of the quarks and how much is due to orbital angular momentum and the spins of the gluons. Since this question arises already on the level of a single quark inside the proton, they study axial vector correlation functions for a quark in the so called Random Instanton Liquid Model (RILM) as well as for the Interacting Instanton Liquid Model (IILM).
Date: December 1, 1997
Creator: Blotz, A. & Shuryak, E.
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Quark-hadron duality in the 't Hooft model for meson weak decays: Different quark diagram topologies

Description: The authors compare the effects of different quark diagram topologies on the weak hadronic width of heavy-light mesons in the large N{sub c} limit. They enumerate the various topologies and show that the only one dominant (or even comparable) in powers of N{sub c} to the noninteracting spectator ''tree'' diagram is the ''annihilation'' diagram, in which the valence quark-antiquark pair annihilate weakly. They compute the amplitude for this diagram in the 't Hooft model (QCD in 1+1 spacetime dimensions with a large number of colors N{sub c}) at the hadronic level and compare to the Born term partonic level. They find that quark-hadron duality is not well satisfied, even after the application of a smearing procedure to the hadronic result. A number of interesting subtleties absent from the tree diagram case arise in the annihilation diagram case, and are described in detail.
Date: May 1, 1998
Creator: Grinstein, Benjamin & Lebed, Richard F.
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Some remarks on discrete physics as an ultimate dynamical theory

Description: The standard model of quarks and leptons currently fails to meet `t Hooft`s criterion for an ``Ultimate Dynamical Theory`` in that it contains 19 parameters which must be taken from experiment. Evaluating discrete physics in the same way we find that it requires 17 parameters and has already succeeded in computing 7 of them. While we are confident that the rest can also be computed, the very concept of an ultimate theory is incompatible with our attitude toward physics.
Date: October 1, 1995
Creator: Noyes, H.P.
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