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O(1/M{sup 3}) effects for heavy-light mesons in lattice NRQCD

Description: The masses of spin-singlet and spin-triplet S-wave mesons containing a single heavy quark are computed in the quenched approximation. The light quark action and gauge field action are both classically-improved and tadpole-improved, and the couplings to the heavy quark are organized by the 1/M expansion of tadpole-improved NRQCD. At each of two lattice spacings, near 0.22fm and 0.26fm, meson masses are obtained for heavy quarks spanning the region between charmed and bottom mesons. Results up to O(1/M), O(1/M{sup 2})and O(1/M{sup 3}) are displayed separately, so that the convergence of the heavy quark expansion can be discussed. Also, the effect of each term in the O(1/M{sup 3}) contribution is computed individually. For bottom mesons the 1/M-expansion appears to be satisfactory, but the situation for charmed mesons is less clear.
Date: March 1998
Creator: Lewis, Randy & Woloshyn, R. M.
Partner: UNT Libraries Government Documents Department

Analogous behavior in the quantum hall effect, anyon superconductivity, and the standard model

Description: Similarities between physical behavior known to occur, or suspected of occurring, in simple condensed matter systems and behavior postulated by the standard model are identified and discussed. Particular emphasis is given to quantum number fractionalization, spontaneous occurrence of gauge forces, spontaneous violation of P and T, and anomaly cancellation. 46 refs.
Date: July 1, 1991
Creator: Laughlin, R.B. (Stanford Univ., CA (United States). Dept. of Physics) & Libby, S.B. (Lawrence Livermore National Lab., CA (United States))
Partner: UNT Libraries Government Documents Department

Anomalies, unitarity and renormalization

Description: It is indicated how renormalizability of a gauge theory with ..gamma../sub 5/ couplings to fermions can require additional dynamical constraints to those already well known in connection with the triangle anomaly. An outline of differences from previous work is given. 11 references. (JFP)
Date: January 1, 1978
Creator: Frampton, P.H.
Partner: UNT Libraries Government Documents Department

The approach to equilibrium in a quark-gluon plasma

Description: The basic questions to be addressed in this paper are: How does the quark-gluon plasma, once formed in heavy-ion collisions, approach equilibrium. What are the basic equilibrium time scales - how do they compare with the plasma lifetime before hadronization and freeze-out set in. In particular, how do the strong color anisotropies, which are presumably present in the initial formation stage disappear and how fast, if at all, do the color degrees of freedom attain local equilibrium. The approach that I wish to present here involves the following chain of arguments: equilibration is related to dissipation of energy and creation of entropy; it is determined by the dissipative, i.e., imaginary part of certain response functions - for example, to calculate the rate of dissipation for a density perturbation in an equilibrium plasma we need to work out the imaginary part of the retarded density-density correlation function; this imaginary part of the response function is dominated by its poles which signal collective modes - for example, phonons in the density-density correlation function, (colored) plasmons in the electric and magnetic response functions, etc.; from the imaginary part one can calculate a damping rate ..gamma.. for these collective modes which in turn yields an estimate for the equilibration time scale tau/sub equ/ approx. h-bar/..gamma... In this contribution I will concentrate on color equilibration and thus focus on color electric and magnetic plasma oscillations and their damping rates. 21 refs.
Date: January 1, 1987
Creator: Heinz, U.
Partner: UNT Libraries Government Documents Department

Aspects of the dynamics of heavy-quark systems

Description: The analysis of bound states composed of heavy quarks and antiquarks has provided a window into the structure of the strong interactions. These systems contain our best evidence that the quarks from which the hadrons are built are ordinary fermions which obey the Dirac equation and which couple to electromagnetism just as electrons do. However, the heavy-quark systems which have been studied to date, the systems of c- anti c and b- anti b bound states, seem to be bound by forces which bear no obvious relation to the gluons which we expect are the fundamental mediators of the strong interactions. The essential difficulty in understanding this connection arises from the fact that the c- anti c and b- anti b systems occupy an intermediate regime in the behavior of the gauge theory. At very small distances the q- anti q potential is expected to become a Coulomb potential, directly reflecting one-gluon exchange. At very large distances, the potential should be proportional to the q- anti q separation, reflecting the formation of confining strings of color flux. For a proper understanding, one would need to see precisely how the collective behavior of gluons modifies and alters single gluon effects. We seem very far from such a detailed understanding. It is possible, however, to gain some insight into the nature of this intermediate regime by considering the behavior of q- anti q systems from a broad perspective, assembling a variety of distinct aspects of these systems which are sensitive to the properties of gauge theories at intermediate distances. 46 references.
Date: December 1, 1983
Creator: Peskin, M.E.
Partner: UNT Libraries Government Documents Department

Cabibbo angle in a six quark gauge model. [Mass matrices]

Description: General structures of the mass matrices resulting from a quark-Higgs Yukawa interaction are discussed. It is assumed that there are two sets of Higgs bosons in a six quark SU(2)/sub L/ x SU(2)/sub R/ x U(1) gauge model and require that the interaction be invariant under a general discrete symmetry. Three physically acceptable mass matrices are found including those of Fritzsch, and Hagiwara et al. Special attention is paid to the phase of the vacuum expectation value of the Higgs boson, which is related to CP violation. A mass relation among six quarks, m/sub t/ = m/sub b/ ..sqrt.. m/sub u/m/sub c//m/sub d/m/sub s/ is obtained for the latter models. No new mass matrices are found when there are three sets of Higgs bosons.
Date: January 1, 1978
Creator: Kitazoe, T. & Tanaka, K.
Partner: UNT Libraries Government Documents Department

Cabibbo current and CP violation in a six quark gauge model

Description: The extended Cabibbo current in a six quark gauge model is obtained in terms of Eulerian angles theta/sub c/, phi and psi which are functions of quark mass ratios and phases in the quark mass matrices. Particular attention is paid to arbitrary phases that lead to CP violation. In the limit m/sub u//m/sub c/ ..-->.. 0 there is no CP violation for parallel ..delta..S parallel = 1 processes. Some phenomenological results of the model are discussed.
Date: January 1, 1977
Creator: Hagiwara, T.; Kitazoe, T.; Mainland, G.B. & Tanaka, K.
Partner: UNT Libraries Government Documents Department

Can EPR non-locality be geometrical?

Description: The presence in Quantum Mechanics of non-local correlations is one of the two fundamentally non-intuitive features of that theory. The non-local correlations themselves fall into two classes: EPR and Geometrical. The non-local characteristics of the geometrical type are well-understood and are not suspected of possibly generating acausal features, such as faster-than-light propagation of information. This has especially become true since the emergence of a geometrical treatment for the relevant gauge theories, i.e. Fiber Bundle geometry, in which the quantum non-localities are seen to correspond to pure homotopy considerations. This aspect is reviewed in section 2. Contrary-wise, from its very conception, the EPR situation was felt to be paradoxical. It has been suggested that the non-local features of EPR might also derive from geometrical considerations, like all other non-local characteristics of QM. In[7], one of the authors was able to point out several plausibility arguments for this thesis, emphasizing in particular similarities between the non-local correlations provided by any gauge field theory and those required by the preservation of the quantum numbers of the original EPR state-vector, throughout its spatially-extended mode. The derivation was, however, somewhat incomplete, especially because of the apparent difference between, on the one hand, the closed spatial loops arising in the analysis of the geometrical non-localities, from Aharonov-Bohm and Berry phases to magnetic monopoles and instantons, and on the other hand, in the EPR case, the open line drawn by the positions of the two moving decay products of the disintegrating particle. In what follows, the authors endeavor to remove this obstacle and show that as in all other QM non-localities, EPR is somehow related to closed loops, almost involving homotopy considerations. They develop this view in section 3.
Date: October 1, 1995
Creator: Ne`eman, Y. & Botero, A.
Partner: UNT Libraries Government Documents Department

t-Channel unitarity construction of small-x kernels

Description: In the leading-log approximation, the small-x behavior of parton distributions in QCD is derived from the BFKL evolution equation. The authors describe the ion as a reggeon Bethe-Salpeter equation and discuss the use of reggeon diagrams to obtain 2-2 and 2-4 reggeon interactions at O(g{sup 4}). They then outline the dispersion theory basis of multiparticle j-plane analysis and describe how a gauge theory can be studied by combining Ward identity constraints with the group structure of reggeon interactions. Gluon reggeization, the O(g{sup 2}) BFKL kernel and O(g{sup 4}) corrections to it, are derived within this formalism. They give an explicit expression for the O(g{sup 4}) forward ``parton`` kernel in terms of logarithms and evaluate the eigenvalues. A separately infra-red finite component with a holomorphically factorizable spectrum is shown to be present and conjectured to be a new leading-order partial-wave amplitude. A comparison is made with Kirschner`s discussion of O(g{sup 4}) contributions from the multi-Regge effective action.
Date: 1994-12~
Creator: Coriano, C. & White, A. R.
Partner: UNT Libraries Government Documents Department

t-Channel unitarity construction of small-x kernels

Description: The authors present the BFKL equation as a reggeon Bethe-Salpeter equation and discuss the use of reggeon diagrams to obtain 2-2 and 2-4 reggeon interactions at O(g{sup 4}). They then outline the dispersion theory basis of multiparticle j-plane analysis and describe how a gauge theory can be studied by combining Ward identity constraints with the group structure of reggeon interactions. The derivation of gluon reggeization, the O(g{sup 2}) BFKL kernel, and O(g{sup 4}) corrections, is described within this formalism. They give an explicit expression for the O(g{sup 4}) forward ``parton`` kernel in terms of logarithms and evaluate the eigenvalues. A separately infra-red finite component with a holomorphically factorizable spectrum is shown to be present and conjectured to be a new leading-order partial-wave amplitude. A comparison is made with Kirschner`s discussion of O(g{sup 4}) contributions from the multi-Regge effective action.
Date: December 1995
Creator: Coriano, C. & White, A. R.
Partner: UNT Libraries Government Documents Department

Chiral anomalies and differential geometry

Description: Some properties of chiral anomalies are described from a geometric point of view. Topics include chiral anomalies and differential forms, transformation properties of the anomalies, identification and use of the anomalies, and normalization of the anomalies. 22 references. (WHK)
Date: October 1, 1983
Creator: Zumino, B.
Partner: UNT Libraries Government Documents Department

Chiral condensate in the deconfined phase of quenched gauge theories

Description: The authors compute the low lying spectrum of the overlap Dirac operator in the deconfined phase of finite-temperature quenched gauge theory. It suggests the existence of a chiral condensate which they confirm with a direct stochastic estimate. They show that the part of the spectrum responsible for the chiral condensate can be understood as arising from a dilute gas of instantons and anti-instantons.
Date: October 25, 1999
Creator: Edwards, R.G..; Heller, U.M..; Kiskis, J. & Narayanan, R.
Partner: UNT Libraries Government Documents Department

Classical geometrical interpretation of ghost fields and anomalies in Yang-Mills theory and quantum gravity

Description: The reinterpretation of the BRS equations of Quantum Field Theory as the Maurer Cartan equation of a classical principal fiber bundle leads to a simple gauge invariant classification of the anomalies in Yang Mills theory and gravity.
Date: May 14, 1985
Creator: Thierry-Mieg, J.
Partner: UNT Libraries Government Documents Department

Classical solutions with both instantons and anti-instantons. [Matrix formalism]

Description: The SO(4) Yang-Mills theory is formulated in terms of matrices and finds solutions with both instantons and anti-instantons. The ''left-handed'' and ''right-handed'' projections of the gauge field yield the instanton and anti-instanton sectors, respectively. There are no interactions among instantons and anti-instantons in this model. The matrix formalism developed will facilitate the analysis of various SO(4) models in which the gauge field is coupled with other fields.
Date: January 1, 1977
Creator: Mainland, G. B.; Takasugi, E. & Tanaka, K.
Partner: UNT Libraries Government Documents Department

A classical theory of continuous spin and hidden gauge invariance

Description: We present a classical higher derivative point particle theory whose quantization gives Wigner's continuous spin representation of the Poincare group. Although the theory is not reparameterization invariant in the usual sense, it does possess a hidden gauge invariance that provides a non-local representation of the reparameterization group. The Hamiltonian of the theory does not vanish and its value is the continuous spin parameter. The theory presented here represents the simplest example of a wide class of higher derivative theories possessing a hidden gauge invariance.
Date: January 1, 1991
Creator: Zoller, D.
Partner: UNT Libraries Government Documents Department

A classical theory of continuous spin and hidden gauge invariance

Description: We present a classical higher derivative point particle theory whose quantization gives Wigner`s continuous spin representation of the Poincare group. Although the theory is not reparameterization invariant in the usual sense, it does possess a hidden gauge invariance that provides a non-local representation of the reparameterization group. The Hamiltonian of the theory does not vanish and its value is the continuous spin parameter. The theory presented here represents the simplest example of a wide class of higher derivative theories possessing a hidden gauge invariance.
Date: December 31, 1991
Creator: Zoller, D.
Partner: UNT Libraries Government Documents Department

Classification of gauge groups for unified weak and electromagnetic interactions. UR-654. [Quarks, Lie group]

Description: General structure of the gauge group C underlying the unified weak and electromagnetic interactions, assuming that G is compact and that all quarks have only electric charges 2/3 and -1/3. Then, it is proven that G cannot contain any exceptional Lie groups G/sub 2/, F/sub 4/, E/sub 6/, E/sub 7/, and E/sub 8/ as its factor. Moreover, the underlying representations for quark multiplets to be used must be one of fundamental representations for each component simple Lie group contained as a factor of G. For example, only spinor representation is allowed for SO(2l + 1) groups. If G is semi-simple in addition, then G must be a product of SU(3l) groups. This latter fact is likely in conflict with the present experimental data.
Date: April 19, 1978
Creator: Okubo, S.
Partner: UNT Libraries Government Documents Department

Composite weak bosons at supercolliders

Description: Following a brief survey of nongauge interactions of composite W and Z from a theoretical viewpoint, we point out some of conspicuous signatures of compositeness at supercolliders, in particular W..gamma.. and Z..gamma.. production through q anti q by interactions of dimension six. In these processes, a suppression factor 1/..lambda../sup 2/ due to compositeness scale ..lambda.. is largely compensated by longitudinal polarizations of W and Z, allowing us to probe up to high values of ..lambda... 10 refs., 3 figs.
Date: June 1, 1987
Creator: Suzuki, Mahiko
Partner: UNT Libraries Government Documents Department

Concerning Gribov vacuum copies in non-abelian gauge theory

Description: Construction of gauge field configurations A/sub ..mu..//sup a/(x) in an SU(2) Yang-Mills theory satisfying everywhere F/sub ..mu nu..//sup a/(x) = 0 is discussed. Using the method of sections, a field related to the zero-size limit of an instanton is presented. The corresponding limit for a multi-instanton solution requires a generalization of the Landau gauge condition. Finally, an alternative method and explicit solution is given for the case of delta/sub ..mu../A/sub ..mu..//sup a/ = 0.
Date: January 1, 1978
Creator: Frampton, P.H.; Palmer, W.F. & Pinsky, S.S.
Partner: UNT Libraries Government Documents Department

Conditions for renormalizability of quantum flavor dynamics

Description: The presence of a new anomaly, in addition to the Adler-Bell-Jackiw (ABJ) anomaly, is shown for gauge theories with ..gamma../sub 5/ couplings. The ABJ anomaly is discussed first by shifting variable of a linearly-divergent integral, then by dimensional regularization. Using the second method, the general nonabelian case is considered, in the presence of an overlapping divergence. A new anomaly is discovered which is not, in general cancelled by the usual restrictions because fermion masses are involved, assuming no cancellation between different Feynman diagrams, and current-algebra quark masses, then leads to the conclusion that the standard model of quantum flavor dynamics (i.e., that of Glashow, Salam, Ward, Weinberg, Kobayashi and Maskawa) is non-renormalizable. Imposition of renormalizability dictates that new dynamical constraints be met. Hence, only that part of the quark mass corresponding to the lepton mass in the same quark-lepton generation is generated by the electroweak interactions. The remaining mass comes presumably from the strong interaction for which the dynamical theory must therefore have at least some flavor dependence; this is not the case for e.g., quantum chromodynamics which is totally flavor-blind. 48 references.
Date: unknown
Creator: Frampton, P.H.
Partner: UNT Libraries Government Documents Department

Confinement and lattice gauge theory

Description: The motivation for formulating gauge theories on a lattice to study non-perturbative phenomena is reviewed, and recent progress supporting the compatibility of asymptotic freedom and quark confinement in the standard SU(3) Yang-Mills theory of the strong interaction is discussed.
Date: June 1, 1980
Creator: Creutz, M
Partner: UNT Libraries Government Documents Department