bluuebunny/crossref_metadata_2025 huggingface dataset:
Hadron Structure from Lattice Quantum Chromo Dynamics (QCD)
Authors: SOMMER R.
Published: November 2004

We give an introduction to the calculational methods used to investigate the structure of strongly interacting particles within the framework of lattice QCD, the fundamental theory of strong interactions. The analogy of and the difference to a calculation of equilibrium properties in statistical mechanics are pointed out. We discuss the algorithm used for the most CPU – intensive part of the calculation: the inversion of a large sparse matrix. The physical examples are the calculations of the strength of beta-decay and the [Formula: see text] mixing matrix element. The latter is of great interest for the interpretation of current high energy experiments and also gives insight into the accuracy of the static approximation for b-quarks.
Local Electronic Structure and Short-Range Order in a Computer Simulated Amorphous Metal
Authors: BELENKII A.Ya. , FRADKIN M.A.
Published: November 2004

The relationship between topological short-range order and a local electronic structure was analyzed in the computer model of an amorphous metal. The model, obtained by means of the original self-consistent cluster simulation procedure was studied with the use of Voronoi tesselation, the distribution of the atomic level stresses and the icosahedral order parameters. It was found that a marked correlation exists within 2 atomic parameter groups, one of which corresponds to the local dilatation and the other to the spherical symmetry distortion.

The local density of electronic d-states (DOS) and the distribution of the electronic parameters was analyzed. The local electronic structure, calculated within the tight-binding approximation, appears to depend on the local atomic order by two-fold means: the interatomic distances decrease leads to the increase of the local bandwidth, and the icosahedral configuration distortion reduces the DOS at the Fermi level. The study of the local configurations stability shows, that the most stable configurations are the slightly distorted icosahedra.
THE 2D HEISENBERG ANTIFERROMAGNET IN HIGH-Tc SUPERCONDUCTIVITY: A Review of Numerical Techniques and Results
Authors: BARNES T.
Published: November 2004

In this article we review numerical studies of the quantum Heisenberg antiferromagnet on a square lattice, which is a model of the magnetic properties of the undoped “precursor insulators” of the high temperature superconductors. We begin with a brief pedagogical introduction and then discuss zero and nonzero temperature properties and compare the numerical results to analytical calculations and to experiment where appropriate. We also review the various algorithms used to obtain these results, and discuss algorithm developments and improvements in computer technology which would be most useful for future numerical work in this area. Finally we list several outstanding problems which may merit further investigation.
A MATHEMATICA™ PACKAGE FOR COMPUTING OPERATOR PRODUCT EXPANSIONS
Authors: THIELEMANS K.
Published: November 2004

A general purpose Mathematica™ package for computing Operator Product Expansions of composite operators in meromorphic conformal field theory is described. Given the OPEs for a set of “basic” fields, OPEs of arbitrarily complicated composites can be computed automatically. Normal ordered products are always reduced to a standard form. Two explicit examples are presented: the conformal anomaly for superstrings and a free field realization for the [Formula: see text] Kač-Moody-algebra.
HIGH SPEED SIMULATIONS OF ORDERED AND DISORDERED CELLULAR AUTOMATA
Authors: GERLING R.W. , STAUFFER D.
Published: November 2004

“Dissident” sites in random Boolean automata always differ from all their four nearest neighbors. We check how their number decreases if for each such site the rule which it obeys is inverted in regular intervals. We updated 0.9 sites per nanosecond on one NEC-SX3 processor; for simple one-dimensional exclusive-or automata, we updated 14 sites per nanosecond.
SPECIAL-PURPOSE ISING MODEL RANDOM LATTICE PROCESSOR
Authors: ANDREICHENKO V.B. , DOTSENKO VL.S. , SHCHUR L.N. , TALAPOV A.L.
Published: November 2004

We have designed and built a special purpose processor with a very good performance to price ratio, which permits to propose a new way for parallel computing. A simple one spin flip Monte Carlo algorithm is realized in hardware, so the processor is suitable for studies of dynamic as well as thermodynamic properties of the two-dimensional Ising model with different types of inhomogeneities. The speed of the processor is defined completely by the speed of memories used in it: to perform an elementary Monte Carlo step the processor needs a time only several percent larger than one memory cycle time. So it realizes the fastest possible one spin flip Monte Carlo processor architecture.
ACCEPTANCES AND AUTOCORRELATIONS IN THE HYBRID MONTE CARLO ALGORITHM
Authors: GUPTA SOURENDU
Published: November 2004

The acceptance probability in Hybrid Monte Carlo simulations of QCD, in particular, its dependence on the lattice size, quark mass and the coupling, is discussed. Results on the tuning of parameters required in order to achieve low autocorrelations in the 2-d XY model are presented. In both phases of this model, the dynamical critical exponent is close to 2 for runs with trajectory lengths between 1 and 3 molecular dynamics units.
TOPOLOGY AND SU(2) LATTICE GAUGE THEORY WITH DYNAMICAL WILSON FERMIONS
Authors: JOZEFINI B. , LINKE V. , MÜLLER-PREUSSKER M. , NAKAMURA A.
Published: November 2004

In this talk we present results of a recent investigation of the topological vacuum structure in SU(2) lattice gauge theory with Wilson fermions. An effective action given by the hopping parameter expansion up to the 6-th order is used. To check the reliability of this approximation we compare it with the outcomes of an exact algorithm. The topological charge is measured according to a geometric prescription.
MULTIGRID INVERSION OF THE STAGGERED FERMION MATRIX WITH U(1) AND SU(2) GAUGE FIELDS
Authors: HULSEBOS A. , SMIT J. , VINK J.C.
Published: November 2004

We describe a ground state decomposition multigrid method for the inversion of fermion matrices and we test it for staggered fermions coupled to U(1) and SU(2) gauge fields on a two dimensional lattice.
A GEOMETRICAL VIEW OF THE MINUS-SIGN PROBLEM
Authors: MURAMATSU A. , ZUMBACH G. , ZOTOS X.
Published: November 2004

It is shown that the sign of the fermionic determinant in the projector Monte Carlo method is directly related to a topological invariant. A key ingredient to obtain this result is the identification of the appropriate manifolds to describe the evolution of a fermionic trial wavefunction. They allow for a purely geometrical consideration of the minus-sign problem.
CLUSTER MONTE CARLO ALGORITHMS IN STATISTICAL MECHANICS
Authors: WANG JIAN-SHENG
Published: November 2004

The cluster Monte Carlo method, where variables are updated in groups, is very efficient at second order phase transitions. Much better results can be obtained with less computer time. This article reviews the method of Swendsen and Wang and some of its applications.
COMPUTATION OF 1-LOOP CONTRIBUTIONS IN Y.M. THEORIES WITH CLASS III NONRELATIVISTIC GAUGES
Authors: BURNEL A. , CAPRASSE H.
Published: November 2004

A program to compute the gluon self-energy diagram in class III nonrelativistic gauges has been constructed. It succeeded to show that axial gauges do not exhibit nonlocal counterterms. The high complexity of the calculations, the need to be able to control intermediate steps of calculations and the necessity to work inside a limited memory of a few Mbytes led us to give it special features which may serve outside the specific application for which it has been designed.

The structure of the program and its salient working features are described. It is divided into four modules, which are almost independent except that they are linked by their respective output. Files containing intermediate results of calculations are automatically generated. The amount of algebraic manipulations has been greatly reduced thanks to a careful choice of the representation of the expression adapted to each stage of the calculation. The adaptative character of this program is discussed as well as the generalization it needs to cover other types of Feynman diagram calculations.
PERIODIC AND QUASIPERIODIC TIME-DEPENDENT BEHAVIOR IN COLLECTIVE ORDERED PHASES
Authors: GALLAS JASON A.C. , BOURBONNAIS ROCH , HERRMANN HANS J.
Published: November 2004

We investigate numerically totalistic cellular automata rules in four and five dimensions that have been recently proposed by Chaté and Manneville and that show periodic or quasiperiodic time sequences in the magnetization. We show how to implement such rules fast on a Connection Machine. We confirm the proposed behavior by analyzing the time and size dependence of the distance from the attractor. Also the dependence of the initial configuration, the behavior of very small systems and mean-field calculations are presented.
STRONG AND WEAK FORMS OF THE METHOD OF MOMENTS AND THE COUPLED DIPOLE METHOD FOR SCATTERING OF TIME-HARMONIC ELECTROMAGNETIC FIELDS
Authors: LAKHTAKIA AKHLESH
Published: November 2004

Algorithms based on the method of moments (MOM) and the coupled dipole method (CDM) are commonly used to solve electromagnetic scattering problems. In this paper, the strong and the weak forms of both numerical techniques are derived for bianisotropic scatterers. The two techniques are shown to be fully equivalent to each other, thereby defusing claims of superiority often made for the charms of one technique over the other. In the final section, reductions of the algorithms for isotropic dielectric scatterers are explicitly given.
THE USE OF NEURAL NETWORK CLASSIFIERS FOR HIGGS SEARCHES
Authors: PETROLINI ALESSANDRO
Published: November 2004

Neural Network Classifiers are used to separate the signal from the background in a High-Energy Physics problem. The basic principles of Multidimensional Analysis by means of Back-Propagation Neural Network Classifiers and the application to the Higgs search are discussed. A search for the Minimal Standard Model Higgs boson, through the reaction [Formula: see text], using the data collected in 1990 by the DELPHI detector at LEP is made. The technique used allows to reach good detection efficiencies and no evidence of the Minimal Standard Model Higgs boson with mass less than 37 GeV is found. The use of Neural Network Classifiers proves to be a very powerful classification method. A comparison of the method with standard analysis techniques is presented.
WETTING OF HOT GLUONS
Authors: WIESE U.-J.
Published: November 2004

In the SU(3) pure gauge theory the high temperature deconfinement phase transition is first order. At the transition the confined phase coexists with three distinct deconfined phases. The interfaces separating the various phases show universal critical behavior when the confined phase completely wets the deconfined-deconfined interfaces. The critical exponents of complete wetting are derived from an interface solution of a Z(3) symmetric effective theory for the Polyakov loop. When complete wetting occurs in the pure glue theory the deconfinement transition proceeds via domain wall splitting. When quarks are present wetting disappears and the standard bubble nucleation scenario applies.
ISING DROPLETS, NUCLEATION, AND STRETCHED EXPONENTIAL RELAXATION
Authors: Stauffer Dietrich
Published: November 2004

The standard Ising model in two and three dimensions was simulated with Metropolis-Glauber kinetics on the Intel Hypercube with 32 MIMD processors of i860 type, each with 16 megabytes of distributed memory, and on 8 such processors of the Alliant FX with shared memory. The nucleation time in reverse magnetic fields h. was found to increase as 1/h2 in three dimensions, for times up to millions of iterations. The relaxation towards the equilibrium spontaneous magnetization was a simple exponential in three dimensions and a stretched exponential in two below the critical temperature; its power-law decay at the critical point lead to z=2.18(d=2) and =2.09 (d=3). The Becker-Döring equation for the growth of microdroplets leads at the critical temperature to a growth rate vanishing with some power of the time.
DYNAMICS OF FULLY CONNECTED NEURAL NETWORKS WITH SIGN CONSTRAINTS
Authors: GUSSO M. , MARANGI C. , NARDULLI G. , PASQUARIELLO G.
Published: November 2004

We consider fully connected neural networks near saturation, trained by a modified Edinburgh algorithm, with sign constraints on the synaptic couplings. We study the domains of attraction of the stored patterns for both the balanced and the unbalanced case (excess of positive over negative constraints). A comparison with the dilute network is also included.
A STUDY OF GLOBAL MONOPOLE IN LYRA GEOMETRY
Authors: RAHAMAN F. , MAL S. , GHOSH P.
Published: November 2004

A class of exact static solution around a global monopole resulting from the breaking of a global SO (3) symmetry is obtained in the context of Lyra geometry.

Our solution is shown to possess an interesting feature like "wormholes" spacetime. It has been shown that the global monopole exerts no gravitational force on surrounding nonrelativistic matter.
TWO-DIMENSIONAL GRAVITY COUPLED TO (p, q) MINIMAL MATTER AND VIRASORO CONSTRAINTS
Authors: SAKAI KENJI
Published: November 2004

We treat 2D gravity coupled to (p, q) minimal conformal matter as 2D string theory. Then its massless tachyon field can be identified with the Zp-twisted boson. We derive the Virasoro constraints on the tachyon S-matrix from the conformal invariance of its general interaction.
INTEGRABLE MODELS OF FIELD THEORY AND SCATTERING ON QUANTUM HYPERBOLOIDS
Authors: ZABRODIN A.
Published: November 2004

We consider the scattering of two dressed excitations in the antiferromagnetic XXZ spin-1/2 chain and show that it is equivalent to the S-wave scattering problem for a free particle on the certain quantum symmetric space “quantum hyperboloid” related to the non-compact quantum group SU q (1, 1).
A CAUSAL, LORENTZ COVARIANT AND GAUGE-INVARIANT VACUUM FOR A DIRAC FIELD IN THE PRESENCE OF AN EXTERNAL ELECTROMAGNETIC FIELD
Authors: CAPRI A.Z. , ROY S.M.
Published: November 2004

We show how to construct, for a Dirac field coupled to time-dependent external electromagnetic field, an instantaneous causal vacuum that depends only on the (planar) hypersurface of instantaneity and is independent of coordinates and gauges. The instantaneous particle states are then defined covariantly and connected to states defined with respect to other hypersurfaces of instantaneity by Bogoliubov transformations.
STATES OF NONZERO GHOST NUMBER IN c<1 MATTER COUPLED TO 2D GRAVITY
Authors: GOVINDARAJAN SURESH , JAYARAMAN T. , JOHN VARGHESE , MAJUMDAR PARTHASARATHI
Published: November 2004

We study c<1 matter coupled to gravity in the Coulomb gas formalism using the double cohomology of the string BRST and Felder BRST charges. We find that states outside the primary conformal grid are related to the states of nonzero ghost number by means of descent equations given by the double cohomology. Some aspects of the Virasoro structure of the Liouville-Fock space are studied. As a consequence, states of nonzero ghost number are easily constructed by “solving” these descent equations. This enables us to map ghost number conserving correlation functions involving nonzero ghost number states into those involving states outside the primary conformal grid.
ON THE FIELD DESCRIPTION OF CONFORMAL GALILEAN PARTICLE WITH INTRINSIC ROTATIONS
Authors: KIREEV A.N. , TAKAHASHI Y.
Published: November 2004

A fiber-preserving realization of conformal extension of the Galilei algebra is found in the presence of intrinsic rotations. The Lagrangian density and the conservation laws of a non-relativistic spinning particle are constructed explicitly.
STABILITY ANALYSIS OF THE ELECTROWEAK SPHALERON
Authors: BAACKE J. , LANGE H.
Published: November 2004

We perform a check of stability of the sphaleron against spherical as well as non-spherical fluctuations, considering the Higgs mass as a parameter which is varied over a wide range. We obtain the equations for the fluctuations in arbitrary K channels, working in the temporal gauge. Using the Jacobi criterion, the numerical analysis shows that there are no other instabilities besides the well known K=0 channel related to the existence of deformed sphalerons.
AN ESTIMATE OF THE REPHASING-INVARIANT QUANTITY J
Authors: KOIDE YOSHIO
Published: November 2004

The 3×3 Kobayashi-Maskawa matrix V is parametrized, without using a CP violation phase parameter explicitly, by four independent parameters α≡|Vus|, β≡|Vcb|, γ≡ |Vub| and ω≡|Vcd|2−|Vus|2. The rephasing-invariant quantity J of CP nonconservation is estimated by means of extrapolation from J=0 at γ2=0. It is speculated that |J|≃αβγ≃3.8×10−5 and ω=−α2β2≃−9.4×10−5.
SYMPLECTIC STRUCTURE OF ISOSPIN PARTICLES IN YANG-MILLS FIELDS
Authors: OH PHILLIAL
Published: November 2004

Using Dirac’s constraint analysis, we explore the Hamiltonian formalism of isospin particles in external Yang-Mills fields without kinetic and potential energy term. We consider an example of isospin particle in ’t Hooft-Polyakov magnetic monopole field and discuss possible quantization condition of magnetic charge in terms of geometric quantization.
PARADOXICAL KINEMATIC ACAUSALITY IN WEINBERG’S EQUATIONS FOR MASSLESS PARTICLES OF ARBITRARY SPIN
Authors: AHLUWALIA D.V. , ERNST D.J.
Published: November 2004

Weinberg’s equations for massless free particles of arbitrary spin are found to have acausal solutions. On the other hand, the m→0 limit of Joos-Weinberg’s finite-mass wave equations satisfied by (j, 0)⊕(0, j) j) covariant spinors are free from all kinematic acausality. This paradoxical situation is resolved and corrected by carefully studying the transition from the classical group theoretical arguments to quantum mechanically interpreted equations.
FUSION RULES FOR THE q-VERTEX OPERATORS OF ${\rm U}_q (\widehat{{\rm sl} (2)})$
Authors: AWATA HIDETOSHI , YAMADA YASUHIKO
Published: November 2004

We analyze the properties of the q-vertex operators [Formula: see text] introduced by Frenkel and Reshetikhin. As the condition for the null vector decoupling, we derive the existence condition of the q-vertex operators (the fusion rules).
QUANTUM KINEMATICS OF THE CHERN-SIMONS FIELD WITH MATTER IN THE LOOP REPRESENTATION
Authors: LEAL LORENZO
Published: November 2004

The scalar field coupled to the Abelian Chern-Simons gauge field is quantized in the loop representation. The physical space of states is found to be labeled by equivalence classes of sets of open paths. The relations among them are studied, showing that the long range interaction provided by the gauge field gives rise to a topological interaction among the paths which is explicitly computed.
HIGHER GENUS CORRELATORS FOR THE COMPLEX MATRIX MODEL
Authors: AMBJØRN J. , KRISTJANSEN C.F. , MAKEENKO YU. M.
Published: November 2004

We describe an iterative scheme which allows us to calculate any multi-loop correlator for the complex matrix model to any genus using only the first in the chain of loop equations. The method works for a completely general potential and the results contain no explicit reference to the couplings. The genus g contribution to the m-loop correlator depends on a finite number of parameters, namely at most 4g−2+m. We find the generating functional explicitly up to genus three. We show as well that the model is equivalent to an external field problem for the complex matrix model with a logarithmic potential.
CHIRAL SCHWINGER MODEL AT FINITE TEMPERATURE
Authors: BOSCHI-FILHO H. , NATIVIDADE C.P.
Published: November 2004

We discuss the chiral Schwinger model at finite temperature using Fujikawa’s method. We solve this model exactly and show that the axial anomaly and the dynamically generated mass for the gauge field are temperature independent.
GENERALIZED REDUCTION PROCEDURE AND NONLINEAR NONSTATIONARY DYNAMICAL SYSTEMS
Authors: MAN’KO V.I. , MARMO G.
Published: November 2004

In this paper a generalized reduction procedure is used to obtain nonlinear nonstationary dynamical systems out of free ones.
TRANSFORMATIONS AND BRST-CHARGES IN (2+1)-DIMENSIONAL GRAVITATION
Authors: FÜLÖP GÉZA
Published: November 2004

Canonical transformations relating the variables of the ADM-, Ashtekar’s and Witten’s formulations of gravity are computed in 2+1 dimensions. Three different forms of the BRST-charge are given in the (2+1)-dimensional Ashtekar formalism, two of them using Ashtekar’s form of the constraints and one of them using the forms suggested by Witten. The BRST-charges are of different rank.
THE STRATEGIC 1P1 STATES OF HEAVY QUARKONIA
Authors: TUAN S.F.
Published: November 2004

In this brief review, we examine carefully and critically the status of search for (i) the ψ(11P1) charmonium state and (ii) the ϒ(11P1) state of bottonium. We wish to emphasize in particular that the strategic debate between Kuang-Yan and Voloshin concerning the size of the branching ratio for the transition ϒ(3S)→ϒ(11P1)ππ and the reality of the ISR events for the existence of ψ(11P1) in charmonium can be resolved in a more straightforward manner by (iii) measuring the decay rates ϒ(1D, 2D)→ϒππ and ψ(3770)→J/ψππ together with the amount of S-D mixing in the ψ′(3684)−ψ″(3770) system. Preliminary data are already available from Crystal Ball, Mark II and Mark III experiments concerning ψ″(3770)→J/ψππ rate supportive of Kuang-Yan. We also discuss the current situation in ϒ(3S)→ϒ(1S, 2S)ππ dipion mass spectra, in the context of the expected mass spectrum for ϒ(3S)→ϒ(11P1)ππ.
QUANTUM EFFECTS NEAR CHARGED DILATONIC BLACK HOLES
Authors: SHIRAISHI KIYOSHI
Published: November 2004

The expectation value <ϕ2> in the Hartle-Hawking vacuum is calculated for minimally-coupled neutral scalar fields at the horizon of a charged dilatonic black hole.
ADJOINT FERMIONS INDUCE QCD
Authors: KHOKHLACHEV S. , MAKEENKO YU.
Published: November 2004

We propose to induce QCD by fermions in the adjoint representation of the gauge group SU (Nc) on the lattice. We consider various types of lattice fermions: chiral, Kogut-Susskind and Wilson ones. Using the mean field method we show that a first order large-N phase transition occurs with decreasing fermion mass. We conclude, therefore, that adjoint fermions induce QCD. We draw the same conclusion for the adjoint scalar or fermion models at large number of flavors Nf when they induce a single-plaquette lattice gauge theory. We find an exact strong coupling solution for the adjoint fermion model and show that it is quite similar to that for the Kazakov-Migdal model with the quadratic potential. We discuss the possibility for the adjoint fermion model to be solvable as Nc→∞ in the weak coupling region where the Wilson loops obey normal area law.
A HEURISTIC STRING-THEORETIC APPROACH TO THE 3D ISING MODEL
Authors: MOJUMDER M. A. , TADASSE MESFIN
Published: November 2004

We have made a modification of a very heuristic relationship available in the literature between the parameter space distance and the embedding space distance on the string worldsheet. This modification along with the input of numerically determined values of the fractal dimension of the fermionic worldsheet and of the Wilson scaling dimensions of conventional ψ2 and ψ4-field theories enables a numerical calculation of the critical exponents α and β of the 3D Ising model. These values are in very good agreement with the experimental and other theoretical values.
ϕ→K+ K-γ AND ITS RELATION TO $\phi \rightarrow K^0 \bar{K}^0\gamma$
Authors: ALVARADO J. J. , LUCIO J. L. M. , VARGAS M.
Published: November 2004

We calculate Γ(ϕ→K+ K-γ) using Low's soft photon theorem and compare it with a model dependent calculation in which the process proceeds through the chain of decays ϕ→K+ K-→f0+γ→K+ K-γ.
EXPERIMENTAL SEARCH FOR ANOMALOUS SPIN-SPIN INTERACTIONS
Authors: PAN SHEAU-SHI , NI WEI-TOU , CHEN SHEN-CHE
Published: November 2004

A Cavendish-type torsion pendulum, having test masses with 2.5×1022 polarized electrons and "attracting" masses with 8×1023 polarized electrons, is used to search for an anomalous spin interaction of macroscopic range. Competition from magnetic forces is reduced by using ferrimagnetic Dy-Fe masses which exhibit orbital compensation of the electron spin magnetic moments. Combined with magnetic shielding, the sensitivity is 2×10-4 of the gravitational force. Fluctuations set the overall experimental limit at about 5 times this level. Our results set limits on electron spin interactions and on moments which are not of electromagnetic origin. In terms of a standard dipole-dipole form, the limit is 1.5 ×10-12 of the interaction strength between the magnetic moments of the electrons. Compared to previous results, this is a six-cold improvement.
NEUTRINO MAGNETIC MOMENTS AND MINIMAL SUPERSYMMETRIC SO(10) MODEL
Authors: FUKUYAMA TAKESHI , KIKUCHI TATSURU , OKADA NOBUCHIKA
Published: November 2004

We examine supersymmetric contributions to transition magnetic moments of Majorana neutrinos. We first give the general formula for it. In concrete evaluations, informations of neutrino mass matrix elements including CP phases are necessary. Using unambiguously determined neutrino mass matrices in recently proposed minimal supersymmetric SO (10) model, the transition magnetic moments are calculated. The resultant neutrino magnetic moments with the input soft supersymmetry breaking masses being of order 1 TeV are found to be roughly an order of magnitude larger than those calculated in the standard model extended to incorporate the see-saw mechanism.
FLAT DIRECTIONS AND THE GOLDSTONE THEOREM
Authors: HOLTKAMP ANNETTE , MECKLENBURG W.
Published: November 2004

We discuss the possibility that systems with flat directions do not display a Goldstone phenomenon. No formal proof is offered. However, a number of difficulties are displayed which are encountered when one defines a perturbative quantum field theory for systems with flat directions.
INDUCED TWO-DIMENSIONAL (2, 0) SUPERGRAVITY AND OSp(2|2) INVARIANCE
Authors: SABRA WAFIC A.
Published: November 2004

We study (2, 0) induced two-dimensional supergravity in the superchiral gauge and derive the corresponding OSp(2|2) current algebra. The renormalization of the central charge of the current algebra and the physical primary state conditions of the fields are derived using the residual gauge transformations and BRST quantization.
PHASE SPACE REDUCTION AND THE CHOICE OF PHYSICAL VARIABLES IN GAUGE THEORIES
Authors: SHABANOV S.V.
Published: November 2004

The connection between the way of separation of physical variables and the form of the Hamiltonian path integral (HPI) is studied for the Yang-Mills quantum mechanics. It is shown that physical degrees of freedom are always described by curvilinear coordinates. It is also found that the ambiguity in determining physical variables follows from the reduction of the physical phase space. The latter leads to a modification of the standard HPI (HPI with gauge conditions).
SUPER WESS-ZUMINO-WITTEN MODELS
Authors: HENNINGSON MÅNS
Published: November 2004

We investigate the general conditions for a Wess-Zumino-Witten model with a super-group as a gauge group to be quantum-mechanically consistent. A specific model with extended space-time supersymmetry is briefly discussed.
INTEGRABLE MODELS AND SPIN ALGEBRAS
Authors: DAS ASHOK , ROY SHIBAJI
Published: November 2004

We show how the entire KdV hierarchy as well as the recursion relation between the conserved quantities can be obtained from a spin-2 flow. The relationship between this approach and the zero curvature formulation of the KdV system based on the group SL(2, R) is clarified. We show that the Boussinesq equation can be derived as a flow of the spin-3 transformations. The Boussinesq hierarchy, as well as the relevant Lenard relation, is derived from a combined flow of the spin-2 and spin-3 transformations. We have also given an independent derivation of the Lenard relation for the Boussinesq equation starting from the third order Schrödinger equation.
TWISTED WZW SUPERSTRING SOLUTIONS
Authors: DE TRAUBENBERG M. RAUSCH , SAVOY C.A.
Published: November 2004

Superstring solutions on twisted group manifolds are investigated, chiefly in the case of fermionizable Wess-Zumino-Witten models that yield space-time N=1 supersymmetry. Both outer and inner automorphisms are admitted as boundary conditions. The representations of the twisted current algebras are studied—their mass spectra match perfectly their fermionic realizations. The supersymmetric solutions are characterized and classified. A few especial ones are identified with Z4 and Z3 orbifolds by using the equality of the fermion equivalents.
GAUGE THEORY ON OPEN MANIFOLDS OF BOUNDED GEOMETRY
Authors: EICHHORN JÜRGEN
Published: November 2004

On compact manifolds (Mn, g) and for r>n/2+1 the configuration space [Formula: see text] is a well-defined object. [Formula: see text] is an affine space with a Sobolev space as vector space, and [Formula: see text] a Hilbert Lie group which acts smoothly and properly on [Formula: see text]. [Formula: see text] is a stratified space with Hilbert manifolds as strata. The existence problem has been solved for many interesting cases by Cliff Taubes and the description of the moduli space of instantons has been given by Donaldson. On noncompact manifolds none of the approaches of the compact case is further valid. We present here an intrinsic, self-consistent approach for gauge theory on open manifolds of bounded geometry up to order n/2+2. The main idea is to endow the space CP of gauge potentials and the gauge group with an intrinsic Sobolev topology. Bounded geometry of the underlying manifold and the considered connections provides all the Sobolev theorems which are needed to prove the existence of instantons if G=SU(2). We prove the existence of instantons if (M4, g) satisfies a certain spectral condition and has a positive definite L2 intersection form.
ON THE POSSIBILITY OF ZN EXOTIC SUPERSYMMETRY IN TWO-DIMENSIONAL CONFORMAL FIELD THEORY
Authors: RAVANINI F.
Published: November 2004

We investigate the possibility to construct extended parafermionic conformal algebras whose generating current has spin [Formula: see text] generalizing the superconformal (spin 3/2) and the Fateev-Zamolodchikov (spin 4/3) algebras. Models invariant under such algebras would possess ZK exotic supersymmetries satisfying (supercharge)K=(momentum). However, we show that for K=4 this new algebra allows only for models at c=1, for K=5 it is a trivial rephrasing of the ordinary Z5 parafermionic model, for K=6, 7 (and, requiring unitarity, for all larger K) such algebras do not exist. Implications of this result for existence of exotic supersymmetry in two-dimensional field theory are discussed.
FADDEEV-JACKIW QUANTIZATION AND CONSTRAINTS
Authors: BARCELOS-NETO J. , WOTZASEK C.
Published: November 2004

In a recent Letter, Faddeev and Jackiw have shown that the reduction of constrained systems into its canonical, first-order form, can bring some new insight into the research of this field. For sympletic manifolds the geometrical structure, called Dirac or generalized bracket, is obtained directly from the inverse of the nonsingular sympletic two-form matrix. In the cases of nonsympletic manifolds, this two-form is degenerated and cannot be inverted to provide the generalized brackets. This singular behavior of the sympletic matrix is indicative of the presence of constraints that have to be carefully considered to yield to consistent results. One has two possible routes to treat this problem: Dirac has taught us how to implement the constraints into the potential part (Hamiltonian) of the canonical Lagrangian, leading to the well-known Dirac brackets, which are consistent with the constraints and can be mapped into quantum commutators (modulo ordering terms). The second route, suggested by Faddeev and Jackiw, and followed in this paper, is to implement the constraints directly into the canonical part of the first-order Lagrangian, using the fact that the consistence condition for the stability of the constrained manifold is linear in the time derivative. This algorithm may lead to an invertible two-form sympletic matrix from where the Dirac brackets are readily obtained. This algorithm is used here to investigate some aspects of the quantization of constrained systems with first- and second-class constraints in the sympletic approach.
TOWARD THE REALISTIC THREE-GENERATION MODEL IN THE (2, 0) HETEROTIC STRING COMPACTIFICATION
Authors: ASATRYAN HRACHIA M. , MURAYAMA AKIHIRO
Published: November 2004

In the three-generation models with SUSY SO(10) or SU(5) GUTs derived from the (2, 0) compactification of E8×E′8 heterotic string, the massless matter field spectra at the GUT scale Mx and the breaking directions of GUT symmetries are discussed. A pseudo-left-right symmetric Pati-Salam model is naturally deduced in the SUSY SO(10) GUT and shown to have an interesting property, Mx≃MP1, MR≃1010 GeV and Ms (the scale of superpartner masses) ≃104 GeV, as a result of the renormalization group equation analysis using the new precise LEP data.
OFF-SHELL TREE AMPLITUDES IN HIKKO’S CLOSED STRING FIELD THEORY
Authors: UKEGAWA AKINOBU
Published: November 2004

Off-shell closed string tree amplitudes are obtained for the HIKKO’s theory, using the method of off-shell conformal field theory.
THE GEOMETRIC PHASE AND THE SCHWINGER TERM IN SOME MODELS
Authors: GROSSE H. , LANGMANN E.
Published: November 2004

We discuss the quantization of fermions interacting with external fields and observe the occurrence of equivalent as well as inequivalent representations of the canonical anticommutation relations. Implementability of gauge and axial gauge transformations leads to generators which fulfil an algebra of current with a Schwinger term. This term can be written as a cocycle and leads to the boson-fermion correspondence.

Transport of a quantum-mechanical system along a closed loop of parameter space may yield a geometric phase. We discuss models for which nonintegrable phase factors are obtained from the adiabatic parallel transport. After second quantization, one obtains, in addition, a Schwinger term. Depending on the type of transformation, a subtle relationship between these two obstructions can occur. We indicate finally how we may transport density matrices along closed loops in parameter space.
N=2 SUPERGRAVITY IN SUPERSPACE AND THE BRS SYMMETRY
Authors: KACHKACHI M. , LHALLABI T.
Published: November 2004

The quantum N=2 Einstein supergravity action is constructed by requiring BRS symmetry. This symmetry is derived by using the distorted horizontality conditions in the curved N=2 harmonic superspace.
UNITARITY AND RENORMALIZABILITY OF CHIRAL QUANTUM ELECTRODYNAMICS
Authors: DEMARCO G.L. , FOSCO C. , TRINCHERO R.C.
Published: November 2004

We consider the proofs of unitarity and renormalizability of (3+1)-dimensional chiral electrodynamics using a quantization previously proposed. The unitarity of the S matrix is shown by employing Cutkovsky rules and the BRST formalism. Renormalizability is considered in detail it is shown that all the divergences can be absorbed in the fermion charge and the mass of the vector field. At least for this Abelian case, cancellation of anomalies by fermion content is not a necessary condition for the quantum consistency of the theory.
DISCRETIZATION IN THE CONTINUUM AND THE SPINORIAL FUNCTIONAL INTEGRAL
Authors: KARANIKAS A.I. , KTORIDES C.N.
Published: November 2004

We introduce a discretization procedure for spinorial field theories which takes place within a continuous space-time background. The implications of our discretization scheme at the quantum level is that integration over fermionic degrees of freedom can be performed in a well-defined manner. The result is a regularized determinant which reproduces known properties of the continuum system. We consider both free and coupled, with a set of external gauge fields, models. We compute the trace of the logarithm of the Euclidean Dirac operator, obtained by our integration, in the representation provided by “position” eigenstates in Euclidean space-time. A two-dimensional application shows compliance of our result with both gauge current conservation and the axial anomaly relation. Finally, we discuss the question whether our discretization scheme provides a nonperturbative definition of spinorial field systems.
GAUGE INVARIANCE AND BROKEN SYMMETRIES IN ANYON SUPERFLUIDS
Authors: BOYANOVSKY DANIEL
Published: November 2004

We review aspects of broken symmetry and the nature of long range order in theories of anyons starting with bosons with a statistical interaction. We introduce a novel gauge invariant quantization scheme that allows the identification of local and gauge invariant order parameters. The connection between spin and statistics is reviewed and the consequences of broken symmetries in the anyon representation are discussed. An anyon gas is studied in the Bogoliubov approximation, it is determined that the ground state is a condensate of charge-flux composites with “quasi-long-range order” at zero temperature, a “weak” gap in the spectrum and finite helicity modulus. The system is disordered at nonzero temperatures. The disorder is not caused by Goldstone bosons but by the strong infrared behavior arising from the Coulomb interaction induced by the long-range statistical interaction. The properties of topological vortices in nonrelativistic and in relativistic Landau-Ginzburg theories are studied in detail. We study the physics of the mean-field ansatz and quasi-long range order in a simple exactly soluble relativistic model. This model exhibits a novel phenomenon of charge redistribution to the boundaries and restoration of translational invariance in the infinite volume limit. It also illuminates the physics of quasi-long-range order with a gap in the spectrum, statistical charge polarization by external magnetic fields and the role of “large” gauge transformations.
METHODS TO DETERMINE THE $B_d - \bar{B}_d $ MIXING PARAMETERS
Authors: DASS G.V. , SARMA K.V.L.
Published: November 2004

The phenomenology of [Formula: see text] mixing involves four parameters: average width Γ, mixing ratio |q|p|, mass difference proportional to x, and width difference proportional to y. We point out the types of experimental inputs that are eventually needed in order to determine the four parameters completely and in a model-independent way. For the sign of y we suggest the measurement (at ϒ(4S) factories) of a certain time-asymmetry when one of the neutral B mesons is tagged and the other decays to a CP-eigenstate. For the sign of x we propose similar time-asymmetries when one of the B mesons undergoes the chain decay: B→KJ/ψ, and the neutral kaon →πlν or π+π−.
QUANTUM NONLOCAL FIELD THEORY: PHYSICS WITHOUT INFINITIES
Authors: CORNISH N.J.
Published: November 2004

It is argued that nonlocality is an essential ingredient in Relativistic Quantum Field Theory in order to have finite theory without recourse to a renormalisation program. A critical review of the physical constraints on the form the nonlocality can take is presented. The conclusion of this review is that nonlocality must be restricted to interactions with the vacuum sea of virtual particles. A successful formulation of such a theory, QNFT, is applied to scalar electrodynamics and serves to illustrate how gauge invariance and manifest finiteness can be achieved. The importance of the infinite dimensional symmetry groups that occur in QNFT are discussed as an alternative to supersymmetry, the ability to generate masses by breaking the nonlocal symmetry with a noninvariant functional measure is given a critical assessment. To demonstrate some of the many novel applications QNFT may make possible two examples are mooted, the existence of electroweak monopoles and the formulation of a finite perturbative theory of Quantum Gravity.
GLUONIC CONTRIBUTIONS TO SPIN-DEPENDENT WEAK STRUCTURE FUNCTIONS: METHOD OF FACTORIZATION
Authors: MATHEWS PRAKASH , RAVINDRAN V.
Published: November 2004

We compute the gluonic contributions to the spin-dependent weak structure functions [Formula: see text](i=1, 3, 4), using the factorization theorem in the minimal subtraction scheme, [Formula: see text]. We have considered the most general case where the quark flavor masses are distinguished and the gluons are off mass shell. The gluonic contribution to the first moment of [Formula: see text] is found to vanish and [Formula: see text] do not receive leading order gluonic contribution. These results are shown to be free of mass singularities.
FROM INHOMOGENEOUS SIX-VERTEX LATTICE MODELS TO CONTINUUM QUANTUM INTEGRABLE MODELS
Authors: ZHOU Y.K.
Published: November 2004

A method to find continuum quantum integrable systems from two-dimensional vertex models is presented. We explain the method with the example where the quantum sine-Gordon model is obtained from an inhomogeneous six-vertex model in its scaling limit. We also show that the method can be applied to other models.
HIGGS DOUBLET AS COMPOSITE GOLDSTONE BOSON: CHALLENGE TO MULTI-TEV ENERGY COLLIDERS
Authors: PIROGOV YU. F.
Published: November 2004

The minimum nonlinear extension SU(3)×U(1)/SU(2)×U(1) to the Standard Model, where the Higgs doublet is a composite Goldstone boson, is investigated. The canonical nonlinear realization of the extended symmetry is constructed in the form maximally close to that of the Standard Model. The corresponding most general effective Lagrangian is built. A simplest linear realization of the extended symmetry in an extended fermion sector is found. The Higgs-Goldstone scenario of the electroweak symmetry breaking is outlined from the standpoint of the multi-TeV energy collider phenomenology.
HELICITY-CHIRALITY CORRELATION AND WEINBERG’S CONSTRAINT IN HIGHER DIMENSIONS
Authors: BHANSALI VINEER
Published: November 2004

We show a simple correspondence between massless fields transforming as representations of the higher (even) dimensional Lorentz group and highest weight states of the little group, under the assumption that the Euclidean translations of the little group act trivially. This yields the generalization to higher dimensions of Weinberg’s (1964) constraint which establishes a connection between helicity and chirality in four dimensions. As a bonus, we obtain restrictions on “gauge invariant” representations for physical particles.
STABILITY AND INSTABILITY OF RENORMALIZATION GROUP FLOWS
Authors: DAMGAARD P.H.
Published: November 2004

Viewed as a dynamical system, a renormalization group transformation can in principle exhibit quite complex behavior, such as limit cycles, intermittency and chaos. We investigate some of the physical consequences of this type of behavior, restricted here for simplicity to real space renormalization group transformations. Conditions for nonsingular behavior of given thermodynamic functions are derived.
CONFORMALLY REDUCED WZNW THEORY, NEW EXTENDED CHIRAL ALGEBRAS AND THEIR ASSOCIATED TODA TYPE INTEGRABLE SYSTEMS
Authors: HOU BO-YU , CHAO LIU
Published: November 2004

We propose and analyze a large class of conformal reductions Cons [g(H, d)] of WZNW theory based on the integral gradations of the underlying Lie algebra g. The W bases of the associated W algebras W[g(H, d)] are constructed under the generalized Drinfeld-Sokolov gauge which we call O’Raifeartaigh gauge of the constrained Kac-Moody currents, and the equations of motion of the extended Toda type integrable systems corresponding to these W algebras are also derived. As an example, we construct explicitly the W algebra associated with the (pqp) block diagonal decomposition of sl2p+q, namely W[(pqp)2], and discuss some of the properties thereof.
THE MODEL OF A FREE RELATIVISTIC PARTICLE WITH FRACTIONAL SPIN
Authors: PLYUSHCHAY M.S.
Published: November 2004

The model of a free relativistic particle with fractional spin in 2+1 dimensions is proposed. It is shown that there are two schemes of the canonical quantization of the model. One of these leads to the description of the physical states of the model as one-particle states of a (2+1)-dimensional Poincare group either by multivalued functions in the case of a standard realization of canonical coordinates and momenta operators, or by single-valued functions in the case of a nonstandard realization of these operators. The second scheme leads to a (2+1)-dimensional analog of an infinite-component Majorana equation and to a mass shell condition as quantum conditions on the physical state vectors. Two variants of action for a free field with arbitrary (fractional) spin are constructed on the basis of these quantum conditions.
SECOND ORDER “FLAVOR” PERTURBATION THEORY FOR THE BARYONS
Authors: SCHECHTER J. , SUBBARAMAN A.
Published: November 2004

We argue that second order flavor perturbation theory may still have some interesting things to say about low energy QCD. Application is made to the technical, but important, question of cleanly extracting the quark mass difference ratio R= [ms−(md+mu)/2]/(md−mu) from the experimental baryon masses. We also give a group theoretical decomposition of the second order contributions according to the SU(3) representation of the intermediate states. This is used to provide constraints on quantum mechanics type models of the nucleon.
THE EFFECTIVE ACTION FOR COMPOSITE HIGGS PARTICLES
Authors: SIEGEMUND-BROKA STEPHAN
Published: November 2004

There is reason to believe that massive composite (fermion-antifermion) scalar particles closely resembling the usual fundamental scalar Higgs fields exist in theories with dynamically broken gauge symmetries. This composite Higgs couples directly to the fermions in proportion to their symmetry-violating self-energies. Induced couplings to the gauge bosons and self-couplings are calculated as loop effects. This involves deriving the effective action in terms of the full propagators and background fields. The couplings between the composite Higgs and the gauge bosons are the same as those in models with fundamental scalars. The self-couplings are determined and fix all parameters associated with the composite scalars. Comments regarding extending this work to higher orders and concerning the symmetry-violating solutions to the fermion Schwinger-Dyson equation are given.
PERTURBING THE GROUND RING OF 2D STRING THEORY
Authors: BARBÓN J.L.F.
Published: November 2004

We use free field techniques in D=2 string theory to calculate the perturbation of the special state algebras when the cosmological constant is turned on. In particular, we find that the “ground cone” preserved by the ring structure is promoted to a three-dimensional hyperboloid as conjectured by Witten. On the other hand, the perturbed (1, 1) current algebra of moduli deformations is computed completely, and no simple geometrical interpretation is found. We also quote some facts concerning the Liouville matrix model dictionary in this class of theories.
SUPERSYMMETRIC CONSTRUCTION OF W ALGEBRAS FROM SUPER TODA AND WZNW THEORIES
Authors: FERREIRA L.A. , GOMES J.F. , RICOTTA R.M. , ZIMERMAN A.H.
Published: November 2004

A systematic construction of super W algebras in terms of the WZNW model based on a super Lie algebra is presented. These are shown to be the symmetry structure of the super Toda models, which can be obtained from the WZNW theory by Hamiltonian reduction. A classification, according to the conformal spin defined by an improved energy-momentum tensor, is discussed in general terms for all super Lie algebras whose simple roots are fermionic. A detailed discussion employing the Dirac bracket structure and an explicit construction of W algebras for the cases of OSP(1, 2), OSP(2, 2), OSP(3,2) and D(2, 1 a) are given. The N=1 and N=2 superconformal algebras are discussed in the pertinent cases.