bluuebunny/crossref_metadata_2025 huggingface dataset:
A NOTE ON THE ZAKHAROV-SHABAT TOPOLOGICAL MODEL
Authors: PASQUINUCCI ANDREA
Published: November 2004

In this note I discuss some features of the topological theory obtained from the Zakharov-Shabat (or general [Formula: see text] hierarchy, and comment on some possible physical and/or mathematical interpretations of it.
THE DEFINITION OF TIME AND QUANTUM VACUUM IN 1 + 1 DIMENSIONS
Authors: CAPRI A. Z. , ROY S. M.
Published: November 2004

We prove that for any (1 + 1)-dimensional globally hyperbolic space-time it is possible to define an instant of time as a special space-like geodesic which is independent of the coordinates chosen. This definition follows uniquely from the requirement of validity of Poincaré symmetry in an infinitesimal neighborhood of the hypersurface of instantaneity. The generator associated with time translation then selects the direction of time. This fact permits unambiguous field quantization of this surface. For flat space-time the corresponding time and vacuum coincide with those of Minkowski space-time. We apply these results to static and Robertson-Walker space-times.
SEARCH FOR NEW PARTICLES IN CDF
Authors: LAASANEN ALVIN
Published: November 2004

The results of new particle searches conducted by the CDF collaboration at the Fermilab [Formula: see text] Collider are given.
FIXING THE TOP-QUARK AND HIGGS-BOSON MASSES
Authors: MA ERNEST
Published: November 2004

If the quadratic divergence of the standard electroweak model and its local variation with mass scale are both assumed to be zero, then a modified one-loop calculation yields mt ≃ 117 GeV and mH ≃ 183 GeV . Such a scenario may be the result of an underlying theory to be revealed at a much higher mass scale.
GAUGE INDEPENDENCE OF THE HOT A0-CONDENSATE
Authors: SKALOZUB V. V.
Published: November 2004

The problem of gauge dependence of the zero gauge field component condensate, A0 = const ., in the framework of finite temperature SU(2) gluodynamics is investigated. In straightforward calculations it is shown that the two-loop effective action W (A0, ξ) satisfies the generalized Nielsen identity. Thus, the gauge invariance of the A0-condensation is proved.
IMPLICATIONS OF A MODEL WITH A LONGER TAU LIFE-TIME
Authors: FOOT R. , LEW H.
Published: November 2004

It is possible that the tau lepton may have a longer life-time than that predicted by the Standard Model. The simplest extension to the Standard Model incorporating a longer tauon life-time involves the addition of a gauge singlet Weyl fermion. We consider the most general model of this kind and evaluate the experimental constraints on the various parameters of this model. We show that the model is consistent with the standard cosmology model for a range of parameters. We then examine possible signatures of the model in certain experiments searching for heavy neutral leptons.
GRAVITATIONAL FIELD OF A GAUGE MONOPOLE
Authors: AGNESE A.G. , CAMERA M. LA
Published: November 2004

It is shown that, in contrast to the global monopoles, no deficit solid angle appears in the solution of the Einstein-Yang-Mills system with Higgs coupling.
PION DOUBLE CHARGE EXCHANGE REACTIONS LEADING TO DOUBLE PIONIC ATOMS
Authors: NIEVES J. , OSET E. , HIRENZAKI S. , TOKI H. , VICENTE-VACAS M.J.
Published: November 2004

We study theoretically pion double charge exchange reactions leading to double pionic atoms. The reaction cross-sections with two pions in the deeper bound pionic orbits in 208Pb are calculated with realistic pionic atom wave functions and distortion effects. The cross-sections are found to be d2σ/dEdΩ~10−3−10−4 µ b/srMeV , which are only a small fraction of the double charge exchange background.
FOUR-DIMENSIONAL TWO-BRANE SOLUTION IN CHIRAL GAUGED WESS-ZUMINO-WITTEN MODEL
Authors: MAHAPATRA SWAPNA
Published: November 2004

An exact conformal field theory describing a four-dimensional two-brane solution is found by considering a chiral gauged Wess-Zumino-Witten theory corresponding to SL (2, R)× R, where one gauges the one-dimensional U(1) subgroup together with a translation in R. The backgrounds for string propagation are explicitly obtained and the target space is shown to have a true curvature singularity.
SUBSTRUCTURE EFFECT ON ρ-ω MIXING IN CHARGE-SYMMETRY VIOLATION
Authors: GOLDMAN T. , HENDERSON J.A. , THOMAS A.W.
Published: November 2004

In generating a charge-symmetry breaking potential using ρ-ω mixing it is usually assumed that the mixing amplitude is constant (at the on-mass-shell value). Since the exchanged meson is actually far off-shell one must question the validity of this assumption. By constructing a simple quark model in which the mixing is generated by the u-d quark mass difference, we find that the assumption seems to be a very poor one.
CANONICAL FORMALISM OF TWO-DIMENSIONAL INDUCED SUPERGRAVITY
Authors: CHUNG WON-SANG
Published: November 2004

Two-dimensional supergravity in the light-cone gauge is canonically discussed and osp(1/2) generators are written in terms of the canonical variables.
COMMENTS ON THE VACUUM ORIENTATIONS IN QCD
Authors: HUANG ZHENG , VISWANATHAN K.S. , WU DAN-DI
Published: November 2004

We study the QCD vacuum orientation angles in correlation with the strong CP phases. A vacuum alignment equation of the dynamical chiral symmetry breaking is derived based on the anomalous Ward identity. It is emphasized that a chiral rotation of the quark field causes a change of the vacuum orientation and a change in the definition of the light pseudoscalar generators. As an illustration of the idea, η→2π decays are carefully studied in different chiral frames.
PRECISE TESTS OF e-μ UNIVERSALITY
Authors: NUMAO TOSHIO
Published: November 2004

The status of experimental tests of electron-muon universality in weak interactions is reviewed. The average of the new measurements of the π+→e+ν branching ratio, R ave =Γ(π→eν+π→eνγ)/Γ(π→μν+π→μνγ)=(1.2312±0.0037)×10−4, is consistent with standard model calculations R th =(1.234±0.001)×10−4 and confirms the hypothesis of electron-muon universality at the 0.2% level.
HOW TO SOLVE THE CKM QUARK MIXING MATRIX
Authors: TERAZAWA HIDEZUMI
Published: November 2004

It was pointed out that given the us element of the CKM quark mixing matrix, all the other elements can be successfully explained or predicted by using the five relations derived in a composite model of quarks (and leptons).
SPACE-TIME FLUCTUATIONS COUPLED TO PRIMARY FIELDS
Authors: CHUNG MYUNG-HOON
Published: November 2004

The β-functions and the c-function are calculated in a two-dimensional field theory where the coupling parameters are functions of fields. The action of the theory is given by a combination of the Polyakov action for string theory and the Zamolodchikov action for the deformation of conformal field theory. The c-function is written as the Landau-Ginzburg type action in terms of the coupling parameter functions. The linear β-functions near fixed points are given by the Klein-Gordon equation. The corresponding well-defined masses are calculated.
UNDERSTANDING SOLITONS ALGEBRAICALLY
Authors: HLOUSEK ZVONIMIR , SPECTOR DONALD
Published: November 2004

We describe techniques we have developed to analyze the physics of topological solitons in a model-independent way. Our central result is to show that topological solitons in generic field theories exhibit Bogomol’nyi bounds and Bogomol’nyi equations. Our methods turn the derivation of these Bogomol’nyi relationships into algebraic calculations and do not depend on the particular equations of motion. We present a discussion of the O(3) nonlinear σ-model as an example of our techniques.
QUANTUM FIELD THEORY OF ORTHOFERMIONS AND ORTHOBOSONS
Authors: MISHRA A.K. , RAJASEKARAN G.
Published: November 2004

We construct the quantum field theory of particles obeying new kinds of quantum statistics, called orthofermi and orthobose statistics. For the orthofermions (orthobosons), the wave function is antisymmetric (symmetric) in one set of indices while no particular symmetry is required for the other set of indices. Nonrelativistic as well as relativistic quantum Held theories with interaction are constructed.
MULTICRITICALITY IN STABILIZED 2D QUANTUM GRAVITY
Authors: DIEGO OSCAR , GONZÁLEZ JOSÉ
Published: November 2004

We study the simplest perturbation of the matrix model for pure gravity susceptible of reaching the k=3 multicritical point in the framework of the stochastic stabilization of 2D quantum gravity. We show the existence of a line of points in the phase diagram with the genuine critical behavior of the k=2 theory. All the points of the critical line, up to the tricritical point, can be approached from a stable phase at the dominant level in 1/N expansion.
DENSITY PERTURBATIONS, GRAVITY WAVES AND THE COSMIC MICROWAVE BACKGROUND
Authors: SOURADEEP TARUN , SAHNI VARUN
Published: November 2004

We assess the contribution to the observed large scale anisotropy of the cosmic microwave background radiation, arising from both gravity waves as well as adiabatic density perturbations, generated by a common inflationary mechanism in the early Universe. We find that for inflationary models predicting power law primordial spectra |δk|2∝kn, the relative contribution to the quadrupole anisotropy from gravity waves and scalar density perturbations, depends crucially upon n. For n<0.84, gravity waves perturb the CMBR by a larger amount than density perturbations, whereas for n>0.84 the reverse is true. Normalizing the amplitude of the density perturbation spectrum at large scales, using the observed value of the COBE quadrupole, we determine (δM/M)16-the rms density contrast on scales [Formula: see text] Mpc, for cosmological models with cold dark matter. We find that for n<0.75, a large amount of biasing is required in order to reconcile theory with observations. We also determine the value of the inflationary Hubble parameter and the COBE-normalized amplitude and spectrum of gravity waves from inflation.
RENORMALIZATION GROUP AND TRIVIALITY IN NONCOMPACT LATTICE QED WITH LIGHT FERMIONS
Authors: AZCOITI V. , CARLO G. Di , GRILLO A.F.
Published: November 2004

In the framework of noncompact lattice QED with light fermions, we derive the functional dependence of the average energy per plaquette on the bare parameters using blockspin Renormalization Group arguments and assuming that the renormalized coupling vanishes. Our numerical results for this quantity in 84 and 104 lattices show evidence for triviality in the weak coupling phase and point to a nonvanishing value for the renormalized coupling constant in the strong coupling phase.
STRINGY QUANTUM EFFECTS IN TWO-DIMENSIONAL BLACK HOLE
Authors: DHAR AVINASH , MANDAL GAUTAM , WADIA SPENTA R.
Published: November 2004

We discuss the classical two-dimensional black hole in the framework of the non-perturbative formulation (in terms of non-relativistic fermions) of c=1 string field theory. We identify an off-shell operator whose classical equation of motion is that of tachyon in the classical graviton-dilaton black hole background. The black hole ‘singularity’ is identified with the Fermi surface in the phase space of a single fermion, and as such is a consequence of the semiclassical approximation. An exact treatment reveals that stringy quantum effects wash away the classical singularity.
UNCERTAINTY PRINCIPLE, SQUEEZING, AND QUANTUM GROUPS
Authors: RAJAGOPAL A.K. , GUPTA VIRENDRA
Published: November 2004

It is shown that the complete form of the Heisenberg Uncertainty Relation (HUR) must be employed in introducing the concepts of squeezing and coherent state in q-quantum mechanics. An important feature of this form of the HUR is that it is invariant under unitary transformation of the operators appearing in it and consequences of this are pointed out.
SPONTANEOUS SYMMETRY BREAKING IN THE RELATIVISTIC MODEL OF ANYON SUPERCONDUCTIVITY
Authors: KAZAKOV DMITRI
Published: November 2004

We consider the renormalizable Abelian Chern–Simons field theory matter in 2+1 dimensions which is claimed to be an effective model for anyon Hign-T c superconductivity. It is shown that a second-order phase transition occurs to a phase with nonzero anomalous v.e.v <ψψ>≠0. This phenomenon can be interpreted as a formation of a condensate of Cooper pairs and leads to spontaneous breaking of the gauge invariance accompanied by the appearance of massless fermion excitations.
GRAVITATIONAL ANOMALY AND THE WORLD TOPOLOGY
Authors: ROY ASHIM , BANDYOPADHYAY PRATUL
Published: November 2004

Here it is shown that the gravitational anomaly is compensated by the torsion term in the Einstein–Cartan action when the geometrical and topological origin of torsion is considered in the context of quantum geometry characterizing the quantization procedure of a fermion. The relationship of this anomaly with Pontryagin index is then established. The relevance of this index in the origin of topological fixtures like wormholes in space-time has also been discussed.
THE MULTICRITICAL KONTSEVICH-PENNER MODEL
Authors: CHEKHOV L. , MAKEENKO Yu.
Published: November 2004

We consider the Hermitian matrix model with an external field entering the quadratic term tr (ΛXΛX) and Penner-like interaction term αN( log (1+X)-X). An explicit solution in the leading order in N is presented. The critical behavior is given by the second derivative of the free energy in α which appears to be a pure logarithm, that is a feature of c=1 theories. Various critical regimes are possible, some of them corresponds to critical points of the usual Penner model, but there exists an infinite set of multicritical points which differ by values of scaling dimensions of proper conformal operators. Their correlators with the puncture operator are given in genus zero by Legendre polynomials whose argument is determined by an analog of the string equation.
ELECTRODYNAMICS IN THE PRESENCE OF AN AXION
Authors: CORIANÒ C.
Published: November 2004

The low energy limit of an axion field coupled to gauge fields is investigated through the behavior of the gauge fields propagator in a local vacuum angle background. The local (singular) part of the effective action for the axion field is calculated at one-loop level. In the case of a time-like, linearly growing axion field, representing a massive axion, we give an asymptotic expansion of the causal propagator and we solve nonlocally for the first coefficient. We show that, for a generic axionic background, short distance propagation of the gauge field is well defined.
ON LOOP EQUATIONS IN KdV EXACTLY SOLVABLE STRING THEORY
Authors: DALLEY SIMON
Published: November 2004

The non-perturbative behavior of macroscopic loop amplitudes in the exactly solvable string theories based on the KdV hierarchies is considered. Loop equations are presented for the real non-perturbative solutions living on the spectral half-line, allowed by the most general string equation [Formula: see text], where [Formula: see text] generates scale transformations. In general the end of the half-line (the 'wall') is a non-perturbative parameter whose role is that of boundary cosmological constant. The properties are compared with the perturbative behavior and solutions of [P, Q]=1. Detailed arguments are given for the (2,2m-1) models while generalization to the other (p,q) minimal models and c=1 is briefly addressed.
ON THE BLACK HOLE CONFORMAL FIELD THEORY COUPLED TO THE POLYAKOV'S STRING THEORY: A NON-PERTURBATIVE ANALYSIS
Authors: MARTELLINI M. , SPREAFICO M. , YOSHIDA K.
Published: November 2004

We coupled the 2D black hole conformal field theory discovered by Witten to a (D-1)-dimensional Euclidean bosonic string. We demonstrate that the resulting planar (=zero genus) string susceptibility is real for any 0≤D≤4.
TEST OF FUNDAMENTAL SYMMETRY PRINCIPLES AT A ϕ FACTORY
Authors: CLINE DAVID B.
Published: November 2004

We describe the tests of various symmetry principles at a ϕ factory. The most important new tests will be for the validity of CPT invariance at an extremely sensitive level. We indicate the current level of model independent limitation on CPT violation. Tests of new gravity interactions as well as CP violation in various K decays are described as well as some interest in new probes of quantum mechanics. A brief description of the Frascati, Novosibirsk and UCLA ϕ factory designs are also given.
A COSMOLOGICAL LOWER LIMIT FOR QUARK COMPOSITENESS ENERGY SCALE
Authors: CHAKRABARTY SOMENATH , DATTA BHASKAR , SINHA BIKASH
Published: November 2004

Baryon number density inhomogeneity in the very early universe, due to an assumed first order preon-to-quark phase transition, at or around the electroweak symmetry breaking energy is discussed. Conformity with primordial nucleosynthesis suggests that quark compositeness energy scale must be higher than 500 GeV.
SIEGEL'S CHIRAL BOSON AND THE CHIRAL SCHWINGER MODEL
Authors: BERGER THILO
Published: November 2004

Siegel's proposal for a Lagrangian formulation of a chiral boson is analyzed by applying recent results on 2d chiral quantum gravity, A model is derived whose solution consists of a massive scalar and two massless chiral scalars. Therefore it is a minimally bosonized two-fermion chiral Schwinger model.
CHARGED TOPOLOGICAL SOLITONS IN (4+1)-DIMENSIONAL YMCS THEORY
Authors: AULAKH C. S.
Published: November 2004

We show that when a Chern-Simons term is added to the action of SU (N) (N≥3) Yang-Mills theory in five dimensions the usual self-dual topological solitons present in the theory necessarily pick up a (topological) electric charge.
THE QUANTUM HALL EFFECT AT ARBITRARY RATIONAL FILLING: A PROPOSAL
Authors: CRISTOFANO G. , MAIELLA G. , MUSTO R. , NICODEMI F.
Published: November 2004

A description of the quantum Hall effect, already proposed for the fractional filling ν=1/m, based on the introduction of Coulomb gas-like vertex operators typical of a two-dimensional conformal field theory, is extended to the case ν=p/m. The resulting physical picture is compared with the hierarchical model.
ON AFFINE VIRASORO CONSTRUCTIONS FOR SL(2,ℝ) CURRENT ALGEBRA
Authors: GORSKY A. S. , SELIVANOV K. G.
Published: November 2004

Some new affine Virasoro constructions for SL (2,ℝ) current algebra have been found. We discuss the generalization of the standard second order constructions to that of the arbitrary order in the currents.
CPN-1 MODEL AS REDUCTION OF GRAVITY THEORIES
Authors: YOON J. H.
Published: November 2004

A complete series of the gauged CP N-1 nonlinear sigma models is obtained from the Einstein's gravitation by a reduction mechanism, assuming the SU (N) symmetry as the isometry of the metric. Some physical implications of this result are discussed briefly.
SINGULAR CONTRACTIONS OF W-ALGEBRAS
Authors: HULL C. M. , PALACIOS L.
Published: November 2004

Many W-algebras are consistent for all values of the central charge except for a discrete set of exceptional values. We show that such algebras can be contracted to new consistent degenerate algebras at these exceptional values of the central charge.
UNITARITY RELATIONS IN c=1 LIOUVILLE THEORY
Authors: LOWE DAVID A.
Published: November 2004

We consider the S-matrix of c=1 Liouville theory with vanishing cosmological constant. We examine some of the constraints imposed by unitarity. These completely determine (N,2) amplitudes at tree level in terms of the (N,1) amplitudes when the "plus" tachyon momenta take generic values. A surprising feature of the matrix model results is the lack of particle creation branch cuts in the higher genus amplitudes. In fact, we show that the naive field theory limit of Liouville theory would predict such branch cuts. However, unitarity in the full string theory ensures that such cuts do not appear in genus one (N,1) amplitudes. We conclude with some comments about the genus one (N,2) amplitudes.
RECONSTRUCTING THE METRIC OF SPACE-TIME FROM CHERN-SIMONS GRAVITY WITH POINT SOURCES
Authors: VAZ CENALO , WITTEN LOUIS
Published: November 2004

We show that a metric theory of gravity in three dimensions arises naturally from Poincaré Chern-Simons gravity, as a theory of the representation space of the Poincaré group. In addition, we obtain exact solutions of the constraints of the Chern-Simons theory with an arbitrary number of isolated point sources in relative motion, and show show the space-time metric is reconstructed.
WARD–TAKAHASHI IDENTITIES AND THE SPIN-0 COMPONENTS OF W AND Z FIELDS
Authors: LI BING AN
Published: November 2004

The Ward–Takahashi (WT) identities of the axial-vector currents and the charged vector currents of fermions are changed after spontaneous symmetry breaking. The spin-0 components of Z and W fields are revealed from the changed WT identities. The masses of these spin-0 components are at 1014 GeV. They are ghosts.
NEW BIANCHI I MODEL
Authors: HAJJ-BOUTROS JOSEPH
Published: November 2004

We deal with a state equation depending on the cosimic time t, i.e. μ=f(t)p. The metric is of L.R. S. Bianchi type I.

The obtained solution describes the initial singularity where radiation dominates and evolves into the matter-dominated regime with increasing time.
ANALYTICAL CALCULATION OF THE FUNDAMENTAL SU(2)-HIGGS MODEL IN LATTICE GAUGE THEORY
Authors: ZHENG XI-TE , LIU BEI-SHU
Published: November 2004

A variational-cumulant expansion method is applied to the lattice SU(2) gauge system coupled with Higgs field in the fundamental representation. The phase diagram of the system is calculated to the third order approximation. The result is in good agreement with Monte Carlo simulations.
THE STRUCTURE OF REPRESENTATION FOR THE W(3) MINIMAL MODEL
Authors: MIZOGUCHI S.
Published: November 2004

Some exact results in the representation theory of the W(3) algebra are presented. The embedding structure of the completely degenerate representation is studied in detail. The character formula is obtained by the Feigen-Fuchs-Rocha-Caridi method. It is manifestly irreducible and coincides with the branching coefficients of diagonal embedding [Formula: see text] in the unitary case. The W(n) character for general n can also be obtained completely in parallel. Four-point functions and fusion rules are calculated explicitly for the Z3 Potts model as a W(3) minimal theory, which agree with the Verlinde formula.
MEASUREMENTS OF THE PROPERTIES OF THE Z BOSON, THE STANDARD MODEL AND BEYOND
Authors: RIZZO THOMAS G.
Published: November 2004

Recent measurements of the properties of the Z boson at the SLC and LEP colliders are compared with the radiatively corrected predictions of the standard model as well as several classes of models containing additional gauge bosons. The possible evidence for new physics beyond the standard model is discussed.
RENORMALIZATION OF THE SINE-GORDON MODEL AND NONCONSERVATION OF THE KINK CURRENT
Authors: HUANG KERSON , POLONYI JANOS
Published: November 2004

We renormalize the (1+1)-dimensional sine-Gordon model by placing it on a Euclidean lattice, and study the renormalization group flow. We start with a compactified theory with controllable vortex activity. In the continuum limit the theory has a phase in which the kink current is anomalous, with divergence given by the vortex density. The phase structure is quite complicated. Roughly speaking, the system is normal for small coupling T. At the Kosterlitz-Thouless point T=π/2, the current can become anomalous. At the Coleman point T=8π, either the current becomes anomalous or the theory becomes trivial.
CORRELATIONS AMONG LOW-ENERGY OBSERVABLES OF THE FOUR-NUCLEON SYSTEM
Authors: BARLETTE VANIA E. , ADHIKARI SADHAN K.
Published: November 2004

Using a simple effective nucleon-trinucleon interaction we predict and study certain new correlations which are expected to exist between low-energy s-wave spin-isospin singlet observables of the four-nucleon system when various potential models yielding essentially identical two- and three-nucleon observables are employed in four-nucleon calculations. The study of such correlations using different realistic potential models is expected to yield information about the nucleon-nucleon and three-nucleon interactions.
PARTICLE PRODUCTION IN π−-NUCLEUS COLLISIONS AT 340 GeV/c
Authors: TUFAIL A. , AHMAD S. , KHAN A.R. , ZAFAR M. , SHAFI M.
Published: November 2004

A study of the angular distributions of charged shower particles produced in 340 GeV π−-nucleus interactions is presented. The variations of mean pseudorapidity and dispersion of the rapidity distribution with various multiplicities have been studied in detail. Rapidity-width distribution has also been investigated.
ANOMALOUS TOPOLOGICAL CURRENT IN THE NONLINEAR SIGMA MODEL
Authors: HUANG KERSON , KOIKE YUJI , POLONYI JANOS
Published: November 2004

It is proposed that a classically conserved current may not be conserved in quantum theory due to singular configurations in the path integral. This is illustrated in the (2+1)-dimensional O(3) nonlinear sigma model with lattice regularization. The current here is that of the topological charge density of “Skyrmions”. On the lattice the current is always “anomalous”, due to the existence of Dirac monopoles. The reason is that the world line of a Skyrmion can be regarded as a Dirac string (in a particular gauge), which is terminated by a monopole. Monte-Carlo simulations indicate that, in the continuum limit, current conservation obtains in a weak-coupling phase, in which monopole and anti-monopoles form bound states that disappear upon coarse-graining; but the anomaly persists in a strong-coupling phase, in which the above-mentioned bound states dissociate into a plasma. In the plasma phase rotational invariance will be broken in the presence of a “Hopf term” in the action.
EQUIVALENT COMPLEX AND REAL FERMIONS IN HETEROTIC SUPERSTRING SOLUTIONS
Authors: DE TRAUBENBERG M. RAUSCH , SAVOY C.A.
Published: November 2004

As a first step towards a classification of the heterotic superstring solutions in the fermionic approach, we study a class of solutions characterized by complex fermions with ZN boundary conditions. The same solutions can be obtained by an equivalent modular invariant system of real fermions with Z2 boundary conditions. The proof is supplied by Riemann identities for Jacobi Θ-functions that we derive. The patterns of the gauge groups of the D-dimensional solutions are determined for 4≤D≤10, and their uniqueness in ten dimensions is checked for the different ZN boundary conditions. A construction of the E8×E8 supersymmetric solution based on nine complex fermions with Z3 periodicity is exhibited.
REMOVING THE TOP AND HIGGS MASS DEPENDENCE FROM PHYSICAL OBSERVABLES
Authors: NARDI ENRICO
Published: November 2004

The dependence of four-fermion neutral and charged current processes on the masses of the top and of the Higgs particles is analyzed. A parametrization of the leading top and Higgs vacuum polarization effects is given in the form of effective amplitudes, and a general procedure for generating quantities that to a large extent are independent of the unknown parameters of the standard model is described. A large set of these quantities is reviewed, and by explicit computation the residual theoretical uncertainty is shown to be negligible.
CHARGE QUANTIZATION, EXOTIC FERMIONS AND SOME EXTENSIONS OF THE STANDARD MODEL
Authors: FOOT ROBERT
Published: November 2004

Some extensions to the standard model have been proposed, which require new fermions for the electroweak anomalies to cancel. We investigate some of these theories, and examine the possibility of cancelling the anomalies and yet preserve the charge quantization feature of the standard model.
VERY CHARMING BARYONS
Authors: SAVAGE MARTIN J. , SPRINGER ROXANNE P.
Published: November 2004

The multiply charmed baryons have a very interesting spectroscopy and provide a unique laboratory for studying the strong interaction dynamics that bind quarks into hadrons. We wish to point out that the weak decay of these hadrons is also interesting and examine the flavor SU(3) predictions for their nonleptonic and semileptonic decay.
EXCITATIONS AND INTERACTIONS IN d=1 STRING THEORY
Authors: SENGUPTA ANIRVAN M. , WADIA SPENTA R.
Published: November 2004

We discuss the singlet sector of the d=1 matrix model in terms of a Dirac fermion formalism. The leading order two- and three-point functions of the density fluctuations are obtained by this method. This allows us to construct the effective action to that order and hence provide the equation of motion. This equation is compared with the one obtained from the continuum approach. We also compare continuum results for correlation functions with the matrix model ones and discuss the nature of gravitational dressing for this regularization. Finally, we address the question of boundary conditions within the framework of the d=1 unitary matrix model, considered as a regularized version of the Hermitian model, and study the implications of a generalized action with an additional parameter (analogous to the θ parameter) which give rise to quasi-periodic wave functions.
ELECTRON SCATTERING FROM NUCLEI
Authors: LALLENA ANTONIO M.
Published: November 2004

The purpose of this work is to discuss the utility of electron scattering in the study of nuclear properties. After an introduction to the subject, we present a historical overview and details of experimental facilities. The bulk of the paper is focused on the analysis of the nuclear response below the pion production threshold. We place special emphasis on what kind of information electron scattering provides about the nuclear structure of closed-shell nuclei and their neighbors. Selected examples are analyzed throughout the paper.
THE EFFECT OF POLARIZATION OF COLLIDING PLANE GRAVITATIONAL WAVES ON FOCUSING SINGULARITIES
Authors: WANG ANZHONG
Published: November 2004

A five-parameter class of colliding plane gravitational wave solutions is obtained by using the soliton technique of Belinsky and Zakharov, which includes most of the important known solutions. A four-parameter subclass of the solutions can be considered as a noncollinear generalization of the famous Szekeres family of colliding collinear polarization plane gravitational wave solutions. The effect of polarization of colliding plane gravitational waves on the formation and nature of singularities is, in turn, investigated.
GENERAL CHARACTERISTICS OF Bc-MESONS: PRODUCTION MECHANISMS AND DECAYS
Authors: GERSHTEIN S.S. , LIKHODED A.K. , SLABOSPITSKY S.R.
Published: November 2004

Using Martin’s potential, independently of b- and c-quark flavours, we calculate the mass spectrum of [Formula: see text]-mesons and widths of electromagnetic transition between them. We obtain the estimates of the production cross-section at e+e− colliders, in hadronic and neutrino interactions. A real possibility of observing Bc-mesons at LEP (up to 500 Bc per 106 Z0) and at hadron colliders [Formula: see text] has been pointed out. The importance of observing the annihilation decay channels of Bc-mesons—Bc→τντ( Br (Bc→τντ)=1.5–2%) and Bc→ϕDs, DK, etc.—has been emphasized.
SYMMETRY IN TWO-DIMENSIONAL GRAVITY
Authors: XU KAI-WEN , ZHU CHUAN-JIE
Published: November 2004

We study the symmetry of two-dimensional gravity by choosing a generic gauge. A local action is derived which reduces to either the Liouville action or the Polyakov one by reducing to the conformal or light-cone gauge respectively. The theory is also solved classically. We show that an SL (2, R) covariant gauge can be chosen so that the two-dimensional gravity has a manifest Virasoro and the sl (2, R)-current symmetry discovered by Polyakov. The symmetry algebra of the light-cone gauge is shown to be isomorphic to the Beltrami algebra. By using the contour integration method we construct the BRST charge QB corresponding to this algebra following the Fradkin-Vilkovisky procedure and prove that the nilpotence of QB requires c=28 and α0=1. We give a simple interpretation of these conditions.
RENORMALONS IN SUPERSYMMETRIC THEORIES
Authors: VERBAARSCHOT J.J.M. , WEST P.
Published: November 2004

Supersymmetric theories are shown to possess singularities of the renormalon type unless the theories are finite. However, the Landau pole found in λϕ4 and QED is replaced by a cut singularity. It is argued that the Wess-Zumino model is trivial.
SINGULARITY-THEORY AND N=2 SUPERSYMMETRY
Authors: CECOTTI S. , GIRARDELLO L. , PASQUINUCCI A.
Published: November 2004

N=2 supersymmetry in two dimensions can be seen as a quantum realization of the geometry of singularity theory. We show this using non-perturbative methods. N=2 susy is related to the Picard-Lefschetz theory much in the same way as N=1 susy is related to Morse theory. All the concepts of singularity theory fit in the physics of the N=2 Landau-Ginsburg models. The critical behaviour of the theory is encoded in a certain natural “gauge-connection” in coupling-constant space. It is flat for a quashihomogeneous superpotential, but not in general. We find an explicit formula relating it to the Gauss-Manin connection of the singularity associated to the superpotential. Our results are valid for both the quasihomogeneous and the non-quasihomogeneous case, but in the former our equations simplify dramatically. We discuss some preliminary applications.
BOGOMOL’NYI EQUATIONS FOR VORTICES IN BORN-INFELD HIGGS SYSTEMS
Authors: SHIRAISHI KIYOSHI , HIRENZAKI SATORU
Published: November 2004

We study vortex solutions in the Born-Infeld theory coupled with a complex scalar field. We show that for a specific form of the “Higgs” potential the vortex satisfies a set of Bogomol’nyi-type equations. Another model, with nonlinear interaction between gauge and Higgs fields, is also considered. We show how it is derived from a supersymmetric extension of the Born-Infeld theory with a minimally coupled complex scalar field.
On E. Verlinde’s Formula in the Context of Stable Bundles
Authors: Bott Raoul
Published: November 2004

E. Verlinde’s formula for the dimension of the nonabelian θ-functions is discussed from an algebraic geometry point of view and related to certain quotient rings of the representative ring of sums.
Universal W-Algebras in Quantum Field Theory
Authors: Bakas Ioannis , Kiritsis Elias B.
Published: November 2004

We outline some of the main results derived recently on the representation theory of universal W-algebras, which arise in two dimensional field theory as large N limits of WN (extended) conformal symmetries. Certain connections with integrable systems of non-linear differential equations, hyper-Kähler geometries in four spacetime dimensions and the infinitely long chain of hermitian matrix models are also discussed.
STOCHASTIC QUANTIZATION AND THE BERRY PHASE
Authors: BANDYOPADHYAY PRATUL , HAJRA KOHINUR
Published: November 2004

We study here the Berry phase from the point of view of stochastic quantization. The relativistic generalization of Nelson’s stochastic quantization procedure can be achieved when the Brownian motion process is taken into account in the internal space (apart from that in the external space). This effectively considers the particle as one that is stochastically extended, and nonrelativistic quantum mechanics is obtained in the sharp point limit. This can be formulated in terms of a gauge-field-theoretical extension of the particle. This inherent gauge field gives rise to the holonomy in a Hermitian line bundle, which appears as an extra phase factor in the adiabatic limit for a parameter-dependent Hamiltonian, and determines a unique connection. When the Hamiltonian is degenerate, the holonomy is defined in a complex vector bundle. In the case of a fermion, this Berry connection is found to be related to the Wess-Zumino term and can be considered to be of topological origin.
FACTORIZABLE S MATRICES FOR PERTURBED W-INVARIANT THEORIES
Authors: de VEGA H.J. , FATEEV V.A.
Published: November 2004

[Formula: see text]-invariant conformal field theories admit perturbations preserving integrability and leading to massive quantum field theories. The unitary and crossing-invariant S matrices of such QFTs are explicitly constructed by restricting the SL (n, q)-symmetric solutions of the Yang-Baxter equations when qn+k=1. These scattering theories possess level-rank duality (n↔k).
SLAVNOV-TAYLOR IDENTITIES FOR YANG-MILLS THEORY IN CONFORMAL GAUGE
Authors: ZAIKOV R.P.
Published: November 2004

Yang-Mills theory in conformal (essentially nonlocal) gauge is considered. This gauge is expressed in a local form by means of two auxiliary scalar fields. By the use of the BRST symmetry, the Slavnov-Taylor identities are obtained. These identities are applied to prove the renormalizability of the theory as well as to investigate the structure of the radiative corrections to the two-point vertex functions. It is shown that here a new class of conformal anomalies arises, connected with the absence of radiative corrections to the propagators including auxiliary fields.
EXISTENCE THEOREM FOR THE EFFECTIVE GAUGE ALGEBRA IN THE GENERALIZED CANONICAL FORMALISM WITH ABELIAN CONVERSION OF SECOND-CLASS CONSTRAINTS
Authors: BATALIN I.A. , TYUTIN I.V.
Published: November 2004

The existence of a solution to generating equations for the effective gauge algebra with Abelian conversion of second-class constraints is established. The characteristic arbitrariness of this solution with given initial Hamiltonian and constraints is also studied.
THE INFINITELY REDUCIBLE GAUGE SYMMETRY IN UNCONSTRAINED BRST YANG-MILLS THEORY
Authors: SPENCE B.
Published: November 2004

A study is made of the infinitely reducible prepotential gauge symmetry recently found in the unconstrained BRST approach to Yang-Mills theory. This symmetry has an associated set of “BRST for BRST” transformations. The unconstrained BRST approach is applied to these, and constraints upon the field strengths of suitable gauge fields are shown to yield the BRST for BRST rules. The unconstrained BRST approach in fact applies ad infinitum, and we give the general form of the gauge-invariant Yang-Mills action in terms of appropriate prepotentials.
THE FULL STRUCTURE OF THE SUPER W3 ALGEBRA
Authors: AHN C. , SCHOUTENS K. , SEVRIN A.
Published: November 2004

We investigate a supersymmetric extension of the W3 algebra, which is common to a c=4 free fermion model and to the generic c<4 supersymmetric coset models based on [Formula: see text] at level (3, m). By using the so-called character technique, we identify a set of eight generating supercurrents of this algebra. For m=1, corresponding to c=10/7, the algebra reduces to the “minimal” super W3 algebra, which has been studied previously.
MASSLESSNESS OF THE PHOTON AND GOLDSTONE THEOREM
Authors: ROSENSTEIN B. , KOVNER A.
Published: November 2004

The relationship between the masslessness of a photon and the realization of global symmetries in QED is examined. We show that the photon is a Goldstone boson resulting from the spontaneous breakdown of a symmetry whose conserved current is [Formula: see text]. In the Higgs phase this symmetry is unbroken, but there are no particles carrying the corresponding charges. Therefore, although the symmetry does not commute with the Lorentz group, there is no contradiction with the Coleman-Mandula theorem. The Coulomb-Higgs phase transition is interpreted as the usual global symmetry breaking phase transition rather than “gauge symmetry breaking.”
AN Sp(2) COVARIANT FORMALISM OF A GENERALIZED CANONICAL QUANTIZATION WITH SECOND-CLASS CONSTRAINTS
Authors: BATALIN I.A. , LAVROV P.M. , TYUTIN I.V.
Published: November 2004

An Sp(2)-covariant version of the generalized canonical quantization method, which we proposed earlier (Ref. 5), is extended to the case of dynamical systems with both first- and second-class constraints.
PARTICLE PRODUCTION BY THE FORMATION OF A GLOBAL MONOPOLE
Authors: LOUSTO CARLOS O.
Published: November 2004

We study pair production by the changing gravitational field of a global monopole during its formation in the very early universe after the breaking of a global symmetry. We obtain a result of the same order of magnitude as in the case of gauge strings ρ~(Gη2)2/τ4, where η is the mean value of the scalar field and τ is the time at which the phase transition occurs. We also discuss how a global monopole inside a mini-black-hole affects its final stages of evolution. We find that neither the Hawking temperature nor the entropy-area relation is essentially modified by the presence of the monopole.
AN OPERATOR REGULARIZATION FOR CHIRAL GAUGE THEORIES
Authors: KUBYSHIN YU. A. , SOTO J.
Published: November 2004

We present a universal regularization of fermionic operators in the canonical formalism which respects all the symmetries which are manifest in that formalism. It allows an a priori discussion of the quantum constraint algebra and makes the formal steps leading to a path integral formula well-defined. We calculate the fermionic contributions to the renormalizations of the Gauss law and verify that the quantum constraint algebra contains Schwinger terms. We suggest a modification in the path integral formula which allows us to recover the classical degrees of freedom.
CONSISTENT CANONICAL QUANTIZATION OF THE CHIRAL SCHWINGER MODEL
Authors: SARADZHEV FUAD M.
Published: November 2004

For the chiral Schwinger model, the canonical quantization formulation consistent with the Gauss law constraint is developed. This requires modification of the canonical variables of the model. The formulation presented is unitary and gauge-invariant under modified gauge transformations. The bound state spectrum of the model is established.
GENERATING A HOT BIG BANG AS A QUANTUM FLUCTUATION
Authors: KANDRUP HENRY E. , MAZUR PAWEL O.
Published: November 2004

This brief review provides an overview of work exploring the hypothesis that the Universe “tunneled into being” as a quantum fluctuation. The basic picture is formulated within the context of a semiclassical description, in which the tunneling is interpreted as a gravitational instanton interpolating between some Planck-sized, metrically and topologically complicated, pretunneling entity and a rapidly expanding, topologically trivial, post-tunneling Universe. It is argued that the tunneling hypothesis may provide a simple explanation of gross observed features of the current Universe, such as the fact that it is big, nearly homogeneous and nearly flat, and that the massless particles contained therein seem characterized by a near-thermal distribution.
POLARIZATION ASYMMETRIES IN FERMION-(ANTI)FERMION SCATTERINGS WITH DIRAC, PAULI, SCALAR, TENSOR AND AXIAL COUPLING FACTORS
Authors: ANDERS T.B. , BARUT A.O. , JACHMANN W.
Published: November 2004

The general helicity amplitudes and all the polarization asymmetries have been evaluated for the scattering of (i) two different fermions, (ii) two identical fermions, and (iii) a fermionantifermion pair. The interaction includes the electric and magnetic vertices (with coupling parameters e and a, respectively) for vector bosons as well as scalar and tensor couplings. And all these interactions contain their axial parts. Symmetries and substitution rules for helicity amplitudes are studied in detail. The amplitudes are explicitly given in the lowest order of perturbation expansion, but all with form factors instead of point vertices. The polarization asymmetries are generally defined and evaluated for colliding beams. The contribution of the magnetic interaction increases with energy, becomes dominant for E>mf/a or approximately E>2m2, and shows large polarization asymmetries.
RECONSTRUCTION THEOREMS AND RATIONAL CONFORMAL FIELD THEORIES
Authors: MAJID SHAHN
Published: November 2004

We obtain an explicit reconstruction theorem for rational conformal field theories and other situations where we are presented with a braided or quasitensor category [Formula: see text]. It takes the form of a generalized Fourier transform. The reconstructed object turns out to be a quantum group in a generalized sense. Our results include both the Tannaka-Krein case where there is a functor [Formula: see text], and the case where there is no functor at all.
ON THE BRST APPROACH TO TWO-DIMENSIONAL GRAVITY IN THE LIGHT-CONE GAUGE
Authors: TANII YOSHIAKI
Published: November 2004

The BRST approach to two-dimensional gravity coupled to conformal field theories is discussed. The ordinary BRST symmetry acts only on the left-moving sector of the theory. It is found that there exists a BRST-like symmetry also in the right-moving sector. The conserved charge of this new symmetry is found to be nilpotent. This symmetry is a result of a redundancy of the parametrization of the gravitational field in terms of a scalar field. We propose that the physical states of the theory should belong to the cohomology of this BRST-like charge to eliminate the redundancy. It is also discussed how to derive the BRST charge from the action and the transformation laws of fields.
GENERALIZED CONFORMAL FLAT D 10 N 1 SUPERGEOMETRY
Authors: PLETNIOV N.G.
Published: November 2004

D 10 N 1 supergeometry of flat superspace conformal deformations is considered on the phase of a spontaneous breakdown of the OSp(32/1) supergroup. The correspondence between the standard set of constraints and the field equations of D 10 N 1 pure supergravity and the linear approximation of nonlinear realizations of OSp(32/1) in vielbein and superconnection definitions is demonstrated.
REMARKS ON THE QUANTUM GROUP STRUCTURE OF THE RATIONAL c<1 CONFORMAL THEORIES
Authors: FURLAN P. , GANCHEV A. CH. , PETKOVA V.B.
Published: November 2004

The rational c<1 theories are reconsidered beyond the space of BRST states, allowing for intermediate states not contained in the Kac table. The intertwining properties of the screening charges Qm and Qp−m are used to derive linear relations for the general conformal blocks. The fusion rules are recovered on BRST states, combining these relations with previously obtained identities for the fusion matrices, due to the corresponding [Formula: see text]-invariant operators. The extended formulation is applied to give meaning for qp=1 to the quantum group covariant conformal correlations initiated by Moore and Reshetikhin. The correlations are manifestly covariant under the action of the R matrix and in the diagonal case they coincide with the averages of the screened vertices, recently proposed by Gómez and Sierra.
ONE-LOOP RADIATIVE CORRECTIONS TO A HEAVY TOP DECAY IN THE STANDARD MODEL
Authors: LIU JIANG , YAO YORK-PENG
Published: November 2004

We study one-loop radiative corrections to the top-quark decay: t→bW. For a heavy top (i.e. mt≳100 GeV ), simple analytic formulas are derived. For the inclusive process, t→bW+X due to QCD, cancellations of infrared and mass singularities are shown explicitly. The final result agrees with an earlier calculation in the literature, and is an 8% reduction in the partial width for αs=0.1. Also, leading terms of the electroweak corrections are shown to be proportional to an enhancement factor [Formula: see text]. Their effect is about 1-3%. We also study the angular distributions of the leptons from the subsequent exclusive (or semi-inclusive) W decay. An asymmetry parameter which measures the polarizations of the W is introduced. We find that it is sensitive to the QCD corrections especially in the vicinity of [Formula: see text].
THE SPIN-STATISTICS THEOREM ON A CIRCLE
Authors: ANEZIRIS CHARILAOS
Published: November 2004

Recently, there has been a certain interest in the statistics of identical particles on a one-dimensional space. In this paper we extend this discussion to a circle by allowing the existence of antiparticles in addition to particles, and to creation-annihilation processes. This leads to much more complicated possibilities for statistics due to the change of the appropriate fundamental group.
SEMICLASSICAL APPROACH FOR NONRELATIVISTIC FERMIONS IN LOW DIMENSIONS
Authors: KARABALI D. , SAKITA B.
Published: November 2004

We present a collective field formalism for nonrelativistic fermions in one spatial dimension. A bosonization technique is used to convert the quantum mechanical fermionic problem to a bosonic one, which is further described as a second quantized Schrödinger field theory. A formulation in terms of current and density variables gives rise to the collective field representation. Applications of our formalism to the D=1 Hermitian matrix model and the system of one-dimensional fermions in the presence of a weak electromagnetic field are discussed.