bluuebunny/crossref_metadata_2025 huggingface dataset:
THE INVARIANT CHARGES OF THE NAMBU–GOTO THEORY: NON-ADDITIVE COMPOSITION LAWS
Authors: POHLMEYER K.
Published: November 2004

With continuity as the essential ingredient, insight is gained into the existence, number and structure of algebraic relations among the invariant charges corresponding to the three branches of a string vertex in the classical Nambu–Goto theory. C-number and algebraic aspects of these relations are discussed.
SOFT PHOTON PRODUCTION FROM QUARK–GLUON PLASMA AND CANCELLATION OF MASS SINGULARITY
Authors: NIÉGAWA A.
Published: November 2004

It has recently been reported that the production rate of soft real photons from a hot quark–gluon plasma exhibits unscreened mass singularities even within the hard-thermal-loop resummation scheme. It is shown that there exist another diagrams that cancel the singular contribution, in accordance with the general theorem of absence of mass singularities in thermal reaction rates, provided one sums over the set of all degenerate initial and final states. An interpretation of the relevant diagrams is given in terms of physical processes taking place in the quark–gluon plasma. The mechanism of canceling mass singularities in this example is similar to the one in vacuum theory.
HETEROTIC COSET MODELS
Authors: JOHNSON CLIFFORD V.
Published: November 2004

A description is given on how to construct (0, 2) supersymmetric conformal field theories as coset models. These models may be used as non-trivial backgrounds for heterotic string theory. They are realized as a combination of an anomalously gauged Wess–Zumino–Witten model, right-moving supersymmetric fermions, and left-moving current algebra fermions. Requiring the sum of the gauge anomalies from the bosonic and fermionic sectors to cancel yields the final model. Applications discussed include exact models of extremal four-dimensional charged black holes and Taub–NUT solutions of string theory. These coset models may also be used to construct important families of (0, 2) supersymmetric heterotic string compactifications. The Kazama–Suzuki models are the left-right symmetric special case of these models.
q-TENSOR METHOD AND QUANTUM SUPERALGEBRA SUq(2|1)
Authors: YANG YAPING , YU ZURONG
Published: November 2004

In this paper, we construct irreducible q-tensor operators of rank 1/2 of quantum algebra SU q(2) using generators of quantum superalgebra SU q(2|1) and their general relations. By means of the property of q-tensor operators, we can easily obtain the irreducible representations. The method does not depend on any concrete realization of SU q(2|1). The result holds in general.
ADDITIONAL SUPERCONFORMAL ALGEBRAS IN TWO DIMENSIONS
Authors: APIKYAN S. A.
Published: November 2004

An SO (N)-invariant algebra of extended superconformal symmetry is obtained in two dimensions with an arbitrary central charge, which besides the energy-momentum tensor contains the currents of 1/2, 1 and 3/2 dimensions.
STRING-LOOP CORRECTIONS TO EFFECTIVE ACTION AND BLACK HOLE INSTABILITIES
Authors: BELOKUROV V. V. , IOFA M. Z.
Published: November 2004

Following the ideas of Ref. 3, to account for instability of 2-D black hole solution, we discuss possible imaginary string-loop corrections to the coefficient at the Einstein term in string effective action (EA). In closed bosonic string theory, such corrections appear because of the tachyon contribution to the integration measure over the moduli. In superstring theory, several possible sources of complex one-string-loop contributions to the EA are considered. It is argued that none of them can account for complex corrections to the Einstein term in the effective action.
UNIFICATION OF SPINS AND CHARGES IN GRASSMANN SPACE?
Authors: MANKOČ-BORŠTNIK NORMA
Published: November 2004

In a space of d(d > 5) ordinary and d Grassmann coordinates, fields manifest in an ordinary four-dimensional subspace as spinor (1/2, 3/2), scalar, vector or tensor fields with the corresponding charges, according to two kinds of generators of the Lorentz transformations in the Grassmann space. Vielbeins and spin connections define gauge fields-gravitational and Yang–Mills. For d = 15 the theory offers the unification of all known charges — spins and Yang–Mills charges — of fermionic and bosonic fields and all known interactions.
DETERMINING αs FROM MEASUREMENTS AT Z: HOW NATURE PROMPTS US ABOUT NEW PHYSICS
Authors: SHIFMAN M.
Published: November 2004

The value of αs (Mz) emerging from the so-called global fits based mainly on the data at the Z peak (and assuming the standard model) is three standard deviations higher than the one stemming from the low-energy phenomenology. The corresponding value of Λ QCD is very large, ~500 MeV, and is incompatible with crucial features of QCD. If persists, the discrepancy should be interpreted as due to contributions to the Z-quark-antiquark vertices which go beyond the standard model.
NEW CHALLENGES IN CHARMONIUM PHYSICS
Authors: GU Y. F. , TUAN SAN FU
Published: November 2004

The puzzle of the absence of VP modes ψ → ρπ, [Formula: see text], is now extended to the VT mode ψ′ → ω0f2(1270) from the recent BES run. This poses additional challenge to phenomenological theory. We study the new situation in terms of the hadron helicity conservation (HHC) theorem and the postulated existence of a trigluonia Omicron [Formula: see text].
COLLECTIVE FIELD APPROACH TO GAUGED PRINCIPAL CHIRAL FIELD AT LARGE-N
Authors: ZAREMBO K.
Published: November 2004

The lattice model of principal chiral field interacting with the gauge fields, which have no kinetic term, is considered. This model can be regarded as a strong coupling limit of lattice gauge theory at finite temperature. The complete set of equations for collective field variables is derived in the large-N limit and the phase structure of the model is studied.
CAUSAL QUANTUM MECHANICS TREATING POSITION AND MOMENTUM SYMMETRICALLY
Authors: ROY S. M. , SINGH VIRENDRA
Published: November 2004

De Broglie and Bohm formulated a causal quantum mechanics with a phase space density whose integral over momentum reproduces the position probability density of the usual statistical quantum theory. We propose a causal quantum theory with a joint probability distribution such that the separate probability distributions for position and momentum agree with the usual quantum theory. Unlike the Wigner distribution the suggested distribution is positive-definite and obeys the Liouville condition.
THE RELATION OF LEMNISCATE AND A LOOP SOLITON AS 3/2 AND 1 SPIN FIELDS ALONG THE MODIFIED KORTEWEG-DE VRIES EQUATION
Authors: MATSUTANI SHIGEKI
Published: November 2004

The modified Korteweg-de Vries equation on a thin elastic rod was studied recently. In this article, we show that the lemniscate is regarded as the elastica embedded in a space with a spin 3/2.
PHYSICAL STATES AND STRING SYMMETRIES
Authors: WEST PETER
Published: November 2004

It is shown that if the momenta belong to an integral lattice, then every physical state of string theory leads to a symmetry of the scattering amplitudes. We discuss the role of this symmetry when the momenta are those provided by the usual D.D.F construction and show that the string compactified on the torus associated with the self-dual Lorentzian lattice, Π25,1 possess the Fake Monster Lie algebra as a symmetry.
THE GENERAL EXPONENTIAL QUADRATIC MULTIMODE SQUEEZED STATES
Authors: MA LEI , ZHANG YONG-DE , PAN JIAN-WEI , WANG XIANG-BIN
Published: November 2004

In this letter the exponential quadratic multimode squeezed states are studied with the aid of the linear quantum transformation. The restrictive relations and the forms of the above general squeezed states are obtained.
A NEW FORMULA FOR THE MASS OF A STATIONARY AXISYMMETRIC CONFIGURATION
Authors: AVAKIAN R. M. , OGANESSYAN G.
Published: November 2004

It has been shown by one of the authors1 that in isotropic spherical coordinates there is a relation between the mass of a static spherical gravitating body and the pressure distribution inside it. In this paper the result is generalized for the case of stationary axisymmetric configurations.
REMARKS ON THE VALUE OF THE HIGGS MASS FROM THE PRESENT LEP DATA
Authors: CONSOLI M. , HIOKI Z.
Published: November 2004

We perform a detailed comparison of the present LEP data with the one-loop standard model predictions. It is pointed out that for mt = 174 GeV the "bulk" of the data prefers a rather large value of the Higgs mass in the range of 500–1000 GeV, in agreement with the indications from the W mass. On the other hand, to accommodate a light Higgs it is crucial to include the more problematic data for the τ FB asymmetry. We discuss further improvements on the data which are required to obtain a firm conclusion.
GAUGE STRUCTURE ON SD
Authors: FUJII KAZUYUKI , KITAKADO SHINSAKU , OHNUKI YOSHIO
Published: November 2004

Gauge structures, emerging in the course of quantization when the configuration space of the system is SD, are completely determined for arbitrary D. For even D, reflecting the non-trivial topology, the gauge potential is that of the generalized BPST instanton configuration. Similar gauge potentials, although topologically trivial, are obtained for odd D>1.
A TRIANGULAR DEFORMATION OF THE TWO-DIMENSIONAL POINCARÉ ALGEBRA
Authors: KHORRAMI M. , SHARIATI A. , ABOLHASSANI M.R. , AGHAMOHAMMADI A.
Published: November 2004

Contracting the h-deformation of SL(2, ℝ), we construct a new deformation of two-dimensional Poincaré's algebra, the algebra of functions on its group and its differential structure. It is seen that these dual Hopf algebras are isomorphic to each other. It is also shown that the Hopf algebra is triangular, and its universal R-matrix is also constructed explicitly. We then find a deformation map for the universal enveloping algebra, and at the end, give the deformed mass shells and Lorentz transformation.
SOME PROPERTIES OF CHARGE-CONJUGATED SPINORS IN D DIMENSIONS
Authors: DE ANDRADE M.A.
Published: November 2004

Spinors for an arbitrary Minkowski space with signature (t, s) are reassessed in connection with D-dimensional free Dirac action. The possibility of writing down kinetic and mass terms for charge-conjugated spinors is discussed in terms of the number of time-like directions of the space-time. The results found here are commented in the light of early works on the subject.
GAUGE PROPERTIES OF CONSERVED CURRENTS IN ABELIAN VERSUS NON-ABELIAN THEORIES
Authors: DESER S. , HENNEAUX MARC
Published: November 2004

We clarify the physical origin of the difference between gauge properties of conserved currents in Abelian and non-Abelian theories. In the latter, but not in the former, such currents can always be written on-shell as gauge invariants modulo identically conserved, superpotential, terms. For the “isotopic” vector and the stress tensor currents of spins one and two respectively, we explain this difference by the fact that the non-Abelian theories are just the self-coupled versions of the Abelian ones using these currents as sources. More precisely, we indicate how the self-coupling turns the noninvariantizable Abelian conserved currents into (on-shell) superpotentials. The fate of other conserved currents is also discussed.
W-STRINGS ON GROUP MANIFOLDS
Authors: MIKOVIĆ ALEKSANDAR , SAZDOVIĆ BRANISLAV
Published: November 2004

We present a procedure for constructing actions describing propagation of W-strings on group manifolds by using the Hamiltonian canonical formalism and representations of W-algebras in terms of Kac-Moody currents. An explicit construction is given for the case of the W3 string.
ELECTROWEAK VORTICES AND GAUGE EQUIVALENCE
Authors: MACDOWELL SAMUEL W. , TÖRNKVIST OLA
Published: November 2004

Vortex configurations in the electroweak gauge theory are investigated. Two gauge-inequivalent solutions of the field equations, the Z and W vortices, have previously been found. They correspond to embeddings of the Abelian Nielsen-Olesen vortex solution into a U(1) subgroup of SU(2)×U(1). It is shown here that any electroweak vortex solution can be mapped into a solution of the same energy with a vanishing upper component of the Higgs field. The correspondence is a gauge equivalence for all vortex solutions except those for which the winding numbers of the upper and lower Higgs components add to zero. This class of solutions, which includes the W vortex, corresponds to a singular solution in the one-component gauge. The results, combined with numerical investigations, provide an argument against the existence of other vortex solutions in the gauge-Higgs sector of the Standard Model.
YUKAWA MODEL IN CURVED SPACETIME
Authors: ELIZALDE E. , ODINTSOV S.D.
Published: November 2004

The Yukawa model in curved spacetime (renormalizable in the usual sense) is considered near the critical point, using the 1/N-expansion and renormalization group techniques. The equivalence of this model with the standard NJL model is proven. The behavior of the graviton-scalar bound state coupling constant near the ir stable fixed point ξ=1/6 is discussed. The effective potential is calculated and a dynamically generated fermionic mass is found. Some applications to quantum gravity which make explicit use of the 1/N-expansion are briefly discussed. In particular, a possible solution of the cosmological constant problem within the framework of conformal factor dynamics is pointed out.
CHIRAL LAGRANGIANS, CURRENT ALGEBRA AND KAON WEAK DECAYS
Authors: KARLSEN R.E. , SCADRON M.D.
Published: November 2004

We show that the weak chiral Lagrangian of Cronin predicts the weak matrix element ratios of K→3π, 2π, π to K→2π, π, vac respectively, which are in complete agreement with the standard current algebra (CA)-partially conserved axial current (PCAC) techniques. Both approaches are in fact compatible with data.
FRACTIONAL SUPERSYMMETRY
Authors: MOHAMMEDI NOUREDDINE
Published: November 2004

A symmetry between bosonic coordinates and some Grassmannian-type coordinates is presented. Commuting two of these Grassmannian-type variables results in an arbitrary phase factor (not just a minus sign). This symmetry is also realized at the level of the field theory.
THE FULL STRUCTURE OF QUANTUM N=2 SUPER-$W_3^{\left( 2 \right)} $ ALGEBRA
Authors: AHN C. , KRIVONOS S. , SORIN A.
Published: November 2004

We present the complete structure of the nonlinear N=2 super extension of Polyakov-Bershadsky, [Formula: see text], algebra with the generic central charge c, at the quantum level. It contains two extra pairs of fermionic currents with integer spins 1 and 2, besides the currents of N=2 superconformal and [Formula: see text] algebras. For c→∞ limit, the algebra reduces to the classical one, which has been studied previously. The “hybrid” field realization of this algebra is also discussed.
NEW POTENTIAL SCALAR MODELS VIA THE KINK OF THE λΦ4 THEORY
Authors: RODRIGUES R. DE LIMA
Published: November 2004

From a scalar field theory in 1+1 dimensions, new nonlinear potential models have been found leading to an enlargement of potential classes that can be solved exactly in the context of quantum and classical theories. The method consists in considering a SUSY N=2 general solution for an unnormalizable state of the supersymmetric partner associated with the zero mode, which provides us with a new class of isospectral potentials that can be expressed in terms of the kink. The model considered here is a double-well potential, the kink of the λΦ4 theory. This self-interaction is part of the interaction that appears in the new potentials.
GENERALIZED GAUSS DECOMPOSITION OF TRIGONOMETRIC R-MATRICES
Authors: KHOROSHKIN S.M. , STOLIN A.A. , TOLSTOY V.N.
Published: November 2004

The general formula for the universal R-matrix for quantized nontwisted affine algebras, obtained by the first and third authors, is applied to zero central charge, highest weight modules of the quantized affine algebras. It is shown how the universal R-matrix produces the Gauss decomposition of trigonometric R-matrix in tensor product of these modules. In particular, [Formula: see text] current realization of the universal R-matrix is presented. It gives a new universal presentation for the trigonometric R-matrix with a parameter in tensor product of Uq(sl2)-Verma modules. Detailed analysis of a scalar factor arising in finite-dimensional representations of the universal R-matrix for any Uq(ĝ) is given. We interpret this scalar factor as a multiplicative bilinear form on highest weight polynomials of irreducible representations and express this form in terms of infinite q-shifted factorials.
CONTACT INTERACTIONS OF FREE ANYONS
Authors: VOROPAEV S.
Published: November 2004

The possibility of the existence of “free” Schrödinger anyons is considered. It is shown that special type of contact interactions exists when scattering does not arise. By formulating the problem for the two-particle system with a finite region of interaction which is then allowed to go to zero, it is established that this type of the contact interactions is the analog of the anomalous magnetic moment for fermions in the Aharonov-Bohm field. Finally, we consider connections with the Dirac anyon physics and low energy dynamics of [U(1)]2 Chern-Simons solitons.
IMPLICATIONS OF GLUON RADIATION EFFECTS AND SOFT TRANSVERSE MOMENTA FOR THE NUCLEON SUBSTRUCTURE IN QCD
Authors: STEFANIS N.G.
Published: November 2004

The proton and neutron helicity-conserving form factors in the spacelike region are studied within a convolution scheme which takes into account: (i) soft-gluon radiative corrections via Sudakov-type form factors, and (ii) the intrinsic k⊥-dependence of the nucleon wave function. Results are presented for a complete set of nucleon distribution amplitudes which comply with QCD sum rules. Implications for the end point behavior of nucleon distribution amplitudes are discussed in the context of Appell decompositions. The calculated leading-order perturbative contribution to both form factors falls short compared to the existing data, indicating substantial higher-order perturbative corrections (i.e. a large K factor) and/or sizeable soft contributions, e.g., higher-twist effects, at presently accessible momentum-transfer values.
ON THE PHASE OF $B^0 - \bar B^0 $ MIXING MATRIX ELEMENT IN THE SUSY STANDARD MODEL
Authors: KURIMOTO T.
Published: November 2004

It is shown that the complex phase of [Formula: see text] mixing matrix element is the same as that of the standard model up to the minor correction of the order of (mc/mt)2 or less in the SUSY standard model. This conclusion is valid as far as the Yukawa coupling constants are perturbative and realistic, and can be available for other realistic models where generation mixing and CP-violation are solely due to Yukawa interaction among quarks and Higgs doublets.
MIRROR SYMMETRY ON ARBITRARY DIMENSIONAL CALABI-YAU MANIFOLD WITH A FEW MODULI
Authors: NAGURA MASARU
Published: November 2004

We calculate the B-model on the mirror pair of X2N−2(2, 2, …, 2, 1, 1), which is an (N−2)-dimensional Calabi-Yau manifold and has two marginal operators, i.e. h1,1(X2N−2(2, 2, …, 2, 1, 1))=2. In Ref. 1 we have discussed about mirror symmetry on XN(1, 1, …, 1) and its mirror pair. However, XN(1, 1, …, 1) had only one moduli. In this letter, we extend its methods to the case with a few moduli using toric geometry.
HAWKING RADIATION FOR TWISTED COMPLEX SCALAR FIELDS ON BLACK HOLES AND DIRAC MONOPOLES
Authors: GONCHAROV YU.P. , YAREVSKAYA J.V.
Published: November 2004

It is shown that the existence of twisted complex scalar fields on black holes can naturally be connected with an infinite set of Dirac magnetic monopoles living on black holes due to nontrivial topological properties of the latter ones. This can lead to an essential contribution to the total luminosity of black hole with respect to the Hawking radiation. The given possibilities for other types of fields are also discussed.
CYCLIC FAMILY SYMMETRY AND LEPTON HIERARCHY IN SUPERSYMMETRY
Authors: DU DONGSHENG , LIU CHUN
Published: November 2004

A cyclic symmetry among the left-handed doublets of the three families is proposed. This symmetry can naturally result in a realistic hierarchical pattern of the fermion masses within the framework of supersymmetry with nonvanishing sneutrino vacuum expectation values.
THE BRANCHING RATIO ${\rm{Br}}(\Omega^- \to \Xi^0 e^- \bar{\nu}_e)$: AN ALGEBRAIC APPROACH
Authors: SLAUGHTER MILTON DEAN
Published: November 2004

The branching ratio [Formula: see text] is calculated using a broken symmetry algebraic approach to QCD, namely asymptotic flavor SU(3) symmetry. Our result is in better agreement with experiment than previous theoretical results based on naive SU F(3) and yields [Formula: see text].
QUARK DELOCALIZATION, COLOR SCREENING, AND NUCLEAR INTERMEDIATE RANGE ATTRACTION II
Authors: WU G.H. , TENG L.J. , PING J.L. , WANG F. , GOLDMAN T.
Published: November 2004

The effect of correction for center-of-mass motion on the quark delocalization model of baryon-baryon interactions is to make the effective interaction a little less attractive; the correction is minor. The intermediate range behavior of the color screening potential is not critical for obtaining an intermediate attractive baryon-baryon interaction. The cluster model and molecular single quark bases give exactly the same results.
ONCE MORE ON THE RADIATIVE CORRECTIONS TO THE NUCLEON STRUCTURE FUNCTIONS IN QCD
Authors: STAMENOV D.B.
Published: November 2004

A new representation of the next-to-leading QCD corrections to the nucleon structure functions is given in terms of parton distributions. All O(αs) corrections to the leading logarithmic approximation (LLA) are included. In contrast to the similar representations in the literature terms of order [Formula: see text] do not appear in our expressions for the nucleon structure functions taken in the next-to-leading logarithmic approximation. This result is generalized for any order in αs beyond the LLA. Terms of order [Formula: see text] which belong only to the approximation considered are present in such a representation for the structure functions.
THE PROCESS $e^+ e^- \to \bar{t}c$ IN THE ONE-GENERATION TECHNICOLOR MODEL
Authors: WANG XUELEI , WAN LINGDE , YANG JINMIN , LU GONGRU
Published: November 2004

At the energy [Formula: see text] of LEPII, we carry out the calculation in the process [Formula: see text] in the framework of the one-generation technicolor model. The results show that the process is immeasurably small in the one-generation TC model.
KNIZHNIK-ZAMOLODCHIKOV EQUATION AND EXTENDED SYMMETRY FOR STABLE HALL STATES
Authors: DE MARTINO A. , MUSTO R.
Published: November 2004

We describe an n-component Abelian Hall fluid as a system of composite bosons moving in an average null field given by the external magnetic field and by the statistical flux tubes located at the position of the particles. The collective vacuum state, in which the bosons condensed, is characterized by a Knizhnik-Zamolodchikov differential equation relative to a Û(1)n Wess-Zumino model. In the case of states belonging to Jain’s sequences the Knizhnik-Zamolodchikov equation naturally leads to the presence of a [Formula: see text] extended algebra. Only the Û(1) mode is charged while the [Formula: see text] modes are neutral, in agreement with recent results obtained in the study of the edge states.
IS THE CONDENSATION OF STRINGS THE ORIGIN OF EINSTEIN GRAVITY?
Authors: KATSUKI MIYUKI , KUBOTANI HIROTO , SUGAMOTO AKIO , NOJIRI SHIN’ICHI
Published: November 2004

We propose a mechanism to generate the metric in which the Kalb-Ramond symmetry existing in the topological BF theory is broken through the condensation of the string fields which are so introduced as to couple the antisymmetric tensor fields B, invariantly under the Kalb-Ramond symmetry. In the chiral decomposition of the local Lorentz group, the non-Abelian B fields need to be generalized to the string fields. The mechanism of the condensation is discussed, in view of the confinement problem and the polymer physics.
OBLIQUE RADIATIVE CORRECTIONS IN THE VECTOR CONDENSATE MODEL OF ELECTROWEAK INTERACTIONS
Authors: CYNOLTER G. , LENDVAI E. , PÓCSIK G.
Published: November 2004

Oblique radiative corrections are calculated to the parameter S in a version of the standard model where the Higgs doublet is replaced by a doublet of vector bosons and the gauge symmetry is broken dynamically. We show that to each momentum scale there exists a domain of the masses of charged and neutral vector bosons where S is compatible with the experiments. At a scale of 1 TeV this requires vector boson masses of at least m0 ≈ 400–550 GeV , m+ ≈ 200–350 GeV .
LIMIT ON THE COLOR-TRIPLET HIGGS MASS IN THE MINIMUM SUPERSYMMETRIC SU(5) MODEL
Authors: HISANO J. , MOROI T. , TOBE K. , YANAGIDA T.
Published: November 2004

In the minimum supersymmetric SU(5) GUT, we derive the upper limit on the mass of the color-triplet Higgs multiplets as [Formula: see text] (90% C.L.) taking all possible corrections into account in a renormalization group analysis. If the above upper limit is compared with a lower limit on [Formula: see text] from the negative search for the proton decay; [Formula: see text] (in which effects of the larger top-quark mass are included), the minimum supersymmetric SU(5) GUT is severely constrained.
IRREDUCIBLE q-BOSON REALIZATIONS
Authors: NEGRO JAVIER
Published: November 2004

A class of q-boson algebra realizations in terms of q-differential operators [Formula: see text] is characterized. Some particular cases have been worked out together with their representation spaces defined through the fundamental states. The hermiticity relations and the scalar product are also discussed for these kinds of realizations.
SCALAR DILATON-QUARKONIUM MESON IN NUCLEON-NUCLEON INTERACTION
Authors: MUSAKHANOV M.M. , RAHIMOV A.M.
Published: November 2004

The problem of missing the central attraction in the NN interaction has been reinvestigated within the effective meson theory, based on chiral and conformal anomalies of QCD. The parameters of the model are chosen to describe correctly Fπ, gπNN and N−Δ mass splitting. The resulting central scalar-isoscalar part of the potential is in qualitative agreement with phenomenological one.
THE GENERALIZED GROSS-NEVEU MODEL ON THE LIGHT-CONE
Authors: PESANDO IGOR
Published: November 2004

We investigate the generalized Gross-Neveu model using the discretized light-cone quantization and we find that the vacuum of the bare theory is nontrivial in the presence of vectorial current coupling when the simplest and most natural form of quantum constraints is used. Nevertheless the vacuum of the renormalized theory is trivial.

In the thermodynamic the Bethe-Salpeter equations which are obtained contain all the terms needed to make them finite.
DOUBLE SCALING LIMITS AND AIRY FUNCTIONS FROM QUASIHOMOGENEOUS SINGULARITIES OF VECTOR SIGMA MODELS
Authors: RÜHL W.
Published: November 2004

A sufficiently large class of vector sigma models admitting r variable singularities is defined. It is shown how quasihomogeneity induces filtrations on algebras of functions and Lie algebras of infinitesimal diffeomorphisms. From the filtrations, double scaling limits and Airy functions are derived.
ON FACTORIZING CORRELATION FUNCTIONS IN STRING THEORY USING LOOP VARIABLES
Authors: SATHIAPALAN B.
Published: November 2004

Factorization of string amplitudes is one way of constructing string interaction vertices. We show that correlation functions in string theory can be conveniently factorized using loop variables representing delta functionals. We illustrate this construction with some examples where one particle is off-shell. These vertices are “correct” in the sense that they are guaranteed, by construction, to reproduce S-matrix elements when combined with propagators in a well-defined way.
NEW HUNT FOR AN INTERMEDIATE MASS HIGGS-BOSON IN PERIPHERAL ULTRARELATIVISTIC HEAVY-ION COLLISIONS
Authors: VIDOVIĆ MARIO , GREINER MARTIN , SOFF GERHARD
Published: November 2004

We reopen the discussion on the two-photon production of the intermediate mass Higgs-boson in peripheral ultrarelativistic heavy-ion collisions at LHC. Due to larger expected luminosity, larger collision energy and higher photon energies, the Higgs production rate is enlarged by more than a factor of 10 in Ca+Ca collisions compared to Pb+Pb collisions. Besides the background of direct [Formula: see text]-production via two-photon fusion, we also discuss photon-gluon fusion into [Formula: see text].
2-D GRAVITY AS A LIMIT OF THE SL(2, ${\mathbb R}$) BLACK HOLE
Authors: ALIMOHAMMADI M. , ARDALAN F.
Published: November 2004

The transformation of the SL(2, [Formula: see text])/U(1) black hole under a boost of the subgroup U(1) is studied. It is found that the tachyon vertex operators of the black hole go into those of the c=1 conformal field theory coupled to gravity. The discrete states of the black hole also tend to the discrete states of the 2-D gravity theory. The fate of the extra discrete states of the black hole under boost are discussed.
HYPER-CHARGED VORTICES AND STRINGS WITH SIGNATURE CHANGE HORIZON
Authors: AULAKH C.S.
Published: November 2004

We show that self-dual Nielsen-Olesen (NO) vortices in three dimensions give rise to a class of exact solutions when coupled to Einstein-Maxwell-Dilaton gravity obeying the Majumdar-Papapetrou (MP) relation between gravitational and Maxwell couplings, provided certain types of Chern-Simons interactions are present. The metric may be solved explicitly in terms of the NO vortex function and becomes degenerate at scales [Formula: see text] where lS is the vortex core size and lp the Planck length. For typical lS≥104lp the horizon is thus pushed out to exponentially large scales. In the intermediate asymptotic region (IAR) lS≪r≪rH there is a logarithmic deviation of the metric from the flat metric and of the electric field from that of a point charge (which makes it decrease slower than r−1: hence the prefix hyper). In the IAR, the ADM energy and charge integrals increase logarithmically with the distance from the core region and finally diverge at the signature change horizon. String solutions in 4+p dimensions are obtained by replacing the Maxwell field with an antisymmetric tensor field (of rank 2+p) and have essentially similar properties with [Formula: see text] and with the antisymmetric charge playing the role of the topological electric charge.
SOME COMMENTS ON N=2 SUPERSYMMETRIC YANG-MILLS
Authors: FAYYAZUDDIN ANSAR
Published: November 2004

We investigate some aspects of the semiclassical BPS saturated states close to the curve ImaD/a=0.
GENERALIZED DEFORMED PARA-BOSE OSCILLATOR AND NONLINEAR ALGEBRAS
Authors: BANG HA HUY
Published: November 2004

Generalized deformed commutation relations for a single mode para-Bose oscillator and for a system of two para-Bose oscillators are constructed. It turns out that generalized deformed para-Bose oscillators are not, in general, exactly independent. Furthermore, we also discuss about the Fock space corresponding to generalized deformed para-Bose oscillators. Finally, we show how SU(2) and SU(1, 1) generators can be constructed in terms of generalized deformed para-Bose creation and annihilation operators. The algebras SU(2) and SU(1, 1) of generalized deformed oscillators14,18 are the special cases of generalized deformed para-Bose oscillators algebras but, interestingly, they have the same form.
ON THE STUDY OF NONLINEAR INTEGRABLE SYSTEMS IN (2+1) DIMENSIONS BY DRINFELD-SOKOLOV METHOD
Authors: MUKHOPADHYAY I. , ROYCHOWDHURY A.
Published: November 2004

The Drinfeld-Sokolov formalism is extended to the case of operator-valued affine Lie algebra to derive nonlinear integrable dynamical systems in (2+1) dimensions. The Poisson structure of these integrable equations are also worked out. While from the first- and second-order flows we get some new integrable equations in (2+1) dimensions, the KP equation is seen to result from the third-order flow. Complete integrability of such equations and the existence of the bi-Hamiltonian structure are demonstrated.
HAWKING TEMPERATURE FROM SCATTERING OFF THE CHARGED 2-D BLACK HOLE
Authors: KIM JIN YOUNG , LEE H.W. , MYUNG Y.S.
Published: November 2004

The charged 2-D black hole is visualized as presenting a potential barrier Vout(r*) to incoming tachyon wave. Since this takes the complicated form, an approximate form VAPP(r*) is used for scattering analysis. We calculate the reflection and transmission coefficients for scattering of tachyon off the charged 2-D black hole. The Hawking temperature is also derived from the reflection coefficient by Bogoliubov transformation. In the limit Q→0, we recover the Hawking temperature of the 2-D dilaton black hole.
QCD ON A TREE
Authors: BOULATOV D.V.
Published: November 2004

We propose a model which can be regarded as a mean field approximation for pure lattice QCD and chiral field. It always possesses a phase transition between a strong-coupling phase (where it reduces to a one-plaquette integral) and a nontrivial weak-coupling one. For the U(N) gauge group, it is equivalent to some hermitian multi-matrix model. This analogy allows us to determine possible large-N critical regimes thus generalizing the Gross-Witten phase transition in the one-plaquette model.
ELASTIC SCATTERING OF DEUTERONS ON α-CLUSTER NUCLEI
Authors: MIKHAILYUK V.P.
Published: November 2004

The differential cross-sections for elastic scattering of deuterons on 12 C and 16 O nuclei at 700 MeV are calculated on the basis of multiple diffraction scattering theory and the α-cluster model with dispersion. For d−12 C scattering it was shown that the results of the calculations by the model, when the effects related with the deuteron structure included via deuteron-α amplitude are in better agreement with the experimental data than those by the model, in which incident deuteron is considered as composed of neutron and proton.
CHAOTIC INFLATION BASED ON AN ABELIAN D-FLAT DIRECTION
Authors: SUEMATSU DAIJIRO , YAMAGISHI YOSHIO
Published: November 2004

We study the inflation due to the D-flat direction of an extra U(1). This scenario is a hybrid of a right-handed sneutrino inflaton scenario and a gauge nonsinglet inflaton scenario. The inflaton is a gauge nonsinglet field which induces a right-handed neutrino mass spontaneously through an extra U(1) D-flat direction. This right-handed neutrino mass can be used to explain the solar neutrino problem. The reheating temperature resulting from the decay of the coherent oscillation of the right-handed sneutrino is sufficiently high so that the baryogenesis based on the lepton number asymmetry can be applicable. We also discuss the realistic model building.
THERMODYNAMICAL FUNCTIONS AND THE HEAVY-QUARK POTENTIAL IN AN SU(2) GLUON PLASMA
Authors: GORENSTEIN M.I. , MILLER H.G. , RITCHIE R.A. , YANG SHIN NAN
Published: November 2004

Monte-Carlo lattice data for thermodynamical functions and the heavy-quark potential for an SU(2) gluon plasma are considered in the “cutoff” model with a temperature dependent cutoff parameter. Good agreement with the data in both cases was found. We compare these results with a model of gluons with a thermal mass and find little difference between the two models. The results obtained for the heavy-quark potential are significantly better in both cases than those obtained from pure perturbative calculations.
ANTIBRACKETS AND NON-ABELIAN EQUIVARIANT COHOMOLOGY
Authors: NERSESSIAN A.
Published: November 2004

The Weyl algebra of a semisimple Lie group and an exterior algebra of a symplectic manifold possesses antibrackets. They are applied to formulate the models of non-Abelian equivariant cohomologies.
A GEOMETRIC PICTURE FOR FERMION MASSES
Authors: ESPOSITO SALVATORE , SANTORELLI PIETRO
Published: November 2004

We describe a geometric picture for the pattern of fermion masses of the three generations which is invariant with respect to the renormalization group below the electroweak scale. Moreover, we predict the upper limit for the ratio between the Dirac masses of the μ and τ neutrinos, [Formula: see text]
FROM A RELATIVISTIC POINT PARTICLE TO STRING THEORY
Authors: NIETO J.A.
Published: November 2004

Using a classical action associated to a point particle in (1+1) dimensions the classical string theory is derived. In connection with this result two aspects are clarified: First, the point particle in (1+1) dimensions is not an ordinary relativistic system, but rather some kind of relativistic top; and second, through the quantization of such kind of top, the ordinary string theory is not obtained, but rather a σ-model associated to a noncompact group which may be understood as an extended string theory.
AN $N = \not 2$ SUSY GAUGE MODEL FOR DYNAMICAL BREAKING OF THE GRAND UNIFIED SU(5) SYMMETRY
Authors: HISANO J. , YANAGIDA T.
Published: November 2004

We construct an extension of the recently proposed dynamical model for the breaking of SU(5)GUT gauge symmetry, in which a pair of massless chiral supermultiplets for Higgs doublets are naturally obtained. We point out that a model at a specific point in the parameter space of superpotential is regarded as a low-energy effective theory of an [Formula: see text] supersymmetric gauge model for the strongly interacting hypercolor sector.
ALGEBRAIC ASPECT AND CONSTRUCTION OF LAX OPERATORS IN QUANTUM INTEGRABLE SYSTEMS
Authors: BASU-MALLICK B. , KUNDU ANJAN
Published: November 2004

An algebraic construction which is more general and closely connected with that of Faddeev,1 along with its application for generating different classes of quantum integrable models is summarized to complement the recent results of Ref. 1.
PRESENT STATUS OF PRIMORDIAL NUCLEOSYNTHESIS AFTER WMAP: RESULTS FROM A NEW BBN CODE
Authors: CUOCO A. , IOCCO F. , MANGANO G. , MIELE G. , PISANTI O. , SERPICO P. D.
Published: November 2004

We report on the status of primordial nucleosynthesis in light of recent results on CMB anisotropies from WMAP experiment. Theoretical estimates for nuclei abundances, along with the corresponding uncertainties, are evaluated using a new numerical code, where all nuclear rates usually considered have been updated using the most recent available data. Moreover, additional processes neglected in previous calculations have been included. The combined analysis of CMB and primordial nucleosynthesis prediction for Deuterium gives an effective number of relativistic degrees of freedom in good agreement with the simplest scenario of three nondegenerate neutrinos. Our findings seem to point out possible systematics affecting 4 He mass fraction measurements, or the effect of exotic physics, like a slightly degenerate relic neutrino background.
LATTICE STUDY ON KAON–NUCLEON SCATTERING LENGTH IN THE I=1 CHANNEL
Authors: MENG GUANGWEI , MIAO CHUAN , DU XINING , LIU CHUAN
Published: November 2004

Using the tadpole improved clover Wilson quark action on small, coarse and anisotropic lattices, KN scattering length in the I=1 channel is calculated within quenched approximation. The results are extrapolated towards the chiral and physical kaon mass region. Finite volume and finite lattice spacing errors are also analyzed and a result in the infinite volume and continuum limit is obtained which is compatible with the experiment and the results from Chiral Perturbation Theory.
SEARCH FOR ODDERON IN THEORY AND EXPERIMENT
Authors: FAZAL-E-ALEEM  , RASHID HARIS , TAHIR SOHAIL AFZAL , SAEED M. ALAM , AFZAL M. QADEER
Published: November 2004

The presence of Odderon at high energy has been in question for quite some time. We have confronted the Odderon description to the available data especially for pp and [Formula: see text] scattering including the most recent measurements by UA4/2, E710, CDF and E811 Collaborations. The Odderon in perturbative and nonperturbative QCD has also been discussed along with some phenomenological approaches. A comparison of the Odderon description with other models has also been made for [Formula: see text] data including the measurements from cosmic ray, which corresponds to the LHC energy of 14 TeV. Our study especially focuses on the measurements at RHIC and LHC and the presence or otherwise of Odderon.
SPACE–TIME FOAM MAY VIOLATE THE PRINCIPLE OF EQUIVALENCE
Authors: ELLIS JOHN , MAVROMATOS NICK E. , NANOPOULOS DIMITRI V. , SAKHAROV ALEXANDER S.
Published: November 2004

The interactions of different particle species with the foamy space–time fluctuations expected in quantum gravity theories may not be universal, in which case different types of energetic particles may violate Lorentz invariance by varying amounts, violating the equivalence principle. We illustrate this possibility in two different models of space–time foam based on D-particle fluctuations in either flat Minkowski space or a stack of intersecting D-branes. Both models suggest that Lorentz invariance could be violated for energetic particles that do not carry conserved charges, such as photons, whereas charged particles such electrons would propagate in a Lorentz-inavariant way. The D-brane model further suggests that gluon propagation might violate Lorentz invariance, but not neutrinos. We argue that these conclusions hold at both the tree (lowest-genus) and loop (higher-genus) levels, and discuss their implications for the phenomenology of quantum gravity.
MONODROMY MATRIX IN THE pp-WAVE LIMIT
Authors: DAS ASHOK , MELIKYAN A. , MAHARANA JNANADEVA
Published: November 2004

We consider the pp-wave limit of an exactly solvable gauged WZWN model proposed by Sfetsos and Tseytlin. The monodromy matrix is constructed for the model by adopting the methods utilized by us earlier. The pole structure of the monodromy matrix is analyzed and their properties are discussed in the context of the pp-wave limit of the gauged WZWN model.
HALL EFFECT, THERMOPOWER AND ELECTRICAL RESISTIVITY OF DOPED RuSr2GdCu2O8 SYSTEM
Authors: ILONCA G. , BEIUSAN F. , POP A. V. , MATEI I. , MACOCIAN E. , YANG T. R.
Published: November 2004

Polycrystalline samples of Ru 1-x Sb x Sr 2 GdCuO 8 doped with Sb , in which magnetic order and superconductivity coexist with T magnetic ≫T c , were prepared by a solid state reaction technique. Lattice parameters, electrical resistivity, Hall and thermopower coefficients measurements on the same sintered ceramic samples are presented.

Both Hall effect and thermopower show anomalous decreases below T magnetic which might be explained with a simple two-band model in the RuO 2 layer at T magnetic . It was also observed that the Sb doping reduce the conductivity of the system and the transition temperature decreases with increasing Sb content. This may be due to a distortion of RuO 6 octahedra which is responsible for the increase of hole localization.
ELECTRIC FIELD EFFECTS ON POLARONS WITH SPATIALLY DEPENDENT MASS IN PARABOLIC QUANTUM WELLS
Authors: ZHAO FENG-QI , GUO ZI-ZHENG
Published: November 2004

The free polaron energy levels in finite GaAs / Al x Ga 1-x As parabolic quantum wells have been investigated by a modified variational method. The effect of the electric field, the electron-phonon interaction including the longitudinal optical phonons and the four branches of interface optical phonons, and the effect of spatial dependent effective mass have been considered in the calculation. The dependence of the energies of free polarons on the alloy composition x is given. The numerical results for finite GaAs / Al x Ga 1-x As parabolic quantum wells are obtained and discussed. The results show that the effect of the electric field and the interface optical phonons as well as the longitudinal optical phonons on the energy levels is obvious. One can find that the effect of the spatially dependent effective masses on the energy levels in finite parabolic quantum wells is considerable except for large well width. Thus, the electron-phonon interaction and the effect of the spatially dependent effective mass should not be neglected for the study of the electron state problem in finite parabolic quantum wells.
STUDY OF POSITRON LIFETIME AND INFRARED SPECTROSCOPY FOR Pr-SUBSTITUTED YBa2Cu3O7-δ SYSTEMS
Authors: CAO GUIXIN , ZHANG JINCANG , CAO SHIXUN , JING CHAO , SHEN XUECHU
Published: November 2004

The Pr -substituted YBa 2 Cu 3 O 7-δ( Y 123) superconducting systems with the content of 0.0–1.0 have been systematically studied by positron lifetime and infrared absorption experiments. The results show that the short lifetime τ1 decreases as a function of Pr -substitution x below x=0.6, but when above x=0.6, it increases inversely. The long lifetime τ2 decreases as a function of Pr -substituted x. Based on the present results, we discuss that Pr 4+ substitutes on Ba 2+ ion and forms Pr Ba defects. The variation of τ1 is caused by the oxygen vacancies and τ2 is probably affected by the absence of Cu due to Pr Ba defects. The infrared absorption of Pr -substituted Y 123 systems gives three variational modes, located at 560 cm -1( A 1), 1435 cm -1( A 2) and 1631 cm -1( A 3) respectively. Here the A 3 mode shows that with Pr content increasing from x=0.1 to 1.0, the infrared absorption decreases and the peak tends to broaden. So, combining with the results of the positron lifetime spectra, we can argue that there always exists portion of Pr Ba defects in the Pr -substituted systems, and the Pr 4+ substituted into Ba 2+ is also increasing with the Pr content increasing. When the Pr content is 0.6, the systems have a metal-insulator transition and Pr Ba defects begin to domain the samples' microstructure.
SPATIOTEMPORAL STRUCTURES IN DISCRETELY-COUPLED ARRAYS OF NONLINEAR CIRCUITS: A REVIEW
Authors: MUÑUZURI A.P. , PÉREZ-MUÑUZURI V. , GÓMEZ-GESTEIRA M. , CHUA L.O. , PÉREZ-VILLAR V.
Published: November 2004

Spatiotemporal pattern formation occurring in discretely-coupled nonlinear dynamical systems has been studied numerically. Reaction-diffusion systems can be viewed as an assembly of a large number of identical local subsystems which are coupled to each other by diffusion. Here, the local subsystems are defined by a system of nonlinear ordinary differential equations. While for continuous systems, the characteristic time scale corresponding to the diffusion is slower than that corresponding to the local subsystems, in discretely-coupled systems, both time scales can be of the same order of magnitude. Discrete systems can exhibit behaviors different from those exhibited by their equivalent continuous model: the wave propagation failure phenomenon occurring in nerve-pulse propagation due to transmission blockage is a case in point. In this case, it is found that the wave fails to propagate at or below some critical value of the coupling coefficient.

Systems of coupled cells can be found to occur in the transformation and transport processes in living cells, tissues, neuron networks, physiological systems and ecosystems, as well as in all forms of chemical, biochemical reactors and combustion systems.

In this paper, we review the possibilities of using arrays of discretely-coupled nonlinear electronic circuits to study these systems. The possibility of building large arrays of these circuits via VLSI technology makes this approach a unique tool for real time applications. Classical examples occurring in other continuous media, such as spiral wave initiation and propagation, and Turing pattern formation, are depicted here. Because of the discrete nature of our system, the influence of inhomogeneities arising from damaged cells, or from an anisotropic media, is analyzed for spiral wave propagation. Spiral wave initiation and vulnerability effects are considered and compared with their corresponding effects in continuous media.

More complex spatiotemporal structures are also studied via three-dimensional arrays of discretely-coupled circuits. Straight and twisted scroll waves, as well as scroll ring waves, are shown to exist in these arrays, where their properties can be easily measured.

Sidewall forcing of Turing patterns is shown to be capable of driving the system into a perfect spatial organization, namely, a rhombic pattern, where no defects occur. The dynamics of the two layers supporting Turing and Hopf modes, respectively, is analyzed as a function of the coupling strength between them. The competition between these two modes is shown to increase with the diffusion between layers.