bluuebunny/crossref_metadata_2025 huggingface dataset:
A NOVEL APPROACH TO THE COSMOLOGICAL CONSTANT PROBLEM
Authors: IGLESIAS ALBERTO , KAKUSHADZE ZURAB
Published: November 2004

We propose a novel infinite-volume brane world scenario where we live on a noninflating spherical 3-brane, whose radius is somewhat larger than the present Hubble size, embedded in higher dimensional bulk. Once we include higher curvature terms in the bulk, we find completely smooth solutions with the property that the 3-brane world-volume is noninflating for a continuous range of positive values of the brane tension, that is, without fine-tuning. In particular, our solution, which is a near-BPS background with supersymmetry broken on the brane around TeV, is controlled by a single integration constant.
SEARCHING FOR EXTRA DIMENSIONS IN THE EARLY UNIVERSE
Authors: BUETTNER DOUGLAS J. , MORLEY P. D. , SCHMIDT IVAN
Published: November 2004

We investigate extra spatial dimensions (D=3+∊) in the early universe using very high resolution molecular rotational spectroscopic data derived from a large molecular cloud containing moderately cold carbon monoxide gas at Z≈6.42. It turns out that the ∊-dependent quantum mechanical wavelength transitions are solvable for a linear molecule and we present the solution here. The CO microwave data allows a very precise determination of <∊>=-0.00000657±0.10003032. The probability that <∊>≠0 is one in 7794, only 850 million years (using the standard cosmology) after the Big Bang.
CONCEPTUAL UNIFICATION OF ELEMENTARY PARTICLES, BLACK HOLES, QUANTUM DE SITTER AND ANTI-DE SITTER STRING STATES
Authors: SANCHEZ NORMA G.
Published: November 2004

We provide a conceptual unified description of the quantum properties of black holes (BH), elementary particles, de Sitter (dS) and Anti-de Sitter (AdS) string states.The conducting line of argument is the classical–quantum (de Broglie, Compton) duality here extended to the quantum gravity (string) regime (wave–particle–string duality). The semiclassical (QFT) and quantum (string) gravity regimes are respectively characterized and related: sizes, masses, accelerations and temperatures. The Hawking temperature, elementary particle and string temperatures are shown to be the same concept in different energy regimes and turn out the precise classical–quantum duals of each other; similarly, this result holds for the BH decay rate, heavy particle and string decay rates; BH evaporation ends as quantum string decay into pure (nonmixed) radiation. Microscopic density of states and entropies in the two (semiclassical and quantum) gravity regimes are derived and related, an unifying formula for BH, dS and AdS states is provided in the two regimes. A string phase transition towards the dS string temperature (which is shown to be the precise quantum dual of the semiclassical (Hawking–Gibbons) dS temperature) is found and characterized; such phase transition does not occurs in AdS alone. High string masses (temperatures) show a further (square root temperature behavior) sector in AdS. From the string mass spectrum and string density of states in curved backgrounds, quantum properties of the backgrounds themselves are extracted and the quantum mass spectrum of BH, dS and AdS radii obtained.
DYNAMICS OF THE SCALAR FIELD IN FIVE-DIMENSIONAL KALUZA–KLEIN THEORY
Authors: WEHUS INGUNN KATHRINE , RAVNDAL FINN
Published: November 2004

Using the language of differential forms, the Kaluza–Klein theory in 4+1 dimensions is derived. This theory unifies electromagnetic and gravitational interactions in four dimensions when the extra space dimension is compactified. Without any ad hoc assumptions about the five-dimensional metric, the theory also contains a scalar field coupled to the other fields. By a conformal transformation the theory is transformed from the Jordan frame to the Einstein frame where the physical content is more manifest. Including a cosmological constant in the five-dimensional formulation, it is seen to result in an exponential potential for the scalar field in four dimensions. A similar potential is also found from the Casimir energy in the compact dimension. The resulting scalar field dynamics mimics realistic models recently proposed for cosmological quintessence.
METAPLECTIC SPINOR FIELDS AND GLOBAL ANOMALIES
Authors: REUTER M.
Published: November 2004

We investigate spinor fields on phase spaces. Under local frame rotations they transform according to the (infinite-dimensional, unitary) metaplectic representation of Sp(2N), which plays a role analogous to the Lorentz group. We introduce a one-dimensional nonlinear sigma model whose target space is the phase space under consideration. The global anomalies of this model are analyzed, and it is shown that its fermionic partition function is anomalous exactly if the underlying phase space is not a spin manifold, i.e. if metaplectic spinor fields cannot be introduced consistently. The sigma model is constructed by giving a path integral representation to the Lie transport of spinors along the Hamiltonian flow.
POISSON LIE GROUP SYMMETRIES FOR THE ISOTROPIC ROTATOR
Authors: MARMO G. , SIMONI A. , STERN A.
Published: November 2004

We find a new Hamiltonian formulation of the classical isotropic rotator where left and right SU(2) transformations are not canonical symmetries but rather Poisson Lie group symmetries. The system corresponds to the classical analog of a quantum-mechanical rotator which possesses quantum group symmetries. We also examine systems of two classical interacting rotators having Poisson Lie group symmetries.
FINITE-TEMPERATURE AND FINITE-DENSITY QED: THE SCHWINGER-DYSON EQUATION IN THE REAL-TIME FORMALISM
Authors: KONDO KEI-ICHI , YOSHIDA KAZUHIRO
Published: November 2004

We derive, based on the real-time formalism (especially thermo-field-dynamics), the Schwinger-Dyson gap equation for the fermion propagator in QED and the four-fermion model at finite temperature and density. We discuss some advantages of the real-time formalism in solving the self-consistent gap equation, in comparison with the ordinary imaginary-time formalism. Once we specify the vertex function, we can write down the SD equation with only continuous variables without performing the discrete sum over Matsubara frequencies which cannot be performed in advance without further approximation in the imaginary-time formalism. By solving the SD equation obtained in this way, we find the chiral-symmetry-restoring transition at finite temperature and present the associated phase diagram of strong-coupling QED. In solving the SD equation, we consider two approximations: instantaneous-exchange and p0-independent ones. The former has a direct correspondence in the imaginary-time formalism; the latter is a new approximation beyond the former, since it is able to incorporate new thermal effects which have been overlooked in the ordinary imaginary-time solution. However, the two approximations are shown to give qualitatively the same results on the finite-temperature phase transition.
N = 2 SUPER W3 ALGEBRA AND N = 2 SUPER BOUSSINESQ EQUATIONS
Authors: IVANOV E. , KRIVONOS S. , MALIK R.P.
Published: November 2004

We study classical N=2 super W3 algebra and its interplay with N=2 supersymmetric extensions of the Boussinesq equation in the framework of the nonlinear realization method and the inverse Higgs-covariant reduction approach. These techniques have been previously used by us in the bosonic W3 case to give a new geometric interpretation of the Boussinesq hierarchy. Here we deduce the most general N=2 super Boussinesq equation and two kinds of the modified N=2 super Boussinesq equations, as well as the super Miura maps relating these systems to each other, by applying the covariant reduction to certain coset manifolds of linear [Formula: see text] symmetry associated with N=2 super W3. We discuss the integrability properties of the equations obtained and their correspondence with the formulation based on the notion of the second Hamiltonian structure.
UNIFORMIZATION THEORY AND 2D GRAVITY I: LIOUVILLE ACTION AND INTERSECTION NUMBERS
Authors: MATONE MARCO
Published: November 2004

This is the first part of an investigation concerning the formulation of 2D gravity in the framework of the uniformization theory of Riemann surfaces. As a first step in this direction we show that the classical Liouville action appears in the expression for the correlators of topological gravity. Next we derive an inequality involving the cutoff of 2D gravity and the background geometry. Another result, still related to uniformization theory, concerns a relation between the higher genus normal ordering and the Liouville action. We introduce operators covariantized by means of the inverse map of uniformization. These operators have interesting properties, including holomorphicity. In particular, they are crucial for showing that the chirally split anomaly of CFT is equivalent to the Krichever-Novikov cocycle and vanishes for deformation of the complex structure induced by the harmonic Beltrami differentials. By means of the inverse map we propose a realization of the Virasoro algebra on arbitrary Riemann surfaces and find the eigenfunctions for the holomorphic covariant operators defining higher order cocycles and anomalies which are related to W algebras. Finally we face the problem of considering the positivity of eσ, with σ the Liouville field, by proposing an explicit construction for the Fourier modes on compact Riemann surfaces. These functions, whose underlying number-theoretic structure seems related to Fuchsian groups and to the eigenvalues of the Laplacian, are quite basic and may provide the building blocks for properly investigating the long-standing uniformization problem posed by Klein, Koebe and Poincaré.
TIME-INDEPENDENT SOLUTIONS TO THE TWO-DIMENSIONAL NONLINEAR O(3) SIGMA MODEL AND SURFACES OF CONSTANT MEAN CURVATURE
Authors: ODY MICHAEL S. , RYDER LEWIS H.
Published: November 2004

It is shown that time-independent solutions to the (2+1)-dimensional nonlinear O(3) sigma model may be placed in correspondence with surfaces of constant mean curvature in three-dimensional Euclidean space. The tools required to establish this correspondence are provided by the classical differential geometry of surfaces. A constant-mean-curvature surface induces a solution to the O(3) model through the identification of the Gauss map, or normal vector, of the surface with the field vector of the sigma model. Some explicit solutions, including the solitons and antisolitons discovered by Belavin and Polyakov, and a more general solution due to Purkait and Ray, are considered and the surfaces giving rise to them are found explicitly. It is seen, for example, that the Belavin-Polyakov solutions are induced by the Gauss maps of surfaces which are conformal to their spherical images, i.e. spheres and minimal surfaces, and that the Purkait-Ray solution corresponds to the family of constant-mean-curvature helicoids first studied by do Carmo and Dajczer in 1982. A generalization of this method to include time dependence may shed new light on the role of the Hopf invariant in this model.
EDGE SINGULARITY IN “INDUCED QCD”
Authors: MATYTSIN ANDREI , MIGDAL ALEXANDER A.
Published: November 2004

The behavior of the master field in “induced QCD” near the edge of its support is studied. An extended scaling domain, where the shape of the master field is a universal function, is found. This function is determined explicitly for the case of dimensions close to 1, and the D−1 expansion is constructed. The problem of the meson spectrum corresponding to this solution is analyzed. As a by-product of these calculations, a new, explicit equation for the meson spectrum in induced QCD with a general potential is derived.
BLACK HOLES AND COSMOLOGICAL CONSTANT IN BOSONIC STRING THEORY: SOME REMARKS
Authors: BELGIORNO F. , CATTANEO A. S.
Published: November 2004

In this work we make a suggestion about the black hole solutions coming from the bosonic string theory with cosmological constant in four dimensions. In our study we are first interested in the effects on the metric of a tree level cosmological constant; then we make a perturbative calculation which is to be compared with the general-relativistic results.
COMPLEX MULTIPLE REFLECTION IN TIME AND PAIR PRODUCTION
Authors: BISWAS S. , GUHA J. , DASGUPTA P.
Published: November 2004

We present a nonperturbative method of calculating the pair production amplitude in a time-varying electric field. The method is a generalization of the complex multiple reflection technique of Knoll and Schaeffer, not in space but in time. We compare the results obtained by this method with standard results.
THE CONSTRAINT CALCULUS IN KONTSEVICH MODELS — THE METHOD OF Q POLYNOMIALS
Authors: KHVIENGIA N. L.
Published: November 2004

w1+∞ constraints for the Kontsevich model partition function/one- and two-matrix models in the framework of the modified technique of Q polynomials are obtained. A detailed description of this technique is given.
QUANTIZATION OF A PSEUDOCLASSICAL MODEL OF THE SPIN 1 RELATIVISTIC PARTICLE
Authors: GITMAN D. M. , GONÇALVES A. E. , TYUTIN I. V.
Published: November 2004

A consistent procedure for canonical quantization of a pseudoclassical model of the spin 1 relativistic particle is considered. Two approaches to treating quantization for the massless case are discussed — the limit of the massive case and independent quantization of a modified action. The quantum mechanics constructed for the massive case proves to be equivalent to the Proca theory; and for massless case, to the Maxwell theory. Results obtained are compared with ones for the case of the spinning (spin 1/2) particle.
RECENT RESULTS IN NEUTRINO PHYSICS
Authors: SARMA K. V. L.
Published: November 2004

This is a survey of the current experimental information on some of the interesting issues in neutrino physics: neutrino species, neutrino masses, neutrino magnetic moments, solar neutrinos, and the atmospheric neutrino anomaly.
PREDICTION OF BEAUTY PARTICLE MASSES WITH THE HEAVY QUARK EFFECTIVE THEORY (II)
Authors: AGLIETTI U.
Published: November 2004

The effective theory for heavy quarks has additional symmetries with respect to QCD, which relate charm and beauty hadron masses. Assuming the spectrum of charmed particles, we predicted in a previous work the masses of some beauty particles. The predictions of the Λb mass, M (Λb) = 5630 MeV , and of the Bs mass, M (Bs) = 5379 MeV , are in agreement with present experimental data. We continue this work using recent experimental data on charm hadron masses. The results are: M (Σb) = 5822±6 MeV , [Formula: see text], M (Ωb) = 6080±7 MeV , [Formula: see text], [Formula: see text], [Formula: see text]. When experimental data for beauty hadron masses are available, a comparison with the theoretical values allows a quantitative estimate of the corrections to the static theory, which contain information on hadron dynamics at low energy.
A UNIVERSAL w STRING THEORY
Authors: KUNITOMO HIROSHI , SAKAGUCHI MAKOTO , TOKURA AKIRA
Published: November 2004

It has been shown that there is a sequential embedding structure in a wN string theory based on a linearized WN algebra. The wN string theory is obtained as a special realization of the wN+1 string. The w∞ string theory is a universal string theory in this sense. We have also shown that there is a similar sequence for N = 1 string theory. The N = 1 wN string can be given as a special case of the N = 1 wN+1 string. In addition, we show that the w3 string theory is obtained as a special realization of the N = 1 w3 string. We conjecture that the wN string can be obtained as a special N = 1 wN string for general wN. If this is the case, the N = 1 w∞ string theory is more universal since it includes both N = 0 and N = 1 wN string theories.
SCALING DIMENSIONS OF MANIFESTLY GENERALLY COVARIANT OPERATORS IN TWO-DIMENSIONAL QUANTUM GRAVITY
Authors: NISHIMURA JUN , TAMURA SHINYA , TSUCHIYA ASATO
Published: November 2004

Using (2+∊)-dimensional quantum gravity recently formulated by Kawai, Kitazawa and Ninomiya, we calculate the scaling dimensions of manifestly generally covariant operators in two-dimensional quantum gravity coupled to (p, q) minimal conformal matter. Although the spectrum includes all the scaling dimensions of the scaling operators in the matrix model except the boundary operators, there are also many others which do not appear in the matrix model. We argue that the partial agreement of the scaling dimensions should be considered as accidental and that the operators considered give a new series of operators in two-dimensional quantum gravity.
ON SW MINIMAL MODELS AND N = 1 SUPERSYMMETRIC QUANTUM TODA FIELD THEORIES
Authors: MALLWITZ STEFFEN
Published: November 2004

Integrable N = 1 supersymmetric Toda field theories are determined by a contragredient simple super-Lie-algebra (SSLA) with purely fermionic lowering and raising operators. For the SSLA's Osp(3|2) and D(2|1; α) we construct explicitly the higher spin conserved currents and obtain free field representations of the super-W-algebras SW(3/2, 2) and SW(3/2, 3/2, 2). In constructing the corresponding series of minimal models using covariant vertex operators, we find a necessary restriction on the Cartan matrix of the SSLA, also for the general case. Within this framework, the restriction claims that there should be a minimum of one nonvanishing element on the diagonal of the Cartan matrix. This condition is without parallel in bosonic conformal field theory. As a consequence only two series of SSLA's yield minimal models, namely Osp(2n|2n−1) and Osp(2n|2n+1). Subsequently some general aspects of degenerate representations of SW algebras, notably the fusion rules, are investigated. As an application we discuss minimal models of SW(3/2, 2), which were constructed by independent methods, in this framework. Covariant formulation is used throughout this paper.
RELATING THE PION DECAY CONSTANT TO THE CHIRAL RESTORATION TEMPERATURE
Authors: BILIĆ N. , CLEYMANS J. , SCADRON M. D.
Published: November 2004

We review the relationship between the pion decay constant fπ, the chiral symmetry restoration temperature Tc and the phenomenology of low energy chiral symmetry breaking in view of the recent confirmation of the existence of a sigma meson with a mass of 600–700 MeV.
THE GOLDSTONE THEOREM AT TWO LOOPS FROM AN ALGEBRAIC IDENTITY
Authors: WALDRON ANDREW , VAN NIEUWENHUIZEN PETER
Published: November 2004

We give an explicit demonstration of the Goldstone theorem at the level of two-loop Feynman graphs in the spontaneously broken O(2) linear σ model by showing that the integrands of the 1PI "pion" self-energy graphs cancel each other at zero momentum as a consequence of the identity m2[k2(k2+m2)]−1 = k−2− (k2+m2)−1. The proof holds for any regularization scheme which respects this identity.
MATRICIAL REPRESENTATION OF RATIONAL POWER OF OPERATORS AND PARA-GRASSMANN EXTENSION OF QUANTUM MECHANICS
Authors: FLEURY N. , TRAUBENBERG M. RAUSCH DE , YAMALEEV R.M.
Published: November 2004

Using para-Grassmann, or generalized Grassmann algebras, we define rational power of annihilation and creation operators, in order to extend supersymmetric quantum mechanics. This extension can be replaced, under some assumptions, in para-Grassmann quantum mechanics. We then apply this method to the construction of an equation which generalizes the (2+1)D Pauli equation to a particle of arbitrary spin s. This is done by means of a Hamiltonian defined as a sum of 2s monomials of degree 2s+1.
A MORE EXACT THEORY OF RELATIVISTIC PHASE TRANSITIONS OF THE EARLY UNIVERSE
Authors: VERESHKOV G.M. , BURDYUZHA V.V.
Published: November 2004

This paper examines the thermodynamics of relativistic phase transitions in which the heterogeneity of the system (the vacuum condensate, scalar and vector particles) is considered evident. The given system does not have a united functional of state which is common to both low-symmetric and high-symmetric phases. The theory acquires the necessary physical content after the introduction of additional parameters of order identified with the parameters of the energetic spectrum (effective masses of particles), The many-parameter thermodynamics of relativistic phase transitions in heterogeneous systems changes the current conceptions about the character of these transitions and about the properties of the system near the critical point. For T>Tcrit the system of Higgs fields has no thermodynamical equilibrium states and it can evolve under stochastic laws only. For T<Tcrit the stochastic regime of evolution begins to relax to the local thermodynamical equilibrium regime.
ON THE CLASSIFICATION OF W-ALGEBRAS
Authors: VERSTEGEN DIRK
Published: November 2004

We review and extend the conformal bootstrap approach to the classification of quantum W-algebras. These are extensions of the Virasoro algebra by a finite set of primary fields. Explicit forms are given for the most general crossing-symmetric four-point functions. Together with a large c expansion of the conformal blocks, this gives a powerful tool for finding all W-algebras that are associative for generic values of the central charge c.
SOME PROPERTIES OF RENORMALONS IN GAUGE THEORIES
Authors: DI CECIO G. , PAFFUTI G.
Published: November 2004

We find the explicit operatorial form of renormalon type singularities in Abelian gauge theory. Local operators of dimension six take care of the first UV renormalon; nonlocal operators are needed for IR singularities. In the effective Lagrangian constructed with these operators nonlocal imaginary parts appearing in the usual perturbative expansion at large orders are canceled.
RADIATION FROM A RINDLER-DIRAC ELECTRON
Authors: JÁUREGUI R.
Published: November 2004

We evaluate the elementary quantum electrodynamics vertex involving Rindler particles and the elementary vertex involving Rindler electrons and a Minkowski photon. Also, we study the general features of the radiation emitted and the possible changes in the electron quantum numbers arising from the corresponding processes. A particularly interesting result is a spin depolarization effect arising even in the absence of external magnetic fields. Similarities to other classical and semiclassical results are briefly discussed.
THE BROKEN PHASE OF THE TOPOLOGICAL σ MODEL
Authors: YUNG A.V.
Published: November 2004

The topological σ model with the semi-infinite cigar-like target space (black hole geometry) is considered. It is shown to possess unsuppressed instantons. The noncompactness of the moduli space of these instantons is responsible for an unusual physics. There is a stable vacuum state in which the vacuum energy is 0, and correlation functions are numbers; thus the model is in the topological phase. However, there are other vacuum states in which correlation functions show the coordinate dependence. Estimation of the vacuum energy indicates that it is nonzero. The states are interpreted as the ones with broken BRST symmetry.
EXTENDED BRST ALGEBRA OF THE FREEDMAN-TOWNSEND MODEL
Authors: ABUD MARIO , CAPPIELLO LUIGI , ADER JEAN-PIERRE
Published: November 2004

We construct an explicit nilpotent extended BRST/anti-BRST algebra for the Freedman-Townsend model, through a change of basis of the fields and a corresponding deformation of the algebra of the Abelian two-form theory. We also discuss the elimination of some auxiliary fields from the gauge-fixed action and make a comparison with the extended Batalin-Vilkovisky formalism.
DYNAMICAL GAUGE FIELD INDUCED BY THE BERRY PHASE MECHANISM
Authors: KIKKAWA KEIJI , TAMURA HUMITAKA
Published: November 2004

Some part of the local gauge symmetries in the low energy region, say, lower than GUT or the Planck energy, can be an induced symmetry that can be described with the holonomy fields associated with a topologically nontrivial structure of partially compactified space.

In the case where a six-dimensional space is compactified by the Kaluza-Klein mechanism into a product of the four-dimensional Minkowski space M4 and a two-dimensional Riemann surface with the genus g, Σg, we show that, in a limit where the compactification mass scale is sent to infinity, a model Lagrangian with a U(1) gauge symmetry produces the dynamical gauge fields in M4 with a product of g U(1)'s symmetry, i.e. U(1)×···×U(1). These fields are induced by a Berry phase mechanism, not by the Kaluza—Klein mechanism. The dynamical degrees of freedom of the induced fields are shown to come from the holonomies, or the solenoid potentials, associated with the cycles of Σg. The production mechanism of kinetic energy terms for the induced fields is discussed in detail.
INTEGRABILITY AND DUALITY IN TWO-DIMENSIONAL QCD
Authors: ABDALLA E. , ABDALLA M.C.B.
Published: November 2004

We consider bosonized QCD2, and prove that after one rewrites the theory in terms of gauge-invariant fields, there exists an integrability condition that is valid for the quantum theory as well. Furthermore, performing a duality type transformation we obtain an appropriate action for the description of the strong coupling limit, which is still integrable. We also prove that the model displays a complicated set of constraints, which restrict the dynamics of part of the theory, but which are necessary for maintaining the positive metric Hilbert space.
REPRESENTATION BLOCKS OF CONFORMAL FIELDS FOR THE N=4SU(2)k SUPERCONFORMAL ALGEBRAS
Authors: MATSUDA SATOSHI
Published: November 2004

The representation theories of the SU(2)k-extended N=4 superconformal algebras (SCA’s) with arbitrary level k are developed, based on their Feigin-Fuchs representations found recently by the present author. A basic unit of the representation blocks consisting of eight “boson-like” and eight “fermion-like” conformal fields is found to describe arbitrary representations of the N=4 SU(2)k SCA’s, including unitary and nonunitary representations. The transformation properties of the fundamental sets of the conformal fields under the N=4 SU(2)k superconformal symmetries are given. Then, the whole sets of the charge screening operators of the N=4 SU(2)k SCA’s are identified out of the 16 conformal fields in the basic unit of the representation blocks. The conditions for the eligible charge screening operators are analyzed in terms of the continuous parameters which enter in our vertex operator forms for the fundamental conformal fields of the representation blocks.
RENORMALIZATION AND BOLTZMANN EQUATIONS IN THERMAL QUANTUM FIELD THEORY
Authors: CHU H. , UMEZAWA H.
Published: November 2004

The renormalization scheme in nonequilibrium thermal quantum field theories is reexamined. Instead of the self-energy diagonalization scheme, we propose to diagonalize Green’s function at equal time. This eliminates the problem of on-shell definition related to time-dependent energies and spatially inhomogeneous situations, and yields a Boltzmann equation that contains memory effect. The new diagonalization scheme and the derivation of the Boltzmann equation from it can be applied to any thermal situation. It allows the treatment of a nonequilibrium problem beyond perturbational calculations in a self-consistent manner. The results are applicable to both thermo field dynamics and the closed time path formalism.
OFF-CRITICAL CURRENT ALGEBRAS
Authors: ABDALLA E. , ABDALLA M.C.B. , SOTKOV G. , STANISHKOV M.
Published: November 2004

We discuss the infinite-dimensional algebras appearing in integrable perturbations of conformally invariant theories, with special emphasis on the structure of the consequent non-Abelian infinite-dimensional algebra generalizing W∞ to the case of a non-Abelian group. We prove that the pure left sector as well as the pure right sector of the thus-obtained algebra coincides with the conformally invariant case. The mixed sector is more involved, although the general structure seems to be near to being unraveled. We also find some subalgebras that correspond to Kac-Moody algebras. The constraints imposed by the algebras are very strong and, in the case of the massive deformation of a non-Abelian fermionic model, the symmetry alone is enough to fix the two- and three-point functions of the theory.
FINAL STATE INTERACTIONS AND PREASYMPTOTIC EFFECTS IN NONLEPTONIC KAON DECAYS
Authors: ŽGANEC S.
Published: November 2004

Nonleptonic decay rates of [Formula: see text] and K− have been estimated using the two independent theoretical schemes. With final state interactions of emitted pions included, both schemes yield qualitatively a correct and consistent description of decay rates. Various contributions to decay rates have also been estimated. It turns out that contributions due to the quark annihilation mechanisms are much larger than the decay term, contrary to the usual beliefs based on helicity arguments.
EFFECTS OF NEW PHYSICS ON THE ρ PARAMETER IN THE SUPERSYMMETRIC STANDARD MODEL
Authors: AOKI KENICHIRO
Published: November 2004

The contribution to the ρ parameter of the quark-Higgs sector of the supersymmetric standard model is computed nonperturbatively using the large-NF expansion. An explicit formula is found for the ρ parameter which is ill-defined unless the triviality cutoff is taken into account. The cutoff dependence of the ρ parameter is found to be large if and only if the top mass is larger than 2v1 so that the cutoff scale is of the order of the electroweak scale. These nonuniversal effects are the reflections at low energies of the physics beyond the supersymmetric standard model. By also considering the effects of the soft-breaking terms, cutoff effects in both decoupling and nondecoupling effects are analyzed.
ENERGY DENSITY, PRESSURE, AND PARTICLES PRODUCED BY A SPHERICAL, STATIC GRAVITATIONAL FIELD
Authors: MASSACAND CHRISTOPHE M.
Published: November 2004

We compute the energy density and pressures due to the quantum production of particles of a scalar field. This scalar field propagates in the external gravitational field of a (3+1)-dimensional, spherically symmetric, static geometry with flat spatial sections. We assume that the gravitational potential is weak, and we work to the first order in the strength of this potential. We consider only the l=0 sector of the scalar field. Our method for computing the energy density is based on the gauge-invariant definition of particles and normal ordering with respect to the energy measurable on a hypersurface with no extrinsic curvature. The initial state of the quantum field is the gauge-invariant vacuum on one of these hypersurfaces. Our computations are finite step by step. For the pressures we use the covariant conservation of Tμν and its four-dimensional trace. We apply our results to the gravitational potential of a homogeneous spherical body. At late times, i.e. when all switch-on effects are far away from the body, the result is that a static, gravitational vacuum polarization cloud of energy and pressure is formed inside and outside the body.
ON THE BREATHERS OF $a_n^{(1)} $ AFFINE TODA FIELD THEORY
Authors: HARDER ULI , ISKANDAR ALEXANDER A. , McGHEE WILLIAM A.
Published: November 2004

Explicit constructions [Formula: see text] of affine Toda field theory breather solutions are presented. Breathers arise either from two solitons of the same species or from solitons which are antispecies of each other. In the first case, breathers carry topological charges. These topological charges lie in the tensor product representation of the fundamental representations associated with the topological charges of the constituent solitons. In the second case, breathers have zero topological charge. The breather masses are, as expected, less than the sum of the masses of the constituent solitons.
ANALYTIC STRUCTURE OF AMPLITUDES IN GAUGE THEORIES WITH CONFINEMENT
Authors: OEHME REINHARD
Published: November 2004

For gauge theories with confinement, the analytic structure of amplitudes is explored. It is shown that the analytic properties of physical amplitudes are the same as those obtained on the basis of an effective theory involving only the composite, physical fields. The corresponding proofs of dispersion relations remain valid. Anomalous thresholds are considered. They are related to the composite structure of particles. It is shown that there are no such thresholds in physical amplitudes which are associated with confined constituents, like quarks and gluons in QCD. Unphysical amplitudes are considered briefly, using propagator functions as an example. For general, covariant, linear gauges, it is shown that these functions must have singularities at finite, real points, which may be associated with confined states.
LEP e+e−→ μ+μ−γγ EVENTS AND THEIR CONSEQUENCES AT FUTURE e+e− COLLIDERS
Authors: LITVIN V.A. , SLABOSPITSKY S.R.
Published: November 2004

The e+e−→l+l−γγ anomalous events, detected by the L3 detector at the e+e− CERN-LEP collider, are analyzed. It is shown that the interpretation of such events as a manifestation of scalar (pseudoscalar) resonance with a mass of 60 GeV contradicts other experimental data. As to the possible existence of that kind of resonance, the prospects for discovering one in some processes at future e+e− colliders are discussed.
THE REACTION $e^+ e^- \to \nu\bar{\nu}b
\bar{b}$ AND THE HIGGS SIGNAL AT LEP200 AND NLC
Authors: BOOS E. , SACHWITZ M. , SCHREIBER H.J. , SHICHANIN S.
Published: November 2004

A complete tree-level calculation of the reaction [Formula: see text] in the electroweak standard theory for the energy range of LEP200 and the Next Linear Collider is presented. The matrix elements were calculated by means of the package CompHEP, and phase space integration and event generation were carried out with the computer programs BASES/SPRING. Cross sections for the [Formula: see text] final state, the rate for Higgs production and for different background contributions are studied as a function of the cms energy and the Higgs mass in the range from 80 to 140 GeV. At LEP200 energies, the Higgs bremsstrahlung reaction and the two-body process e+e−→ZZ are dominant while near 500 GeV the Higgs fusion and two-to-three body background processes govern the [Formula: see text] final state. Interference patterns were searched for and found to be negligible except for [Formula: see text], where interferences are found to be of comparable strength with the Higgs signal diagrams. Some cancellations between different background diagrams are observed which are expected within the Standard Model. Missing transverse momentum and visible energy distributions for the [Formula: see text] final state indicate some further possibilities of removing background for Higgs searches. A suggestion for an approximate treatment of the reaction [Formula: see text] is presented so that much computer time can be saved in Monte Carlo simulations.
DIRAC HAMILTONIAN ON A LATTICE
Authors: CHAKRABARTI J.
Published: November 2004

We explore alternative solutions of the Dirac equation on a lattice. In this sector we examine the characteristics of the states and argue that the excitation spectrum is different.
POLYNOMIAL IDENTITIES OF THE ROGERS-RAMANUJAN TYPE
Authors: FODA OMAR , QUANO YAS-HIRO
Published: November 2004

Presented are polynomial identities which imply generalizations of Euler and Rogers-Ramanujan identities. Both sides of the identities can be interpreted as generating functions of certain restricted partitions. We prove the identities by establishing a graphical one-to-one correspondence between those two kinds of restricted partitions.
COVARIANT DERIVATIVES AND THE RENORMALIZATION GROUP EQUATION
Authors: DOLAN BRIAN P.
Published: November 2004

The renormalization group equation for N-point correlation functions can be interpreted in a geometrical manner as an equation for Lie transport of amplitudes in the space of couplings. The vector field generating the diffeomorphism has components given by the β functions of the theory. It is argued that this simple picture requires modification whenever any one of the points at which the amplitude is evaluated becomes close to any other. This modification necessitates the introduction of a connection on the space of couplings and new terms appear in the renormalization group equation involving covariant derivatives of the β function and the curvature associated with the connection. It is shown how the connection is related to the operator product expansion coefficients, but there remains an arbitrariness in its definition.
KNIZHNIK-ZAMOLODCHIKOV-BERNARD EQUATIONS ON RIEMANN SURFACES
Authors: IVANOV D.
Published: November 2004

Knizhnik-Zamolodchikov-Bernard equations for twisted conformal blocks on compact Riemann surfaces with marked points are written explicitly in a general projective structure in terms of correlation functions in the theory of twisted b−c systems. It is checked that on the moduli space the equations provide a flat connection with the spectral parameter.
QUANTUM VACUUM AND ANOMALIES
Authors: FUMITA NORIYUKI
Published: November 2004

Chiral, conformal and ghost number anomalies are discussed from the viewpoint of the quantum vacuum in Hamiltonian formalism. After introducing the energy cutoff, we derive known anomalies in a new way. We give an interpretation of the anomalies in connection with the zero-point fluctuation of bosonic or fermionic field. We first point out that the chiral U(1) anomaly is understood as the creation of the chirality at the bottom of the regularized Dirac sea in classical electromagnetic field. In the study of the (1+1)-dimensional quantum vacuum of matter field coupled to the gravity, we give a physically intuitive picture of the conformal anomaly. The central charges are evaluated from the vacuum energy. We clarify that the non-Hermitian regularization factor of the vacuum energy is responsible for the ghost number anomaly.
CRITICAL SCALING AND CONTINUUM LIMITS IN THE D>1 KAZAKOV-MIGDAL MODEL
Authors: MAKEENKO YU.
Published: November 2004

I investigate the Kazakov-Migdal (KM) model — the Hermitian gauge-invariant matrix model on a D-dimensional lattice. I use an exact large N solution of the KM model with a logarithmic potential to examine its critical behavior. I find critical lines associated with γstr=−1/2 and γ str =0 as well as a tricritical point associated with a phase transition of the Kosterlitz-Thouless type. The continuum theories are constructed expanding around the critical points. The one associated with γ str =0 coincides with a d=1 string while a phase transition of the Kosterlitz-Thouless type separates it from that with γ str =−1/2, which is indistinguishable from pure 2D gravity for local observables but has a continuum limit for correlators of extended Wilson loops at large distances due to a singular behavior of the Itzykson-Zuber correlator of the gauge fields. I re-examine the KM model with an arbitrary potential in the large D limit and show that it reduces at large N to a one-matrix model whose potential is determined self-consistently. A relation with discretized random surfaces is established via the gauged Potts model, which is equivalent to the KM model at large N providing the coordination numbers coincide.
THE CASIMIR FORCE BETWEEN PLATES WITH SMALL DEVIATIONS FROM PLANE PARALLEL GEOMETRY
Authors: BORDAG M. , KLIMCHITSKAYA G.L. , MOSTEPANENKO V.M.
Published: November 2004

We present a general calculation of the corrections to the Casimir force between plates with small deviations from plane parallel geometry of the arbitrary type. These corrections are considered up to the fourth order with respect to the relative amplitudes of the deviations. The developed formalism is applied to the cases of nonparallel plates and of large scale as well as short scale deformations of the surfaces of different types. A number of particular examples are explicitly calculated. The method used is the previously developed method of additive summation of the Casimir force potentials with a subsequent renormalization. The results obtained by this method are tested by comparison with the results from the Green function method. A special investigation is performed into the role of mixed terms in the expansion with respect to the deviation amplitudes resulting from different plates. It is shown that such contributions are present already in the first nonvanishing correction to the Casimir force, so that this correction is nonadditive.
TECHNIQUE FOR DERIVING FEYNMAN INTEGRALS IN AXIAL-TYPE GAUGES
Authors: FACHIN STEFANO , LEIBBRANDT GEORGE
Published: November 2004

Employing the [Formula: see text] prescription for axial-type gauges, and working in the unified-gauge formalism defined by nμ and the null vector Fμ, we develop a simple technique for evaluating higher-rank integrals from known lower-rank integrals. Based on partial differentiation and implementation of an auxiliary constraint condition, the technique is applicable to a wide variety of integrals containing either single, double or triple spurious poles. We illustrate our procedure with several examples. There are strong indications that the new technique is also capable of generating the finite parts of axial-type integrals.
STRUCTURE FUNCTIONS AND PARTON DISTRIBUTIONS
Authors: MARTIN A.D. , ROBERTS R.G. , STIRLING W.J.
Published: November 2004

The MRS parton distribution analysis is described. The latest sets are shown to give an excellent description of a wide range of deep-inelastic and other hard scattering data. Two important theoretical issues—the behavior of the distributions at small x and the flavor structure of the quark sea—are discussed in detail. A comparison with the new structure function data from HERA is made, and the outlook for the future is discussed.
THE PARTON DISTRIBUTION FUNCTION LIBRARY
Authors: PLOTHOW-BESCH H.
Published: November 2004

This article describes an integrated package of Parton Density Functions called PDFLIB which has been added to the CERN Program Library Pool W999 and is labelled as W5051. In this package all the different sets of parton density functions of the Nucleon, the Pion and the Photon which are available today have been put together. All these sets have been combined in a consistent way such that they all have similar calling sequences and no external data files have to be read in anymore. A default set has been prepared, although those preferring their own set or wanting to test a new one may do so within the package. The package also offers a program to calculate the strong coupling constant αs to first or second order. The correct ΛQCD associated to the selected set of structure functions and the number of allowed flavours with respect to the given Q2 is automatically used in the calculation. The selection of sets, the program parameters as well as the possibilities to modify the defaults and to control errors occurred during execution are described.
PRODUCTION OF DRELL-YAN PAIRS IN pp COLLISIONS
Authors: GAVIN S. , GUPTA S. , KAUFFMAN R. , RUUSKANEN P.V. , SRIVASTAVA D.K. , THEWS R.L.
Published: November 2004

We compute cross sections for the Drell-Yan process in N-N collisions at next-to-leading order in αs. The mass, rapidity, transverse momentum, and angular dependence of these cross sections are presented. An estimate of higher order corrections is obtained from next-to-next-to-leading order calculation of the mass distribution. We compare the results with some of the existing data to show the quality of the agreement between calculations and data. We present predictions for energies that will become available at the RHIC and LHC colliders. Uncertainties in these predictions due to choices of scale, scheme and parton distribution are discussed.
CONFINEMENT OF QUARKS AND GLUONS II
Authors: NISHIJIMA KAZUHIKO
Published: November 2004

It is shown that color confinement is a consequence of BRS invariance and asymptotic freedom of quantum chromodynamics. BRS invariance is exploited to define color confinement, and asymptotic freedom is utilized to prove it. The proof presented in this paper is an extension of the one in the preceding paper.
ONE-LOOP CORRECTIONS TO WWγ AND WWZ VERTICES IN THE THDM
Authors: BENAOUM H.B. , BOUAMRANE R.
Published: November 2004

The one-loop corrections to the three-boson vertices WWγ and WWZ are studied in the context of the minimal standard model (MSM) as well as the two-Higgs-doublet model (THDM). Analytic expressions of the magnetic dipole and electric quadrupole form factors are given and discussed as functions of various parameters.
ON A RESIDUE REPRESENTATION OF DEFORMATION, KOSZUL AND CHIRAL RINGS
Authors: BERGLUND PER , HÜBSCH TRISTAN
Published: November 2004

A residue-theoretic representation is given for massless matter fields in (quotients of) (weighted) Calabi-Yau complete intersection models and the corresponding chiral operators in Landau-Ginzburg orbifolds. The well-known polynomial deformations are thus generalized, and the universal but somewhat abstract Koszul computations acquire a concrete realization and a general but more heuristic reinterpretation. Also, a direct correspondence with a BRST type analysis of constrained systems emerges naturally.
CLASSICAL YANG-MILLS THEORY WITH FERMIONS I: GENERAL PROPERTIES OF A SYSTEM WITH CONSTRAINTS
Authors: LUSANNA LUCA
Published: November 2004

A review is made of the basic properties of the Hamiltonian description of classical Yang-Mills theory with fermions described by Grassmann-valued Dirac spinors, in the case of a trivial principal bundle with a compact, semisimple, connected, simply connected Lie structure group over Minkowski space-time. The Poincaré group is assumed to be globally implementable and only the field configurations producing finite Poincaré generators are considered. A detailed study of the Hamiltonian group of gauge transformations is made, trying to elucidate the meaning of the global gauge transformations (connected with the non-Abelian charges and with the center of the gauge group), of the winding number (connected with the large gauge transformations and with the topological charge) and of the small gauge transformations generated by the first class constraints. This leads to the identification of boundary conditions on the gauge potentials and their conjugate momenta suitable for the Hamiltonian description and allowing covariance of the non-Abelian charges. Finally, a review is made of the problem of the Gribov ambiguity, whose basis is connected with the existence of stability subgroups of gauge transformations for certain gauge potentials (gauge symmetries) and/or certain field strengths (gauge copies) in generic Sobolev spaces.
INTERMITTENCY AND BOSE-EINSTEIN CORRELATIONS
Authors: ANDREEV I.V. , DREMIN I.M. , BIYAJIMA M. , SUZUKI N.
Published: November 2004

The role of Bose-Einstein (BE) correlations in a widely discussed intermittency phenomenon is reviewed. In particular, it is shown that particle correlations of different origins are better displayed when analyzed as functions of appropriately chosen variables. Correspondingly, if the shape of the BE contribution is chosen to be Gaussian in three-momentum transferred, it provides the power-like law in four-momentum squared and is smeared out in (pseudo)rapidity. The increase in factorial moments in small cells of the phase space looks also different in different variables, which is ascribed to varying shares of various mechanisms of both dynamical (e.g. parton jets) and symmetry (BE correlations) origin.
N=1 SUPERCONFORMAL MINIMAL MODEL CORRELATION FUNCTIONS ON THE TORUS
Authors: ABDURRAHMAN A. , ANTON F. , NAMAZIE M.A. , NÚÑEZ C.
Published: November 2004

The Coulomb gas formalism is employed to construct contour integral representations of two-point correlation functions on the torus for the N=1 superconformal unitary discrete series, characterized by the single integer p. (For the particular case of the tricritical Ising model, these include the energy and vacancy density operators.) Modular and monodromy properties of the superconformal blocks are examined, and the generalization to superconformal theories of Verlinde’s results on modular transformations and the fusion algebra are discussed in some detail. For p odd the relevant modular matrix is (with respect to a particular basis) symmetric and unitary, as in ordinary rational conformal theory. However, for p even, there appears to be an obstruction due to the Ramond vacuum state.