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HEAVY QUARK EFFECTIVE THEORY ON THE LIGHT FRONT
Authors: ZHANG WEI-MIN , CHEUNG CHI-YEE , LIN GUEY-LIN
Published: October 2004

The light front heavy quark effective theory is derived to all orders in 1/mQ. In the limit mQ→∞, the theory exhibits the familiar heavy quark spin-flavor symmetry. This new formalism permits a straightforward canonical quantization to all orders in 1/mQ; moreover, higher order terms have rather simple operator structures. The light front heavy quark effective theory can serve as a useful framework for the study of nonperturbative QCD dynamics of heavy hadron bound states.
MASSIVE SPINNING PARTICLE ON ANTI-DE SITTER SPACE
Authors: KUZENKO S.M. , LYAKHOVICH S.L. , SEGAL A. YU. , SHARAPOV A.A.
Published: October 2004

To describe a massive particle with fixed, but arbitrary, spin on d=4 anti-de Sitter space M4, we propose the point particle model with configuration space ℳ6=M4×S2, where the sphere S2 corresponds to the spin degrees of freedom. The model possesses two gauge symmetries expressing strong conservation of the phase space counterparts of the second and fourth order Casimir operators for so (3, 2). We prove that the requirement of energy to have a global positive minimum Eo over the configuration space is equivalent to the relation Eo>s, s being the particle’s spin, which presents the classical counterpart of the quantum massive condition. States with minimal energy are studied in detail. The model is shown to be exactly solvable. It can be straightforwardly generalized to describe a spinning particle on d-dimensional anti-de Sitter space Md, with ℳ2(d−1)=Md×S(d−2) the corresponding configuration space.
HOW TO CONSTRUCT A COORDINATE REPRESENTATION OF A HAMILTONIAN OPERATOR ON A TORUS
Authors: ISHIKAWA SUMIO , MIYAZAKI TADASHI , YAMAMOTO KAZUYOSHI , YAMANOBE MOTOWO
Published: October 2004

The dynamical system of a point particle constrained on a torus is quantized à la Dirac with two kinds of coordinate systems respectively; the Cartesian and toric coordinate systems. In the Cartesian coordinate system, it is difficult to express momentum operators in coordinate representation owing to the complication in structure of the commutation relations between canonical variables. In the toric coordinate system, the commutation relations have a simple form and their solutions in coordinate representation are easily obtained with, furthermore, two quantum Hamiltonians turning up. A problem comes out when the coordinate system is transformed, after quantization, from the Cartesian to the toric coordinate system.
BRST ANALYSIS OF QCD2 AS A PERTURBED WZW THEORY
Authors: CABRA D.C. , ROTHE K.D. , SCHAPOSNIK F.A.
Published: October 2004

The integrability of quantum chromodynamics in 1+1 dimensions has recently been suggested by formulating it as a perturbed conformal Wess—Zumino—Witten theory. This paper further elucidates this formulation by presenting a detailed BRST analysis.
THE SEARCH FOR NEUTRINO SOURCES BEYOND THE SUN
Authors: BARWICK S. , HALZEN F. , PRICE P.B.
Published: October 2004

It is hoped that in the near future, neutrino astronomy, born with the identification of thermonuclear fusion in the sun and the particle processes controlling the fate of a nearby supernova, will reach throughout and beyond our galaxy and make measurements relevant to cosmology, astrophysics, cosmic-ray physics and particle physics. The construction of a high-energy neutrino telescope requires a huge volume of very transparent, deeply buried material, such as ocean water or ice, which acts as the medium for detecting the particles. The AMANDA1 muon and neutrino telescope, now operating four strings of photomultiplier tubes buried in deep ice at the South Pole, is scheduled to be expanded to a ten-string array. The data collected over the first two years cover the three basic modes in which such instruments are operated: (i) the burst mode which monitors the sky for supernovae, (ii) the detection of electromagnetic showers initiated by PeV-energy cosmic electron neutrinos, and (iii) muon trajectory reconstruction for neutrino and gamma-ray astronomy. We speculate on the possible architectures of kilometer-scale instruments, using early data as a guideline.
TWISTED QUANTUM AFFINE ALGEBRAS AND SOLUTIONS TO THE YANG-BAXTER EQUATION
Authors: DELIUS GUSTAV W. , GOULD MARK D. , ZHANG YAO-ZHONG
Published: October 2004

We construct spectral-parameter-dependent R matrices for the quantized enveloping algebras of twisted affine Lie algebras. These give new solutions to the spectral-parameter-dependent quantum Yang-Baxter equation.
STRING NO-SCALE SUPERGRAVITY
Authors: LOPEZ JORGE L. , NANOPOULOS D.V.
Published: October 2004

We explore the postulates of string no-scale supergravity in the context of free-fermionic string models. The requirements of vanishing vacuum energy, flat directions of the scalar potential, and stable no-scale mechanism impose strong restrictions on possible string no-scale models, which must possess only two or three moduli, and a constrained massless spectrum. The soft-supersymmetry-breaking parameters involving all twisted and untwisted fields are given explicitly. Our calculations take into account the possible existence of an anomalous U A(1) factor in the gauge group, and reveal some novel effects concerning the stability of the no-scale mechanism in the presence of U A(1). This class of models contains no free parameters, i.e. in principle all supersymmetric particle masses and interactions are completely determined. A computerized search for free-fermionic models with the desired properties yields a candidate SU (5)×U(1) model containing extra [Formula: see text] matter representations that allow gauge coupling unification at the string scale. Our candidate model possesses a benign nonuniversal assignment of supersymmetry-breaking scalar masses, which may have interesting low-energy experimental consequences.
THERMODYNAMIC PROPERTIES, PHASES AND CLASSICAL VACUA OF TWO-DIMENSIONAL R2 GRAVITY
Authors: ICHINOSE SHOICHI
Published: October 2004

Two-dimensional quantum R2 gravity is studied in the semiclassical way. The thermodynamic properties, such as the equation of state, the temperature and the entropy, are examined. The classical solutions (vacua) of the R2 Liouville equation are obtained by making use of the well-known solution of the ordinary Liouville equation. They are constant curvature solutions. The positive constant curvature solution and the negative one are, after proper infrared regularization, “dual” each other. Each solution has two branches (±). We characterize all phases appearing in all solutions and branches. The topology constraint and the area constraint are properly taken into account. A total derivative term and an infrared regularization play important roles. The topology of a sphere is mainly considered.
BRST QUANTIZATION OF SU(2/1) ELECTROWEAK THEORY IN THE SUPERCONNECTION APPROACH, AND THE HIGGS MESON MASS
Authors: HWANG DAE SUNG , LEE CHANG-YEONG , NE’EMAN YUVAL
Published: October 2004

A superconnection, in which a scalar field enters as a zero-form in the odd part of the superalgebra, is used in the BRST quantization of the SU (2/1) “internally superunified” electroweak theory. A quantum action is obtained, by applying symmetric BRST/anti-BRST invariance. Evaluating the mass of the Higgs field, we exhibit the consistency between two approaches: (a) applying the supergroup’s (gauge) value for λ, the coupling of the scalar field’s quartic potential, to the conventional (spontaneous symmetry breakdown) evaluation; (b) dealing with the superconnection components as a supermultiplet of an (global) internal supersymmetry. This result thus provides a general foundation for the use of “internal” supergauges. With SU (2/1) broken by the negative squared mass term for the Higgs field and with the matter supermultiplets involving added “effective” ghost states, there is no reason to expect the symmetry’s couplings not to be renormalized. This explains the small difference between predicted and measured values for sin2θw, namely the other coupling fixed by SU (2/1) beyond the Standard Model’s SU(2)×U(1), and where the experimental results are very precise. Using the renormalization group equations and those experimental data, we thus evaluate the energy E8 at which the SU (2/1) predicted value of 0.25 is expected to correspond to the experimental values. With SU (2/1) precise at that energy Es=5 TeV , we then apply the renormalization group equations again, this time to evaluate the corrections to the above λ, the quartic coupling of the scalar fields; as a result we obtain corrections to the prediction for the Higgs meson’s mass. Our result predicts the Higgs’ mass [170 GeV, according to unrenormalized SU (2/1)] to be as low as 130±6 GeV , using for the top quark mass the recently measured value of 174 GeV .
THE ANTIFIELD BRST-ANTI-BRST QUANTIZATION OF MASSIVE AND NONMASSIVE ABELIAN THREE-FORM GAUGE FIELDS
Authors: BIZDADEA C. , SALIU S.O.
Published: October 2004

The antifield BRST-anti-BRST quantization of Abelian three-form gauge fields is achieved in detail. The nonminimal sector of the antifield BRST formalism appears now naturally. It is shown that the quantization of the massive case implies in fact the BRST or BRST-anti-BRST quantization of Abelian three-form gauge fields coupled to Abelian two-form gauge fields. This mixing-component system preserves in a certain way the reducibility of the nonmassive Abelian three-form gauge fields.
RENORMALIZATION AND THE ACTION PRINCIPLE
Authors: BURGESS MARK
Published: October 2004

An action principle technique provides an unusual perspective on the infrared problem in the effective action for gauge field theories. It is shown by means of a dynamical analogy that the renormalization group and the ansatz of nonlocal sources can be simultaneously presented through generalized variations of an action supplemented by sources in the manner of the Schwinger action principle. Indiscriminate resummations of the effective potential often lead to erroneous conclusions about phase transitions in a gauge theory if they resum matter self-energies at the expense of the gauge sector. The action principle method illuminates the reason for this and shows a way of proceeding, without having to go to nonzero momentum. Some examples are computed to the lowest order, reproducing results previously obtained through the renormalization group, and a new example is computed in Yang–Mills theory. The dynamical analogy leads to a comparison with a class of phenomenological nonequilibrium Lagrangians in which time-dependent couplings are used to model the influence of an external system. These models and some of their implications are discussed in terms of the action principle.
CHERN-SIMONS DUALITY AND THE QUANTUM HALL EFFECT
Authors: BALACHANDRAN A.P. , CHANDAR L. , SATHIAPALAN B.
Published: October 2004

In previous work on the quantum Hall effect on an annulus, we used O(d, d; Z) duality transformations on the action describing edge excitations to generate the Haldane hierarchy of Hall conductivities. Here we generate the corresponding hierarchy of “bulk actions” which are associated with Chern-Simons (CS) theories, the connection between the bulk and edge arising from the requirement of anomaly cancellation. We also find a duality transformation for the CS theory exactly analogous to the [Formula: see text] duality of the scalar field theory at the edge.
PAIRED ACCELERATED FRAMES
Authors: GERLACH ULRICH H.
Published: October 2004

The geometrical and quantum-mechanical basis for Davies’ and Unruh’s acceleration temperature is traced to a type of quantum-mechanical (“achronal”) spin. Its existence and definition are based on pairs of causally disjoint accelerated frames. For bosons the expected spin vector of monochromatic particles is given by the “Planckian power” and the “r.m.s. thermal fluctuation” spectra. Under space–time translation the spin direction precesses around that “Planckian” vector. By exhibiting the conserved achronal spin four-current, we extend the identification of achronal spin from single quanta to multiparticle systems. Total achronal spin conservation is also shown to hold, even in the presence of quadratic interactions.

In addition, the Lorentz invariance of the acceleration temperature is made explicit by the introduction of pairs of “spherical” Rindler frames.
GEOMETRICAL ASPECTS OF THE HELICITY FORMALISM
Authors: ROGALYOV R.N.
Published: October 2004

A bilinear combination of Dirac spinors is expressed in terms of Lorentz vectors. The result is represented in a convenient form, which can lead to using it for analytical calculations of multiparticle amplitudes. A geometrical interpretation of the introduced vectors is given and the correspondence between Dirac spinors and two-forms in complexified Minkowski space is clarified.
THE CORRECTIONS TO THE CASIMIR FORCES FOR CONFIGURATIONS USED IN EXPERIMENTS: THE SPHERICAL LENS ABOVE THE PLANE AND TWO CROSSED CYLINDERS
Authors: KLIMCHITSKAYA G.L. , PAVLOV YU. V.
Published: October 2004

A general calculation of the corrections to the Casimir force for configurations used in experiments is presented. These corrections are considered up to the second order with respect to the relative amplitudes of the deviations. It is shown that in the case of long scale deviations the leading correction is the first order one and may be both positive and negative. The relative corrections have estimated values of several tens of percent, so they must be taken into account in precision experiments on Casimir force measurements.
FEASIBILITY OF EXTRACTING Vtd FROM RADIATIVE B(Bs) DECAYS
Authors: ATWOOD D. , BLOK B. , SONI A.
Published: October 2004

We use experimental information on D−→K*0ρ− and B→ψ+K*, coupled with flavor independence of QCD, and with vector meson dominance, to show that long distance (LD) contributions to B→ρ+γ, especially to B−→ρ−+γ, are potentially very serious. Estimates based on the annihilation graph are shown to lead to similar conclusions. We emphasize that LD contributions can be appreciably different in B−→ρ−+γ and B0→ρ0(ω)+γ. All radiative decays of B, Bs are shown to be governed essentially by two LD and two short distance (SD) hadronic entities. Despite the presence of considerable LD contributions, we show how separate measurements of B−→ρ−+γ, B0→ρ0(ω)+γ, along with B→K*+γ, can be used for a systematic extraction of Vtd. Measurements of Bs→ɸ+γ and K*0+γ could also provide very useful consistency checks.
FIELD-ANTIFIELD QUANTIZATION OF THE YANG-MILLS THEORY WITH EXTENDED BRST INVARIANCE IN THE COLLECTIVE FIELD APPROACH
Authors: BRAGA NELSON R.F. , SOUZA SERGIO M. DE
Published: October 2004

The collective field procedure is an interesting way of deriving the field-antifield formalism from a standard BRST approach. Trivial shift symmetries are introduced in the original gauge theory and then a judicious choice of gauge-fixing leads to the identification of the antighosts of these extra symmetries as the antifields. When explicit extended BRST invariance (BRST and anti-BRST invariance) is required, two collective fields are necessary, and the gauge-fixing structure is more complex. In this article, with the purpose of clarifying some aspects of this procedure, we consider in detail the example of the Yang–Mills theory.
FLUCTUATION-INDUCED R2 GRAVITY IN TWO DIMENSIONS
Authors: HEIßNER UWE
Published: October 2004

Motivated by the work of Kawai and Nakayama1 on R2 gravity in two dimensions, we consider a simple massive stringlike model with one scalar bosonic field. We show that the conformal anomaly in terms of the Liouville action occurring in the usual Polyakov model does not appear in the presence of a finite massive term, because the conformal anomaly originating from the kinetic term of the model is canceled by a corresponding term originating from the massive part. Instead of this term, we obtain a power series in the inverse mass, where the coefficients are integrals over the manifold of scalar polynomials in the metric, the Gaussian curvature and its covariant derivatives. The lowest-order term is an R2 term.
ON AN INCLUSIVE DETERMINATION OF HADRONIC WIDTH/MASS RATIOS
Authors: MITRA A.N. , SHARMA ANJU
Published: October 2004

An inclusive determination of the (Γ/M) ratios of mesons and baryons is made from the ansatz that there exists a short breathing mode for the temporary dissociation of a hadron into a pair of “quasifree” quarks (q) and/or diquarks (D) with significantly lower masses than their constituent values which subsequently hadronize with certainty. The coupling scheme for mesons to these [Formula: see text] and DD* pairs (which yields Γ directly) is determined by Schwinger’s partial symmetry for quarks (which “subsumes” the Sakurai gauge principle for ρ, ω, ɸ couplings to [Formula: see text] pairs). A similar construction holds for baryon couplings to quark(q)-diquark(D) pairs, with the same overall coupling constant(gs) for both systems. Its tentative identification with the QCD value yields a surprisingly good pattern of agreement with data for both hadron types, using just two inputs (mud and ms). The Γ/M ratios (R) are expressible as αs(M2) f(J, M/mq), and indicate discreteness in R iff the standard Regge slope patterns in M2 are taken into account.
OBSERVATION OF THE TOP QUARK
Authors: KIM SOO-BONG
Published: October 2004

Top-quark production is observed in [Formula: see text] collisions at [Formula: see text] at the Fermilab Tevatron. The CDF and DØ collaborations observe signals consistent with [Formula: see text] to [Formula: see text] but inconsistent with the background prediction by 4.8σ (CDF) and 4.6σ (DØ). Additional evidence for the top quark is provided by a peak in the reconstructed mass distribution. The kinematic properties of the excess events are consistent with the top-quark decay. The top-quark mass has been measured to be 176±8 (stat.) ±10 (sys.) GeV /c2 (CDF) and [Formula: see text]±22(sys.)GeV/c2 (DØ), and the [Formula: see text]-production cross section to be [Formula: see text] and 6.4±2.2 pb (DØ).
REGGE TRAJECTORIES AND CRITICAL FIELDS OF THE CHARGED STRING IN A MAGNETIC BACKGROUND
Authors: FERRER EFRAIN J. , INCERA VIVIAN DE LA
Published: October 2004

The Regge trajectories of a charged string in a magnetic background are derived by using a decomposition of the rest energy in terms of the Casimir operators of the theory. The first Regge trajectory is given by a family of infinitely many parallel straight lines, one for each spin projection along the magnetic field. Using the trajectories linking rest energy and spin, a critical magnetic field is found, for each spin value, at which the correspondent spin state with the highest spin projection becomes massless.
QUANTUM EVOLUTION OF SCALAR FIELDS IN ROBERTSON-WALKER SPACE-TIME
Authors: REIS H.C. , ÉBOLI O.J.P.
Published: October 2004

We study the λɸ4 field theory in a flat Robertson-Walker space-time using the functional Schrödinger picture. We introduce a simple Gaussian approximation to analyze the time evolution of pure states and we establish the renormalizability of the approximation. We also show that the energy–momentum tensor in this approximation is finite once we consider the usual mass and coupling constant renormalizations.
A ONE-COMPONENT DIRAC EQUATION
Authors: LEO STEFANO DE
Published: October 2004

We develop a relativistic free wave equation on the complexified quaternions, linear in the derivatives. Even if the wave functions are only one-component, we show that four independent solutions, corresponding to those of the Dirac equation, exist. A partial set of translations between complex and complexified quaternionic quantum mechanics may be defined.
CONTINUUM AND LATTICE OVERLAP FOR CHIRAL FERMIONS ON THE TORUS
Authors: FOSCO C.D.
Published: October 2004

The overlap formulation is applied to calculate the chiral determinant on a two-dimensional torus with twisted boundary conditions. We first evaluate the continuum overlap, which is convergent and well-defined, and yields the correct string theory result for both the real and imaginary parts of the effective action. We then show that the lattice version of the overlap gives the continuum overlap results in the limit where the lattice spacing tends to zero, and that the subleading terms in that limit are irrelevant.
THE EFFECT OF SPATIAL CURVATURE ON CLASSICAL AND QUANTUM STRINGS
Authors: LARSEN A.L. , SÁNCHEZ N.
Published: October 2004

We study the effects of spatial curvature on classical and quantum string dynamics. We find the general solution of the circular string motion in static Robertson–Walker space-times with closed or open sections. This is given closely and completely in terms of elliptic functions. The physical properties, string length, energy and pressure are computed and analyzed. We find the back-reaction effect of these strings on the space-time: the self-consistent solution to the Einstein equations is a spatially closed (K>0) space-time with a selected value of the curvature index K (the scale factor is normalized to unity). No self-consistent solutions with K≤0 exist. We semiclassically quantize the circular strings and find the mass m in each case. For K>0, the very massive strings, oscillating on the full hypersphere, have m2~Kn2(n∈N0)independent of α' and the level spacing grows with n, while the strings oscillating on one hemisphere (without crossing the equator) have m2α′~n and a finite number of states N~1/Kα′. For K<0, there are infinitely many string states with masses m log m ~ n, i.e. the level spacing grows slower than n.

The stationary string solutions as well as the generic string fluctuations around the center of mass are also found and analyzed in closed form.
NON-ABELIAN BOSONIZATION AND HIGHER SPIN SYMMETRIES
Authors: ZAIKOV RAIKO P.
Published: October 2004

The higher spin properties of non-Abelian bosonization in the classical theory are investigated. Both the symmetry transformation algebra and the classical current algebra for the non-Abelian free-fermionic model are linear Gel’fand–Dickey type algebras. However, for the corresponding WZNW model these algebras are different. There exist symmetry transformations whose algebra remains the linear Gel’fand-Dickey algebra, while in the corresponding current algebra nonlinear terms arise. Moreover, this algebra is closed (in Casimir form) only in an extended current space in which nonlinear currents are included. In the affine sector, it is necessary to include higher isotopic spin current too. As a result we have a triple extended algebra.
VACUUM ENERGY IN SPHERICAL DOMAINS: WKB AND UNIFORM ASYMPTOTIC EXPANSIONS
Authors: ROMEO AUGUST
Published: October 2004

We evaluate the finite part of the regularized zero-point energy for a massless scalar field confined in the interior of a D-dimensional spherical region. While some insight is offered into the dimensional dependence of the WKB approximations by examining the residues of the spectral-zeta-function poles, a mode-sum technique based on an integral representation of the Bessel spectral zeta function is applied with the help of uniform asymptotic expansions (u.a.e.’s).
B DECAYS AND CP VIOLATION
Authors: NEUBERT MATTHIAS
Published: October 2004

We review the status of the theory and phenomenology of heavy-quark symmetry, exclusive weak decays of B mesons, inclusive decay rates and lifetimes of b hadrons, and CP violation in B-meson decays.
HETEROTIC TYPE II STRING DUALITY AND THE H MONOPOLE PROBLEM
Authors: GIRARDELLO LUCIANO , PORRATI MASSIMO , ZAFFARONI ALBERTO
Published: October 2004

Since T duality has been proved only perturbatively and most of the heterotic states map into solitonic, nonperturbative, type II states, the six-dimensional string-string duality between the heterotic string and the type II string is not sufficient for proving the S duality of the former, in terms of the known T duality of the latter. We nevertheless show in detail that the perturbative T duality, together with the heterotic type II duality, does imply the existence of heterotic H monopoles, with the correct multiplicity and multiplet structure. This construction is valid at a generic point in the moduli space of heterotic toroidal compactifications.
PHASE TRANSITION OF N-COMPONENT SUPERCONDUCTORS
Authors: BERGERHOFF B. , LITIM D.F. , LOLA S. , WETTERICH C.
Published: October 2004

We investigate the phase transition in the three-dimensional Abelian Higgs model for N complex scalar fields, using the gauge-invariant average action Γk. The dependence of Γk. on the effective infrared cutoff k is described by a nonperturbative flow equation. The transition turns out to be first or second order, depending on the ratio between the scalar and gauge coupling. We look at the fixed points of the theory for various N and compute the critical exponents of the model. Our results suggest the existence of a parameter range with a second order transition for all N, including the case of the superconductor phase transition for N=1.
DECAY RATES OF METASTABLE STATES IN CUBIC POTENTIAL BY VARIATIONAL PERTURBATION THEORY
Authors: KLEINERT H. , MUSTAPIC I.
Published: October 2004

Variational perturbation theory is used to determine the decay rates of metastable states across a cubic barrier of arbitrary height. For high barriers, a variational resummation procedure is applied to the complex energy eigenvalues obtained from a WKB expansion. For low barriers, the variational resummation procedure converts the non-Borel-summable Rayleigh-Schrödinger expansion into an exponentially fast convergent approximation. The results in the two regimes match each other well and yield very accurate imaginary parts for the energy eigenvalues. This is demonstrated by comparison with the complex eigenvalues obtained from solutions of the Schrödinger equation via the complex-coordinate rotation method.
NEW EQUATIONS FOR VACUUM CORRELATORS IN FIELD THEORY
Authors: ANTONOV D.V. , SIMONOV YU. A.
Published: October 2004

Stochastic quantization is used to derive exact equations connecting an infinite set of multilocal field correlators in the φ3 theory and gluodynamics. In the latter case the obtained equations are explicitly gauge-invariant. In the bilocal approximation, corresponding to the Gaussian stochastic ensemble, a minimal finite system of equations is obtained and investigated in the lowest orders of perturbation theory. A gauge-invariant diagrammatic technique in gluodynamics is developed.
AN EXACT S2 SYMMETRY FOR QUARK MASS MATRICES?
Authors: YAO YORK-PENG
Published: October 2004

We show that an exact S2 symmetry can be imposed on quark mass matrices and is not in conflict with available experimental data. We obtain a constraint, [Formula: see text] Further tests may be performed in neutral flavor violation processes t→u, c and b→d, s in a multi-Higgs model, with a typical Yukawa coupling strength of order 10−3−10−2.
TWO-DIMENSIONAL QCD WITH ADJOINT MATTER
Authors: DEMETERFI KREŠIMIR
Published: October 2004

We review the recent work on the light-cone quantization of (1+1)-dimensional large N QCD coupled to adjoint matter. The spectrum of these models consists of glueball-like bound states which, in the large N limit, can be pictured as closed strings that cannot split or join. The pair creation (annihilation) inside the string is not suppressed even in the large N limit, giving rise to complex dynamics similar to that of genuine higher dimensional gauge theories. The mass spectra of such models exhibit an exponential growth of the density of states (Hagedorn behavior) and the absence of massless glueballs even in the case of massless constituents.
HAMILTONIAN DESCRIPTION OF HIGHER ORDER LAGRANGIANS
Authors: RASHID M. S. , KHALIL S. S.
Published: October 2004

Using Dirac’s analysis of second class constraints, a Hamiltonian formulation of higher order Lagrangians is reached. The new Hamiltonian description recovers the conventional description of such systems due to Ostrogradsky, but unlike the latter, it provides a simpler structure for the phase space and consequently the underlying symplectic structure.
CURVATURE-INDUCED PHASE TRANSITION IN A FOUR-FERMION THEORY USING THE WEAK CURVATURE EXPANSION
Authors: INAGAKI TOMOHIRO
Published: October 2004

Curvature–induced phase transition is thoroughly investigated in a four-fermion theory with N components of fermions for arbitrary space–time dimensions (2≤D<4). We adopt the 1/N expansion method and calculate the effective potential for a composite operator [Formula: see text]. The resulting effective potential is expanded asymptotically in terms of the space–time curvature R by using the Riemann normal coordinate. We assume that the space–time curves slowly, and we keep only terms independent of R and terms linear in R. In evaluating the effective potential it is found that first order phase transition is caused and the broken chiral symmetry is restored for a large positive curvature. In the space–time with a negative curvature the chiral symmetry is broken down even if the coupling constant of the four-fermion interaction is sufficiently small. We present the behavior of the dynamically generated fermion mass. The critical curvature, R cr , which divides the symmetric and asymmetric phases, is obtained analytically as a function of the space–time dimension D. At the four-dimensional limit our result R cr agrees with the exact results known in de Sitter space and the Einstein universe.
ON A CLASS OF TOPOLOGICAL QUANTUM FIELD THEORIES IN THREE DIMENSIONS
Authors: ASANO MASAKO
Published: October 2004

We investigate the Chung–Fukuma–Shapere theory, or Kuperberg theory, of three-dimensional lattice topological field theory. We construct a functor which satisfies Atiyah’s axioms of topological quantum field theory by reformulating the theory as a Turaev–Viro type state sum theory on a triangulated manifold. This corresponds to giving the Hilbert space structure to the original theory. The theory can be extended to give a topological invariant of manifolds with boundary.
SINGULAR VECTORS OF THE TOPOLOGICAL CONFORMAL ALGEBRA
Authors: SEMIKHATOV A. M. , YU. TIPUNIN I.
Published: October 2004

A general construction is found for “topological” singular vectors of the twisted N=2 superconformal algebra. It demonstrates many parallels with the known construction for affine sℓ(2) singular vectors due to Malikov–Feigin–Fuchs, but is formulated independently of the latter. The two constructions taken together provide an isomorphism between the topological and affine sℓ(2) singular vectors. The general formula for topological singular vectors can be reformulated as a chain of direct recursion relations that allow one to derive a given singular vector | S(r, s)〉 from the lower ones | S(r, s′<s)〉. We also introduce generalized Verma modules over the twisted N=2 algebra and show that they provide a natural setup for the new construction for topological singular vectors.
THEORY OF KÄHLER GRAVITY
Authors: BERSHADSKY M. , SADOV V.
Published: October 2004

In this paper we discuss the connection on a space of N = 2 TCFT's that appears in the context of background (in)dependence. We formulate a family of target space field theories with a similar connection on it. Each theory is a gauge theory (with the gauge group being [Formula: see text] Diff in the case of three-fold). It describes deformations of Kähler structures much like Kodaira Spencer theory describes deformations of the complex structures. It is manifestly background-independent. It appears to be a target space field theory for supersymmetric quantum mechanics.
SOFTLY BROKEN N = 2 QCD
Authors: ÁLVAREZ-GAUMÉ LUIS , KOUNNAS COSTAS , DISTLER JACQUES , MARIÑO MARCOS
Published: October 2004

We analyze the possible soft breaking of (N = 2)-supersymmetric Yang–Mills theory with and without matter flavor preserving the analyticity properties of the Seiberg–Witten solution. For a small supersymmetry-breaking parameter with respect to the dynamical scale of the theory we obtain an exact expression for the effective potential. We describe in detail the onset of the confinement transition and some of the patterns of chiral symmetry breaking. If we extrapolate the results to the limit where supersymmetry decouples, we obtain hints indicating that perhaps a description of the QCD vacuum will require the use of Lagrangians containing simultaneously mutually nonlocal degrees of freedom (monopoles and dyons).
THE HIGGS PHENOMENON
Authors: RODENBERG RUDOLF
Published: October 2004

We briefly discuss why we are forced to use the Higgs–Kibble mechanism just, for example, to be able to "present" masses and what in this sense the so-called Higgs phenomenon really means. But, independent of this fact that we cannot calculate physical masses, we, in spite of this reality, briefly demonstrate presently available theoretical methods for understanding the top-Higgs-mass correlations, for example, especially since the discovery of the top quark at FNAL. It is possible that model-dependent ways, using SUSY and SUGRA models, for example, to overcome the so-called scale dependence (just from the Planck down to the Fermi scale), nonlinear realizations of SUSY and also the requirement of phase coexistence of the two minima of the effective potential with one-loop corrections and its degeneracy ("multiple point criticality principle"), might indicate that in this sense the existence of supersymmetry can be "partially" ruled out. In this context the top-Higgs-mass spectrum belongs neither to the SM nor to SUSY. Also, the loss of quantum coherence, which is very small at low energies for everything except scalar fields, leads to the prediction that we may never observe the Higgs particle either.
N = 2 CHIRAL WZNW MODEL IN SUPERSPACE
Authors: DELDUC F. , MAGRO M.
Published: October 2004

We study the Poisson bracket algebra of the (N = 2)-supersymmetric chiral WZNW model in superspace. It involves two classical r matrices, one of which comes from the geometrical constraints implied by N = 2 supersymmetry. The phase space itself consists of superfields satisfying constraints involving this r matrix. An attempt is made to relax these constraints. The symmetries of the model are investigated.
SEMICLASSICAL BLOCKS AND CORRELATORS IN RATIONAL AND IRRATIONAL CONFORMAL FIELD THEORY
Authors: HALPERN M. B. , OBERS N. A.
Published: October 2004

The generalized Knizhnik–Zamolodchikov equations of irrational conformal field theory provide a uniform description of rational and irrational conformal field theory. Starting from the known high-level solution of these equations, we first construct the high-level conformal blocks and correlators of all the affine-Sugawara and coset constructions on simple g. Using intuition gained from these cases, we then identify a simple class of irrational processes whose high-level blocks and correlators we are also able to construct.
GROUP-THEORETICAL STRUCTURE OF N = 1 AND N = 2 TWO-FORM SUPERGRAVITY
Authors: NOJIRI SHIN'ICHI
Published: October 2004

We clarify the group-theoretical structure of N = 1 and N = 2 two-form supergravity, which is classically equivalent to the Einstein supergravity. N = 1 and N = 2 two-form supergravity theories can be formulated as gauge theories. By introducing two Grassmann variables θA (A = 1, 2), we construct the explicit representations of the generators Qi of the gauge group, which makes it possible to express any product of the generators as a linear combination of the generators [Formula: see text]. By using the expression and the tensor product representation, we show how to construct finite-dimensional representations of the gauge groups. Based on these representations, we construct the Lagrangians of N = 1 and N = 2 two-form supergravity theories.
THE QUEST FOR THE QUARK–GLUON PLASMA
Authors: JACOB MAURICE
Published: October 2004

Heavy-ion collisions at very high energy offer conditions such that a quark–gluon plasma could be formed. Specific signals are used to probe what is actually happening. A first round of tests, with small- to medium-sized ions, has been completed. New rounds of tests using the heaviest ions and, later on, much higher energies, are proceeding. The present situation is assessed.
REMARKS ON VIRASORO AND KAC–MOODY ALGEBRAS
Authors: GRABOWSKI J. , MARMO G. , PERELOMOV A. , SIMONI A.
Published: October 2004

Parametric realizations of Virasoro or Kac–Moody algebras are constructed on a generic manifold carrying an appropriate vector field. It is shown that the centrally extended algebras cannot be realized as algebras of vector fields on finite-dimensional manifolds.
SIGNIFICANCE OF ZERO MODES IN PATH INTEGRAL QUANTIZATION OF SOLITONIC THEORIES WITH BRST INVARIANCE
Authors: ZHOU J.-G. , ZIMMERSCHIED F. , MÜLLER-KIRSTEN H. J. W. , LIANG J.-Q. , TCHRAKIAN D. H.
Published: October 2004

The significance of zero modes in the path integral quantization of some solitonic models is investigated. In particular a Skyrme-like theory with topological vortices in 1 + 2 dimensions is studied, and with a BRST-invariant gauge fixing a well-defined transition amplitude is obtained in the one-loop approximation. We also present an alternative method which does not necessitate evoking the time dependence in the functional integral, but is equivalent to the original one in dealing with the quantization in the background of the static classical solution of the nonlinear field equations. The considerations given here are particularly useful in — but also limited to — the one-loop approximation.
EXACT SOLUTIONS OF THE REISSNER–NORDSTRÖM TYPE IN EINSTEIN–YANG–MILLS SYSTEMS WITH ARBITRARY GAUGE GROUPS AND SPACE–TIME DIMENSIONS
Authors: RUDOLPH GERD , TOK TORSTEN , VOLOBUEV IGOR P.
Published: October 2004

We present a class of solutions in Einstein–Yang–Mills systems with arbitrary gauge groups and space–time dimensions, which are symmetric under the action of the group of spatial rotations. Our approach is based on the dimensional reduction method for gauge and gravitational fields and relates symmetric Einstein–Yang–Mills solutions to certain solutions of two-dimensional Einstein–Yang–Mills–Higgs-dilaton theory. Application of this method to four-dimensional spherically symmetric (pseudo-)Riemannian space–time yields, in particular, new solutions describing both a magnetic and an electric charge at the center of a black hole. Moreover, we give an example of a solution with non-Abelian gauge group in six-dimensional space–time. We also comment on the stability of the obtained solutions.
UNITARY MATRIX INTEGRALS IN THE FRAMEWORK OF THE GENERALIZED KONTSEVICH MODEL
Authors: MIRONOV A. , MOROZOV A. , SEMENOFF G. W.
Published: October 2004

We advocate a new approach to the study of unitary matrix models in external fields which emphasizes their relationship to generalized Kontsevich models (GKM's) with nonpolynomial potentials. For example, we show that the partition function of the Brezin–Gross–Witten model (BGWM), which is defined as an integral over unitary N × N matrices, [Formula: see text], can also be considered as a GKM with potential [Formula: see text]. Moreover, it can be interpreted as the generating functional for correlators in the Penner model. The strong and weak coupling phases of the BGWM are identified with the "character" (weak coupling) and "Kontsevich" (strong coupling) phases of the GKM, respectively. This type of GKM deserves classification as a p = −2 model (i.e. c = 28 or c = −2) when in the Kontsevich phase. This approach allows us to further identify the Harish-Chandra–Itzykson–Zuber integral with a peculiar GKM, which arises in the study of c = 1, theory, and, further, with a conventional two-matrix model which is rewritten in Miwa coordinates. Some further extensions of the GKM treatment which are inspired by the unitary matrix models which we have considered are also developed. In particular, as a by-product, a new, simple method of fixing the Ward identities for matrix models in an external field is presented.
STATUS OF THE PROTON SPIN PROBLEM
Authors: CHENG HAI-YANG
Published: October 2004

The proton spin problem triggered by the EMC experiment and its present status are closely examined. Recent experimental and theoretical progresses and their implications are reviewed. It is pointed out that the sign of the sea quark polarization generated perturbatively by hard gluons via the anomaly mechanism is predictable. It is negative if the gluon spin component is positive. We stress that the polarized nucleon structure function g1(x) is independent of the k⊥ factorization scheme chosen in defining the quark spin density and the hard photon–gluon scattering cross-section. Consequently, the anomalous gluon and sea quark interpretations for Γ1, the first moment of g1(x), are equivalent. It is the axial anomaly that accounts for the observed suppression of [Formula: see text].
CHIRAL LAGRANGIANS FOR BARYONS COUPLED TO MASSIVE SPIN-1 FIELDS
Authors: BORASOY B. , MEIßNER ULF-G.
Published: October 2004

We analyze the effective low energy field theory of Goldstone bosons and baryons chirally coupled to massive spin-1 fields. We use the electromagnetic baryon form factors to demonstrate the formal equivalence between the vector and the tensor field formulation for the spin-1 fields. We also discuss the origin of the so-called Weinberg term in pion–nucleon scattering and the role of ρ meson exchange. Chirally coupled vector mesons do not give rise to this two-pion nucleon seagull interaction but rather to higher order corrections. Some problems of the formal equivalence arising in higher orders and related to loops are touched upon.
SIMPLE UNDERSTANDING OF THE ENERGY DEPENDENCE OF THE B/M RATIO AND HADRON MULTIPLICITIES IN e+e− ANNIHILATION
Authors: WANG QUN , SI ZONG-GUO , XIE QU-BING
Published: October 2004

With the help of the color dipole model (CDM) in describing the parton shower process in the perturbative phase in e+e− annihilation, we extend the quark combination model (QCM) of the original form to a more general one in a multiparton system. Then we derive baryon and meson multiplicity formulas for the multiparton system. The new multiplicity formulas are expressed in terms of CDM quantities [Formula: see text] and [Formula: see text]. From these formulas, we can readily understand that the energy behavior of the B/M ratio implied by the multiplicity data in e+e− annihilation is the consequence of two competitive processes: one is the dipole splitting which makes B/M decrease and the other is the increase in combination chain length which makes it higher. To check these basic formulas further, we give multiplicities of most ground hadrons at three energies, 10, 30, 90 GeV, by using five main energy-independent parameters, 75% of which agree with data within 1.5 standard error.
A GENERAL HIGGS SECTOR: CONSTRAINTS AND PHENOMENOLOGY
Authors: KUNDU ANIRBAN , MUKHOPADHYAYA BISWARUP
Published: October 2004

We have investigated some phenomenological aspects of an SU (2) × U (1) scenario where scalars belonging to arbitrary representations of SU(2) are involved in electroweak symmetry breaking. The resulting interaction terms are derived. Some constraints are obtained on the arbitrary scalar sector from the requirement of tree-level unitarity in longitudinal gauge boson scattering. We also show that there is a remarkable complimentarity between the constraints on a general structure from the ρ parameter and those from precision measurement of the [Formula: see text] vertex. Finally, some salient features about the production of such Higgs bosons in e+e− collision are discussed.
CONFORMAL MODELS OF MAGNETOHYDRODYNAMIC TURBULENCE
Authors: COCEAL OMDUTH , THOMAS STEVEN
Published: October 2004

Following the previous work of Ferretti and Yang on the role of magnetic fields in the theory of conformal turbulence, we show that nonunitary minimal model solutions to two-dimensional magnetohydrodynamics (MHD) obtained by dimensional reduction from three dimensions exist under different (and more restrictive) conditions. From a three-dimensional point of view, these conditions are equivalent to perpendicular flow, in which the magnetic and velocity fields are orthogonal. We extend the analysis to the finite conductivity case and present some approximate solutions, whose connection with the exact ones of the infinite conductivity case is also discussed.
BRST FORMALISM FOR SYSTEMS WITH HIGHER ORDER DERIVATIVES OF GAUGE PARAMETERS
Authors: NIROV KH. S.
Published: October 2004

For a wide class of mechanical systems, invariant under gauge transformations with arbitrary higher order time derivatives of gauge parameters, the equivalence of Lagrangian and Hamiltonian BRST formalisms is proved. It is shown that the Ostrogradsky formalism establishes the natural rules to relate the BFV ghost canonical pairs with the ghosts and antighosts introduced by the Lagrangian approach. Explicit relation between corresponding gauge-fixing terms is obtained.
STRONG COULOMB COUPLING IN THE TODOROV EQUATION
Authors: BAWIN M. , CUGNON J. , SAZDJIAN H.
Published: October 2004

A positronium-like system with strong Coulomb coupling, considered in its pseudoscalar sector, is studied in the framework of relativistic quantum constraint dynamics with the Todorov choice for the potential. Case’s method of self-adjoint extension of singular potentials, which avoids explicit introduction of regularization cut-offs, is adopted. It is found that, as the coupling constant α increases, the bound state spectrum undergoes an abrupt change at the critical value α=αc=1/2. For α>αc, the mass spectrum displays, in addition to the existing states for α<αc, a new set of an infinite number of bound states concentrated in a narrow band starting at mass W=0; all the states have indefinitely oscillating wave functions near the origin. In the limit α→αc from above, the oscillations disappear and the narrow band of low-lying states shrinks to a single massless state with a mass gap with the rest of the spectrum. This state has the required properties to represent a Goldstone boson and to signal spontaneous breakdown of chiral symmetry.
FORM FACTORS AND CORRELATION FUNCTIONS OF THE STRESS-ENERGY TENSOR IN MASSIVE DEFORMATION OF THE MINIMAL MODELS (En)1⊗ (En)1/(En)2
Authors: ACERBI C. , VALLERIANI A. , MUSSARDO G.
Published: October 2004

The magnetic deformation of the Ising model, and the thermal deformations of both the tricritical Ising model and the tricritical Potts model, are governed by an algebraic structure based on the Dynkin diagram associated with the exceptional algebras En (respectively for n = 8, 7, 6). We make use of these underlying structures as well as the discrete symmetries of the models to compute the matrix elements of the stress-energy tensor and its two-point correlation function by means of the spectral representation method.
POSSIBLE LONG RANGE COMPONENT IN THE NUCLEAR FORCE
Authors: SAWADA T.
Published: October 2004

In search of the possible long range force between hadrons, S wave phase shift data of the proton-proton scattering are analyzed. In the analysis, the once subtracted Kantor amplitude is calculated, and the one-pion exchange contribution is separated. The remainder of the Kantor amplitude has a huge cusp at the threshold with the attractive sign. It is shown that such a cusp cannot be fitted by the spectral function of the twopion exchange, since it starts at [Formula: see text]. The cusp is fitted by a potential of the long range type with the asymptotic form of V(r) ~ −C/rα. After the chi square search, it turns out α is 6.1~7 and C is positive and has the strength of the strong interaction. It is consistent with the potential of the strong van der Waals force. The transition from the London type to the Casimir-Polder type of the van der Waals interaction is examined. Possible experiments to observe directly such a long range force in the nuclear force are also indicated.