bluuebunny/crossref_metadata_2025 huggingface dataset:
Z-Symmetry and Polyakov Loops in Hot Abelian Gauge Theories
Authors: Grignani G. , Sodano P. , Semenoff G. , Tirkkonen O.
Published: October 2003

We discuss the Z symmetry of finite temperature QED, which is related to the confinement properties of the theory. We show the correlators of Polyakov loop operators with incommensurate charges can be used as order parameters for this symmetry. The screening or confining properties of lower dimensional abelian gauge theories are analyzed. In the Schwinger model, the Z-symmetry is broken and the system is in a screening phase; with a non-vanishing fermion mass the symmetry is recovered and the system confines. In parity invariant 2+1-dimensional QED, there is a phase transition between phases with unbroken and broken realizations of this symmetry. This confinement–deconfinement transition is of the Berezinskii–Kosterlitz–Thouless (BKT) type. When there is a topological mass the model exhibits a screening phase. However, if the topological mass is much smaller than the other dimensional parameters there is a vestige of the BKT transition separating regions with screening and confining behavior.
Self-Duality and Maximally Helicity Violating QCD Amplitudes
Authors: Cangemi Daniel
Published: October 2003

I review some recent work that describes the close analogy between self-dual Yang–Mills amplitudes and QCD amplitudes with external gluons of positive helicity. This analogy is carried at tree level for amplitudes with two external quarks and up to one-loop for amplitudes involving only external gluons.
Condensation of p-Branes and Generalized Higgs/Confinement Duality
Authors: Quevedo Fernando , Trugenberger Carlo A.
Published: October 2003

We review our recent work on the low-energy actions and the realizations of strong-weak coupling dualities in non-perturbative phases of compact antisymmetric tensor field theories due to p-brane condensation. As examples we derive and discuss the confining string and confining membrane actions obtained from compact vector and tensor theories in 4D. We also mention the relevance of our results for the description of the Hagedorn phase transition of finite temperature strings.
Integrable Models, SUSY Gauge Theories and String Theory
Authors: Nam Soonkeon
Published: October 2003

We consider the close relation between duality in N = 2 SUSY gauge theories and integrable models. Various integrable models ranging from Toda lattices, Calogero models, spinning tops, and spin chains are related to the quantum moduli space of vacua of N = 2 SUSY gauge theories. In particular, SU(3) gauge theories with two flavors of massless quarks in the fundamental representation can be related to the spectral curve of Goryachev–Chaplygin top, which is a Nahm's equation in disguise. This can be generalized to the cases with massive quarks, and Nf = 0,1,2, where a system with seven dimensional phase space has the relevant hyperelliptic curve appear in the Painlevè test. To understand the string origin of the integrability of these theories we obtain exact nonperturbative point particle limit of type II string compactified on a Calabi–Yau manifold, which gives the hyperelliptic curve of SU(2) QCD with Nf = 1 hypermultiplet.
High Energy Scattering of Non-Critical Strings
Authors: Aoki Kenichiro , D'Hoker Eric
Published: October 2003

We summarize recent work, in which we consider scattering amplitudes of non-critical strings in the limit where the energy of all external states is large compared to the string tension. We show that the high energy limit is dominated by a saddle point that can be mapped onto an electrostatic equilibrium configuration of an assembly of charges associated with the external states, together with a density of charges arising from the Liouville field. The Liouville charges accumulate on line segments, which produce quadratic branch cuts on the worldsheet. The electrostatic problem is solved for string tree level in terms of hyperelliptic integrals and is given explicitly for the 3- and 4-point functions. For generic values of the central charge, the high energy limit behaves in a string-like fashion, with exponential energy dependence.
Constrained KP Hierarchies: Additional Symmetries, Darboux–Bäcklund Solutions and Relations to Multi-Matrix Models
Authors: Aratyn H. , Nissimov E. , Pacheva S.
Published: October 2003

This paper provides a systematic description of the interplay between a specific class of reductions denoted as cKP r,m(r,m ≥ 1) of the primary continuum integrable system — the Kadomtsev–Petviashvili (KP) hierarchy and discrete multi-matrix models. The relevant integrable cKP r,m structure is a generalization of the familiar r-reduction of the full KP hierarchy to the SL (r) generalized KdV hierarchy cKP r,0. The important feature of cKP r,m hierarchies is the presence of a discrete symmetry structure generated by successive Darboux–Bäcklund (DB) transformations. This symmetry allows for expressing the relevant tau-functions as Wronskians within a formalism which realizes the tau-functions as DB orbits of simple initial solutions. In particular, it is shown that any DB orbit of a cKP r,1 defines a generalized two-dimensional Toda lattice structure. Furthermore, we consider the class of truncated KP hierarchies (i.e. those defined via Wilson–Sato dressing operator with a finite truncated pseudo-differential series) and establish explicitly their close relationship with DB orbits of cKP r,m hierarchies. This construction is relevant for finding partition functions of the discrete multi-matrix models.

The next important step involves the reformulation of the familiar nonisospectral additional symmetries of the full KP hierarchy so that their action on cKP r,m hierarchies becomes consistent with the constraints of the reduction. Moreover, we show that the correct modified additional symmetries are compatible with the discrete DB symmetry on the cKP r,m DB orbits.
Leading Weak Corrections to the Production of Heavy Top Quarks at Hadron Colliders
Authors: Kao Chung , Ladinsky G. A. , Yuan C.-P.
Published: October 2003

We calculate the leading weak corrections at [Formula: see text] to the QCD production of heavy top quark pairs via [Formula: see text] at hadron colliders and compare them with the complete one-loop weak corrections. We find that these corrections dominate the threshold region for a heavy top quark if the Higgs boson is light. For a heavy Higgs boson, these corrections are generally small. The chromo-anapole form factor of the top quark and effects of parity violation are studied in the Standard Model (SM). The parity violation effect in [Formula: see text] from the SM weak corrections is found to be very small, so any observation of large parity violation in this process would indicate new physics. The polarization of the [Formula: see text] pairs is also discussed, including the effect that this has on proposed techniques for measuring the top quark mass.
Microcosmos and Macrocosmos: A Look at these Two Universes in a Unified Way
Authors: Silva P. R.
Published: October 2003

An extension of the MIT bag model, developed to describe the strong interaction inside the hadronic matter (nucleons), is proposed as a means to account for the confinement of matter in the universe. The basic hypotheses of the MIT bag model are worked out in a very simplified way and are also translated in terms of the gravitational force. We call the nucleon "microcosmos" and the bag-universe "macrocosmos." We have found a vacuum pressure of 10-15 atm at the boundary of the bag-universe as compared with a pressure of 1029 atm at the boundary of the nucleon. Both universes are also analyzed in the light of Sciama's theory of inertia, which links the inertial mass of a body to its interaction with the rest of the universe. One of the consequences of this work is that the Weinberg mass can be interpreted as a threshold mass, namely the mass where the frequency of the small oscillations of a particle coupled to the universe matches its de Broglie frequency. Finally, we estimate an averaged density of matter in the universe, corresponding to [Formula: see text] of the critical or closure density.
Relativistic Quark Model Based Description of Low Energy NN Scattering
Authors: Antalik R. , Lyubovitskij V. E.
Published: October 2003

A model describing the NN scattering phase shifts is developed. Two nucleon interactions induced by meson exchange forces are constructed starting from π, η, η′ pseudoscalar-, the ρ, ϕ, ω vector-, and the ε(600), a0, f0(1400) scalar — meson–nucleon coupling constants, which we obtained within a relativistic quantum field theory based quark model. Working within the Blankenbecler–Sugar–Logunov–Tavkhelidze quasipotential dynamics, we describe the NN phase shifts in a relativistically invariant way. In this procedure we use phenomenological form factor cutoff masses and effective ε and ω meson–nucleon coupling constants, only. Resulting NN phase shifts are in a good agreement with both, the empirical data, and the entirely phenomenological Bonn OBEP model fit. While the quality of our description, evaluated as a ratio of our results to the Bonn OBEP model χ2 ones is about 1.2, other existing (semi)microscopic results gave qualitative results only.
The Geometry of the Master Equation and Topological Quantum Field Theory
Authors: Alexandrov M. , Schwarz A. , Zaboronsky O. , Kontsevich M.
Published: October 2003

In Batalin–Vilkovisky formalism, a classical mechanical system is specified by means of a solution to the classical master equation. Geometrically, such a solution can be considered as a QP-manifold, i.e. a supermanifold equipped with an odd vector field Q obeying {Q, Q} = 0 and with Q-invariant odd symplectic structure. We study geometry of QP-manifolds. In particular, we describe some construction of QP-manifolds and prove a classification theorem (under certain conditions).

We apply these geometric constructions to obtain in a natural way the action functionals of two-dimensional topological sigma-models and to show that the Chern–Simons theory in BV-formalism arises as a sigma-model with target space [Formula: see text]. (Here [Formula: see text] stands for a Lie algebra and Π denotes parity inversion.)
Perturbative QCD at High Temperature
Authors: Nieto Agustin
Published: October 2003

Recent developments of perturbation theory at finite temperature based on effective field theory methods are reviewed. These methods allow the contributions from the different scales to be separated and the perturbative series to be reorganized. The construction of the effective field theory is shown in detail for ϕ4 theory and QCD. It is applied to the evaluation of the free energy of QCD at order g5 and the calculation of the g6 term is outlined. Implications for the application of perturbative QCD to the quark–gluon plasma are also discussed.
A Proposed Experiment Using a Sphere with an Eccentric Cavity for Hypothetical Long-Range Interactions
Authors: Klimchitskaya G. L. , Mostepanenko V. M. , Romero C. , Krivtsov Ye. P. , Sinelnikov A. Ye.
Published: October 2003

The constraints are examined which may be obtained for the parameters of long-range hypothetical interactions by the use of the precise experimental setup created originally for the calibration of accelerometers. This setup includes the large rotating steel sphere with a nonconcentric spherical cavity in which the strictly homogeneous gravitational field arises. The field of additional interaction produced by the atoms of the sphere, however, is not homogeneous. The essential features required of the detector of additional interaction which is the torsional pendulum of high sensitivity are discussed. Both the cases of the Yukawa-type and degree-type hypothetical interactions are investigated. It is shown that the known-to-date constraints for Yukawa-type interactions may be strengthened by a factor of 400 in the appropriate interaction range. For the degree-type hypothetical forces decreasing with distance as r-3, r-4 and r-5 correspondingly the known constraints may be strengthened by the factors of 90, 35 and 20. The conclusion is made that with the use of the specially created related setup it will be conceivable to strengthen the constraints for Yukawa-type interactions up to 4500 times over a wide interaction range.
SU(n) ⊗ U(1)c Gauge Models with Spontaneous Symmetry Breaking
Authors: Cotăescu Ion I.
Published: October 2003

A possible generalization of the technique of the standard model to SU (n) ⊗ U (1) gauge models is proposed. A special Higgs mechanism and a new kind of Yukawa couplings in unitary gauge are introduced. These allow us to obtain a general method for deriving boson mass spectrum and coupling coefficients which will be used to find an exact solution of the Frampton–Pisano–Pleitez three-generation SU (3) ⊗ U (1) model.
Conformal Symmetry in a Six-Vertex Model
Authors: Ho-Kim Q. , Truong T. T.
Published: October 2003

The concept of lattice Virasoro symmetry in completely integrable models of statistical mechanics is discussed in parallel with the notion of lattice Poincaré symmetry. To illustrate the general idea, we make an explicit construction of the full Virasoro algebra in terms of the lattice fermion field of the free-fermion six-vertex model in an external noncritical field. The conserved charges that characterize complete integrability are similarly obtained.
Unified Einstein–Virasoro Master Equation in the General Nonlinear Sigma Model
Authors: de Boer J. , Halpern M. B.
Published: October 2003

The Virasoro master equation (VME) describes the general affine-Virasoro construction T = LabJa Jb + iDa ∂ Ja in the operator algebra of the WZW model, where Lab is the inverse inertia tensor and Da is the improvement vector. In this paper, we generalize this construction to find the general (one-loop) Virasoro construction in the operator algebra of the general nonlinear sigma model. The result is a unified Einstein–Virasoro master equation which couples the space–time spin-2 field Lab to the background fields of the sigma model. For a particular solution [Formula: see text], the unified system reduces to the canonical stress tensors and conventional Einstein equations of the sigma model, and the system reduces to the general affine-Virasoro construction and the VME when the sigma model is taken to be the WZW action. More generally, the unified system describes a space of conformal field theories which is presumably much larger than the sum of the general affine-Virasoro construction and the sigma model with its canonical stress tensors. We also discuss a number of algebraic and geometrical properties of the system, including its relation to an unsolved problem in the theory of G-structures on manifolds with torsion.
Virasoro Character Identities from the Andrews–Bailey Construction
Authors: Foda Omar , Quano Yas-Hiro
Published: October 2003

We prove q series identities between bosonic and fermionic representations of certain Virasoro characters. These identities include some of the conjectures made by the Stony Brook group as special cases. Our method is a direct application of Andrews' extensions of Bailey's lemma to recently obtained polynomial identities.
Tachyons and Preferred Frames
Authors: Rembieliński Jakub
Published: October 2003

Quantum field theory of spacelike particles is investigated in the framework of an absolute causality scheme preserving Lorentz symmetry. It is related to an appropriate choice of the synchronization procedure (definition of time). In this formulation existence of field excitations (tachyons) distinguishes an inertial frame (privileged frame of reference) via spontaneous breaking of the so-called synchronization group. In this scheme the relativity principle is broken but Lorentz symmetry is exactly preserved in agreement with local properties of the observed world. It is shown that tachyons are associated with unitary orbits of Poincaré mappings induced from the SO(2) little group instead of the SO(2,1) one. Therefore the corresponding elementary states are labeled by helicity. The cases of the helicity λ = 0 and [Formula: see text] are investigated in detail and a corresponding consistent field theory is proposed. In particular, it is shown that the Dirac-like equation proposed by Chodos et al.,1 inconsistent in the standard formulation of QFT, can be consistently quantized in the presented framework. This allows us to treat more seriously the possibility that neutrinos might be fermionic tachyons, as is suggested by experimental data about neutrino masses.2–4
Bosonization of Quantum Sine–Gordon Field with Boundary
Authors: Hou Bo-Yu , Shi Kang-Jie , Wang Yan-Shen , Yang Wen-Li
Published: October 2003

Boundary operators and boundary ground states in sine–Gordon model with a fixed boundary condition are studied using bosonization and q-deformed oscillators. We also obtain the form-factors of this model.
Gravitational Quantum Cohomology
Authors: Eguchi Tohru , Hori Kentaro , Xiong Chuan-Sheng
Published: October 2003

We discuss how the theory of quantum cohomology may be generalized to "gravitational quantum cohomology" by studying topological σ models coupled to two-dimensional gravity. We first consider σ models defined on a general Fano manifold M (manifold with a positive first Chern class) and derive new recursion relations for its two-point functions. We then derive bi-Hamiltonian structures of the theories and show that they are completely integrable at least at the level of genus 0. We next consider the subspace of the phase space where only a marginal perturbation (with a parameter t) is turned on and construct Lax operators (superpotentials) L whose residue integrals reproduce correlation functions. In the case of M = CP N the Lax operator is given by [Formula: see text] and agrees with the potential of the affine Toda theory of the A N type. We also obtain Lax operators for various Fano manifolds; Grassmannians, rational surfaces, etc. In these examples the number of variables of the Lax operators is the same as the dimension of the original manifold. Our result shows that Fano manifolds exhibit a new type of mirror phenomenon where mirror partner is a noncompact Calabi–Yau manifold of the type of an algebraic torus C *N equipped with a specific superpotential.
Finite Temperature Lattice QCD in the Large N Limit
Authors: Billó M. , Caselle M. , d'Adda A. , Panzeri S.
Published: October 2003

Our aim is to give a self-contained review of recent advances in the analytic description of the deconfinement transition and determination of the deconfinement temperature in lattice QCD at large N. We also include some new results, as for instance in the comparison of the analytic results with Monte Carlo simulations. We first review the general set-up of finite temperature lattice gauge theories, using asymmetric lattices, and develop a consistent perturbative expansion in the coupling βs of the spacelike plaquettes. We study in detail the effective models for the Polyakov loop obtained, in the zeroth order approximation in βs, both from the Wilson action (symmetric lattice) and from the heat kernel action (completely asymmetric lattice). The distinctive feature of the heat kernel model is its relation with two-dimensional QCD on a cylinder; the Wilson model, on the other hand, can be exactly reduced to a twisted one-plaquette model via a procedure of the Eguchi–Kawai type. In the weak coupling regime both models can be related to exactly solvable Kazakov–Migdal matrix models. The instability of the weak coupling solution is due in both cases to a condensation of instantons; in the heat kernel case, this is directly related to the Douglas–Kazakov transition of QCD2. A detailed analysis of these results provides rather accurate predictions of the deconfinement temperature. In spite of the zeroth order approximation they are in good agreement with the Monte Carlo simulations in 2 + 1 dimensions, while in 3 + 1 dimensions they only agree with the Monte Carlo results away from the continuum limit.
Variational Approach to Higgs Mass Bound
Authors: Choudhury S. R. , Mamta
Published: October 2003

We present a variational study of the Higgs sector of the standard model (with a single doublet Higgs) regarding it as an effective field theory with an ultraviolet cutoff. Our results yield a maximum value of the Higgs mass about 10.8 times the W-mass.
Quantum Hamilton–Jacobi Analysis of Phases of Supersymmetry in Quantum Mechanics
Authors: Bhalla R. S. , Kapoor A. K. , Panigrahi P. K.
Published: October 2003

In the framework of the quantum Hamilton–Jacobi (QHJ) formalism, we show how both the unbroken and the spontaneously broken phase of supersymmetry in quantum mechanics can arise in a natural manner, for appropriate ranges of the parameters appearing in the potential. The Gozzi index, which is related to the quantum action variable in the QHJ formalism, is shown to correctly differentiate the two phases of supersymmetry.
Topological Symmetry Breaking on Einstein Manifolds
Authors: Sako A.
Published: October 2003

It is known that if gauge conditions have Gribov zero modes, then topological symmetry is broken. In this paper we apply it to the Witten type topological gravitational theory in dimension n ≥ 3. Our choice of the gauge condition for conformal invariance is R + α = 0, where R is the Ricci scalar curvature. We find when α ≠ 0, topological symmetry is not broken, but when α = 0 and solutions of the Einstein equations exist then topological symmetry is broken. These conditions connect to the Yamabe conjecture, namely negative constant scalar curvature exist on manifolds of any topology, but existence of nonnegative constant scalar curvature is restricted by topology. This fact is easily seen in this theory. Topological symmetry breaking means BRS symmetry breaking in cohomological field theory. But it is found that another BRS symmetry can be defined and physical states are redefined. The divergence due to the Gribov zero modes is regularized, and the theory after topological symmetry breaking becomes semiclassical Einstein gravitational theory under a special definition of observables.
Lie Point Symmetries of Duff–Inami–Pope–Sezgin–Stelle Bosonic Membrane Equations
Authors: Satir Ahmet
Published: October 2003

Lie point symmetries of the bosonic membrane equations of Duff–Inami–Pope–Sezgin–Stelle (DIPPS) are given. Different finite subgroups of the Lie group are used to reduce the membrane equations to various equations involving two independent variables, and then one. Integrability properties of the reduced equations are also discussed.
On Fusion Rules in Logarithmic Conformal Field Theories
Authors: Flohr Michael A. I.
Published: October 2003

We find the fusion rules for the cp,1 series of logarithmic conformal field theories. This completes our attempts to generalize the concept of rationality for conformal field theories to the logarithmic case. A novelty is the appearance of negative fusion coefficients which can be understood in terms of exceptional quantum group representations. The effective fusion rules (i.e. without signs and multiplicities) resemble the BPZ fusion rules for the virtual minimal models with conformal grid given via c = c3p,3. This leads to the conjecture that (almost) all minimal models with c = cp,q, gcd (p,q) > 1, belong to the class of rational logarithmic conformal field theories.
n-Point Functions of 2d Yang–Mills Theories on Riemann Surfaces
Authors: Alimohammadi M. , Khorrami M.
Published: October 2003

Using the simple path integral method we calculate the n-point functions of field strength of Yang–Mills theories on arbitrary two-dimensional Riemann surfaces. In U(1) case we show that the correlators consist of two parts, a free and an x-independent part. In the case of non-Abelian semisimple compact gauge groups we find the nongauge-invariant correlators in Schwinger–Fock gauge and show that it is also divided to a free and an almost x-independent part. We also find the gauge-invariant Green functions and show that they correspond to a free field theory.
Quantitative Measure of Dynamical Fluctuations in Multiparticle Production
Authors: Yang C. B. , Cai X.
Published: October 2003

A schedule is proposed to seek a quantitative measure of nonstatistical fluctuations in high energy multiparticle production in the framework of the multifractal moments. The dynamical fluctuations are studied with two toy models representing the weak and strong correlations, respectively. A quantity, χ, is proposed to be used as the probe for the existence and to measure the size of such fluctuations.
T-S-T Dual Black Hole
Authors: Andreas Björn
Published: October 2003

The sequence of intertwined T-S-T duality transformations acting on the 4D static uncharged black hole leads to a black hole background with horizon and singularity exchanged. It is shown that this space–time is extendible too. In particular we will see that a string moving into a black hole is dual to a string leaving a white hole. That offers the possibility that a test-string does not see the singularity.
The Nonminimal Supersymmetric Standard Model at Large tan β
Authors: Ananthanarayan B. , Pandita P. N.
Published: October 2003

We present a comprehensive analysis of the Nonminimal Supersymmetric Standard Model (NMSSM) for large values of tan β, the ratio of the vacuum expectation values of the two Higgs doublets, which arise when we impose the constraint of the unification of Yukawa couplings in the model. In this limit, we show that the vacuum expectation value of the singlet is forced to be large, of the order of 10 TeV. The singlet decouples from the lightest CP-even neutral Higgs boson and the neutralinos. We compare our results with the corresponding particle spectrum of the Minimal Supersymmetric Standard Model in the same limit. With the exception of the lightest Higgs boson, the particle spectrum in the model turns out to be heavy. The Higgs boson mass, after the inclusion of radiative corrections, is found to be in the neighborhood of ~ 130 GeV.
Topological Invariance of Fractional Spin of the Abelian CSH Vortex
Authors: Roy Ashim Kumar
Published: October 2003

The Abelian Chern–Simons–Higgs model in 2 + 1 dimensions exhibit vortex solutions with fractional spin. Although it is known that the normal, underformed charged vortex has a fractional spin related to its topological charge, it is not clear whether the value of this fractional spin is stable under changes in gauge-fixing conditions and regular deformations of the vortex field configurations. Recently, some authors have reported about the gauge as well as shape dependence of the fractional spin for the CSH vortex, which is contrary to our usual belief. However, their analysis is inconsistent and calls for a careful scrutiny. An explicit analysis is presented in this paper to show that the fractional spin for the Abelian CSH charged vortex may indeed be taken to be a gauge (small) and shape independent and hence, a topologically invariant quantity. The subtle points missed out by the other authors leading to inconsistency and the contradictory result are discussed in all essential details to resolve the issue.
q-Schrödinger Equations for V = u2 + 1/u2 and Morse Potentials in Terms of the q-Canonical Transformation
Authors: Dayi Ö. F. , Duru I. H.
Published: October 2003

The realizations of the Lie algebra corresponding to the dynamical symmetry group SO(2,1) of the Schrödinger equations for the Morse and the V = u2 + 1/u2 potentials were known to be related by a canonical transformation. q-deformed analog of this transformation connecting two different realizations of the sl q(2) algebra is presented. By the virtue of the q-canonical transformation, a q-deformed Schrödinger equation for the Morse potential is obtained from the q-deformed V = u2 + 1/u2 Schrödinger equation. Wave functions and eigenvalues of the q-Schrödinger equations yielding a new definition of the q-Laguerre polynomials are studied.
Geodesic Renormalization Group Flow
Authors: Dolan Brian P.
Published: October 2003

It is shown that the renormalization group flow in coupling constant space can be interpreted in terms of a dynamical equation for the couplings analogous to viscous fluid flow under the action of a potential. Using a specific definition of a metric the renormalization group flow for free scalar field theory is geodesic in two dimensions, while for D ≠ 2 it is only geodesic for vanishing external source. For the 1D Ising model the renormalization flow is geodesic when the external magnetic field vanishes.
Nonsymmetric Gravitational Theories in Hamiltonian Form
Authors: Clayton M. A.
Published: October 2003

The dynamics of a class of nonsymmetric gravitational theories are presented in Hamiltonian form. The derivation begins with the first-order action, treating the generalized connection coefficients as the canonical coordinates and the densitized components of the inverse of the fundamental tensor as conjugate momenta. The phase space of the symmetric sector is enlarged over that of conventional treatments of general relativity by a canonical pair that represents the metric density and its conjugate, removable by imposing strongly an associated pair of second-class constraints and introducing Dirac brackets. In the antisymmetric sector, all six components of the fundamental tensor contribute conjugate pairs for the massive theory, and the absence of additional constraints gives six configuration space degrees of freedom per space–time point.
CP Violation and the Role of Electroweak Penguins in Nonleptonic B Decays
Authors: Fleischer Robert
Published: October 2003

The phenomenon of CP violation in the B system and strategies for extracting CKM phases are reviewed. We focus both on general aspects and on some recent developments including CP-violating asymmetries in Bd decays, the Bs system in light of a possible width difference ΔΓs, charged B decays, and SU(3) relations among certain transition amplitudes. In order to describe the relevant nonleptonic B decays, low energy effective Hamiltonians calculated beyond the leading logarithmic approximation are used. Special emphasis is given to the role of electroweak penguin operators in such transitions. These effects are analyzed both within a general framework and more specifically in view of the theoretical cleanliness of methods to determine CKM phases. Strategies for obtaining insights into the world of electroweak penguins are discussed.
Toda Fields of SO(3) Hyper-Kahler Metrics and Free Field Realizations
Authors: Bakas Ioannis , Sfetsos Konstadinos
Published: October 2003

The Eguchi–Hanson, Taub–NUT and Atiyah–Hitchin metrics are the only complete nonsingular SO(3)-invariant hyper-Kahler metrics in four dimensions. The presence of a rotational SO(2) isometry allows their unified treatment based on solutions of the 3D continual Toda equation. We determine the Toda potential in each case and examine the free field realization of the corresponding solutions, using infinite power series expansions. The Atiyah–Hitchin metric exhibits some unusual features attributed to topological properties of the group of area preserving diffeomorphisms. The construction of a descending series of SO(2)-invariant 4D regular hyper-Kahler metrics remains an interesting question.
Faces of Relativistic Toda Chain
Authors: Kharchev S. , Mironov A. , Zhedanov A.
Published: October 2003

We demonstrate that the generalization of the relativistic Toda chain (RTC) is a special reduction of two-dimensional Toda lattice hierarchy (2DTL). This reduction implies that the RTC is gauge equivalent to the discrete AKNS hierarchy and, which is the same, to the two-component Volterra hierarchy while its forced (semi-infinite) variant is described by the unitary matrix integral. The integrable properties of the RTC hierarchy are revealed in different frameworks of the Lax representation, orthogonal polynomial systems, and τ-function approach. Relativistic Toda molecule hierarchy is also considered, along with the forced RTC. Some applications to biorthogonal polynomial systems are discussed.
Parasupersymmetric Quantum Mechanics and Indices of Fredholm Operators
Authors: Mostafazadeh Ali
Published: October 2003

The general features of the degeneracy structure of (p = 2) parasupersymmetric quantum mechanics are employed to yield a classification scheme for the form of the parasupersymmetric Hamiltonians. The method is applied to parasupersymmetric systems whose Hamiltonian is the square root of a fourth order polynomial in the generators of the parasupersymmetry. These systems are interesting to study for they lead to the introduction of a set of topological invariants very similar to the Witten indices of ordinary supersymmetric quantum mechanics. The topological invariants associated with parasupersymmetry are shown to be related to a pair of Fredholm operators satisfying two compatibility conditions. An explicit algebraic expression for the topological invariants of a class of parasupersymmetric systems is provided.
Applicability of Heavy Quark Effective Theory to the Radiative Decay B → K*γ
Authors: Chakraverty Debrupa , De Triptesh , Dutta-Roy Binayak , Kundu Anirban
Published: October 2003

In the context of the observed decay B → K*γ the applicability of the heavy quark effective theory (HQET), treating both b and s as heavy quarks, is examined. We show that the heavy s-quark approximation, as can be found in the literature, in this context, is not reliable.
High Spin States in the Odd–Odd 150Eu Nucleus
Authors: Chatterjee J. M. , Basu Somapriya , Datta Pramanik U. , Bhattacharya S. , Chattopadhyay R. K. , Chugre S. S. , Rodrigues G. , Singh R. P. , Bhowmik R. K.
Published: October 2003

High spin rotational bands in the odd–odd 150Eu nucleus, produced in the 148Nd(7Li,5n) reaction, were investigated by in-beam γ spectroscopy. Seven bands above the 588.8 keV (45 ns) isomeric level were observed. Probable single- and double-octupole-phonon coupling states were identified. Two positive parity bands are interpreted in terms of two quasiparticles (a proton and a neutron) coupled to an axially symmetric rotor core. Otherwise, the rest of the high spin levels are described by multiparticle–hole excitations.
A New Approach to Turbulence
Authors: Canuto V. M. , Dubovikov M. S.
Published: October 2003

We propose a closed set of dynamic equations to describe turbulence. The equations are the result of systematic and heuristic elements. Specifically, the UV part of the nonlinear interactions, represented by a dynamical viscosity, is computed for a stirring force of a particular nature. However, since the results exhibit a general structure, we suggest heuristically to extend them to arbitrary flows. Because of nonrenormalizable divergences, the IR part of the nonlinear interactions has constituted a serious problem. We suggest a heuristic model, the basic ingredient of which is that the transfer of energy among eddies is mostly a local process. We show that possible adjustable parameters are actually fixed by the model itself. Because of the heuristic nature of one part of the model, its overall validity rests largely on the accumulated evidence gathered from checking its predictions against data from a wide variety of flows. The model has been tested against more than seventy turbulence statistics for homogeneous isotropic and anisotropic flows (the Kolmogorov constant is predicted to be Ko = 5/3). The overall performance is good.

Here, we first extend the model to inhomogeneous flows and test the predictions using the newest laboratory and DNS data on turbulent convection at large Ra (Rayleigh number). The model reproduces both types of data quite accurately.

Second, we study the problem of the so-called "sweeping effect" and derive the relation between the ω and k-spectra.

Third, we show that for shear driven flows the present model reproduces well the data at large strain rates while the widely used K - ∊ model does not.
A μ+μ- Quantum Collider using Novel Crystal-Based Accelerator Components
Authors: Bogacz S. A. , Cline D. B.
Published: October 2003

We outline a concept of a 250 × 250 GeV μ+ μ- collider that uses bent crystals for beam confinement and steering instead of conventional magnets. The collider ring is based on a novel bending-focusing crystal cell. Beam optics of the proposed model cell has all the features of the alterating gradient FODO cell. Furthermore, alternating (horizontal-vertical) focusing provides unique betatron phase stability in both planes, while bending of particle trajectories due to crystal curvature is fully achromatic. We also explore the ionization energy loss of channeling muons interacting with the electron gas in a crystal channel as a possible cooling mechanism. Finally, a use of low Z binary crystals (such as LiF) for final focus at the interaction point is proposed. Bringing the μ+μ- into collision inside a crystal channel results in quantum confinement at the collision point. For such a collider the number of required μ± may be very low (~108μ per pulse), so that this collider has few problems from μ → e backgrounds or heating, which is a virtue of paramount importance. A low intensity hadronic μ± source (p + A → π → μ) can be utilized provided that an effective method of fast muon cooling is used. For example, the use of frictional cooling for low energy μ± beams could initially reduce the longitudinal phase–space, before the final transverse cooling is applied. Here, we outline such a "crystal cooler" that explores ionization energy loss in the ultrastrong focusing environment of a crystal channel. Employing all the above-mentioned novel crystal-based accelerator components, a possible luminosity of about 1032 cm-2 sec-1, is estimated for the proposed quantum collider. We also discuss a list of problems one needs to solve in order to make such a collider a real possibility.
Weak Form Factors for Semileptonic Transitions of Baryons in a Relativistic Potential Model of Independent Quarks
Authors: Jena S. N. , Behera M. R.
Published: October 2003

Weak electric and magnetic form factors for semileptonic transitions of baryons are calculated in a relativistic quark model with the independent quark confining potential of the form [Formula: see text], a > 0. The values obtained for g2/g1 for various decay modes compare well with the nonrelativistic results of Donoghue and Holstein. The values of g1/f1 extracted from our model calculations of f2/f1 in the Cabibbo limit are not very different from those of the experiment. The values calculated for f2/f1 for various semileptonic transitions also agree well with those of the MIT bag model. The SU(3) symmetry breaking does not degenerate appreciable departures in f2/f1 values from the corresponding Cabibbo values.
Geometrical Foundations of Fractional Supersymmetry
Authors: Dunne R. S. , Macfarlane A. J. , de Azcárraga J. A. , Pérez Bueno J. C.
Published: October 2003

A deformed q-calculus is developed on the basis of an algebraic structure involving graded brackets. A number operator and left and right shift operators are constructed for this algebra, and the whole structure is related to the algebra of a q-deformed boson. The limit of this algebra when q is an nth root of unity is also studied in detail. By means of a chain rule expansion, the left and right derivatives are identified with the charge Q and covariant derivative D encountered in ordinary/fractional supersymmetry, and this leads to new results for these operators. A generalized Berezin integral and fractional superspace measure arise as a natural part of our formalism. When q is a root of unity the algebra is found to have a nontrivial Hopf structure, extending that associated with the anyonic line. One-dimensional ordinary/fractional superspace is identified with the braided line when q is a root of unity, so that one-dimensional ordinary/fractional supersymmetry can be viewed as invariance under translation along this line. In our construction of fractional supersymmetry the q-deformed bosons play a role exactly analogous to that of the fermions in the familiar supersymmetric case.
Variational Solution of the Gross–Neveu Model: Finite N and Renormalization
Authors: Arvanitis C. , Geniet F. , Iacomi M. , Kneur J.-L. , Neveu A.
Published: October 2003

We show how to perform systematically improvable variational calculations in the O(2N) Gross–Neveu model for generic N, in such a way that all infinities usually plaguing such calculations are accounted for in a way compatible with the perturbative renormalization group. The final point is a general framework for the calculation of nonperturbative quantities like condensates, masses, etc., in an asymptotically free field theory. For the Gross–Neveu model, the numerical results obtained from a "two-loop" variational calculation are in a very good agreement with exact quantities down to low values of N.
Summary of Experimental Data on High Energy Spin Physics
Authors: Nurushev S. B.
Published: October 2003

High Energy Spin Physics has made significant progress. During a very short period a set of new phenomena have been established — relevant to the spin structure of the nucleons, hyperon polarization, the single- and double-spin asymmetries. The recent advent of the polarized proton and antiproton beams, and unpolarized Σ - beam opened a new avenue for study of spin physics at high energy, like the flavor dependence of the spin effect, the spin transfer mechanism, the comparative study of the hyperon polarization and analyzing power, etc. These and other news in High Energy Spin Physics are discussed in this review.
Geometric Models of the Relativistic Harmonic Oscillator
Authors: Cotăescu Ion I.
Published: October 2003

A family of relativistic geometric models is defined as a generalization of the actual anti-de Sitter (1 + 1) model of the relativistic harmonic oscillator. It is shown that all these models lead to the usual harmonic oscillator in the nonrelativistic limit, even though their relativistic behavior is quite different. Among quantum models we find a set of models with countable energy spectra, and another one having only a finite number of energy levels and in addition a continuous spectrum.
On the Combinatorics of Row and Corner Transfer Matrices of the $A^{(1)}_{n-1}$ Restricted Face Models
Authors: Dasmahapatra Srinandan
Published: October 2003

We establish a weight-preserving bijection between the index sets of the spectral data of row-to-row and corner transfer matrices for [Formula: see text] restricted interaction round a face (IRF) models. The evaluation of momenta by adding Takahashi integers in the spin chain language is shown to directly correspond to the computation of the energy of a path on the weight lattice in the two-dimensional model. As a consequence we derive fermionic forms of polynomial analogs of branching functions for the cosets [Formula: see text], and establish a bosonic–fermionic polynomial identity.
Batalin–Fradkin Approach to (1 + 1)-Dimensional Massive Vector Fields and the Gluonic Effective Action for Hard Thermal Loops
Authors: Sawayanagi Hirohumi
Published: October 2003

The Lagrangian of (1 + 1)-dimensional massive vector fields is studied. Since this system has second class constraints, the method of Batalin–Fradkin, which introduces new fields to convert second class constraints into first class ones, is applied in an extended manner. Instead of the usual treatment, which uses the Stueckelberg field as a new field, we can use a pseudoscalar field. We will show there are at least two ways to introduce a pseudoscalar. At the quantum level, one way leads to the system that is equivalent to the original system, and the other way gives an inequivalent system. The relation of these two ways is clarified. As an application of the latter way, we consider QCD at finite temperature and the gluonic effective action for hard thermal loops is constructed.
The Use of Power Expansions in Quantum Field Theory
Authors: Fischer Jan
Published: October 2003

Methods of summation of power series relevant to applications in quantum theory are reviewed, with particular attention to expansions in powers of the coupling constant and in inverse powers of an energy variable. Alternatives to the Borel summation method are considered and their relevance to different physical situations is discussed. Emphasis is placed on quantum chromodynamics. Recent applications of the renormalon language to perturbation expansions (resummation of bubble chains) in various QCD processes are reported and the importance of observing the full renormalization-group invariance in predicting observables is emphasized. News in applications of the Borel-plane formalism to phenomenology are conveyed. The properties of the operator-product expansion along different rays in the complex plane are examined and the problem is studied as to how the remainder after subtraction of the first n terms depends on the distance from the Euclidean region. Estimates of the remainder are explicitly calculated and their strong dependence on the nature of the discontinuity along the cut is shown. Relevance of this subject to calculations of various QCD effects is discussed.
Gauss–Bonnet Type Identity in Weyl–Cartan Space
Authors: Babourova O. V. , Frolov B. N.
Published: October 2003

The Gauss–Bonnet type identity is derived in a Weyl–Cartan space on the basis of the variational method.
Vacuum State of Lattice Gauge Theory with Fermions in 2 + 1 Dimensions
Authors: Abe Hideyuki
Published: October 2003

We investigate the vacuum state of the lattice gauge theory with fermions in 2 + 1 dimensions. The vacuum in the Hermite form for the fermion part is obtained; the vacuum in the unitary form has been proposed by Luo and Chen. It is shown that the Hermite vacuum has a lower energy than the unitary one through the variational method.
No Eigenvalue in Finite Quantum Electrodynamics
Authors: Acharya R. , Narayana Swamy P.
Published: October 2003

We re-examine Quantum Electrodynamics (QED) with massless electron as a finite quantum field theory as advocated by Gell-Mann–Low, Baker–Johnson, Adler, Jackiw and others. We analyze the Dyson–Schwinger equation satisfied by the massless electron in finite QED and conclude that the theory admits no nontrivial eigenvalue for the fine structure constant.
Noncritical String Field Theory for 2d Quantum Gravity Coupled to (p, q)-Conformal Fields
Authors: Ambjørn J. , Watabiki Y.
Published: October 2003

We propose a noncritical string field theory for 2d quantum gravity coupled to (p, q) conformal fields. The Hamiltonian is described by the generators of the Wp algebra, and the Schwinger–Dyson equation is equivalent to a vacuum condition imposed on the generators of Wp algebra.
Dirac's Observables for the Higgs Model II: The Non-Abelian SU(2) Case
Authors: Lusanna Luca , Valtancoli Paolo
Published: October 2003

We search a canonical basis of Dirac's observables for the classical non-Abelian Higgs model with fermions in the case of a trivial SU(2) principal bundle with a complex doublet of Higgs fields and with the fermions in a given representation of SU(2). Since each one of the three Gauss law first class constraints can be solved either in the corresponding longitudinal electric field or in the corresponding Higgs momentum, we get a priori eight disjoint phases of solutions of the model. The only two phases with SU(2) covariance are the SU(2) phase with massless SU(2) fields and the Higgs phase with massive SU(2) fields. The Dirac observables and the reduced physical (local) Hamiltonian and (non-local) Lagrangian of the Higgs phase are evaluated:the main result is the nonanalyticity in the SU(2) coupling constant, or equivalently in the sum of the residual Higgs field and of the mass of the SU(2) fields. Some comments on the function spaces needed for the gauge fields are made.