bluuebunny/crossref_metadata_2025 huggingface dataset:
TENSORIAL CENTRAL CHARGES AND NEW SUPERPARTICLE MODELS WITH FUNDAMENTAL SPINOR COORDINATES
Authors: BANDOS IGOR , LUKIERSKI JERZY
Published: May 2003

We consider firstly simple D=4 superalgebra with six real tensorial central charges Zμν, and discuss its possible realizations in massive and massless cases. Massless case is dynamically realized by generalized Ferber–Shirafuji (FS) model with fundamental bosonic spinor coordinates. The Lorentz invariance is not broken due to the realization of central charges generators in terms of bosonic spinors. The model contains four fermionic coordinates and possesses three κ-symmetries thus providing the BPS configuration preserving 3/4 of the target space supersymmetries. We show that the physical degrees of freedom (eight real bosonic and one real Grassmann variable) of our model can be described by OSp (8|1) supertwistor. The relation with recent superparticle model by Rudychev and Sezgin is pointed out. Finally we propose a higher-dimensional generalization of our model with one real fundamental bosonic spinor. D=10 model describes massless superparticle with composite tensorial central charges and in D=11 we obtain zero-superbrane model with nonvanishing mass which is generated dynamically.
KAON WEAK DECAYS IN CHIRAL THEORIES
Authors: SCADRON M. D.
Published: May 2003

The ten nonleptonic weak decays K→2π, K→ 3π, KL→2γ, KS→2γ, KL→π02γ, are predicted for a chiral pole model based on the linear sigma model theory which automatically satisfies the partial conservation of axial current (PCAC) hypothesis. These predictions, agreeing with data to the 5% level and containing no or at most one free parameter, are compared with the results of chiral perturbation theory (ChPT). The latter ChPT approach to one-loop level is known to contain at least four free parameters and then predicts a KL→π0γγ rate which is 60% shy of the experimental value.
COSMIC RAYS PROPAGATION IN A PSEUDO-SCALAR MEDIUM
Authors: SAHU SARIRA
Published: May 2003

We have calculated the dispersion relation for the high energy cosmic rays (protons, electrons and neutrinos) propagating in the Bose gas as well as Bose condensate (BC) medium of the pseudo-scalar particles (axions and majorons). For cosmic rays propagating in the Bose gas, the mass of the particle will decrease and this is proportional to the boson density in the medium. On the other hand, the BC of the same particle will increase the mass of the fermion. If the propagating fermion is massless, it will develop an imaginary mass and thus will be absorbed in the medium. But if the condition m2/mϕp0≃ 1 is satisfied, the cosmic rays will propagate freely without losing energy in the BC medium. The Bose gas and BC of the pseudo-scalar background contribution to the dispersion relation of the high energy cosmic rays is too small to have any practical importance to high energy cosmic rays physics.
EFFECTS OF MATTER DENSITY FLUCTUATION IN LONG BASELINE NEUTRINO OSCILLATION EXPERIMENTS
Authors: KOIKE MASAFUMI , SATO JOE
Published: May 2003

The effects of matter density fluctuation in long baseline neutrino oscillation experiments are studied. Effects of short wavelength fluctuations are irrelevant. Effects of long wavelength fluctuations must be checked on a case-by-case basis. As an example we checked the fluctuation effects and showed its irrelevance in a case of K2K experiments.
HIDDEN SYMMETRY OF THE YANG–COULOMB MONOPOLE
Authors: MARDOYAN L. G. , SISSAKIAN A. N. , TER-ANTONYAN V. M.
Published: May 2003

Bound system composed of the Yang monopole coupled to a particle of the isospin by the SU(2) and Coulomb interaction is considered. The generalized Runge–Lenz vector and the SO(6) group of hidden symmetry are established. It is also shown that the group of hidden symmetry makes it possible to calculate the spectrum of system by a pure algebraic method.
UNIFIED APPROACH TO STUDY QUANTUM PROPERTIES OF PRIMORDIAL BLACK HOLES, WORMHOLES AND OF QUANTUM COSMOLOGY
Authors: NOJIRI S. , OBREGON O. , ODINTSOV S. D.
Published: May 2003

We review the anomaly induced effective action for dilaton coupled spinors and scalars in large-N and s-wave approximation. It may be applied to study the following fundamental problems: construction of quantum corrected black holes (BHs), inducing of primordial wormholes in the early Universe (this effect is confirmed) and the solution of initial singularity problem. The recently discovered anti-evaporation of multiple horizon BHs is discussed. The existence of such primordial BHs may be interpreted as SUSY manifestation. Quantum corrections to BHs thermodynamics may also be discussed within such scheme.
CHIRAL ASYMMETRY AND GAUGE INVARIANCE
Authors: MARQUES G. C. , SPEHLER D.
Published: May 2003

In this letter we address the question on whether gauge invariance can be derived from general basic principles. We show that, within the chiral spinorial approach developed by us, gauge invariance can be seen as a result of the left–right asymmetry of nature. This is valid for Abelian and non-Abelian gauge theories. In order to select the right couplings of the chiral components, we just have to require masslessness of the photon (or gluon) and renormalizability of the theory.
CAN THREE-DIMENSIONAL EXTREME BLACK HOLES DEVELOP FROM THEIR NONEXTREME COUNTERPARTS?
Authors: WANG BIN , ABDALLA ELCIO , SU RU-KENG
Published: May 2003

By applying the gedanken experiments, we have proved that the three-dimensional nonextreme charged and rotating black hole cannot become extreme by absorbing test particles to increase their charge and angular momentum.
D=10 CHIRAL TENSIONLESS SUPER p-BRANES
Authors: BOZHILOV P.
Published: May 2003

We consider a model for tensionless (null) super-p-branes with N chiral supersymmetries in ten-dimensional flat space–time. After establishing the symmetries of the action, we give the general solution of the classical equations of motion in a particular gauge. In the case of a null superstring (p=1) we find the general solution in an arbitrary gauge. Then, using a harmonic superspace approach, the initial algebra of first- and second-class constraints is converted into an algebra of Lorentz-covariant, BFV-irreducible, first-class constraints only. The corresponding BRST charge is as for a first rank dynamical system.
PION INTERACTIONS IN CHIRAL FIELD THEORIES
Authors: SCADRON M. D.
Published: May 2003

We study in various chiral models the pion charge radius, πe3 form factor ratio, π0→γγ amplitude, charge pion polarizabilities, γγ→π0π0 amplitude at low energies and the ππs-wave I=0 scattering length. We find that a quark-level linear sigma approach (also being consistent with tree-level vector meson dominance) is quite compatible with all of the above data.
Z′-GAUGE BOSON AND INFLATION IN THE ELECTROWEAK SCALE
Authors: DEO B. B.
Published: May 2003

An enlarged electroweak symmetry group SU L(2)⊗ U Y(1)⊗ U ′(1) is broken to U em(1) at σ=246 GeV due to radiative corrections. The resulting Coleman–Weinberg potential explains the inflation at 246 GeV scale successfully and the mass of the additional weakly coupled gauge boson Z′ has a value close to 252 GeV accessible to present-day high energy accelerators.
REDUCING THE EXPERIMENTAL UNCERTAINTY ON THE CKM ANGLE α
Authors: COLANGELO P. , IORIO L. , NARDULLI G.
Published: May 2003

We investigate possible strategies to reduce the experimental uncertainty on the CKM angle α, in the working conditions of an asymmetric e+ e-B-factory. We propose to use information from the time-dependent asymmetry of neutral B-decays to π+ π-, together with the ratio [Formula: see text]. We also consider the possibility of using information on the ratio [Formula: see text]. An error analysis on α depending on the expected experimental uncertainties on the input quantities is carried out.
MORE SIGNATURES OF THE INTERMEDIATE MASS HIGGS BOSON
Authors: AGRAWAL PANKAJ
Published: May 2003

We examine the potential signatures of the Higgs boson when it decays into a tau–lepton pair. We show that with the proper identification of the tau-jet, this decay mode can lead to the identification of the Higgs boson over most of the intermediate mass range (MW<MH<2MW).
LOW ENERGY DATA AND A MODEL OF FLAVOR MIXING
Authors: MALKAWI EHAB , YUAN C.-P.
Published: May 2003

We consider a model in which the third family fermions are subjected to an SU(2) interaction different from the first two family fermions. Constrained by the Z-pole data, the heavy gauge boson mass is bounded from below to be about 1.7 TeV at the 2σ level. In this model, the flavor mixing between τ and μ can be so large that [Formula: see text] and Br (τ→μμμ) provide a better constraint than the LEP/SLC data in some region of parameter space. Furthermore, flavor-changing neutral currents are unavoidable in the quark sector of the model. Significant effects to the [Formula: see text] mixing and the rare decays of the K and B mesons, such as [Formula: see text], [Formula: see text], Bs→τ+τ-, μ+μ- and Bs,d→μ±τ∓, are expected.
T-DUALITY IN SIGMA MODELS WITH KALUZA–KLEIN METRIC AS ELECTRIC–MAGNETIC DUALITY
Authors: JAFARIZADEH M. A. , REZAEI-AGHDAM A.
Published: May 2003

It is shown that T-duality in a σ-model with Kaluza–Klein metric, with or without a torsion term, can be interpreted as electric–magnetic duality for some of their solitonic solutions. Actually Buscher's duality transformation interchanges the topological and Noether charges.
IMPLICIT REGULARISATION TECHNIQUE: CALCULATION OF THE TWO-LOOP $\varphi^4_4$-THEORY β-FUNCTION
Authors: BRIZOLA A. , BATTISTEL O. , SAMPAIO MARCOS , NEMES M. C.
Published: May 2003

We propose an implicit regularisation scheme. The main advantage is that since no explicit use of a regulator is made, one can in principle avoid undesirable symmetry violations related to its choice. The divergent amplitudes are split into basic divergent integrals which depend only on the loop momenta and finite integrals. The former can be absorbed by a renormalisation procedure whereas the latter can be evaluated without restrictions. We illustrate with the calculation of the QED and [Formula: see text]-theory β-function to one- and two-loop orders, respectively.
DISSIPATIVE CONTRIBUTIONS TO ε′/ε
Authors: BENATTI F. , FLOREANINI R.
Published: May 2003

The time evolution and decay of the neutral kaon system can be described using quantum dynamical semigroups. Non-standard terms appear in the expression of relevant observables; they can be parametrized in terms of six new phenomenological constants. We discuss how the presence of these constants affects the determination of the parameter ε′/ε.
DOES A DYNAMICAL SYSTEM LOSE ENERGY BY EMITTING GRAVITATIONAL WAVES?
Authors: COOPERSTOCK F. I.
Published: May 2003

We note that Eddington's radiation damping calculation of a spinning rod fails to account for the complete mass integral as given by Tolman. The missing stress contributions precisely cancel the standard rate given by the "quadrupole formula". This indicates that while the usual "kinetic" term can properly account for dynamical changes in the source, the actual mass is conserved. Hence gravity waves are not carriers of energy in vacuum. This supports the hypothesis that energy including the gravitational contribution is confined to regions of nonvanishing energy–momentum tensor Tik.
COSMIC ACCELERATION: INHOMOGENEITY VERSUS VACUUM ENERGY
Authors: PASCUAL-SÁNCHEZ J.-F.
Published: May 2003

In this letter, we present an alternative explanation for the cosmic acceleration which appears as a consequence of recent high redshift supernova data. In the usual interpretation, this cosmic acceleration is explained by the presence of a positive cosmological constant or vacuum energy, in the background of Friedmann models. Instead, we shall consider a local rotational symmetric (LRS) inhomogeneous space–time, with a barotropic perfect fluid equation of state for the cosmic matter. Within this framework the kinematical acceleration of the cosmic fluid or, equivalently, the inhomogeneity of matter, is just the responsible of the SNe Ia measured cosmic acceleration. Although in our model the Cosmological Principle is relaxed, it maintains local isotropy about our worldline in agreement with CBR observations.
ON THE EFFECTIVE POTENTIAL OF THE $Dp -\overline{Dp}$ SYSTEM IN TYPE II THEORIES
Authors: PESANDO I.
Published: May 2003

We compute the effective potential of a system composed of a Dp-brane and a separated [Formula: see text]-brane at tree level in string theory. We show explicitly that the tachyon condenses and that the scalars which describe transverse fluctuations acquire a vev proportional to the distance.
RADIATIVE RARE DECAY OF KAONS
Authors: MAITI A. K. , ROUTH H. , GAUTAM V. P.
Published: May 2003

The parity conserving (PC) and the parity violating (PV) coupling constants are evaluated by considering the PC and PV poles and these coupling constants are respectively given by: C=1.12× 10-7 and D=1.15× 10-7. Using these coupling constants we have estimated the decay width of [Formula: see text] and [Formula: see text]. Our estimated decay width of [Formula: see text] is in good agreement with the recent experimental result.
FREE ENERGIES AND PROBE ACTIONS FOR NEAR-HORIZON D-BRANES AND D1+D5 SYSTEM
Authors: RYANG SHIJONG
Published: May 2003

By working with the free energy for the type II supergravity near-horizon solution of N coincident non-extremal Dp-branes, we study the transitions among the non-conformal Dp-brane system, the perturbative super-Yang–Mills theory and a certain system associated with M theory. We derive a relation between this free energy and the action of a Dp-brane probe in the N Dp-brane background. Constructing the free energy for the five-dimensional black hole labeled by the D1-brane and D5-brane charges, we find the similar relation between it and the action of a D1 or D5 brane probe in the D1+D5 brane background. These relations are explained by the massive open strings stretched between the relevant D-branes.
q-DERIVATION, SINE ALGEBRA AND Ut(sl(2))
Authors: EL KINANI E. H.
Published: May 2003

We review the q-pseudo-differential operators algebra(q-ψ DO ) and some of its properties. Based on the fact that w∞ and U t( sl (2)) can be constructed from the trigonometric sine algebra (F.F.Z. algebra), we propose the embedding of w∞ and U t( sl (2)) in (q-ψ DO ). The correspondence with 2-D fractional supersymmetry algebra is examined.
ALTERNATIVE LINEAR CHIRAL MODELS FOR NUCLEAR MATTER
Authors: DELFINO A. , NAVARRA F. S. , NIELSEN M. , PRANDINI R. B. , CHIAPPARINI M.
Published: May 2003

The equation of state of a family of alternative linear chiral models in the mean field approximation is discussed. We investigate the analogy between some of these models and current models in the literature, and we show that it is possible to reproduce very well the saturation properties of nuclear matter.
EXACT PARAMETRIZATION OF MAJORANA NEUTRINO MASS MATRIX WITH LARGE MIXING
Authors: KIMURA K. , TAKAMURA A.
Published: May 2003

Under the assumption that the neutrinos are Majorana particles we study how the lepton mass matrices can be transformed into the simple form which has the same physical quantities by removing redundant parameters. We propose the exact parametrization of the lepton mass matrices which reflects the small νe-νμ mixing and the large νμ-ντ mixing. The relations between the 12 parameters and the physical quantities are shown. Furthermore we calculate the MNS matrix by applying the assumptions used in the quark sector. Finally we also check the validity of these assumptions from the experimental values.
SPONTANEOUS SUPERSYMMETRIC GENERATION OF AN INDETERMINATE MASS SCALE AND A POSSIBLE LIGHT STERILE NEUTRINO
Authors: MA ERNEST
Published: May 2003

If a global continuous symmetry of a supersymmetric field theory is spontaneously broken while preserving the supersymmetry, the resulting theory has a massless superfield. One of its two bosonic degrees of freedom is the familiar phase rotation of the usual massless Nambu–Goldstone boson, but the other is a scale transformation. An indeterminate mass scale is thus generated. In the fermion sector, a seesaw texture appears which may be suitable for a possible light sterile neutrino. This feature persists even after the gauging of the continuous symmetry or the breaking of the supersymmetry to resolve the aforementioned mass-scale ambiguity.
OPEN GROUP TRANSFORMATIONS
Authors: BATALIN IGOR , MARNELIUS ROBERT
Published: May 2003

Open groups whose generators are in arbitrary involutions may be quantized within a ghost extended framework in terms of a nilpotent BFV–BRST charge operator. Previously we have shown that generalized quantum Maurer–Cartan equations for arbitrary open groups may be extracted from the quantum connection operators and that they also follow from a simple quantum master equation involving an extended nilpotent BFV–BRST charge and a master charge. Here we give further details of these results. In addition we establish the general structure of the solutions of the quantum master equation. We also construct an extended formulation whose properties are determined by the extended BRST charge in the master equation.
PROBING THE QUANTUM MICROSTRUCTURE OF SPACE–TIME
Authors: PADMANABHAN T.
Published: May 2003

The question of how tightly one can constrain the microscopic theory of quantum gravity from the known features of low energy gravity is addressed. To begin with, from the very fact that our universe made a transition from a quantum regime to classical one, it is possible to conclude that infinite number of degrees of freedom had to be integrated out from the fundamental theory to obtain the low energy Einstein Lagrangian. Further constraints can be imposed from the fact that the quantum state describing a black hole has to possess certain universal form of density of states, in any microscopic description of space–time, which can be ascertained from general considerations. Since a black hole can be formed from the collapse of any physical system with a low energy (E ≪ Ep) Hamiltonian H, it is possible to obtain the form the effective high energy (E ≫ Ep) Hamiltonian from general consideration. These results provide the physical reasons for some of the mathematical features underlying string theories and other models for quantum gravity.
A PERTURBATIVE APPROACH TO THE RELATIVISTIC HARMONIC OSCILLATOR AND UNITARITY
Authors: GUERRERO J. , ALDAYA V.
Published: May 2003

A quantum realization of the relativistic Harmonic oscillator is achieved in terms of the spatial variable x and [Formula: see text] (the minimal canonical representation). The Hamiltonian operator is found (at lower order) by using a perturbative expansion in the constant c-1. Unlike the Foldy–Wouthuysen version of the relativistic hydrogen atom, conventional perturbation theory cannot be applied and a perturbation of the scalar product itself is required to make the theory unitary.
FCNC PROCESS IN B DECAY AND THE VECTOR MESON DOMINANCE
Authors: BISWAS SURATH KUMAR , GAUTAM V. P.
Published: May 2003

We investigate how the vector meson dominance affects the O(αs) virtual corrections in addition to the bremsstrahlung correction while working out the matrix elements for b→sγ and b→ dγ decays. Long-distance effect alone is not appreciable but it is a good supplement to the short-distance contribution. We obtain better results for the inclusive decays.
ON THE ENTROPY CHANGE FOR A FLUID CONTAINING SWIMMING MICRO-ORGANISMS
Authors: BREVIK I. , HAUGEN O.
Published: May 2003

We consider the two-dimensional hydrodynamical theory of nearly circular biological objects (cilia) in the creeping approximation, focusing on the time rate of entropy production in the fluid as calculated by means of functional integration methods. It is pointed out that the formalism leads to an entropy change in the fluid which is always negative. This change has, for thermodynamic reasons, to be compensated for, by a change of entropy for the micro-organism itself which is positive, and which is large enough to outweigh the entropy change in the fluid. We consider also briefly the generalization to nonuniform closed objects.
POTENTIAL ENERGY OF YANG–MILLS VORTICES IN THREE AND FOUR DIMENSIONS
Authors: DIAKONOV DMITRI
Published: May 2003

We calculate the energy of a Yang–Mills vortex as function of its magnetic flux or as the Wilson loop surrounding the vortex center. The calculation is performed in the one-loop approximation. A parallel line with a potential as function of the Polyakov at nonzero temperatures is drawn. We find that quantized Z(2) vortices are dynamically preferred though vortices with arbitrary fluxes cannot be ruled out.
HETERODYNE DETECTION OF GRAVITATIONAL WAVES EMITTED FROM BINARY PULSARS
Authors: BRAUTTI G.
Published: May 2003

The gravitational waves (GWs) emitted by binary pulsars have very long periods, and are buried within the terrestrial noise. We propose to shift their signals to higher frequency by modulating the amplitude, using a resonant of the Weber type on a rotating platform, and using phase locked detection. We evaluate orders of magnitude of the expected sensitivity and noise. The results show that the signals from PSRB1913 + 16 can be detected by long term observation and digital spectral filtering with a small, rather inexpensive antenna.
THE STRING DEVIATION EQUATION
Authors: ROBERTS MARK D.
Published: May 2003

It is well known that the relative motion of many particles can be described by the geodesic deviation equation. Less well known is that the geodesic deviation equation can be derived from the second covariant variation of the point particle's action. Here it is shown that the second covariant variation of the string action leads to a string deviation equation. This equation is a candidate for describing the relative motion of many strings, and can be reduced to the geodesic deviation equation. Like the geodesic deviation equation, the string deviation equation can also be expressed in terms of momenta and projecta. It is also shown that a combined action exists, the first variation of which gives the deviation equations. The combined actions allow the deviation equations to be expressed solely in terms of the Riemann tensor, the coordinates and momenta. In particular geodesic deviation can be expressed as: [Formula: see text] and string deviation can be expressed as: [Formula: see text]
VACUUM STRUCTURE OF GAUGE THEORY ON LATTICE WITH TWO PARALLEL PLAQUETTES ACTION
Authors: FARAKOS K. , SAVVIDY G. K.
Published: May 2003

We perform Monte–Carlo simulations of a lattice gauge system with an action which contains two parallel plaquettes. The action is defined as a product of gauge group variables over two parallel plaquettes belonging to a given three-dimensional cube. The peculiar property of this system is that it has strong degeneracy of the vacuum state inherited from the corresponding gonihedric Z2 gauge spin system. These vacua are well separated and cannot be connected by a gauge transformation. We measure different observables in these vacua and compare their properties.
THE ACTION OF NEUTRINO PONDEROMOTIVE FORCE ON SUPERNOVA DYNAMICS
Authors: ESPOSITO SALVATORE
Published: May 2003

Collective interactions of a beam of neutrinos/antineutrinos traversing a dense magnetized plasma of electrons/positrons, protons and neutrons are studied with particular reference to the case of a supernova. We find that the ponderomotive force exerted by neutrinos gives, contrary to expectations, a negligible contribution to the revival of the shock for a successful supernova explosion, although new types of convection and plasma cooling processes induced by the ponderomotive force could be, in principle, relevant for the dynamics itself.
NONLEPTONIC WEAK DECAYS $\bar B\to D^*_2P (V)$ IN HQET
Authors: MOHANTA RUKMANI , GIRI ANJAN K.
Published: May 2003

The two-body nonleptonic weak decays [Formula: see text], where [Formula: see text] is a narrow p-wave charm resonance, are investigated using the generalized factorization hypothesis along with the HQET. The estimated decay rates for these processes are below the current experimental upper limits.
REAL STRUCTURES IN CLIFFORD ALGEBRAS AND MAJORANA CONDITIONS IN ANY SPACE–TIME
Authors: DE ANDRADE M. A. , TOPPAN F.
Published: May 2003

Clifford algebras and Majorana conditions are analyzed in any space–time. An index labelling inequivalent Γ-structures up to orthogonal conjugations is introduced.

Inequivalent charge-operators in even dimensions, invariant under Wick rotations, are considered. The hermiticity condition on free-spinors Lagrangians is presented. The constraints put by the Majorana condition on the free-spinors dynamics are analyzed. Tables specifying which space–times admit Lagrangians with nonvanishing kinetic, massive or pseudo-massive terms (for both charge-operators in even dimensions) are given. The admissible free Lagrangians for free Majorana–Weyl spinors are fully classified.
ENSEMBLE OF VORTEX LOOPS IN THE ABELIAN-PROJECTED SU(3)-GLUODYNAMICS
Authors: ANTONOV DMITRI
Published: May 2003

Grand canonical ensemble of small vortex loops emerging in the London limit of the effective Abelian-projected theory of the SU(3)-gluodynamics is investigated in the dilute gas approximation. An essential difference of this system from the SU(2)-case is the presence of two interacting gases of vortex loops. Two alternative representations for the partition function of such a grand canonical ensemble are derived, and one of them, which is a representation in terms of the integrals over vortex loops, is employed for the evaluation of the correlators of both kinds of loops in the low-energy limit.
AN ISOSPIN ANALYSIS OF NONFACTORIZABLE CONTRIBUTIONS TO HADRONIC DECAYS OF BOTTOM MESONS
Authors: SHARMA K. K. , KATOCH A. C.
Published: May 2003

We investigate nonfactorizable contributions to [Formula: see text] and [Formula: see text] decay modes. Obtaining the factorizable contributions from spectator-quark diagrams for N c =3, we determine nonfactorizable isospin amplitudes required to explain the data for these modes. We observe that theoretical ratio of these amplitudes seem to follow a universal value for [Formula: see text] and [Formula: see text] decay modes. We predict the branching ratios for these decay modes.
CENTRAL CHARGES AND COHOMOLOGICAL PROPERTIES IN PHASE SPACE
Authors: CABO A. , LUCIO J. L. , VILLANUEVA V. M.
Published: May 2003

We consider the algebra associated to a group of time-dependent coordinate transformations which are symmetries of a regular mechanical system (i.e. system free of constraints). We derive expressions for the central extension of the algebra that may appear at the classical level. We analyze the variation of the phase space Lagrangian under finite transformations extending thus the usual configuration space cochain concepts to phase space.
ON THE RESPONSE OF DETECTORS IN CLASSICAL ELECTROMAGNETIC BACKGROUNDS
Authors: SRIRAMKUMAR L.
Published: May 2003

We study the response of a detector that is coupled nonlinearly to a quantized complex scalar field in different types of classical electromagnetic backgrounds. Assuming that the quantum field is in the vacuum state, we show that, when in inertial motion, the detector responds only when the electromagnetic background produces particles. However, we find that the response of the detector is not proportional to the number of particles produced by the background.
CONICAL SPACE–TIMES: A DISTRIBUTION THEORY APPROACH
Authors: DAHIA F. , ROMERO C.
Published: May 2003

We consider the problem of calculating the Gaussian curvature of a conical two-dimensional metric by using concepts and techniques of distribution theory. We apply the results obtained to calculate the Riemannian curvature of the four-dimensional conical space–time. We show that the method can be extended for calculating the curvature of a special class of more general space–times with conical singularity.
VORTEX SOLUTION IN (2+1)-DIMENSIONAL PURE YANG–MILLS THEORY AT HIGH TEMPERATURES
Authors: DIAKONOV DMITRI
Published: May 2003

At high temperatures the A0 component of the Yang–Mills field plays the role of the Higgs field, and the one-loop potential V(A0) plays the role of the Higgs potential. We find a new stable vortex solution of the Abrikosov–Nielsen–Olesen type, and discuss its properties and possible implications.
TIME-VARYING FINE-STRUCTURE CONSTANT REQUIRES COSMOLOGICAL CONSTANT
Authors: KÜHNE RAINER W.
Published: May 2003

Webb et al. presented preliminary evidence for a time-varying fine-structure constant. We show Teller's formula for this variation to be ruled out within the Einstein–de Sitter universe, however, it is compatible with cosmologies which require a large cosmological constant.
R&D PROGRESS TOWARD FUTURE LINEAR COLLIDERS
Authors: VOSS G.-A.
Published: May 2003

During the last 20 years there has been a worldwide effort to develop the physics and technology of linear colliders. Present goals at SLAC, KEK and DESY are to bring the R&D efforts to the point where proposals for 500/1000 GeV cms electron–positron colliders can be officially submitted in the years 2002/2003. The CLIC study at CERN aims at a second generation very high energy electron–positron collider, to be considered after completion of the LHC.

The main areas of hardware R&D include efficient accelerating waveguides without harmful higher order mode (h.o.m) effects, high peak power klystrons, klystron modulators and rf-power compression. Test facilities have been put in place for the testing of h.o.m behavior of new waveguide designs (ASSET), focusing on low emittance beams to spot sizes in the nanometer range (FFTB) and damping particle oscillations in a special damping ring (ATF) to prepare low emittance bunch trains of electrons for injection into linear colliders. The TESLA collaboration is making a major effort to develop the required technology for a superconducting linear collider.

Test accelerator sections, which employ all the necessary new accelerator components, have been built and are currently being tested at SLAC and DESY.
TOPOLOGICAL INVARIANTS AND ANYONIC PROPAGATORS
Authors: DA CRUZ WELLINGTON
Published: May 2003

We obtain the Hausdorff dimension, h=2-2s, for particles with fractional spins in the interval, 0≤ s ≤0.5, such that the manifold is characterized by a topological invariant given by, [Formula: see text]. This object is related to fractal properties of the path swept out by fractional spin particles, the spin of these particles, and the genus (number of anyons) of the manifold. We prove that the anyonic propagator can be put into a path integral representation which gives us a continuous family of Lagrangians in a convenient gauge. The formulas for, h and [Formula: see text], were obtained taking into account the anyon model as a particle-flux system and by a qualitative inference of the topology.
TOPOLOGICAL FEATURES IN NON-ABELIAN GAUGE THEORY
Authors: MALIK R. P.
Published: May 2003

We discuss the BRST cohomology and exhibit a connection between the Hodge decomposition theorem and the topological properties of a two-dimensional free non-Abelian gauge theory (having no interaction with matter fields). The topological nature of this theory is encoded in the vanishing of the Laplacian operator when equations of motion are exploited. We obtain two sets of topological invariants with respect to BRST and co-BRST charges on the two-dimensional compact manifold and show that the Lagrangian density of the theory can be expressed as the sum of terms that are BRST and co-BRST invariants. Thus, this theory captures together some of the salient features of both Witten and Schwarz type of topological field theories.
QUANTUM ERGOSPHERE AND HAWKING PROCESS
Authors: LI ZHONG-HENG
Published: May 2003

We study both spherically symmetric and rotating (Kerr) nonstationary black holes and discuss the radiation of these black holes via the Hawking process. We find that the thermal radiation spectrum of a nonstationary black hole is obviously dependent on the spin state of a particle and is different from the case of a stationary black hole. This effect originates from the quantum ergosphere. We also find that the field equations of spin s=0,1/2,1 and 2 can combine into a generalized Teukolsky-type master equation with sources for any spherically symmetric black hole.
AdS3 GRAVITATIONAL INSTANTONS FROM CONFORMAL FIELD THEORY
Authors: MANO SHUHEI
Published: May 2003

A conformal field theory on the boundary of three-dimensional asymptotic anti-de Sitter spaces which appear as near horizon geometry of D-brane bound states is discussed. It is shown that partition functions of gravitational instantons appear as high and low temperature limits of the partition function of the conformal field theory. The result reproduces phase transition between the anti-de Sitter space and the BTZ black hole in the bulk gravity.
THE HAMILTON–JACOBI EQUATIONS FOR STRINGS AND p-BRANES
Authors: HOSOTANI YUTAKA , NAKAYAMA RYUICHI
Published: May 2003

Simple derivation of the Hamilton–Jacobi equation for bosonic strings and p-branes is given. The motions of classical strings and p-branes are described by two and p+1 local fields, respectively. A variety of local field equations which reduce to the Hamilton–Jacobi equation in the classical limit are given. They are essentially nonlinear, having no linear term.
A GLUON PLASMA GIANT RESONANCE AND COLOR-SINGLETNESS AT FINITE TEMPERATURE
Authors: PARIA LINA , ABBAS AFSAR , MUSTAFA M. G.
Published: May 2003

By imposing the SU(3) color-singletness constraint on a gluonic system, a heavy gluon–plasma giant resonance is shown to arise at finite temperature. This is made possible through the proper incorporation of the finite size correction brought in by the color-singletness restriction.
TOPOLOGICAL CURRENT OF POINT DEFECTS AND ITS BIFURCATION
Authors: DUAN YISHI , FU LIBIN , ZHANG HONG
Published: May 2003

From the topological properties of a three-dimensional vector order parameter, the topological current of point defects is obtained. One shows that the charge of point defects is determined by Hopf indices and Brouwer degrees. The evolution of point defects is also studied. One concludes that there exist crucial cases of branch processes in the evolution of point defects when the Jacobian [Formula: see text].
FOUR DIMENSIONALITY IN NON-COMPACT KALUZA–KLEIN MODEL
Authors: GOGBERASHVILI MERAB
Published: May 2003

Five-dimensional model with extended dimensions investigated. It is shown that four dimensionality of our world is the result of the stability requirement. Extra component of five-dimensional Einstein's equations that is responsible for trapping of matter fields coincides with the condition of stability.
SHORT STRINGS IN THE ABELIAN HIGGS MODEL
Authors: GUBAREV F. V. , POLIKARPOV M. I. , ZAKHAROV V. I.
Published: May 2003

We consider the monopole–antimonopole static potential in the confining phase of the Abelian Higgs model and in particular the corrections to the Coulomb-like potential at small distances r. By minimizing numerically the classical energy functional, we observe a linear in r, stringy correction even at distances much smaller than the apparent physical scales. We argue that this term is a manifestation of the condition that the monopoles are connected by a mathematically thin line along which the scalar field vanishes. These short strings modify the operator product expansion as well. Implications for QCD are discussed.
SQUEEZED GLUON VACUUM AND THE GLOBAL COLOR MODEL OF QCD
Authors: NATALE A. A.
Published: May 2003

We discuss how the vacuum model of Celenza and Shakin with a squeezed gluon condensate can explain the existence of an infrared singular gluon propagator frequently used in calculations within the global color model. In particular, it reproduces a recently proposed QCD-motivated model where low energy chiral parameters were computed as a function of a dynamically generated gluon mass. We show how the strength of the confining interaction of this gluon propagator and the value of the physical gluon condensate may be connected.
ORBITAL RADIUS OF A HYDROGEN-LIKE MESON IN S-, P- AND D-STATES
Authors: AVILA M. A.
Published: May 2003

Radial probability density function of a heavy quark–light quark [Formula: see text] system in the states S, P and D, is studied numerically. It is found that the maximum of this function at r=a0 and the light quark energy (Eq) are related through [Formula: see text], where l is the orbital angular momentum, Z=0.446/ξ, and ξ is the strength of the color Coulomb potential. Phenomenology predicts that to difference of the hydrogen atom of QED, the "color atomic number" is such that Z≤1. This can be thought of as due to an anti-screening effect from the gluons. The respective expectation value for the radial coordinate in these states is found to be [Formula: see text] These results are valid for ξ in the range 0.446<ξ<0.646 and a light quark mass in the range 0<m<300 MeV. The above relations coincide with the maximum value of the slope of the Isgur–Wise at zero recoil point in the following way [Formula: see text] The relations found in the present work imply that [Formula: see text], from which we argue that the value of ξ′(1) is very sensitive to the color Coulomb-like interaction U=-ξ/r.
A DERIVATION OF THE CORRECT TREATMENT OF ${1\over (\eta\cdot {\lc k})^{\lc p}}$ SINGULARITIES IN AXIAL GAUGES
Authors: JOGLEKAR SATISH D. , MISRA A.
Published: May 2003

We use the earlier results on the correlations of axial gauge Green's functions and the Lorentz gauge Green's functions obtained via finite field-dependent BRS transformations to study the question of the correct treatment of [Formula: see text]-type singularities in the axial gauge boson propagator. We show how the known treatment of the [Formula: see text]-type singularity in the Lorentz-type gauges can be used to write down the axial propagator via field transformation. We examine the singularity structure of the latter and find that the axial propagator so constructed has no spurious poles, but a complex structure near [Formula: see text]. We also give the form of the much simpler propagator which can effectively replace the complicated structure near the region [Formula: see text].
CP-ODD HIGGS BOSON PRODUCTION IN ASSOCIATION WITH NEUTRAL GAUGE BOSON IN HIGH ENERGY e+e- COLLISIONS
Authors: AKEROYD A. G. , ARHRIB A. , PEYRANÉRE M. CAPDEQUI
Published: May 2003

We study the associated production of a CP-odd Higgs boson A0 with a neutral gauge boson (Z or photon) in high-energy e+e- collisions at the one-loop level in the framework of two Higgs doublet models (THDM). We find that in the small tan β regime, the top quark loop contribution is enhanced leading to significant cross-sections (about a few fb), while in the large tan β regime the cross-section does not attain observable rates.
CONSTRUCTION OF COMPLETELY INTEGRABLE SYSTEMS BY POISSON MAPPINGS
Authors: GRABOWSKI J. , MARMO G. , MICHOR P. W.
Published: May 2003

Pulling back sets of functions in involution by Poisson mappings and adding Casimir functions during the process allows one to construct completely integrable systems. Some examples are investigated in detail.
MASSLESS FIELDS OVER R1×H3 SPACE–TIME AND COHERENT STATES FOR THE LORENTZ GROUP
Authors: POL'SHIN S. A.
Published: May 2003

The solutions of the arbitrary-spin massless wave equations over R1×H3 space are obtained using the generalized coherent states for the Lorentz group. The use of these solutions for the construction of invariant propagators of quantized massless fields with an arbitrary spin over the R1×H3 space is considered. The expression for the scalar propagator is obtained in the explicit form.
MASSIVE GAUGE AXION FIELDS
Authors: ARIAS P. J. , KHOUDEIR A.
Published: May 2003

A gauge-invariant formulation for the massive axion is considered. The axion acquires mass through a topological term which couples a (pseudo)scalar and a third rank antisymmetric tensor. Duality, local and canonical equivalences with the non-gauge invariant proposal are established. The supersymmetric version of the gauge-invariant model is constructed.
DEFORMED GALILEI SYMMETRY
Authors: KOSIŃSKI PIOTR , MAŚLANKA PAWEł
Published: May 2003

A particular deformation of centrally extended Galilei group is considered. It is shown that the deformation influences the rules of constructing the composed systems while one-particle states remain basically unaffected. In particular, the mass appears to be nonadditive.
A REMARK ON WITTEN EFFECT FOR QCD MONOPOLES IN MATRIX QUANTUM MECHANICS
Authors: GABADADZE GREGORY , KAKUSHADZE ZURAB
Published: May 2003

In a recent work3 we argued that a certain matrix quantum mechanics may describe 't Hooft's monopoles which emerge in QCD when the theory is projected to its maximal Abelian subgroup. In this letter we find further evidence which supports this interpretation. We study the theory with a nonzero theta-term. In this case, 't Hooft's QCD monopoles become dyons since they acquire electric charges due to the Witten effect. We calculate a potential between a dyon and an anti-dyon in the matrix quantum mechanics, and find that the attractive force between them grows as the theta angle increases.
ON THE OCCURRENCE OF A POSITIVE VACUUM ENERGY IN A QUANTUM MODEL FOR SPACE–TIME
Authors: CHAPLINE GEORGE
Published: May 2003

It is shown that a previously proposed quantum model for four-dimensional space–time based on an SU (∞) generalization of anyonic superconductivity can be regarded as a discrete form of Polyakov's string theory. This suggests that in a Robertson–Walker universe there is a positive vacuum energy that is on the order of the string tension divided by square of the distance scale factor. This leads to a new type of cosmological model that, even though it resembles more an open universe than an accelerating universe, is apparently consistent with current observational constraints on cosmological models.
WKB WAVE FUNCTIONS WITH THE INDUCED GRAVITY THEORY
Authors: ZHU ZONG-HONG , CAO LI
Published: May 2003

The Wheeler–DeWitt equation for the induced gravity theory is constructed in the mini superspace approximation, and then solved using the WKB method under three types of boundary condition proposed respectively by Hartle & Hawking ("no boundary"), Linde and Vilenkin ("tunneling from nothing"). It is found that no matter how the gravitational and cosmological "constants" vary in the classical models, they will acquire constant values when the universe comes from quantum creation, and that, in particular, the resulting tunneling wave function under the Linde or Vilenkin boundary condition reaches its maximum value if the cosmological constant vanishes.
BLACK HOLE SOLUTIONS FROM TWO-DIMENSIONAL BOHMIAN QUANTUM MECHANICS
Authors: ALVES M.
Published: May 2003

We show, in a very simple way, how a scalar matter source can generate curvature to the two-dimensional space–time in the framework of the Bohmian quantum mechanics. For the particular case studied, the curvature is obtained without a specific equation for the gravity itself. We also show that there are black hole solutions from quantum corrections given by this description.
NEUTRINO OSCILLATIONS IN BRANS–DICKE THEORY OF GRAVITY
Authors: CAPOZZIELLO S. , LAMBIASE G.
Published: May 2003

Flavor oscillations of neutrinos are analyzed in the framework of Brans–Dicke theory of gravity. We find a shift of quantum mechanical phase of neutrino proportional to GNΔm2 and depending on the parameter ω. Consequences on atmospheric, solar and astrophysical neutrinos are discussed.
STRINGENT CONSTRAINT ON THE SCALAR–NEUTRINO COUPLING CONSTANT FROM QUINTESSENTIAL COSMOLOGY
Authors: HORVAT R.
Published: May 2003

An extremely light (mϕ≪10-33 eV ), slowly-varying scalar field ϕ (quintessence) with a potential energy density as large as 60% of the critical density has been proposed as the origin of the accelerated expansion of the universe at present. The interaction of this smoothly distributed component with another predominantly smooth component, the cosmic neutrino background, is studied. The slow-roll approximation for generic ϕ potentials may then be used to obtain a limit on the scalar–neutrino coupling constant, found to be many orders of magnitude more stringent than the limits set by observations of neutrinos from SN 1987A. In addition, if quintessential theory allows for a violation of the equivalence principle in the sector of neutrinos, the current solar neutrino data can probe such a violation at the 10-10 level.
THE FUNCTIONAL DERIVATION OF MASTER EQUATIONS
Authors: ELZE HANS-THOMAS
Published: May 2003

Master equations describe the quantum dynamics of open systems interacting with an environment. They play an increasingly important role in understanding the emergence of semiclassical behavior and the generation of entropy, both being related to quantum decoherence. Presently we derive the exact master equation for a homogeneous scalar Higgs or inflaton like field coupled to an environment field. It is represented here by an infinite set of harmonic oscillators with a given spectral density. Our nonperturbative result follows directly from the path integral representation of the density matrix propagator. Applications and generalizations are discussed.
GENERATING Λ FROM THE VACUUM
Authors: SAHNI VARUN
Published: May 2003

The close relationship between the cosmological constant and the vacuum has been emphasized in the past by Zeldovich amongst others. We briefly discuss different approaches to the cosmological constant issue including the possibility that Λ could be generated by vacuum polarization in a static universe. Fresh possibilities occur in an expanding universe. An inflationary universe generically leads to particle creation from the vacuum, the nature and extent of particle production depending upon the mass of the field and its coupling to gravity. For ultra-light, non-minimally coupled scalar fields, particle production can be large and the resulting vacuum energy–momentum tensor will have the form of an effective cosmological constant. The inflationary scenario therefore, could give rise to a universe that is both flat andΛ-dominated, in agreement with observations.
MASS PROTECTION VIA TRANSLATIONAL INVARIANCE
Authors: ALONSO JOSÉ LUIS , CORTÉS JOSÉ LUIS , BOUCAUD PHILIPPE , CARMONA JOSÉ MANUEL , POLONYI JANOS , SIJS ARJAN VAN DER
Published: May 2003

We propose a way of protecting a Dirac fermion interacting with a scalar field from acquiring a mass from the vacuum. It is obtained through an implementation of translational symmetry when the theory is formulated with a momentum cutoff, which forbids the usual Yukawa term. We consider that this mechanism can help to understand the smallness of neutrino masses without a tuning of the Yukawa coupling. The prohibition of the Yukawa term for the neutrino forbids at the same time a gauge coupling between the right-handed electron and neutrino. We prove that this mechanism can be implemented on the lattice.
A HAMILTONIAN FORMALISM FOR CLASSICAL SYSTEMS INTERACTING WITH QUANTUM SYSTEMS
Authors: ANTONIOU I. , GUNZIG E. , NARDONE P. , PRONKO G. P.
Published: May 2003

We propose a general framework of the combined description of a classical system with a quantum system by representing the quantum system as a Hamiltonian field and defined the evolution of the whole system as Hamiltonian flow. We illustrate the general formalism in two cases, namely the classical particle coupled with a quantum oscillator and classical particle with quantum spin in electromagnetic field.
RADIATIVE LEPTONIC Bc DECAYS
Authors: COLANGELO P. , FAZIO F. DE
Published: May 2003

We analyze the radiative leptonic Bc decay mode: Bc→ℓνγ(ℓ=e,μ) using a QCD-inspired constituent quark model. The prediction: ℬ(Bc→ℓνγ)≃3 × 10-5 confirms that this channel is experimentally promising in view of the large number of Bc mesons which are expected to be produced at the future hadron facilities.