bluuebunny/crossref_metadata_2025 huggingface dataset:
Factored Coset Approach to Bosonization in the Context of Topological Backgrounds and Massive Fermions
Authors: Manías M. V. , Naón C. M. , Trobo M. L.
Published: October 2003

We consider a recently proposed approach to bosonization in which the original fermionic partition function is expressed as a product of a G/G-coset model and a bosonic piece that contains the dynamics. In particular we show how the method works when topological backgrounds are taken into account. We also discuss the application of this technique to the case of massive fermions.
On the Vanishing of Spherical Shell Gap at N = 28 in 44S Using Relativistic Mean-Field Model
Authors: Gupta Raj K. , Patra S. K. , Greiner W.
Published: October 2003

Use of the NL-SH parameter set is re-analyzed and a new parameter set TM2 is used for the first time in the axially deformed self-consistent relativistic mean-field calculations for 44 S and its neighboring nuclei 40 Mg and 42 Si . The spherical shell gap at N=28 in 44 S is found to be intact for the TM2 parameter set since it predicts the ground state of 44 S as nearly spherical, irrespective of the strength of the pairing force. The predictions of the NL-SH parameter set for 44 S are found to depend strongly on the pairing strength and, due to shape coexistence, the ground state could be strongly prolate or strongly oblate deformed. Hence, for the NL-SH parameter set, the spherical shell gap at N=28 in 44 S is broken for either of the prolate/oblate deformation. For 40 Mg and 42 Si , the spherical shell gap at N=28 is found broken under all conditions since the predicted deformations are large, independent of both the pairing strength and the choice of parameter set. This calls for immediate measurements of the deformations of these nuclei, particularly for 44 S which will decide its shell structure as well as the region of deformation in light nuclei.
Molecular Vibrational States in the Binary Cold Fission of 252Cf
Authors: Mişicu Ş. , Săndulescu A. , Greiner W.
Published: October 2003

We predict a molecular vibrational state in the cold binary fission of 252 Cf using a simple decay cluster model. The Hamiltonian of two even–even fragments in the pole–pole configuration is built in the same fashion as that for the dinuclear molecule formed in heavy-ions collisions. The interaction between the two fragments is described by the double-folding M3Y potential. The spectrum of the butterfly vibrations is derived and its dependence on fragments deformation and mass-asymmetry is discussed. Some experimental implications are commented.
A Pseudo-Conformal Representation of the Virasoro Algebra
Authors: Aghamohammadi A. , Alimohammadi M. , Khorrami M.
Published: October 2003

Generalizing the concept of primary fields, we find a new representation of the Virasoro algebra, which we call pseudo-conformal representation. In special cases, this representation reduces to ordinary- or logarithmic-conformal field theory. There are, however, other cases in which the Green functions differ from those of ordinary- or logarithmic-conformal field theories. This representation is parametrized by two matrices. We classify these two matrices, and calculate some of the correlators for a simple example.
Nonperturbative Expansion, Renormalons and τ-Decay
Authors: Jones H. F. , Ritz A. , Solovtsov I. L.
Published: October 2003

We analyze inclusive τ-decay using a modified version of the a expansion, a nonperturbative technique in which the effective coupling is analytic in the infrared region. The modification involves renormalization group improvement of the integrand in a spectral representation for the D-function prior to implementing the a expansion. The advantage of this approach is that it enables us to monitor the structure of the induced power corrections and to ensure that these are consistent with the operator product expansion. Numerically the method agrees well with experiment: the comparison is made with the physical quantity RZ using Rτ as input.
Coulomb–Nucleon Phase and Spin Effects in the Diffraction Dip Domain
Authors: Selyugin O. V.
Published: October 2003

A new form for the Coulomb–hadron phase which can be used in a wide region of transfer momenta is obtained. The total phase of the Coulomb–hadron interaction is calculated with the true hadron scattering amplitude and with the Coulomb amplitude including the form factor of hadrons. As an example, the additional contribution to analyzing power AN owing to the Coulomb–hadron interference is calculated in the whole diffraction dip domain of high–energy elastic hadron scattering.
Classicality, Matter–Antimatter Asymmetry, and Quantum Gravity Deformed Uncertainty Relations
Authors: Amelino-Camelia Giovanni
Published: October 2003

Some of the recent work on quantum gravity has involved modified uncertainty relations such that the products of the uncertainties of certain pairs of observables increase with time. It is here observed that this type of modified uncertainty relations would lead to quantum decoherence, which could explain the classical behavior of macroscopic systems, and CPT-violation, which could provide the seed for the emergence of a matter–antimatter asymmetry.
Two-Dimensional R-Matrices — Descendants of Three-Dimensional R-Matrices
Authors: Sergeev S. M.
Published: October 2003

Finite layers of three-dimensional models can be regarded as two-dimensional with complicated multi-stated weights. The tetrahedron equation in 3D provides the Yang–Baxter equation for this composite weights in 2D. Such solutions of the Yang–Baxter equation are constructed for the simplest operator solution of the tetrahedron equation. These R-matrices can be regarded as a special projection of universal R-matrix for some Drinfeld double [Formula: see text], associated with the affine algebra [Formula: see text]. Usual R-matrix for [Formula: see text] is another projection of [Formula: see text].
Gravitation at the Mesoscopic Scale
Authors: Onofrio R. , Viola L.
Published: October 2003

Free fall experiments are discussed by using test masses associated to quantum states not necessarily possessing a classical counterpart. The times of flight of the Galilean experiments using classical test masses are replaced in the quantum case by probability distributions which, although still not defined in an uncontroversial manner, become manifestly dependent upon the mass and the initial state. Such a dependence is also expected in non-inertial frames of reference if the weak equivalence principle still holds. The latter could be tested, merging recent achievements in mesoscopic physics, by using cooled atoms in free fall and accelerated frames initially prepared in nonclassical quantum states.
Dynamics of the Universal Confining String Theory on the Loop Space
Authors: Antonov D. V.
Published: October 2003

Starting with the representation of the Wilson average in the Euclidean 4D compact QED as a partition function of the universal confining string theory, we derive the corresponding loop equation, an alternative to the familiar one.

In the functional momentum representation the obtained equation decouples into two independent ones, which describe the dynamics of the transverse and longitudinal components of the area derivative of the Wilson loop. At some critical value of the momentum discontinuity, which can be determined from a certain equation, the transverse component does not propagate.

Next, we derive the equation for the momentum Wilson loop, where the left-hand side represents the sum of the squares of the momentum discontinuities, multiplied by the loop, which describes its free propagation, while the right-hand side describes the interaction of the loop with the functional vorticity tensor current.

Finally, using the method of inversion of the functional Laplacian, we obtain for the Wilson loop in the coordinate representation a simple Volterra type-II linear integral equation, which can be treated perturbatively.
Coherent States of suq(2)-Covariant Oscillators
Authors: Chung W.-S.
Published: October 2003

In this letter two types of coherent states of suq(2)-covariant oscillators are investigated.
Squeezed States, Black Holes and Entropy Generation
Authors: Suresh P. K. , Kuriakose V. C.
Published: October 2003

Using squeezed state formalism of quantum optics, we examine particle production by black holes and study the associated entropy generation, change in mass parameter and obtain an expression for the Hawking temperature in terms of the squeezing parameter.
p-Brane Solutions in IKKT IIB Matrix Theory
Authors: Fayyazuddin Ansar , Smith Douglas J.
Published: October 2003

We find p-brane solutions to the recently proposed IKKT IIB matrix theory for all odd p. We also propose central charges for the p-branes.
p-Adic Path Integrals for Quadratic Actions
Authors: Djordjević G. S. , Dragovich B.
Published: October 2003

The Feynman path integral in p-adic quantum mechanics is considered. The probability amplitude [Formula: see text] for one-dimensional systems with quadratic actions is calculated in an exact form, which is the same as that in ordinary quantum mechanics.
Testing Complete Positivity
Authors: Benatti Fabio , Floreanini Roberto
Published: October 2003

We study the modified dynamical evolution of the neutral kaon system under the condition of complete positivity. The accuracy of the data from planned future experiments is expected to be sufficiently precise to test such a hypothesis.
Quantum Chaos in a Yang–Mills–Higgs System
Authors: Salasnich Luca
Published: October 2003

We study the energy fluctuations of a spatially homogeneous SU(2) Yang–Mills–Higgs system. In particular, we analyze the nearest-neighbour spacing distribution which shows a Wigner–Poisson transition by increasing the value of the Higgs field in the vacuum. This transition is a clear quantum signature of the classical chaos–order transition of the system.
Conformal and B.R.S. Invariance of the Super-Wess–Zumino–Witten Model — A Fujikawa Regularization
Authors: Mesref L.
Published: October 2003

Based on a path integral prescription for anomaly calculation and on the Fujikawa regularization of the anomalous current, we study the conformal and B.R.S. invariance of the super-Wess–Zumino–Witten model. We compute finally the critical dimension of the model and we recover the known result which fixes the coupling constant α=1 in a rigorous way.
Wave Function for the Reissner–Nordström Black Hole
Authors: Moniz P. V.
Published: October 2003

We study the quantum behavior of Reissner–Nordström (RN) black holes interacting with a complex scalar field. A Maxwell field is also present. Our analysis is based on M. Pollock's1 method and is characterized by solving a Wheeler–DeWitt equation in the proximity of an apparent horizon of the RN space–time. Subsequently, we obtain a wave function Ψ RN [M,Q] representing the RN black hole when its charge, |Q|, is small in comparison with its mass, M. We then compare quantum-mechanically the cases of (i) Q=0 and (ii) M≥|Q|≠0. A special emphasis is given to the evolution of the mass-charge rate affected by Hawking radiation.
Deformation of the Unitary Group SU(3) and Gell-Mann–Okubo Mass Relation for Mesons and Baryons
Authors: Bose S. K. , Gupta N.
Published: October 2003

We obtain here a simple version of deformed unitary group SU(3) and study the effect of deformation on Gell-Mann–Okubo mass relation for mesons and baryons.
A Linear Realization for the New Space–Time Superalgebras in 10 and 11 Dimensions
Authors: Deriglazov Alexei , Galajinsky Anton
Published: October 2003

The new extensions of the Poincaré superalgebra found recently in 10 and 11 dimensions are shown to admit a linear realization. The generators of the nonlinear and linear group transformations are shown to fall into equivalent representations of the superalgebra. The parametrization of the coset space G/H, with G a given extended supergroup and H the Lorentz subgroup, that corresponds to the linear transformations is presented.
Effective SU(2)L⊗U(1) Theory and the Higgs Boson Mass
Authors: Fang Zhen Yun , Castro G. López , Pestieau J. , Lucio J. L. M.
Published: October 2003

We assume the stability of the vacuum expectation value of the Higgs boson field under radiative corrections in the context of the standard electroweak theory. We find that this theory behaves as a good effective model already at cutoff energy scales as low as 0.7 TeV. This stability criterion allows us to predict mH=318±13 GeV for the Higgs boson mass.
On the Scattering of Gravitons on Two Parallel D-Branes
Authors: Pasquinucci Andrea
Published: October 2003

We discuss the scattering of a graviton (or a dilaton, or an antisymmetric tensor) on two parallel static Dp-branes. The graviton belongs to a type II string in 10D.
Remark on the Kinematics of the One-Photon Production in Electron–Proton Scattering
Authors: Lu Wei
Published: October 2003

We clarify some misleading mistakes in the literature about the phase space for the one-photon production in electron–proton scattering and present the correct overall phase space factor in the cross-section formula. Our conclusion is that the earlier diquark model predictions for the cross-sections of the one-photon production in electron–proton scattering are unreliable. Furthermore, we specify the phase space boundaries. In relation to the recent proposal to measure the off-diagonal quark distribution functions in the deeply virtual Compton scattering off the proton, we point out that the kinematics strongly disfavors such experiments.
Negative Energy Bound States in Relativistic Mean Field Theory
Authors: Patra S. K. , Panda P. K. , Maruhn J. , Stöcker H. , Greiner W.
Published: October 2003

We study the negative energy bound states of a nucleus utilizing the relativistic mean field theory for different parameter sets. It is found that for the TM1 parameter set, the depth of the negative-energy potential is small as compared to the NL-1, NL-SH and NL-Z parameter sets. The high density scenario in the mean field theory is achieved by a scaling procedure for the density and radius. The production of antibaryon clusters is predicted for very high density and temperature and its possible experimental investigation is also addressed.
O(d, d)-Symmetry and Ernst Formulation of Einstein–Kalb–Ramond Theory
Authors: Herrera-Aguilar Alfredo , Kechkin Oleg
Published: October 2003

A Ernst-like matrix representation of (3+d)-dimensional Einstein–Kalb–Ramond theory is developed. The analogy with the Einstein and Einstein–Maxwell–Dilaton–Axion theories is discussed. The subsequent reduction to two dimensions is considered. It is shown that, in this case, the theory allows two different Ernst-like d×d-matrix formulations: the real nondualized target space, and the Hermitian dualized nontarget space one. The O(d, d)-symmetry is written in an SL (2,R) matrix-valued form in both cases. The Kramer–Neugebauer transformation, which algebraically maps the nondualized Ernst potential onto the dualized one, is presented.
Pseudo-Differential Operators $(\psi{\cal D}{\cal O})$ Algebra and Certain Infinite-Dimensional Lie Algebras
Authors: Kinani E. H. El
Published: October 2003

The class of pseudo-differential operators Lie algebra [Formula: see text] on the quantum plane [Formula: see text] is introduced. The embedding of certain infinite-dimensional Lie algebras which occur in the physics literature in [Formula: see text] is discussed as well as the correspondence between [Formula: see text] and [Formula: see text] as k→+∞ is examined.
Constant Threshold Correction to Electrically Charged Dilatonic Black Holes
Authors: Chan Kwan-Leung
Published: October 2003

We investigate the effect of a constant threshold correction to a general non-extreme, static, spherically symmetric, electrically charged black hole solution of the dilatonic Einstein–Maxwell Lagrangian, with an arbitrary coupling β between the electromagnetic tensor and the dilaton field. For a small β, an exact analytical solution is obtained. For an arbitrary β, a close form solution, up to first-order in the constant threshold correction, of the metric and the dilaton are presented. In the extremal limit, the close form solution is reduced to an exact analytical form.
Singularities of the Partition Function for the Ising Model Coupled to 2D Quantum Gravity
Authors: Ambjørn J. , Anagnostopoulos K. N. , Magnea U.
Published: October 2003

We study the zeros in the complex plane of the partition function for the Ising model coupled to 2D quantum gravity for complex magnetic field and real temperature, and for complex temperature and real magnetic field, respectively. We compute the zeros by using the exact solution coming from a two-matrix model and by Monte–Carlo simulations of Ising spins on dynamical triangulations. We present evidence that the zeros form simple one-dimensional curves in the complex plane, and that the critical behaviour of the system is governed by the scaling of the distribution of the singularities near the critical point. Despite the small size of the systems studied, we can obtain a reasonable estimate of the (known) critical exponents.
Double Ernst Solution in Einstein–Kalb–Ramond Theory
Authors: Herrera-Aguilar Alfredo , Kechkin Oleg
Published: October 2003

The Kähler formulation of five-dimensional Einstein–Kalb–Ramond (EKR) theory admitting two commuting Killing vectors is presented. Three different Kramer–Neugebauer-like maps are established for the two-dimensional case. A class of solutions constructed on the basis of the double Ernst one is obtained. It is shown that the double Kerr solution corresponds to a EKR dipole configuration with horizon.
Completely Integrable Systems — A Generalization
Authors: Alekseevsky D. V. , Grabowski J. , Marmo G. , Michor P. W.
Published: October 2003

We present a slight generalization of the notion of completely integrable systems such that they can be integrated by quadratures. We use this generalization to integrate dynamical systems on double Lie groups.
Asymptotic Freedom and Confinement Imply Spontaneously Broken Chiral Symmetry in Quantum Chromodynamics
Authors: Acharya R. , Swamy P. Narayana
Published: October 2003

We utilize Coleman's theorem and show that quantum chromodynamics based on asymptotic freedom and confinement must have chiral symmetry realized as a spontaneously broken symmetry.
Possible Identification of Double Pomeron Exchange Processes
Authors: Sosa M.
Published: October 2003

The t distributions and rapidity gaps in high energy pp collisions are analyzed. For rapidity gaps Δ1≠Δ2 of both outgoing nucleons from the central cluster and four-momentum transfers t1≠ t2, the Δiti distributions are shown to be the same. It is postulated that this may be interpreted as a limit condition for pure DPE processes. Deviations from this behavior are probably related to non-DPE processes, such as Reggeon–Pomeron and Reggeon–Reggeon exchange.
A Method for Improving the Constraint on the Tensor Coupling Constant in Radiative Pion Decay
Authors: Chernyshev A. V. , Krasulin A. B. , Laptev V. D. , Matveev V. A. , Cooper M. D.
Published: October 2003

The possibility exists for improving the present experimental constraint on the tensor coupling constant in radiative pion decay by at least a factor of six. The method emphasizes relative decay probabilities rather than absolute rates.
Supersymmetric Cosets from Gauged SWZW Models
Authors: Figueroa-O'Farrill José M. , Stanciu Sonia
Published: October 2003

In this letter, which complements and extends our work7 on the superconformal field theories obtained from SWZW models based on general self-dual Lie algebras, we prove the quantum equivalence of the two known descriptions of the gauged supersymmetric WZW model, and as a corollary we show that in the case of the topological G/G gauging, the supersymmetric and nonsupersymmetric theories agree.
Explicit Connection Between Conformal Field Theory and 2+1 Chern–Simons Theory
Authors: Cabra Daniel C. , Rossini Gerardo L.
Published: October 2003

We give explicit field theoretical representations for the observables of (2+1)-dimensional Chern–Simons theory in terms of gauge-invariant composites of 2-D WZW fields. To test our identification we compute some basic Wilson loop correlators and re-obtain the known results.
Equation for a Composite Scalar Particle in (2+1)-D and its Solutions
Authors: Kruglov S. I.
Published: October 2003

A model of a scalar particle in (2+1)-dimensional space with an internal structure in external electromagnetic fields is considered. Exact solutions of the equation for such scalar particle were obtained in the field of a plane electromagnetic wave with the arbitrary polarization and in the quantized electromagnetic field of the linearly polarized wave. The relativistic coherent states of the particle in the field of n photons were constructed. When the photon number goes to infinity, this wave function transforms to the solution corresponding to the external classical electromagnetic wave.
Effect on the Electron EDM Due to Abelian Gauginos in SUSY Extra U(1) Models
Authors: Suematsu Daijiro
Published: October 2003

The electric dipole moment of an electron (EDME) is investigated in the supersymmetric extra U(1) models. Neutralino sector is generally extended in these models and the neutralino contribution will then be important for the analysis of the EDME. Kinetic term mixings of Abelian gauginos are taken into account in our analysis. Numerical results for the extra U(1) models show that the EDME can be affected by the extra U(1) in a certain range of soft supersymmetry breaking parameters even if the extra U(1) gauge boson is heavy. The EDME may be a clue to find an extended gauge structure in the supersymmetric models.
What Can We Learn about Leptoquarks at LEP200?
Authors: Doncheski Michael A. , Godfrey Stephen
Published: October 2003

We investigate the discovery potential for first generation leptoquarks at the LEP200 e+e- collider. We consider direct leptoquark searches using single leptoquark production via resolved photon contributions which offers a much higher kinematic limit than the more commonly considered leptoquark pair production process. Depending on the coupling strength of the leptoquark, search limits can be obtained to within a few GeV of [Formula: see text]. We also consider LQ limits that can be obtained from t-channel interferences effects in e+e-→ hadrons .
Implications of Pure Phase Mass Matrices
Authors: Fishbane Paul M. , Hung P. Q.
Published: October 2003

We find an example of Higgs field interactions that can produce fermion mass matrices in the highly textured symmetric pure phase form, a form consistent with phenomenology. The potential we study implies a simple set of discrete symmetries in the structure of the Lagrangian, symmetries closely connected to the hierarchical structure of fermion masses and the CKM matrix.
The Chiral Supereigenvalue Model
Authors: Akemann Gernot , Plefka Jan C.
Published: October 2003

A supereigenvalue model with purely positive bosonic eigenvalues is presented and solved by considering its superloop equations. This model represents the supersymmetric generalization of the complex one-matrix model, in analogy to the relation between the supereigenvalue and the Hermitian one-matrix model. Closed expressions for all planar multi-superloop correlation functions are found. Moreover an iterative scheme allows the calculation of higher genus contributions to the free energy and the correlators. Explicit results for genus one are given.
Quantum Decoherence in a D-Foam Background
Authors: Ellis John , Mavromatos N. E. , Nanopoulos D. V.
Published: October 2003

Within the general framework of Liouville string theory, we construct a model for quantum D-brane fluctuations in the space–time background through which light closed-string states propagate. The model is based on monopole and vortex defects on the worldsheet, which have been discussed previously in a treatment of (1+1)-dimensional black hole fluctuations in the space–time background, and makes use of a T-duality transformation to relate formulations with Neumann and Dirichlet boundary conditions. In accordance with previous general arguments, we derive an open quantum-mechanical description of this D-brane foam which embodies momentum and energy conservation and small mean energy fluctuations. Quantum decoherence effects appear at a rate consistent with previous estimates.
On the Geometry of Relativistic Anyon
Authors: Nersessian A.
Published: October 2003

A twistor model is proposed for the free relativistic anyon. The Hamiltonian reduction of this model by the action of the spin generator leads to the minimal covariant model; whereas that by the action of spin and mass generators leads to the anyon model with free phase space which is a cotangent bundle of the Lobachevsky plane with twisted symplectic structure. Quantum mechanics of that model is described by irreducible representations of the (2+1)-dimensional Poincaré group.
Masses and Decays of Charmed and Bottom Baryons
Authors: Fayyazuddin  , Riazuddin
Published: October 2003

Using SU(3) and the nonrelativistic quark model, the masses and the strong hadronic decays of heavy baryons are discussed. A number of results for the decay widths are obtained using the present experimental data as input.
Instantonic Approach to Triple-Well Potential
Authors: Lee Soo-Young , Kahng Jae-Rok , Yoo Sahng-Kyoon , Park D. K. , Lee C. H. , Park Chang Soo , Yim Eui-Soon
Published: October 2003

By using the usual instanton method, we obtain the energy splitting due to quantum tunneling through the triple-well barrier. It is shown that the term related to the midpoint of the energy splitting in propagator is quite different from that of double-well case, in that it is proportional to the algebraic average of the frequencies of the left and central wells. The result of the energy splitting is consistent with the known variational calculation.
Spin-Dependent Relativistic Effect on Heavy Quarkonium Thermal Properties
Authors: Dong Yu-Bing
Published: October 2003

Spin-dependent relativistic effect on binding and dissociation properties of heavy quarkonium in a thermal environment is investigated. The result shows that fine and hyperfine interactions influence the description of the thermal properties of the heavy quarkonium, such as ηc and J/ψ.
SO(3)×U(1) Isometric Instantons with Non-Abelian Hair in Four-Dimensional String Theory
Authors: Lugo Adrián R.
Published: October 2003

We compute the exact effective string vacuum backgrounds of the level k=81/19 SU(2,1)/U(1) coset model. A compact SU(2) isometry present in this seven-dimensional solution allows one to interpret it after compactification as a four-dimensional non-Abelian SU(2) charged instanton with a singular submanifold and an SO(3) × U(1) isometry. The semiclassical backgrounds, solutions of the type II strings, present similar characteristics
Comment on Z′'s and the H1 and ZEUS High Q2 Anomalies
Authors: Godfrey Stephen
Published: October 2003

We investigate the effects of extra neutral gauge bosons on the high Q2 region of the e+p→ e+X cross-section at [Formula: see text] GeV. We found that the only models with electroweak strength coupling, typical of extended gauge theories, that give a better fit to the H1 and ZEUS high Q2 data than the standard model, are ruled out by the existing data from the Tevatron. From general scaling arguments, using the allowed contact interactions, the only allowed models with Z′'s would be those with strong couplings although even in this case the statistical evidence is not compelling.
BRST Cohomology and Renormalizability of Quantum Gravity Near Two Dimensions
Authors: Kitazawa Yoshihisa , Kuriki Rie , Shigura Katsumi
Published: October 2003

We discuss the renormalizability of quantum gravity near two dimensions based on the results obtained by a computation of the BRST-antibracket cohomology in the space of local functionals of the fields and antifields. We justify the assumption on the general structure of the counterterms which have been used in the original proof of renormalizability of the quantum gravity near two dimensions.
Model for Gravitational Radiation from the Galactic Center: Infall of a Particle into a Black Hole
Authors: Lousto Carlos O.
Published: October 2003

We present here the results of the study of the gravitational radiation generated by the infall (from rest at radius r0) of a point particle of mass m0 into a Schwarzschild black hole of mass M. We use Laplace's transform methods and find that the spectra of radiation for ~5M<r0<∞ presents a series of evenly spaced bumps. The total radiated energy is not monotonically decreasing with r0, but presents a joroba (hunch-back) at around r0≈4.5M. We finally discuss the detectability of the gravitational radiation coming from the black hole in the center of our galaxy.
A Class of Non-Singular Gravi–Dilaton Backgrounds
Authors: Buonanno A. , Ungarelli C. , Gasperini M.
Published: October 2003

We present a class of static, spherically symmetric, non-singular solutions of the tree-level string effective action, truncated to first order in α′. In the string frame the solutions approach asymptotically (as r→ 0 and r→∞) two different anti-de Sitter configurations, thus interpolating between two maximally symmetric states of different constant curvatures. The radial-dependent dilaton defines a string coupling which is everywhere finite, with a peak value that can be chosen arbitrarily small so as to neglect quantum-loop corrections. This example stresses the possible importance of finite-size α′ corrections, typical of string theory, in avoiding space–time singularities.
An Accurate Method for the Numerical Solution of the Schrödinger Equation
Authors: Simos T. E.
Published: October 2003

We present here an accurate method for the numerical integration of the radial Schrödinger equation. The formula considered contains free parameter which are defined in order to integrate exponential functions. Numerical results also indicate that the new methods are much more accurate than other Numerov-type well-known methods.
Thermodynamics of Pion Gas Using States Predicted from κ-Deformed Poincaré Algebra
Authors: Cordeiro Claudette E. , Delfino Antonio , Dey Jishnu
Published: October 2003

κ-deformed Poincaré algebra, which preserves rotational and translational symmetries, can successfully predict the angular and radial excited states of the pion. In a thermal bath with temperature, T, these states can be excited in the pion gas, in addition to the usual momentum excitation. We exploit this situation to look at the pion free energy, to find that it increases linearly with T. The energy per particle and the entropy show interesting structures around T=0.2 GeV.
The Unification in the String Theories with the G × G Gauge Groups
Authors: Maslikov A. , Naumov I. , Volkov G.
Published: October 2003

In the framework of the four-dimensional heterotic superstring with free fermions we discuss the rank eight and/or 16 Grand Unified String Theories (GUSTs) which contain the SU (3)H-gauge family symmetry. We explicitly investigate the paths of the unification in the GUST with gauge symmetry G × G = [ SU (5)× U (1)×( SU (3)× U (1))H]⊗2. We show that the GUSTs with the G × G gauge group allow one to make the scale of unification to be consistent with the string scale M SU ~ g str ×5×1017 GeV.
Integrable $A^{(1)}_{n-1}$ IRF Model with Reflecting Boundary Conditions
Authors: Fan Heng , Hou Bo-Yu , Li Guang-Liang , Shi Kang-Jie
Published: October 2003

By using the intertwiners of Zn symmetric vertex model and [Formula: see text] IRF model, we find explicitly the dual reflection equation for [Formula: see text] IRF model. The integrability of the [Formula: see text] IRF model with reflecting boundary conditions is proved.
PCAC and Modifications in Hadron Properties in Nuclear Medium
Authors: Pasupathy J.
Published: October 2003

It is known that the Adler zero condition when imposed on pion amplitudes leads to several relations between hadron masses through the dual resonance formula of Lovelace, Shapiro and Veneziano. In particular the Lovelace quantization condition leads to the relation [Formula: see text] which is well satisfied experimentally. The Regge slope parameter α′ can be related to the gluon condensate. The latter is modified in the nuclear medium as compared to its value in the QCD vacuum. Combining the PCAC hypothesis with changes in gluon condensate leads to lowering of vector masses in the nuclear medium. It also leads to predictions regarding, nucleon isobar mass differences, pion decay constant in the medium, pion amplitudes and transverse momentum distribution of secondaries in heavy ion collisions.
A Note on the Toda Criterion for Interacting Dipole–Quadrupole Vibrations
Authors: Manfredi V. R. , Salasnich L.
Published: October 2003

The Toda criterion of the Gaussian curvature is applied to calculate analytically the transition energy from regular to chaotic motion in a schematic model describing the interaction between collective dipole and quadrupole modes in atomic nuclei.
On Spinor Representations in the Weyl Gauge Theory
Authors: Barbashov B. M. , Pestov A. B.
Published: October 2003

A spinor current-source is found in the Weyl non-Abelian gauge theory which does not contain the abstract gauge space. It is shown that the searched spinor representation can be constructed in the space of external differential forms and it is a 16-component quantity for which a gauge-invariant Lagrangian is determined. The connection between the Weyl non-Abelian gauge potential and the Cartan torsion field, and the problem of a possible manifestation of the considered interactions are considered.
Recent Direct Measurement of the Top Quark Mass and Quasi-Infrared Fixed Point
Authors: Brahmachari Biswajoy
Published: October 2003

We note that the recent direct measurement of the top quark mass at 173.3±5.6 ( stat ) ±6.2 ( syst ) by DØ, collaboration severely constrains the theoretically attractive infrared fixed point scenario of the top quark Yukawa coupling in supersymmetric GUTs. For one-step unified models the above-mentioned measurement bounds the arbitrary but experimentally determinable parameter tan β to the range 1.3≤ tan β≤2.1. Further crunch on the top quark mass may determine tan β even more accurately within the fixed point scenario. On the other hand, an experimental value of tan β>2.1 will rule out the fixed point scenario bounding [Formula: see text] to 0.022 from above.
Zero-Point Problem in Fixed-Point Gauge of Nonperturbative QCD
Authors: Yang Jian-Jun , Shen Hong-Qing , Li Guang-Lie
Published: October 2003

We discuss the essence of the zero-point in fixed-point gauge of nonperturbative QCD and describe how to set the zero-point appropriately in deriving the nonperturbative quark–gluon three-point vertex functions including gluon condensates.
The Ostrogradsky Prescription for BFV Formalism
Authors: Nirov Khazret S.
Published: October 2003

Gauge-invariant systems of a general form with higher order time derivatives of gauge parameters are investigated within the framework of the BFV formalism. Higher order terms of the BRST charge and BRST-invariant Hamiltonian are obtained. It is shown that the identification rules for Lagrangian and Hamiltonian BRST ghost variables depend on the choice of the extension of constraints from the primary constraint surface.
Space–Time Defects: Torsion Walls
Authors: de Andrade L. C. Garcia
Published: October 2003

The geometry of torsion defects in Weitzenböck space–time is investigated. Conformal de Sitter space–time outside the defect is obtained. Geodesic motion of test particles outside the torsion wall is given. Torsion defect wall is shown to have repulsive gravitational fields. Static torsion defect is obtained by gluing together two half Minkowski spaces across a torsion wall junction.
The Search for New Physics by the Measurement of the Four-Jet Cross-Section at LHC and Tevatron
Authors: Bityukov S. I. , Krasnikov N. V.
Published: October 2003

We investigate the possibility to look for new physics by the measurement of the four-jet cross-section at LHC and Tevatron. In particular, we consider the model with scalar colour octet and the supersymmetric model with R-parity violation. In both models, pair produced new particles decay into two jets thus leading to four-jet events. Therefore, the measurement of the four-jet events allows one to look for new physics. The main background comes from the standard QCD four-jet events. We find that it would be possible to discover scalar colour octet particles with a mass ≤ 900 GeV at the LHC and up to about 175 GeV at the Tevatron.
On the Space–Time Uncertainty Relations of Liouville Strings and D-Branes
Authors: Amelino-Camelia G. , Mavromatos N. E. , Ellis John , Nanopoulos D. V.
Published: October 2003

Within a Liouville approach to noncritical string theory, we argue for a nontrivial commutation relation between space and time observables, leading to a nonzero space–time uncertainty relation δx δt>0, which vanishes in the limit of weak string coupling.
Curvature Expansion for the Gluodynamics String Including Perturbative Gluonic Contributions
Authors: Antonov D. V. , Ebert D.
Published: October 2003

Perturbation theory, which represents a Wilson loop in the SU(2) gluodynamics as an integral over all the orientations in color space, in the nonperturbative QCD vacuum and the non-Abelian Stokes theorem is applied to a derivation of the correction to the string effective action in the lowest order in the coupling constant g. This correction is due to the interaction of perturbative gluons with the string worldsheet and affects only the coupling constant of the rigidity term, while its contribution to the string tension of the Nambu–Goto term vanishes. The obtained correction to the rigidity coupling constant multiplicatively depends on the color "spin" of the representation of the Wilson loop under consideration and a certain path integral, which includes the background Wilson loop average.
On the Experimental Verification of the Wheeler–DeWitt Equation
Authors: Pollock M. D.
Published: October 2003

The Wheeler–DeWitt equation ℋΨ=0 for the wave function of the Universe Ψ can be written, in the Friedmann space–time (mini-superspace approximation) [Formula: see text], as the Schrödinger equation [Formula: see text], where ξ≡ dα/dt. The meaning of the pseudo-Hamiltonian [Formula: see text], which reduces to the potential V at low energies, is discussed both classically and quantum theoretically, this equation gives rise to a local gravitational Schrödinger equation which has been verified in the neutron interferometry experiment of Colella et al. By demanding the existence of a global ground state with nonvanishing probability density ΨΨ* for which V=0 (implying the vanishing of the cosmological constant), we argue that this experiment also constitutes evidence for the whole quantization procedure.
The Orientation Dependence of the Real Part of the Ion–Ion Potential between Two Nuclei
Authors: Ismail M. Y. , Ramadan Kh. A. , Osman M. M. , Salah F. , Ellithi A. Y.
Published: October 2003

The energy density formalism derived from both the conventional Skyrme force with parameter set SIII and the extended Skyrme force with parameters SKE1, SKE2, SKE3 and SKE4 has been used to study the orientation dependence of the real part of the ion–ion potential for the 238 U + 238 U system. Also, we considered the interaction potential between 238 U and three spherical nuclei. We compared our results for the real potential with the experimental results.
Extended Algebraic Structure of N=1 Conformal Superalgebra
Authors: Pilot Christopher , Rajpoot Subhash
Published: October 2003

It is shown that the usual algebraic structure of the commutation and anticommutation relations of the N=1 conformal superalgebra can be extended to include additional terms. These terms transform as parity odd under the discrete symmetry operation associated with parity. The constraints resulting from the Jacobi identities required for the consistency of the extended algebraic structure are also given. One limiting case of the algebra is shown to reduce to the algebra of Kaku, van Nieuwenhuizen and Townsend.
Trace Anomaly and Nonlocal Effective Action for 2-D Conformally Invariant Scalar Interacting with Dilaton
Authors: Nojiri Shin'ichi , Odintsov Sergei D.
Published: October 2003

Using the results of the calculation of the one-loop effective action (E. Elizalde et al., Phys. Rev.D49, 2852 (1994)), we find the trace anomaly for most general conformally invariant 2-D dilaton coupled scalar–dilaton system (the contribution of dilaton itself is included). The nonlocal effective action induced by conformal anomaly for such system is found. That opens new possibilities in generalizing of CGHS-like model for the study of back-reaction of matter to 2-D black holes.
A Symmetric Formulation of Maxwell's Equations
Authors: Múnera Héctor A. , Guzmán Octavio
Published: October 2003

The electromagnetic field formed by the pair (E, B) obeying Maxwell's equations (MEs) is reformulated as another pair (P, N) obeying a symmetric set of four equations tautologically equivalent to MEs. The symmetric set is formed by a pair of induction and a pair of source equations, each pair with exactly the same structure. In contrast to (E, B), charge and current densities contribute equally to both P and N. The equation of continuity is not an independent condition, but it is automatically fulfilled by any four-tuple (P, N, J, ρ) solving the symmetric MEs.

The symmetric equations in terms of potentials may be explicitly solved for a variety of constraint conditions, thus leading to different classes of solutions. Each class represents a family of problems defined by the constraints. One such family is the conventional class of solutions of MEs. Some unexpected results regarding the conventional solutions of MEs in terms of potentials are: (a) it is a particular case, (b) it may contain magnetic scalar potentials, and (c) there is no Coulomb gauge, thus removing the magnetic transversality constraint. It is not known whether the other classes of solutions correspond to physical problems.
Investigation on the Tachyonic Neutrino
Authors: Park Mu-In , Park Young-Jai
Published: October 2003

According to the experimental data, it is still controversial whether the neutrinos, especially the electron–neutrino and muon–neutrino, can be considered as the fermionic spinorial tachyons, and there is still no reliable report on the existence of the right-handed neutrinos. In this letter, we show that only the neutrinos with both handedness can be the tachyons, while the single handedness neutrinos are impossible to be the tachyons. Several implications of this result are discussed.
Freezing of the Affine Gravity and Singularity Free Cosmological Models
Authors: Scipioni R.
Published: October 2003

A modified version of the Einstein theory of gravity is proposed in which the constant G is dynamical, that is dependent on the energy stress tensor. This permits one to obtain a model in which the Planck's energy density is unbounded, meaning that gravity never reaches the condition ρ>ρ P . This permits one to separate the affine description from the quantum one, which has recently been observed not to be completely compatible. We describe moreover how this can bring us to violate the strong energy condition so as to avoid the constraints of singularity theorems.
On the Correspondence between Exact Solutions in Kaluza–Klein Theory and in Scalar–Tensor Theories
Authors: Billyard Andrew , Coley Alan
Published: October 2003

Using the formal equivalences between Kaluza–Klein gravity, Brans–Dicke theory and general relativity coupled to a massless scalar field, exact solutions obtained in one theory will correspond to analogous solutions in the other two theories. Often exact solutions in one theory are "rediscovered" since theory are not recognized as analogs of the corresponding solutions in one of the other theories. We review here a number of exact solutions in each of the theories, with an emphasis on identifying and presenting the higher-dimensional version of the solutions. We also briefly comment upon the formal equivalence between Kaluza–Klein theory and scalar–tensor theories in general.
B and D Meson Decay Constants Revisited
Authors: Chakrabarti B.
Published: October 2003

The ratios of B and D meson decay constants and also the double ratio (fBs/fBd)/(fDs/fDd) have been calculated using the variational method in conjunction with the relativistic Hamiltonian of the heavy meson in the framework of the statistical model. Using six different potentials of the potential model, we have obtained reliable results for them which are in good agreement with those of the lattice calculations.
The Phase-Difference Properties of Two-Mode Coherent States
Authors: Yang Yaping , Feng Weiguo , Wu Xiang
Published: October 2003

In this letter, we have constructed the creation and annihilation operators of phase-difference quanta and some of other operators in phase space. The algebraic properties of these operators and the phase-difference properties of two-mode coherent states are discussed.
Extended Conformal Symmetry of the One-Dimensional Bose Gas
Authors: Maule Milena , Sciuto Stefano
Published: October 2003

We show that the low-lying excitations of the one-dimensional Bose gas are described, at all orders in a 1/N expansion and at the first order in the inverse of the coupling constant, by an effective Hamiltonian written in terms of an extended conformal algebra, namely the Cartan subalgebra of the [Formula: see text] algebra. This enables us to construct the first interaction term which corrects the Hamiltonian of the free fermions equivalent to a hard-core boson system.
Mixing Angles and Decay Constants in the SU(4) Mixing Scheme of η–η′–ηc–ι
Authors: Nandy M. , Gautam V. P.
Published: October 2003

We extend the SU(3) mixing of isosinglet pseudoscalar mesons to the SU(4) level with η, η′, ηc and ι. The quarkonium gluonium content of the physical states at the SU(4) level are being numerically estimated. We derive a mass relation at the SU(4) level taking the divergence of vector current into account and solve for the SU(4) mixing angles and decay constants using the constraints obtained from anomalous Ward identities, the mass relation, topological susceptibility, SU(4) transformation properties of pseudoscalar density, experimental data and other presently available constraints. The mixing has suggested that besides charm quark content, ηc meson has some percentage of normal and strange quarks along with gluonium as its constituents.
Quanta Without Quantization
Authors: Wheeler James T.
Published: October 2003

The dimensional properties of fields in classical general relativity lead to a tangent tower structure which gives rise directly to quantum mechanical and quantum field theory structures without quantization.

We derive all the fundamental elements of quantum mechanics from the tangent tower structure, including fundamental commutation relations, a Hilbert space of pure and mixed states, measurable expectation values, Schrödinger time evolution, "collapse" of a state and the probability interpretation.

The most central elements of string theory also follow, including an operator valued mode expansion like that in string theory as well as the Virasoro algebra with central charges.
Five-Dimensional Gauge Theories and Whitham–Toda Equation
Authors: Hisakado Masato
Published: October 2003

The five-dimensional supersymmetric SU (N) gauge theory is studied in the framework of the relativistic Toda chain. This equation can be embedded in two-dimensional Toda lattice hierarchy. This system has the conjugate structure which corresponds to the charge conjugation.
Scaling Law for Baryon Coupling to its Current and its Possible Applications
Authors: Dey Jishnu , Dey Mira , Frederico T. , Tomio Lauro
Published: October 2003

The baryon coupling to its current (λB), in conventional QCD sum rule calculations (QCDSR), is shown to scale as the cubic power of the baryon mass, MB. Some theoretical justification for it comes from a simple light-cone model and also general scaling arguments for QCD. But more importantly, taken as a phenomenological ansatz for the present, this may find very good use in current explorations of possible applications of QCDSR to baryon physics both at temperature T=0, T≠0 and/or density ρ=0, ρ≠0.