bluuebunny/crossref_metadata_2025 huggingface dataset:
Crystal Structure of the 65-Kilodalton Heat Shock Protein, Chaperonin 60.2, ofMycobacterium tuberculosis
Authors: Qamra Rohini , Mande Shekhar C.
Published: November 2004

Chaperonin 60s are a ubiquitous class of proteins that promote folding and assembly of other cellular polypeptides in an ATP-dependent manner. The oligomeric state of chaperonin 60s has been shown to be crucial to their role as molecular chaperones. Chaperonin 60s are also known to be important stimulators of the immune system.Mycobacterium tuberculosispossesses a duplicate set of chaperonin 60s, both of which have been shown to be potent cytokine stimulators. TheM. tuberculosischaperonin 60s are present in the extracellular milieu at concentrations that are extremely low for the formation of an oligomer. Here we present the crystal structure of one of the chaperonin 60s ofM. tuberculosis, also called Hsp65 or chaperonin 60.2, at 3.2-Å resolution. We were able to crystallize the protein in its dimeric state. The unusual dimerization of the protein leads to exposure of certain hydrophobic patches on the surface of the protein, and we hypothesize that this might have relevance in binding to immunogenic peptides, as it does in the eukaryotic homologs.
A Self-Splicing Group I Intron in DNA Polymerase Genes of T7-Like Bacteriophages
Authors: Bonocora Richard P. , Shub David A.
Published: November 2004

Group I introns are inserted into genes of a wide variety of bacteriophages of gram-positive bacteria. However, among the phages of enteric and other gram-negative proteobacteria, introns have been encountered only in phage T4 and several of its close relatives. Here we report the insertion of a self-splicing group I intron in the coding sequence of the DNA polymerase genes of ΦI and W31, phages that are closely related to T7. The introns belong to subgroup IA2 and both contain an open reading frame, inserted into structural element P6a, encoding a protein belonging to the HNH family of homing endonucleases. The introns splice efficiently in vivo and self-splice in vitro under mild conditions of ionic strength and temperature. We conclude that there is no barrier for maintenance of group I introns in phages of proteobacteria.
Type II Isopentenyl Diphosphate Isomerase fromSynechocystissp. Strain PCC 6803
Authors: Barkley Sam J. , Desai Shrivallabh B. , Poulter C. Dale
Published: November 2004

Open reading framesll1556in the cyanobacteriumSynechocystissp. strain 6803 encodes a putative type II isopentenyl diphosphate (IPP) isomerase. The His6-tagged protein was produced inEscherichia coliand purified by Ni2+chromatography. The homotetrameric enzyme required NADPH, flavin mononucleotide, and Mg2+for activity;KmIPPwas 52 μM, andkcatIPPwas 0.23 s−1.
A glossary of terms for navigating the field of social network analysis
Authors: Hawe Penelope , Webster Cynthia , Shiell Alan
Published: November 2004

Social network analysis is the study of social structure. This glossary introduces basic concepts in social network analysis. It is designed to help researchers to be more discriminating in their thinking and choice of methods.
A FUZZY NEURAL NETWORK FOR KNOWLEDGE LEARNING
Authors: FU H.C. , SHANN J.J.
Published: November 2004

This paper presents a fuzzy neural network for learning the knowledge of a fuzzy logic rule-based system. The network contains five layers: an Input Layer, Membership-function Layer, AND Layer, OR Layer, and Defuzzification Layer. We propose a backpropagation-like learning algorithm to train this neural network to acquire the fuzzy rules and to fine-tune the knowledge on the parameters of AND and OR nodes. Compared with methods other than the gradient descent search, the proposed learning process acquires more precise knowledge. In addition, the functions of the AND and OR nodes in the network are formulated with the minimum or maximum operations, respectively. Therefore, the adjustments of the learnable weights (parameters) can be focused on the dominant terms related to the (minimum/maximum) operations. The convergence time for the proposed learning algorithm is much faster than that for conventional backpropagation algorithms. In summary, the learnable weights (parameters) of the network are adjusted very quickly to obtain precise knowledge. Simulation results show that in learning the truck backer-upper problem, our network completes the training procedure in only several dozen epochs with an error rate of less than 1%.
ON THE CLASSIFICATION CAPABILITY OF A DYNAMIC THRESHOLD NEURAL NETWORK
Authors: CHIANG CHENG-CHIN , FU HSIN-CHIA
Published: November 2004

This paper proposes a new type of neural network called the Dynamic Threshold Neural Network (DTNN) which is theoretically and experimentally superior to a conventional sigmoidal multilayer neural network in classification capability, Given a training set containing 4k+1 patterns in ℜn, to successfully learn this training set, the upper bound on the number of free parameters for a DTNN is (k+1)(n+2)+2(k +1), while the upper bound for a sigmoidal network is 2k(n+1)+(2k+1). We also derive a learning algorithm for the DTNN in a similar way to the derivation of the backprop learning algorithm. In simulations on learning the Two-Spirals problem, our DTNN with 30 neurons in one hidden layer takes only 3200 epochs on average to successfully learn the whole training set, while the single-hidden-layer feedforward sigmoidal neural networks have never been reported to successfully learn the given training set even though more hidden neurons are used.
NEURAL NETWORK FOR CONTROL OF REARRANGEABLE CLOS NETWORKS
Authors: PARK YOUNG-KEUN , CHERKASSKY VLADIMIR
Published: November 2004

Rapid evolution in the field of communication networks requires high speed switching technologies. This involves a high degree of parallelism in switching control and routing performed at the hardware level. The multistage crossbar networks have always been attractive to switch designers. In this paper a neural network approach to controlling a three-stage Clos network in real time is proposed. This controller provides optimal routing of communication traffic requests on a call-by-call basis by rearranging existing connections, with a minimum length of rearrangement sequence so that a new blocked call request can be accommodated. The proposed neural network controller uses Paull’s rearrangement algorithm, along with the special (least used) switch selection rule in order to minimize the length of rearrangement sequences. The functional behavior of our model is verified by simulations and it is shown that the convergence time required for finding an optimal solution is constant, regardless of the switching network size. The performance is evaluated for random traffic with various traffic loads. Simulation results show that applying the least used switch selection rule increases the efficiency in switch rearrangements, reducing the network convergence time. The implementation aspects are also discussed to show the feasibility of the proposed approach.
LOCAL NOISE IN NEURAL NETWORKS MODELS WITH SELF-CONTROL
Authors: ŻOCHOWSKI MICHAL , LEWENSTEIN MACIEJ , NOWAK ANDRZEJ
Published: November 2004

We modify neural networks models of the Hopfield type so that they can recognize the degree of novelty of the input stimuli on a local level. The networks control themselves the quality of recognition and can also recognize locally the bits of information in the input patterns which do not agree with known patterns, i.e. stored memories. This task is achieved by introducing local variations of the noise level β in the network. Noise level in a given location depends on the flip frequency of the neurons close to that location.
THERMODYNAMIC q-DISTRIBUTIONS THAT AREN’T
Authors: VOKOS STAMATIS , ZACHOS COSMAS
Published: November 2004

Bosonic q-oscillators commute with themselves and so their free distribution is Planckian. In a cavity, their emission and absorption rates may grow or shrink – and even diverge – but they nevertheless balance to yield the Planck distribution via Einstein’s equilibrium method, (a careless application of which might produce spurious q-dependent distribution functions). This drives home the point that the black-body energy distribution is not a handle for distinguishing q-excitations from plain oscillators. A maximum cavity size is suggested by the inverse critical frequency of such emission/absorption rates at a given temperature, or a maximum temperature at a given frequency. To remedy fragmentation of opinion on the subject, we provide some discussion, context, and references.
IS THE MILNE COORDINATE SYSTEM A GOOD ONE?
Authors: ARCURI R.C. , SVAITER B.F. , SVAITER N.F.
Published: November 2004

The upper and lower quadrants of flat space-time can be described using the Milne coordinate system. The Klein-Gordon equation of a scalar field in such a coordinate system admits at least two sets of solutions. Based on the Feynman propagator behavior it is shown that only one of the two sets gives the conventional interpretation of quantum field theory, based on a Fock space. Therefore, discarding the other set, one can still keep the Milne coordinate system.
QUANTUM MECHANICS ON A CLOSED LOOP
Authors: OHNUKI Y. , KITAKADO S.
Published: November 2004

Quantum mechanics on the loop of arbitrary shape is formulated, which is an extension of previous formulations of quantum mechanics on S1 preserving its topology. It is shown that the representation spaces of the algebra do not change under the extension. We also derive, in the x-diagonal representation, the explicit expressions for the operators px and py that satisfy the constraints of the Dirac quantization on the closed loop.
CONFORMAL INVARIANCE IN CLASSICAL FIELD THEORY
Authors: GRIGORE D.R.
Published: November 2004

A geometric generalization of the first order Lagrangian formalism is used to analyze a conformal field theory for an arbitrary primary field. We require that the global conformal transformations are Noetherian symmetries and we prove that the action functional can be taken strictly invariant with respect to these transformations. In other words, there does not exist a “Chern-Simons” type Lagrangian for a conformally invariant Lagrangian theory.
ON THE DEFINITENESS OF THE CONFORMAL ANOMALY IN NONCONFORMAL GAUGES
Authors: MÖDRITSCH W.
Published: November 2004

The critical dimension of the bosonic string in the harmonic and the deDonder gauge may be calculated from the time ordered product of two energy momentum tensors. We show that recently found ambiguities within that method in nonconformal gauges can be resolved by a treatment keeping a nonflat background.
HEAVY QUARK PRODUCTION BY HARD DIFFRACTIVE SCATTERING
Authors: ARISAWA TETSUO
Published: November 2004

Heavy quark production in hard diffractive scattering is analyzed with evaluation of cross-sections and Monte-Carlo event generations. “Super hard” Pomeron, the existence of which was recently supported by the UA8 collaboration at CERN [Formula: see text] Collider [Formula: see text], is included by proposing a new method of determining Pomeron structures. Detection of (anti-)top quarks in the single diffractive processes is also mentioned.
FREE SUPERFIELD REALIZATION OF N=2 QUANTUM SUPER-W3 ALGEBRA
Authors: AHN CHANGHYUN
Published: November 2004

We rewrite N=2 quantum super-W3 algebra, a nonlinear extended N=2 super Virasoro algebra, containing one additional primary superfield of dimension two which has no U(1) charge, besides the super stress energy tensor of dimension one in N=2 superspace. The free superfield realization of this algebra is obtained by two N=2 chiral fermionic superfields of dimension 1/2 satisfying N=2 complex U(1) Kac-Moody algebras.
LIMIT TO SPACE-TIME MEASUREMENT
Authors: JACK NG Y. , VAN DAM H.
Published: November 2004

Applying simultaneously the principles of quantum mechanics and general relativity we find an intrinsic limitation to quantum measurements of space-time distances. The intrinsic uncertainty of a length is shown to be proportional to the one third power of the length itself. This uncertainty in space-time measurements implies an intrinsic uncertainty of the space-time metric and yields quantum decoherence for particles heavier than the Planck mass.
QUANTUM DILOGARITHM
Authors: FADDEEV L.D. , KASHAEV R.M.
Published: November 2004

A quantum generalization of Rogers’ five-term, or “pentagon” dilogarithm identity is suggested. It is shown that the classical limit gives the usual Rogers’ identity. The case where the quantum identity is realized in finite-dimensional space is also considered and the quantum dilogarithm is constructed as a function on Fermat curve, while the identity itself is equivalent to the restricted star-triangle relation introduced by Bazhanov and Baxter.
STANDARD MODEL CP-VIOLATION AND BARYON ASYMMETRY
Authors: GAVELA M. B. , HERNÁNDEZ P. , ORLOFF J. , PÈNE O.
Published: November 2004

In CP arguments, we argue against a Standard Model explanation of the baryon asymmetry of the universe in the presence of a first order phase transition. A CP-asymmetry is found in the reflection coefficients of quarks hitting the phase boundary created during the electroweak transition. The problem is analyzed both in an academic zero temperature case and in the realistic finite temperature one. The building blocks are similar in both cases: Kobayashi-Maskawa CP-violation, CP-even phases in the reflection coefficients of quarks, and physical transitions due to fermion self-energies. In both cases an effect is present at order [Formula: see text] in rate. A regular GIM behavior is found as intuitively expected. In the finite temperature case, a crucial role is played by the damping rate of quasiparticles in a hot plasma, which is a relevant scale together with MW and the temperature. The effect is many orders of magnitude below what observation requires, and indicates that non-standard physics is indeed needed in the cosmological scenario.
TARGET SPACE OF AN ASYMMETRIC CHIRAL GAUGED WZW MODEL
Authors: KAR SUPRIYA , KUMAR ALOK , SENGUPTA GAUTAM
Published: November 2004

It is shown that the asymmetric chiral gauging of the WZW models give rise to consistent string backgrounds. The target space structure of the chiral gauged SL (2, ℝ) WZW model, with the gauging of subgroups SO(1, 1) in the left and U(1) in the right moving sector, is obtained. We then analyze the symmetries of the background and show the presence of a non-trivial isometry in the canonical parametrization of the WZW model. Using these results, the equivalence of the asymmetric models with the symmetric ones is demonstrated.
ON THE POINCARÉ POLYNOMIALS FOR LANDAU-GINZBURG ORBIFOLDS
Authors: SATO HITOSHI
Published: November 2004

We construct the Poincaré polynomials for Landau-Ginzburg orbifolds with projection operators. Using them we show that special types of dualities including Poincaré duality are realized under certain conditions. When Calabi-Yau interpretation exists, two simple formulas for Hodge numbers h2,1 and h1,1 are obtained.
CHIRAL SYMMETRY BREAKING IN THE d = 3 NAMBU-JONA-LASINIO MODEL IN CURVED SPACE-TIME
Authors: ELIZALDE E. , ODINTSOV S. D. , SHIL'NOV YU. I.
Published: November 2004

The phase structure of the d = 3 Nambu-Jona-Lasinio model in curved space-time is considered to leading order in the 1/N-expansion and in the linear curvature approximation. The possibility of a curvature-induced first order phase transition is investigated numerically. The dynamically generated fermionic mass is calculated for some values of the curvature.
GAUGE FIELDS ON RIEMANN-CARTAN SPACE-TIMES
Authors: SAA ALBERTO
Published: November 2004

Gauge fields are described on a Riemann-Cartan space-time by means of tensor-valued differential forms and exterior calculus. It is shown that minimal coupling procedure leads to a gauge invariant theory where gauge fields interact with torsion, and that consistency conditions for the gauge fields impose restrictions in the non-Riemannian structure of space-time. The new results differ from the well established ones obtained by using minimal coupling procedure at the action formulation. The sources of these differences are pointed out and discussed.
TEST OF GOLDSTONE BOSON EQUIVALENCE THEOREM
Authors: DUTTA B. , NANDI S.
Published: November 2004

We study the convergence (with energy) of the exact longitudinal gauge boson scattering amplitude to that given by the equivalence theorem. For low Higgs boson masses, this convergence is rather slow, and can have significant effect at the SSC energies. We find that in addition to [Formula: see text] terms, the two amplitudes differ by terms of [Formula: see text]. We incorporate the presence of such terms in the general proof of the equivalence theorem.
SUSY BREAKING IN CELKA-HUSSIN'S GENERAL 3D MODEL OSCILLATOR HAMILTONIAN AND THE WIGNER PARAMETER
Authors: JAYARAMAN J. , DE LIMA RODRIGUES R.
Published: November 2004

The free parameter of the generalized 3D SUSY model oscillator Hamiltonian of Celka and Hussin is identified here with the Wigner parameter of a related super-realized general 3D Wigner oscillator system satisfying a super-generalized quantum commutation rule. The super-oscillator technique is then advantageously employed to determine fully a previously only partially given spectrum by Celka and Hussin for their Hamiltonian. The dependence of the spectrum on the Wigner parameter and the consequent occurrence of exceptional SUSY breakings in the model are clearly brought out.
SEARCH FOR CHARGINO AND NEUTRALINO PRODUCTION AT THE LHC IN THE LEFT-RIGHT SUPERSYMMETRIC MODEL
Authors: SAIF H. N.
Published: November 2004

An extension of the supersymmetric Standard Model to the left-right supersymmetric model (L-R SUSY), SU (2) L × SU (2) R × U (1)B-L, is considered. We investigate the possibility of detecting chargino and neutralino production at the LHC [Formula: see text] through the process [Formula: see text]. A numerical analysis is presented for the chargino mass [Formula: see text] neutralino mass [Formula: see text] and tan θκ = 1.6. Based on reasonable assumptions on W R , and assuming g L ≃ g R ≃ g, we take MW R = 1 TeV . The results are compared with the conventional background signal of the process [Formula: see text].
A SOLVABLE 2D GRAVITY MODEL WITH γ>0
Authors: AMBJØRN J. , DURHUUS B. , JONSSON T.
Published: November 2004

We consider a model of discretized 2D gravity interacting with Ising spins where the phase boundaries are restricted to have minimal length and show analytically that the critical exponent, γ, is 1/3 at the spin transition point. The model captures the numerically observed behavior of standard multiple Ising spins coupled to 2D gravity.
LEPTON SPECTRA AND THE b POLARIZATION AT LEP
Authors: MELE BARBARA
Published: November 2004

I review the present state of knowledge on lepton energy spectra in the inclusive semileptonic decay of beauty hadrons (Hb→ℓν…) as a means to measure b polarization effects on the Z0 peak. Charged-lepton as well as neutrino spectra are considered.
BRST COHOMOLOGY IN QUANTUM AFFINE ALGEBRA $U_q \left( {\widehat{sl_2 }} \right)$
Authors: KONNO HITOSHI
Published: November 2004

Using free field representation of quantum affine algebra [Formula: see text], we investigate the structure of the Fock modules over [Formula: see text]. The analysis is based on a q-analog of the BRST formalism given by Bernard and Felder in the affine Kac-Moody algebra [Formula: see text]. We give an explicit construction of the singular vectors using the BRST charge. By the same cohomology analysis as the classical case (q=1), we obtain the irreducible highest weight representation space as a non-trivial cohomology group. This enables us to calculate a trace of the q-vertex operators over this space.
A NOVEL COVARIANT APPROACH TO THE QUANTIZATION OF INTERACTIVE CHIRAL BOSONS
Authors: ZHOU JIAN-GE , MIAO YAN-GANG , LIU YAO-YANG
Published: November 2004

A new covariant quantization of chiral bosons in the chiral Schwinger model with faddeevian regularization is carried out from Batalin-Fradkin (BF) algorithm. In order to turn the second class chiral constraint into first class constraints, infinitely many BF fields are first introduced. When combined with Batalin-Fradkin-Vilkovisky (BFV) formalism, two kinds of BRST-invariant actions have been derived. The first contains the Wess-Zumino action induced from the usual path-integral approach. But the second includes Wotzasek’s Wess-Zumino action coupled to the gauge fields.
THE EFFECTS OF THE QCD CORRECTIONS TO $\Gamma \left( {H^0 \to b\bar b} \right)$
Authors: KATAEV ANDREI L. , KIM VICTOR T.
Published: November 2004

We consider in detail various theoretical uncertainties of the perturbative predictions for the decay width of [Formula: see text] process in the region 60 GeV<MH≤2 MW. We calculate the order [Formula: see text]-contributions to the expression for [Formula: see text] through the pole b-quark mass mb and demonstrate that they are important for the elimination of the numerical difference between the corresponding expression and the renormalization-group (RG) which can be improved by the running b-quark mass. In the case of mb=4.8 GeV and [Formula: see text] we observe the identical cancellation of the next-to-leading order RG-improved corrections to [Formula: see text] at Mch=130 (65) GeV and the indications to the asymptotic explosion of the corresponding next-to-next-to-leading parametrization. The theoretical importance of the order [Formula: see text] massive corrections [Formula: see text] to for modeling the threshold effects is demonstrated.
THE CHARGED NEUTRINO: A NEW APPROACH TO THE SOLAR NEUTRINO PROBLEM
Authors: IGNATIEV A.YU. , JOSHI G.C.
Published: November 2004

We have considered the effect of the reduction of the solar neutrino flux on earth due to the deflection of the charged neutrino by the magnetic field of the solar convective zone. The antisymmetry of this magnetic field about the plane of the solar equator induces the anisotropy of the solar neutrino flux thus creating the deficit of the neutrino flux on the earth. The deficit has been estimated in terms of solar and neutrino parameters and the condition of a 50% deficit has been obtained: Qν grad H≥10−18 eG/cm where Qν is the neutrino electric charge, grad H is the gradient of the solar toroidal magnetic field, e is the electron charge. Some attractive experimental consequences of this scenario are qualitatively discussed.
EXCHANGE RELATIONS OF LAX PAIR FOR NONLINEAR SIGMA MODELS
Authors: HOU BO-YU , DING XIANG-MAO , WANG YAN-SHEN , HOU BO-YUAN
Published: November 2004

We find that the non-ultralocal term s in classical Yang-Baxter r−s matrix consist of Riemann’s connections of target manifold G/H and field-independent projection operators in local coordinates on symmetric space G/H. We give the gauge transformations formula for the Poisson bracket of Lax pair and r−s matrix, and relate these expressions in terms of moving frame with that of fixed frame by current algebra.
ON SPHALERON DEFORMATIONS INDUCED BY YUKAWA INTERACTIONS
Authors: AXENIDES MINOS , JOHANSEN ANDREI , NIELSEN HOLGER BECH
Published: November 2004

Due to the presence of the chiral anomaly sphalerons, half a number of Chern-Simons (CS=1/2) are the only static configurations that allow a fermion level crossing in the two-dimensional Abelian-Higgs model with massless fermions, i.e. in the absence of Yukawa interactions. In the presence of fermion-Higgs interactions we demonstrate the existence of zero energy solutions to the one-dimensional Dirac equation at deformed sphalerons with CS ≠ 1/2. Induced level crossing due to Yukawa interactions illustrates a non-trivial generalization of the Atiyah-Patodi-Singer index theorem and of the equivalence between parity anomaly in odd and chiral anomaly in even dimensions. We discuss a subtle manifestation of this effect in the standard electroweak theory at finite temperatures.
POSSIBLE HUGE ENHANCEMENT IN THE RADIATIVE DECAY OF THE WEAK W BOSON INTO A PION OR A CHARMED Ds MESON
Authors: KEUM Y.Y. , PHAM X.Y.
Published: November 2004

We point out that the rare decay modes [Formula: see text], [Formula: see text] could be very much enhanced, with a branching ratio around 10−6 which is some hundreds times larger than previous predictions. Its observation will determine the W boson mass with great accuracy, providing additional high precision test of the Standard Model, as well as reveal eventual deviation from the trilinear non-Abelian gauge coupling.
THE SOLUTIONS OF AFFINE AND CONFORMAL AFFINE TODA FIELD THEORIES
Authors: PAPADOPOULOS G. , SPENCE B.
Published: November 2004

We give new formulations of the solutions of the field equations of the affine Toda and conformal affine Toda theories on a cylinder and two-dimensional Minkowski space-time. These solutions are parametrized in terms of initial data and the resulting covariant phase spaces are diffeomorphic to the Hamiltonian ones. We derive the fundamental Poisson brackets to the parameters of the solutions and give the general static solutions for the affine theory.
ON THE LIMITATIONS OF NEUTRINO EMISSIVITY FORMULA OF IWAMOTO
Authors: GHOSH SANJAY K. , PHATAK S.C. , SAHU PRADIP K.
Published: November 2004

The neutrino emissivity from two- and three-flavor quark matter is numerically calculated and compared with Iwamoto’s formula. We find that the calculated emissivity is smaller than Iwamoto’s result by orders of magnitude when pf(u)+pf(e)−pf(d(s)) is comparable with the temperature. We attribute it to the severe restriction imposed by momentum conservation on the phase space integral. We obtain an alternative formula for the neutrino emissivity which is valid for any value of pf(u)+Pf(e)−Pf(d(s)) when the quarks and electrons are degenerate.
THREE-DIMENSIONAL $\left( {\bar \psi \psi } \right)^2 $ MODEL AND OPTIMIZED EXPANSION
Authors: KLIMENKO K.G.
Published: November 2004

An alternative way to study the (2+1)-dimensional four-fermion model using the method of optimized expansions has been proposed. Contrary to Ref. 5 we use the technique of auxiliary scalar fields. In this the interpolation Lagrangian becomes nonlinear over the parameter ε. The effective potential has been constructed with the help of the canonical optimized procedure. A similar phase structure, as in the 1/N expansion, has been predicted. The β-function of the theory has been calculated in the framework of the optimized expansion method.
THE RETARDATION EFFECT ON 1P1 STATES OF HEAVY QUARKONIUM
Authors: YU-BING DONG , JUNCHEN SU , SHISHU WU
Published: November 2004

By employing the two-body relativistic equation as the starting point to calculate the spin-averaged spectrum of heavy quarkonium, we obtain a negative P-state energy difference ΔEP=E(3Pcog)−E(1P1) of charmonium, which fits the data.
LINEAR TIME-DEPENDENT INVARIANTS FOR SCALAR FIELDS AND NOETHER’S THEOREM
Authors: CASTAÑOS O. , LÓPEZ-PEÑA R. , MAN’KO V.I.
Published: November 2004

The infinite number of time-dependent linear in field and conjugated momenta invariants is derived for the scalar field using the Noether’s theorem procedure.
RELATIONS BETWEEN HYPERELLIPTIC INTEGRALS
Authors: PAKULIAK S. , PERELOMOV A.
Published: November 2004

A simple property of the integrals over the hyperelliptic surfaces of arbitrary genus is observed. Namely, the derivatives of these integrals with respect to the branching points are given by the linear combination of the same integrals. We check that this property is responsible for the solution to the level zero Knizhnik-Zamolodchikov equation given in terms of hyperelliptic integrals.
WORMHOLE SOLUTIONS IN THE KANTOWSKI-SACHS SPACE-TIME
Authors: CAVAGLIÀ MARCO
Published: November 2004

I present quantum wormhole solutions in the Kantowski-Sachs space-time generated from coupling the gravitational field to the axion and EM fields. These solutions correspond to the classical ones found by Keay and Laflamme and by Cavaglià et al.
GEOMETRIC PHASE FACTORS AND GENERALIZED AHARONOV-BOHM EFFECT
Authors: LEAL LORENZO
Published: November 2004

The quantum mechanics of charged particles or strings interacting with static vortices is written down in a geometric language. The wave function acquires a topological path dependence or surface dependence whose physical interpretation is discussed.
PHYSICAL STATES IN TOPOLOGICAL N=2 SUPERSYMMETRIC WZW MODELS
Authors: PARKHOMENKO S.E.
Published: November 2004

N=2 supersymmetric WZW models associated with finite-dimensional Manin triples are considered. The spectrum and the ring structure of physical states in topological version of these models are computed.
2D ISING MODEL WITH A DEFECT LINE
Authors: CABRA D. , NAÓN C.
Published: November 2004

We study the two-dimensional Ising model with a defect line and evaluate multipoint energy correlation functions using nonperturbative field-theoretical methods. We also discuss the evaluation of the two-spin correlator on the defect line.
TOPOLOGICAL ELECTROPOLES IN (4+1)-DIMENSIONAL EYMCS THEORY
Authors: AULAKH C.S. , SONI V.
Published: November 2004

A class of explicit exact solutions of Einstein-Yang-Mills-Chern-Simons (EYMCS) theory corresponding to topological solitons carrying non-Abelian topological electric charge is obtained. This verifies a conjecture made in Refs. 1 and 2 regarding the stabilization of the corresponding charged configurations in the theory without gravity.
LOCAL MAGNETIZATION IN CRITICAL ISING MODEL WITH BOUNDARY MAGNETIC FIELD
Authors: CHATTERJEE R. , ZAMOLODCHIKOV A.
Published: November 2004

We describe a simple way to derive spin correlation functions in 2-D Ising model at critical temperature but with nonzero magnetic field at the boundary. Local magnetization (i.e. one-point function) is computed explicitly for half-plane and disk geometries.
ON THE NATURE OF NONPERTURBATIVE EFFECTS IN STABILIZED 2-D QUANTUM GRAVITY
Authors: DIEGO OSCAR , GONZÁLEZ JOSÉ
Published: November 2004

We remark that the weak coupling regime of the stochastic stabilization of 2-D quantum gravity has a unique perturbative vacuum. By means of Monte-Carlo simulations we show that the nonperturbative vacuum has no bounded eigenvalues around the local minimum of the stabilized potential. Nonperturbative effects can be assessed in the loop equation. This can be derived from the Ward identities of the stabilized model and is shown to be modified by nonperturbative terms.
DISCRETE QUANTUM FIELD THEORIES AND THE INTERSECTION FORM
Authors: BIRMINGHAM DANNY , RAKOWSKI MARK
Published: November 2004

It is shown that the standard mod-p valued intersection form can be used to define Boltzmann weights of subdivision invariant lattice models with gauge group Zp. In particular, we discuss a four-dimensional model which is based on the assignment of field variables to the two-simplices of the simplicial complex. The action is taken to be the intersection form defined on the second cohomology group of the complex, with coefficients in Zp. Subdivision invariance of the theory follows when the coupling constant is quantized and the field configurations are restricted to those satisfying a mod-p flatness condition. We present an explicit computation of the partition function for the manifold ± CP 2, demonstrating non-triviality.
LIOUVILLE THEORY: WARD IDENTITIES FOR GENERATING FUNCTIONAL AND MODULAR GEOMETRY
Authors: TAKHTAJAN LEON A.
Published: November 2004

We continue the study of quantum Liouville theory through Polyakov’s functional integral,1,2 started in Ref. 3. We derive the perturbation expansion for Schwinger’s generating functional for connected multi-point correlation functions involving stress-energy tensor, give the “dynamical” proof of the Virasoro symmetry of the theory and compute the value of the central charge, confirming previous calculation in Ref. 3. We show that conformal Ward identities for these correlation functions contain such basic facts from Kähler geometry of moduli spaces of Riemann surfaces, as relation between accessory parameters for the Fuchsian uniformization, Liouville action and Eichler integrals, Kähler potential for the Weil-Petersson metric, and local index theorem. These results affirm the fundamental role that universal Ward identities for the generating functional play in Friedan-Shenker modular geometry.4
MODEL FOR GLUON PROPAGATOR FROM ANALYSIS IN RENORMALIZATION GROUP
Authors: KISELEV V.V.
Published: November 2004

The gluon propagator is considered on the basis of one-loop calculations in the renormalization group. To describe a set of nonperturbative phenomena such as heavy quark potential, gluon and quark condensates, constituent masses of light quarks, this analysis allows one to propose a model for the gluon propagator in the vicinity of ir region.
ELECTRON-POSITRON PRODUCTION IN STRONG FIELD PULSES
Authors: MENDES R. VILELA
Published: November 2004

A short critical review is presented concerning the physical interpretation of electron and positron production data at the GSI accelerator in Darmstadt. The only reliable conclusions seem to be that the creation mechanism is a strong field effect and that the phenomenon is largely independent of the characteristic time of the collision.

Before looking for new (exotic) physics it seems reasonable to inquire whether non-perturbative QED is fully understood. Following this motivation a rigorous but, at the same time, sufficiently explicit nonperturbative calculation scheme is developed, for QED in strong fields of short duration. The possible occurrence of correlated e+e− narrow structures is discussed in this framework.
ANISOTROPIC SOLUTIONS FOR ORBIFOLD MODULI FROM DUALITY INVARIANT GAUGINO CONDENSATES
Authors: BAILIN D. , LOVE A. , SABRA W.A. , THOMAS S.
Published: November 2004

The values of the T and U moduli are studied for those ZN Coxeter orbifolds with the property that some of the twisted sectors have fixed planes for which the six-torus T6 cannot be decomposed into a direct sum T2⊕T4 with the fixed plane lying in T2. Such moduli in general transform under a subgroup of the modular group SL (2,ℤ). The moduli are determined by minimizing the effective potential derived from a duality invariant gaugino condensate.
QUANTUM MECHANICS AS BAYESIAN COMPLEX PROBABILITY THEORY
Authors: YOUSSEF SAUL
Published: November 2004

As a possible alternative to conventional quantum mechanics, the Bayesian version of probability theory is extended to include complex probabilities. An additional assumption of realism restores a frequency interpretation while coexisting with Bell’s theorem. Such complex probabilities are shown to have a superposition principle, to include wave functions which are expansions in eigenfunctions of Hermitian operators, to have a path-integral representation and to describe both pure and mixed systems. A scalar particle in Rd is shown to obey the Schrödinger equation with mass, vector potential and metric appearing as moments of a fundamental probability. Illustrative examples are given. The quantum version of Bayesian inference is discussed.
ELECTROWEAK BARYOGENESIS AND THE PHASE TRANSITION DYNAMICS
Authors: YAMAGUCHI AZUSA , SUGAMOTO AKIO
Published: November 2004

The baryogenesis is reanalyzed based on the model by Cohen et al., in which the lepton number, generated by the neutrinos scattering from the bubble walls appearing in the development of the electroweak phase transition, is converted to the baryon number excess through the sphaleron transition. A formula obtained in this paper on the lepton number production rate is correct for both the thin and thick walls within the linear approximation.

Investigation on the time development of the first order phase transition is simulated, including the temporal change of the wall velocity as well as the fusion effect of the bubbles. The details of such phase transition dynamics are found to affect considerably the final value of the baryon number excess.
COSMIC STRINGS AND ELECTROWEAK SYMMETRY RESTORATION IN THE TWO-HIGGS DOUBLET MODEL
Authors: TRODDEN MARK
Published: November 2004

We investigate the region of restored electroweak symmetry around a superconducting cosmic string coupled to the Weinberg-Salam model with an extra Higgs doublet. We show that the presence of the extra Higgs fields, and in particular their CP violating relative phase, does not qualitatively affect the results of Perkins and Davis1 obtained for the standard electroweak theory. This result is necessary to ensure the validity of some recently proposed string-mediated electroweak baryogenesis scenarios.
QUANTUM GRAVITY AND NON-UNITARITY IN BLACK HOLE EVAPORATION
Authors: KIEFER CLAUS , MÜLLER RAINER , SINGH TEJINDER P.
Published: November 2004

We discuss the relevance of quantum gravitational corrections to the functional Schrödinger equation for black hole evaporation. These corrections are found from the Wheeler–DeWitt equation through a semiclassical expansion scheme. The dominant contribution in the final evaporation stage, when the black hole approaches the Planck regime, is a term which explicitly violates unitarity in the non-gravitational sector. While pure states remain pure, there is an increase in the degree of purity for non-pure states in this sector. This result holds irrespective of whether full quantum gravity respects unitarity or not.
INFRARED STRUCTURE OF (2 + 1)-DIMENSIONAL QUANTUM ELECTRODYNAMICS
Authors: GIROTTI H. O. , GOMES M. , DA SILVA A. J.
Published: November 2004

The Bloch–Nordsieck approximation is used to study the ir structure of quantum electrodynamics in 2 + 1 dimensions. Unlike in QED 4, the ir singularities occurring in each order of perturbation theory do not add up to a finite limit. However, the resummation of vacuum polarization graphs is shown to induce a mass which solves the ir problem.
ZERO SOUND VELOCITY IN π, ρ MESON GASES
Authors: DEY JISHNU , DEY MIRA , DE ARAUJO CARLOS F. , TOMIO LAURO
Published: November 2004

Sharp transitions are perhaps absent in QCD, so that one looks for physical quantities which may reflect the phase change. One such quantity is the sound velocity which was shown in lattice theory to become zero at the transition point for pure glue. We show that even in a simple bag model the sound velocity goes to zero at temperature T = Tv ≠ 0 and that the numerical value of this Tv depends on the nature of the meson. The average thermal energy of mesons goes linearly with T near Tv, with much smaller slope for the pion. The Tv − s can be connected with the Boltzmann temperatures obtained from transverse momentum spectrum of these mesons in heavy-ion collision at mid-rapidity. It would be interesting to check the presence of different Tv − s in present day finite T lattice theory.
THE STOCHASTIC QUANTIZATION METHOD IN PHASE SPACE AND A NEW GAUGE FIXING PROCEDURE
Authors: MOCHIZUKI RIUJI
Published: November 2004

We study the stochastic quantization of the system with first class constraints in phase space. Though the Langevin equations of the canonical variables are defined without ordinary gauge fixing procedure, gauge fixing conditions are automatically selected and introduced by imposing stochastic consistency conditions upon the first class constraints. Then the equilibrium solution of the Fokker–Planck equation is identical to the corresponding path-integral distribution.
THE CALCULATION OF THE HADRONIC CONTRIBUTION TO THE $\alpha (M_z^2)$
Authors: KRASNIKOV N. V.
Published: November 2004

We calculate the hadronic contribution to the [Formula: see text] using quasi-analytical approximation for the cross-section of e+e− → hadrons . We find [Formula: see text].
CONSISTENT AXIAL-LIKE GAUGE FIXING ON HYPERTORI
Authors: LANGMANN EDWIN , SALMHOFER MANFRED , KOVNER ALEX
Published: November 2004

We analyze the Gribov problem for SU (N) and U (N) Yang–Mills fields on d-dimensional tori, d = 2, 3, …. We give an improved version of the axial gauge condition and find an infinite, discrete group [Formula: see text] where r = N − 1 and N for G = SU (N) and U (N) respectively, containing all gauge transformations compatible with that condition. This residual gauge group [Formula: see text] provides all Gribov copies for nondegenerate configurations in d = 2 and for those of them for which all winding numbers of the Wilson–Polyakov loop in one direction vanish in d ≥ 3. This shows that the space of gauge orbits is an orbifold. We derive this result both in the Lagrangian and in the Hamiltonian framework.
OFF-SHELL Z0 PAIR PRODUCTION IN e+e− ANNIHILATION
Authors: LEHNER DIETRICH
Published: November 2004

A study of the standard model reaction [Formula: see text] including the effects of the finite Z0 width and initial state radiative corrections is presented. All angular phase space integrations are performed analytically. The remaining invariant masses are integrated numerically. Semianalytical and numerical results in the energy range [Formula: see text] to 1 TeV are reported. The generalization of the analytical method to include photon exchange and also models with more neutral gauge bosons is outlined.
MANIFESTLY PARITY COVARIANT FRONT-FORM QUANTIZATION
Authors: JACOB OVID C.
Published: November 2004

Recently, we proposed a new front-form quantization which treated both the x+ and the x− coordinates as front-form ‘times’. This quantization was found to preserve parity explicitly. In this letter we extend this construction to fermion fields in the context of the Yukawa theory. We quantize this theory using a method proposed originally by Faddeev and Jackiw. We find that P− and P+ become dynamical and that the theory is manifestly invariant under parity.
AN EFFECTIVE 3-D RIGID STRING AT θ=π
Authors: PAWEŁCZYK JACEK
Published: November 2004

An effective sigma model describing behavior of the 3-D rigid string with a θ-term at θ=π is proposed. It contains nonperturbative corrections resulting from summation over different genera of the 2-D surfaces. The effective theory is the SU(2) WZW model coupled to the Nambu-Goto action. RG analysis shows the existence of an ir fixed point at which the normal to the surface has long range correlations. A similar model can describe critical behavior of the 3-D YM fields or the Ising model.
ON CHIRAL SYMMETRY BREAKING WITH MASSLESS FERMIONS
Authors: DICK RAINER
Published: November 2004

It is shown that Weyl spinors in Minkowski space are isomorphic to primary fields of half-integer conformal weights. This yields representations of fermionic two-point functions in terms of correlators of primary fields with a factorized transformation behavior under the Lorentz group. As an application we determine the general structure of the corresponding Lorentz covariant correlators by methods similar to that employed in conformal field theory to determine two- and three-point functions of primary fields. In particular, the chiral symmetry breaking terms resemble fermionic two-point functions of 2-D CFT up to a function of the product of momenta.
UNRUH-DEWITT DETECTORS IN THE PRESENCE OF SCALAR SOURCES
Authors: MATSAS GEORGE E.A. , SUDARSKY DANIEL
Published: November 2004

We analyze the response of Unruh-DeWitt detectors in the presence of inertial scalar sources. We show that, in general, a detector responds to the corresponding Coulomb field. However, in some cases, pure vacuum contributions can overwhelm the influence of the Coulomb field rendering the effect of the external source on the detector’s response arbitrarily small. We revisit in this context the celebrated question of whether uniformly accelerated observers can see the radiation coming from an inertial charge, and point out the present impediments to answering this question.
Q-BOSON OSCILLATOR ALGEBRA WITH COMPLEX DEFORMATION PARAMETER
Authors: FALCO L. DE , JANNUSSIS A. , MIGNANI R. , SOTIROPOULOU A.
Published: November 2004

We study a general q-deformed Heisenberg-Weyl algebra with complex deformation parameter. The q-boson realization of such an algebra is obtained by means of a complex generalization of the bosonization method. The real spectrum of the corresponding complex deformed oscillator is derived for two special cases of the q-commutation relations. The bosonic realization of the related SU(2) algebra is also briefly considered.
LIMITS ON THE MEASURABILITY OF SPACE-TIME DISTANCES IN (THE SEMICLASSICAL APPROXIMATION OF) QUANTUM GRAVITY
Authors: AMELINO-CAMELIA GIOVANNI
Published: November 2004

By taking into account both quantum mechanical and general relativistic effects, an equation that describes some limitations on the measurability of space-time distances can be derived. We then discuss possible features of quantum gravity which are suggested by this equation.
MORE ON q-HERMITE POLYNOMIALS
Authors: DEBERGH N.
Published: November 2004

The oscillator quantum algebra is extended, through a general approach, in order to put in evidence new q-Hermite polynomials and to discuss the already known ones. Such an approach constraints possible brackets. New sets of corresponding q-bosonic operators are pointed out, reducing for specific values of the subtended parameters to the parabosonic operators.
AN ATTEMPT AT A NEW CLASSIFICATION OF CICY MANIFOLDS
Authors: GAGNON M. , HO-KIM Q.
Published: November 2004

Using a recently proposed list of 97,360 complete intersection Calabi-Yau manifolds, we attempt to select some promising three- and four-generation manifolds. We classify the configurations surviving the selection tests by breaking the associated diagrams into kernels and extensions and by regrouping configurations having the same kernels into families. The resulting classification for the surviving three- and four-generation manifolds is presented.
QUANTUM DILOGARITHM AS A 6j-SYMBOL
Authors: KASHAEV R.M.
Published: November 2004

The cyclic quantum dilogarithm is interpreted as a cyclic 6j-symbol of the Weyl algebra, considered as a Borel subalgebra BU q( sl (2)). Using modified 6j-symbols, an invariant of triangulated links in triangulated three-manifolds is constructed. Apparently, it is an ambient isotopy invariant of links.
EVIDENCE OF INTRA- AND INTERGROUP AZIMUTHAL CORRELATIONS IN NUCLEAR INTERACTIONS AT A FEW GeV/c
Authors: GHOSH DIPAK , BISWAS BISWANATH , ROYCHOWDHURY JAYANTA , MUKHOPADHYAY AMITABHA , GHOSH ANIT , ROY JAYA DEB
Published: November 2004

The paper presents new data on azimuthal correlations in angles between different types of secondary charged particles emitted in inelastic interactions between 24Mg nuclei with the AgBr nuclei of nuclear emulsion. Azimuthal correlations are observed in some cases of intergroup correlations, and an asymmetry is found to exist in the emission of the same type of particles. The present data is compared in some cases, with those of p-emulsion, d-emulsion, α-emulsion and 12C-emulsion interactions at 4.5 A GeV/c and 84Kr-emulsion interaction at 1.4 A GeV.
SCALING VIOLATION IN O(N) VECTOR MODELS
Authors: NISHIGAKI SHINSUKE
Published: November 2004

We investigate O(N)-symmetric vector field theories in the double scaling limit. Our model describes branched polymeric systems in D dimensions, whose multicritical series interpolates between the Cayley tree and the ordinary random walk. We give explicit forms of residual divergences in the free energy, analogous to those observed in the strings in one dimension.
GEOMETRICAL ASPECTS OF ZN ORBIFOLD PHENOMENOLOGY
Authors: KOBAYASHI TATSUO , OHTSUBO NORIYASU
Published: November 2004

We study the geometrical and phenomenological aspects of ZN orbifold models. Conditions on the background moduli and Wilson lines are clarified. We investigate the explicit ZN-invariant states through a modified GSO projection and calculate Yukawa coupling conditions due to space-group and SO(10) invariance. We estimate a contribution of a holomorphic instanton to the couplings.
ON-MASS-SHELL RENORMALIZATION IN THE PRESENCE OF DYNAMICAL CONTRIBUTIONS TO QUARK MASSES
Authors: HILL N.C.A. , ELIAS V.
Published: November 2004

We extend the standard on-mass-shell renormalization prescription to account for massshell shifts arising from the presence of dynamical contributions to quark self-energies generated by the nonperturbative content of the vacuum. We then consider a number of ways in which dimension-3 fermion-antifermion condensates could enter known interaction physics, with particular emphasis given to the dynamical generation of fermion masses.