December 1995 arXiv papers — page 5

Marilyn A. Walker

This squib examines the role of limited attention in a theory of discourse structure and proposes a model of attentional state that relates current hierarchical theories of discourse structure to empirical evidence about human discourse processing capabilities. First, I present examples that are not predicted by Grosz and Sidner's stack model of attentio

N. E. Mavromatos, D. V. Nanopoulos

Microtubule (MT) networks, subneural paracrystalline cytosceletal structures, seem to play a fundamental role in the neurons. We cast here the complicated MT dynamics in the form of a $1+1$-dimensional non-critical string theory, thus enabling us to provide a consistent quantum treatment of MTs, including enviromental {\em friction} effects. Quantum space-ti

Paul Federbush

We consider theories with gauged chiral fermions in which there are abelian anomalies, and no nonabelian anomalies (but there may be nonabelian gauge fields present). We construct an associated theory that is gauge invariant, renormalizable, and with the same particle content, by adding a finite number of terms to the action. Alternatively one can view the n

A. Krzywicki

We briefly overview the development of Euclidean quantum gravity in four dimensions regarded as a branch of statistical mechanics of discretized random manifolds.

Yu. L. Dokshitzer, G. Marchesini, B. R. Webber

We consider power-behaved contributions to hard processes in QCD arising from non-perturbative effects at low scales which can be described by introducing the notion of an infrared-finite effective coupling. Our method is based on a dispersive treatment which embodies running coupling effects in all orders. The resulting power behaviour is consistent with ex

Gabriel Lopes Cardoso, Gottfried Curio, Dieter Lust, Thomas Mohaupt

We study the BPS spectrum in $D=4, N=4$ heterotic string compactifications, with some emphasis on intermediate $N=4$ BPS states. These intermediate states, which can become short in $N=2$ compactifications, are crucial for establishing an $S-T$ exchange symmetry in $N=2$ compactifications. We discuss the implications of a possible $S-T$ exchange symmetry for

G. Cvetic, N. D. Vlachos

We study the Higgs condensation $H={\bar t}t$ mechanism in the Top-mode Standard Model at the next-to-leading order in 1/Nc. The calculation includes the effects of the Goldstone fields, but not the effects of the transverse components of the electroweak gauge bosons. The resulting effective theory is parametrized by means of a finite energy cut-off $Ł$ at w

P. Colangelo, C. A. Dominguez, G. Nardulli, N. Paver

We consider the problem of determining the matrix element of the heavy quark kinetic energy operator between $Λ_b$ baryonic states by three point function QCD sum rules in the Heavy Quark Effective Theory. We discuss the main features and the uncertainties associated to such an approach. Numerically, we find the result: ${\langle{\cal K}\rangle}_{Λ_b} = - (0

Roberto Casadio, Giovanni Venturi

The semiclassical collapse of a homogeneous sphere of dust is studied. After identifying the independent dynamical variables, the system is canonically quantised and coupled equations describing matter (dust) and gravitation are obtained. The conditions for the validity of the adiabatic (Born--Oppenheimer) and semiclassical approximations are derived. Furthe

A. B. Arbuzov, V. S. Fadin, E. A. Kuraev, L. N. Lipatov

The elastic and inelastic high--energy small--angle electron--positron scattering is considered. All radiative corrections to the cross--section with the relative accuracy $δσ/ σ= 0.1 \% $ are explicitly taken into account. According to the generalized eikonal representation for the elastic amplitude, in higher orders only diagrams with one exchanged photon

Mirjam Cvetic, Donam Youm

We present the most general static, spherically symmetric solutions of heterotic string compactified on a six-torus that conforms to the conjectured ``no-hair theorem'', by performing a subset of O(8,24) transformations, i.e., symmetry transformations of the effective three-dimensional action for stationary solutions, on the Schwarzschild solution. The expli

Martin Schlichenmaier, Oleg K. Sheinman

We show how to obtain from highest weight representations of Krichever-Novikov algebras of affine type (also called higher genus affine Kac-Moody algebras) representations of centrally extended Krichever-Novikov vector field algebras via the Sugawara construction. This generalizes classical results where one obtains representations of the Virasoro algebra. R

Boris Malomed, Herbert Winful

As is known, a solitary pulse in the complex cubic Ginzburg-Landau (GL) equation is unstable. We demonstrate that a system of two linearly coupled GL equations with gain and dissipation in one subsystem and pure dissipation in another produces absolutely stable solitons and their bound states. The problem is solved in a fully analytical form by means of the

C. E. Aguiar, T. Kodama, R. A. M. S. Nazareth, G. Pech

We argue that the non-perturbative Schwinger mechanism may play an important role in the hadronic production of charm. We present a flux tube model which assumes that the colliding hadrons become color charged because of gluon exchange, and that a single non-elementary flux tube is built up as they recede. The strong chromoelectric field inside this tube cre

Mihai Putinar

All extremal solutions of the truncated $L$-problem of moments in two real variables , with support contained in a given compact set, are described as characteristic functions of semi-algebraic sets given by a single polynomial inequality. An exponential kernel, arising as the determinantal function of a naturally associated hyponormal operator with rank-one

Kelvin Pilgrim, Tan Lei

Using Thurston's characterization of postcritically finite rational functions as branched coverings of the sphere to itself, we give a new method of constructing new conformal dynamical systems out of old ones. Let $f(z)$ be a rational map and suppose that the postcritical set $P(f)$ is finite. Let $α$ be an embedded closed arc in the sphere and suppose

Victor Kac, Andrey Radul

In our paper~\cite{KR} we began a systematic study of representations of the universal central extension $\widehat{\Cal D}\/$ of the Lie algebra of differential operators on the circle. This study was continued in the paper~\cite{FKRW} in the framework of vertex algebra theory. It was shown that the associated to $\widehat {\Cal D}\/$ simple vertex algebra $

R. R. Khuri, R. C. Myers

We discuss the low-energy dynamics of generalized extremal higher membrane black hole solutions of string theory and higher membrane theories following Manton's prescription for multi-soliton solutions. A flat metric is found for those solutions which possess $κ$-symmetry on the worldvolume.

Henric Rhedin

We start by giving a brief introduction to string theory with emphasis on the example of the bosonic string. In order to fully appreciate string theory it is necessary to study the dynamics of the surface that the string traces out when moving in space-time. This is described by what is known as conformal field theory, which is the subject of chapter two. Af

C. R. Preitschopf

We apply the techniques of $S^7$-algebras to the construction of N=5-8 superconformal algebras and of S{\bf O}(1,9), a modification of SO(1,9) which commutes with $S^7$-transformations. We discuss the relevance of S{\bf O}(1,9) for off-shell super-Maxwell theory in D=(1,9).

John Ellis

This paper is based on lectures presented to mathematical physicists and attempts to provide an overview of the present status of the Standard Model, its experimental tests, phenomenological and experimental motivations for going beyond the Standard Model via supersymmetry and grand unification, and ways to test these ideas with particle accelerators.

Guido Cognola, Ilya L. Shapiro

At the very early Universe the matter fields are described by the GUT models in curved space-time. At high energies these fields are asymptotically free and conformally coupled to external metric. The only possible quantum effect is the appearance of the conformal anomaly, which leads to the propagation of the new degree of freedom - conformal factor. Simult

A. D. Popov, C. R. Preitschopf

We describe an infinite-dimensional Kac-Moody-Virasoro algebra of new hidden symmetries for the self-dual Yang-Mills equations related to conformal transformations of the 4-dimensional base space.

Noureddine Mohammedi

A method for implementing non-Abelian duality on string backgrounds is given. It is shown that a direct generalisation of the familiar Abelian duality induces an extra local symmetry in the gauge invariant theory. The non-Abelian isometry group is shown to be enlarged to a non-semi-simple group. However, upon eliminating the gauge fields to obtain the dual t

Jens Schnittger

We demonstrate how negative powers of screenings arise as a nonperturbative effect within the operator approach to Liouville theory. This explains the origin of the corresponding poles in the exact Liouville three point function proposed by Dorn/Otto and $(\hbox{Zamolodchikov})^2$ (DOZZ) and leads to a consistent extension of the operator approach to arbitra

F. L. Bezrukov, M. V. Libanov, D. T. Son, S. V. Troitsky

We consider the features of multiparticle tree cross sections in scalar theories in the framework of a semiclassical approach. These cross sections at large multiplicities have exponential form, and the properties of the exponent in different regimes are discussed.

G. Kramer, W. Palmer, Y. L. Wu

The influence of strong and electroweak penguin amplitudes in $B/ \bar B \rightarrow π^+π^-$ is investigated in connection with the determination of the unitarity triangle angle $α$ of the CKM matrix. A relation between the observable asymmetry, the angle $α$, and the penguin amplitude is established. A model calculation of the penguin amplitude shows that t

J. Kripfganz, A. Laser, M. G. Schmidt

The main perturbative contribution to the free energy of an electroweak interface is due to the effective potential and the tree level kinetic term. The derivative corrections are investigated with one-loop perturbation theory. The action is treated in derivative, in heat kernel, and in a multi local expansion. The massive contributions turn out to be well d

D. Delepine, J. -M. Gerard, R. Gonzalez Felipe

In the standard electroweak model, the measured top quark mass requires a sizeable Yukawa coupling to the fundamental scalar. This large coupling alone might induce a dynamical breaking of the electroweak symmetry as well as non-perturbative effects. If such is the case, even a standard Higgs scalar as light as 80 GeV should have a non-negligible $t \bar{t}$

Barry R. Holstein

Measurement of the $γ3π$ process has revealed a possible conflict with what should be a solid prediction generated by the chiral anomaly. We show that inclusion of appropirate energy-momentum dependence in the matrix element reduces the discrepancy.

Gian F. Giudice, Alex Pomarol

The search for charginos and neutralinos at LEP2 can become problematic if these particles are almost mass degenerate with the lightest neutralino. Unfortunately this is the case in the region where these particles are higgsino-like. We show that, in this region, radiative corrections to the higgsino mass splittings can be as large as the tree-level values,

John Ellis

Supersymmetry and Grand Unification are the two most promising directions for physics beyond the Standard Model. They receive indirect experimental support from the apparent lightness of the Higgs boson, the values of the gauge couplings measured at LEP and elsewhere, and the persistent solar neutrino deficit. Phenomenological constraints and theoretical mod

Yoshiya Takeda, Isao Umemura, Katsuji Yamamoto, Dai Yamazaki

The neutron electric dipole moment is investigated in a supersymmetric electroweak model admitting $ {\rm SU(2)}_W $ singlet and $ Q = -1/3 $, say $ D $-type, quarks. Significant $ CP $ violating phases appear in the coupling between the singlet $ D $-type quarks and the ordinary $ d $-type quarks. Then, through the $ d $-$ D $ mixing effects on the squark m

Hilmar Forkel

We discuss two descriptions of the nucleon's strange vector form factors in the framework of vector meson dominance. The first, an updated and extended version of Jaffe's dispersion analysis, approximates the spectral functions of the form factors as a sum of vector meson poles, whereas the second combines vector meson dominance in the $ω$ and $ϕ$ me

Shailesh Chandrasekharan, Suzhou Huang

It was recently observed in a lattice QCD measurement that the chiral condensate in the quenched approximation shows dramatically different behavior in the three $Z_3$-equivalent de-confined phases. We argue that this phenomenon can be understood qualitatively as an effect of $Z_3$ twists on fermionic fields. Quarks under these $Z_3$-twists become global any

Hideo Suganuma, Atsunori Tanaka, Shoichi Sasaki, Osamu Miyamura

The correlation between instantons and QCD-monopoles is studied both in the lattice gauge theory and in the continuum theory. An analytical study in the Polyakov-like gauge, where $A_4(x)$ is diagonalized, shows that the QCD-monopole trajectory penetrates the center of each instanton, and becomes complicated in the multi-instanton system. Using the SU(2) lat

Giampiero Esposito, Gennaro Miele, Pietro Santorelli

The flat-space limit of the one-loop effective potential for SO(10) GUT theories in spatially flat Friedmann-Robertson-Walker cosmologies is applied to study the dynamics of the early universe. The numerical integration of the corresponding field equations shows that, for such grand unified theories, a sufficiently long inflationary stage is achieved for sui

S. Gudmundsson, J. C. Wood

We obtain conditions on the Lee form under which a holomorphic map between almost Hermitian manifolds is a harmonic map or morphism. Then we discuss under what conditions (i) the image of a holomorphic map from a cosymplectic manifold is also cosymplectic, (ii) a holomophic map with Hermitian image defines a Hermitian structure on its domain.

Y. Zha, D. Z. Liu

We investigate localization properties in the highly anisotropic and intrinsically disordered layered material, which is analogous to high-Tc cuprates. By varying the anisotropy of the system which is parameterized by the interlayer hopping $tp$, we find a crossover from two-dimensional (2D) to three-dimensional (3D) behavior at a critical hopping amplitude

S. La Rosa, R. J. Kelley, C. Kendziora, G. Margaritondo

We performed angle-resolved photoemission experiments on overdoped single crystal $Bi_2Sr_2CaCu_2O_{8+x}$ samples with Tc values as low as 55K and very narrow transitions as measured by AC susceptibility. The photoemission data indicate the presence of a ``shadow'' peak in the quasiparticle spectral function $A(ω)$ shifted by $(π,π)$ from the convent

Dirk K. Morr, Andrey V. Chubukov, Arno P. Kampf, G. Blumberg

Two--magnon Raman scattering is a useful tool to verify recent suggestions concerning the value of the interplanar exchange constant in antiferromagnetic two--layer systems, such as $YBa_2Cu_3O_{6+x}$. We present a theory for Raman scattering in a two--layer antiferromagnet. We study the spectra for the electronic and magnetic excitations across the charge t

Miguel A. Martin-Delgado, Javier Rodriguez-Laguna, German Sierra

We formulate the standard real-space renormalization group method in a way which takes into account the correlation between blocks. This is achieved in a dynamical way by means of operators which reflect the influence on a given block of its neighbours. We illustrate our method in the example of the tight-binding model in 1D and 2D for various types of bound

R. Pirc, B. Tadic, R. Blinc

The static behavior of orientational glasses is discussed in terms of a replica theory based on the infinite range random bond--random field model. A general version of the model applicable to dipolar and quadrupolar glasses is presented using a symmetry-adapted representation for the order parameter fields. Numerical results for the $<100>$ quadrupolar glas

Thomas Dupré

We present a combination of analytical and numerical calculations for the critical behavior of a supersymmetric non-linear $σ$-model within the context of the localization transition of a disordered one-electron system. As a result, we obtain a localization length exponent and a set of inverse participation numbers in three dimensions. We find a continuous p

F. Dominguez-Adame

We study electron dynamics in a two-band delta-doped semiconductor within the envelope-function approximation. Using a simple parametrization of the confining potential arising from the ionized donors in the delta-doping layer, we are able to find exact solutions of the Dirac-type equation describing the coupling of host bands. As an application we then cons

J. A. Carlisle, A. Chaiken, R. P. Michel, L. J. Terminello

Soft x-ray fluorescence spectroscopy has been employed to obtain information about the Si-derived valence band states of Fe/Si multilayers. The valence band spectra are quite different for films with and without antiferromagnetic interlayer exchange coupling, demonstrating that these multilayers have different silicide phases in their spacer layers. Comparis

M. E. Raikh, L. I. Glazman, L. E. Zhukov

We show the existence of bound two-electron states in an almost depleted two-dimensional island. These two-electron states are carried by special compact configurations of four single-electron levels. The existence of these states does not require phonon mediation, and is facilitated by the disorder-induced potential relief and by the electron-electron repul

Martin Haehnelt, Matthias Steinmetz, Michael Rauch

We investigate the heavy element QSO absorption systems caused by gas condensations at high redshift which evolve into galaxies with circular velocity of 100 to 200 km/s at the present epoch. Artificial QSO spectra were generated for a variety of lines-of-sight through regions of the universe simulated with a hydrodynamics code. The CIV and HI absorption fea

Wayne Landsman, Theodore Simon, Pierre Bergeron

We have obtained low-dispersion IUE spectra of the stars 56 Persei (F4 V) and HR 3643 (F7 II), as part of a survey of late-type stars with a 1565 A flux excess in the TD-1 ultraviolet sky survey. The IUE spectrum of each star reveals the presence of a hot white dwarf companion. We fit the Ly alpha profile and ultraviolet continuum using pure hydrogen models,

R. J. R. Williams, J. E. Dyson

We exploit a generic instability in the integration of steady, sonic, near-isothermal flows to find the complete transition diagram for recombination fronts (for a model system of equations). The instability requires the integration of the flow equations for speeds between the isothermal and adiabatic sound speeds to be performed with particular care. As a r

M. Coleman Miller, Tomasz Bulik

The association of all three soft gamma-ray repeaters (SGRs) with supernova remnants has made possible estimates of the distance to and luminosity of the sources of SGRs, which have provided a starting point for detailed modeling. One of the most popular classes of models involves strongly magnetized neutron stars, with surface dipole fields $B\sim 10^{14}-1

Emilio Molinari, Riccardo Smareglia

We show the possibility to exploit the non-linear behaviour of artificial neural network (ANN) for the identification of the early-type component of the population of the core of clusters of galaxies. We result in a measurement of the luminosity function of the E/S0 galaxies which disfavours the hypothesis of a universal LF and calls for dynamical influences

U. Gorti, H. C. Bhatt

The evolution of a protostellar binary system is investigated while it is embedded in its parent molecular cloud core and acted upon by gas drag due to dynamical friction. Approximate analytical results are obtained for the energy and angular momentum evolution of the orbit in the limiting cases, where the velocity is much smaller than, and much larger than

R. J. Cumming, P. Lundqvist, L. J. Smith, M. Pettini

We searched for narrow H$α$ in a high-resolution spectrum of SN 1994D taken 10 days before maximum, and found none. We estimate the limit this places on the progenitor mass loss, and find that it is competitive with recent radio limits, and excludes the highest-mass-loss-rate symbiotic systems as possible progenitors of the normal Type Ia SN 1994D.

A. Biviano, F. Durret, D. Gerbal, O. LeFevre

We have assembled a large data-set of 613 galaxy redshifts in the Coma cluster, the largest presently available for a cluster of galaxies. We have defined a sample of cluster members complete to b$_{26.5}=20.0$, using a membership criterion based on the galaxy velocity, when available, or on the galaxy magnitude and colour, otherwise. Such a data set allows

C. Klimcik, P. Severa

Global issues of the Poisson-Lie T-duality are addressed. It is shown that oriented open strings propagating on a group manifold $G$ are dual to $D$-brane - anti-$D$-brane pairs propagating on the dual group manifold $\ti G$. The $D$-branes coincide with the symplectic leaves of the standard Poisson structure induced on the dual group $\ti G$ by the dressing

A. A. Kehagias

We consider the $N\!=\!1$ supersymmetric $σ$-model and we examine the transformation properties of the partition function under target-space duality. Contrary to what one would expect, we find that it is not, in general, invariant. In fact, besides the dilaton shift emerging from the Jacobian of the duality transformation of the bosonic part, there also exis

Ling-Lie Chau, Itaru Yamanaka

From the time-independent current $\tcj(\bar y,\bar k)$ in the quantum self-dual Yang-Mills (SDYM) theory, we construct new group-valued quantum fields $\tilde U(\bar y,\bar k)$ and $\bar U^{-1}(\bar y,\bar k)$ which satisfy a set of exchange algebras such that fields of $\tcj(\bar y,\bar k)\sim\tilde U(\bar y,\bar k)~\partial\bar y~\tilde U^{-1}(\bar y,\bar

Shing-Tung Yau, Eric Zaslow

We describe the counting of BPS states of Type II strings on K3 by relating the supersymmetric cycles of genus $g$ to the number of rational curves with $g$ double points on K3. The generating function for the number of such curves is the left-moving partition function of the bosonic string.

Marek Jezabek

Recent results on production and decays of polarized top quarks are reviewed. Top quark pair production in $e^+e^-$ annihilation is considered near energy threshold. For longitudinally polarized electrons the produced top quarks and antiquarks are highly polarized. Dynamical effects originating from strong interactions and Higgs boson exchange in the $t-\bar

C. Diaconu, J. G. Körner, D. Pirjol, M. Talby

We discuss a few possible strategies for measuring the polarization of the $Λ_{\mathrm{b}}$ baryons produced in $e^+e^-$-annihilation at the $\mathrm{Z}$ resonance through their inclusive semileptonic decays. After reviewing the existing methods, a new method is proposed, based on the ratio of the averages of the squared electron and neutrino energy, includi

Xiang-Ping Wu

This work reviews the basic theoretical aspects, the main observational evidences and the recent applications of gravitational lensing in the Universe. The article is aimed particularly at providing the readers who don&#39;t work on gravitational lensing a relatively easy introduction to this active research field in today&#39;s astrophysics.

J. Oscar Rosas-Ortiz

The dynamical algebra associated to a family of Isospectral Oscillator Hamiltonians, named {\it Distorted Heisenberg Algebra} because its dependence on a distortion parameter $W \geq 0$, has been recently studied. The connection of this algebra with the Hilbert space of entire functions of growth (1/2, 2) is analized.

W. Buchmuller, A. Hebecker

Inclusive and diffractive structure functions for electron-proton scattering are calculated in a semiclassical approach at large momentum transfer $Q^2$ and small values of the scaling variable $x$. The basic process is the production of a quark-antiquark pair in the colour field of the proton. The structure functions are expressed in terms of Wilson lines a

S. Frixione, Z. Kunszt, A. Signer

One- and two-jet inclusive quantities in hadron collisions have already been calculated to next-to-leading order accuracy, using both the subtraction and the cone method. Since the one-loop corrections have recently been obtained for all five-parton amplitudes, three-jet inclusive quantities can also be predicted to next-to-leading order. The subtraction met

Joan Najita, John Carr, Al Glassgold, Frank Shu

We report high spectral resolution observations of the CO vibrational overtone emission from the young stellar object 1548C27; our observations include both the CO(2-0) and CO(5-3) bandhead regions. These data and similar observations of the young stellar object WL16, reported in a previous contribution to this journal, provide some of the most compelling ev

B. -Y. Park, F. Myhrer, J. R. Morones, T. Meissner

The usual theoretical treatments of the near-threshold $pp \rightarrow ppπ^0$ reaction are based on various phenomenological Lagrangians. In this work we examine the relationship between these approaches and a systematic chiral perturbation method. Our chiral perturbation calculation indicates that the pion rescattering term should be significantly enhanced

T. Kinoshita, M. Nio

This is the first of a series of papers on a systematic application of the NRQED bound state theory of Caswell and Lepage to higher-order radiative corrections to the hyperfine structure of the muonium ground state. This paper describes the calculation of the $α^2 (Zα)$ radiative correction. Our result for the complete $α^2 (Zα)$ correction is 0.424(4) kHz,

Arvind, N. Mukunda, R. Simon

A new operator based condition for distinguishing classical from non-classical states of quantised radiation is developed. It exploits the fact that the normal ordering rule of correspondence to go from classical to quantum dynamical variables does not in general maintain positivity. It is shown that the approach naturally leads to distinguishing several lay

M. J. W. Dodgson, M. A. Moore

We report results from Monte Carlo simulations of a thin film superconductor in a spherical geometry within the lowest Landau level approximation. We observe the absence of a phase transition to a low temperature vortex solid phase with these boundary conditions; the system remains in the vortex liquid phase for all accessible temperatures. The correlation l

N. Dorey, C. Fraser, T. J. Hollowood, M. A. C. Kneipp

A semi-classical check of the Goddard-Nuyts-Olive (GNO) generalized duality conjecture for gauge theories with adjoint Higgs fields is performed for the case where the unbroken gauge group is non-abelian. The monopole solutions of the theory transform under the non-abelian part of the unbroken global symmetry and the associated component of the moduli space

T. Buchert

Average properties of general inhomogeneous cosmological models are discussed in the Newtonian framework. It is shown under which circumstances the average flow reduces to a member of the standard Friedmann--Lema\^ıtre cosmologies. Possible choices of global boundary conditions of inhomogeneous cosmologies as well as consequences for the interpretation of co

Anna Okopińska

The effective action for the local composite operator $Φ^2(x)$ in the scalar quantum field theory with $λΦ^4$ interaction is obtained in the expansion in two-particle-point-irreducible (2PPI) diagrams up to five-loops. The effective potential and 2-point Green&#39;s functions for elementary and composite fields are derived. The ground state energy as well as

A. A. Bel&#39;kov, M. Dillig, A. V. Lanyov

The total cross section for Coulomb photoproduction of neutral pion pairs in the reaction gamma A --> pi0 pi0 A is estimated within the effective chiral lagrangian approach. The amplitude of gamma gamma* --> pi0 pi0 with one off-shell photon is calculated at O(p^6) in the momentum expansion; in addition, nuclear absorption is taken into account. Besides its

Wladyslaw Marcinek

The model of generalized quons is described in a purely algebraic way. Commutation relations and corresponding consistency conditions for our generalized quons system are studied in terms of quantum Weyl algebras. Fock space representation and corresponding scalar product is also given.

J. G. K&#34;orner

We discuss the Lambda_b-polarization of the bottom baryon Lambda_b in its production and in its decay. Standard Model predictions for b-quark polarization on the Z-peak are reviewed, including beam-quark orientation effects and O(as) radiative corrections to the polarization. The b-quark polarization is expected to be handed over to the Lambda_b into which i

Andrew R Liddle, David H Lyth, Pedro T P Viana, Martin White

We use linear and quasi-linear perturbation theory to analyse cold dark matter models of structure formation in spatially flat models with a cosmological constant. Both a tilted spectrum of density perturbations and a significant gravitational wave contribution to the microwave anisotropy are allowed as possibilities. We provide normalizations of the models

Sean J. Yoon, Yong-Wan Kim, Young-Jai Park

We apply the Batalin-Tyutin Hamiltonian method to the Abelian Proca model in order to convert a second class constraint system into a first class one systematically by introducing the new fields. Then, according to the BFV formalism we obtain that the desired resulting Lagrangian preserving standard BRST symmetry naturally includes the well-known Stükelberg

K. S. Virbhadra, S. Jhingan, P. S. Joshi

We study the static and spherically symmetric exact solution of the Einstein-massless scalar equations given by Janis, Newman and Winicour. We find that this solution satisfies the weak energy condition and has strong globally naked singularity.

Glennys R. Farrar

When the gluino is light and long lived, missing energy is a poor signature for both squarks and gluinos. Instead, $S_q S_q^*$ production in $e^+ e^-$ and $p \bar{p}$ collisions characteristically results in events with $\ge 4$ jets. Methods are proposed for deciding whether an observed excess of 4-jet events is due to $S_q S_q^*$ production. The recent repo

Sean Fleming, Ivan Maksymyk

The NRQCD factorization formalism of Bodwin, Braaten, and Lepage prescribes how to write quarkonium production rates as a sum of products of short-distance coefficients times non-perturbative long-distance NRQCD matrix elements. We present, in the true spirit of the factorization formalism, a detailed calculation of the inclusive cross section for hadronic $

M. Burkardt, B. Klindworth

Pure glue QCD is formulated on a 2+1 dimensional transverse lattice, using discrete light-front quantization. The transverse component of the gauge fields is taken to be compact, but in a linearized approximation with an effective potential. The (rest-frame) $Q\bar{Q}$ potential is evaluated numerically using Lanzcos matrix diagonalization. We first discuss

Saharon Shelah

Shelah Spencer [ShSp:304] proved the 0-1 law for the random graphs G(n,p_n), p_n=n^{- alpha}, alpha in (0,1) irrational (set of nodes in [n]= {1, ...,n}, the edges are drawn independently, probability of edge is p_n). One may wonder what can we say on sentences psi for which Prob (G(n,p_n) models psi) converge to zero, Lynch asked the question and did the an

Saharon Shelah

We prove (ZF+DC) e.g. : if mu =|H(mu)| then mu^+ is regular non measurable. This is in contrast with the results for mu = aleph_{omega} on measurability see Apter Magidor [ApMg]

Arthur Apter, Saharon Shelah

Generalizing some earlier techniques due to the second author, we show that Menas&#39; theorem which states that the least cardinal kappa which is a measurable limit of supercompact or strongly compact cardinals is strongly compact but not 2^kappa supercompact is best possible. Using these same techniques, we also extend and give a new proof of a theorem of

Gregory Force

This is an exposition of the known techniques for constructing $\Cal L_p$-spaces for $p\in (1,\infty)\setminus \{2\}$, including some unpublished work of Alspach. Isomorphic and complemented embedding relations between these spaces are also explored.

C. R. Fernández-Pousa, M. V. Gallas, J. L. Miramontes, J. Sánchez Guillén

A unified description of the relationship between the Hamiltonian structure of a large class of integrable hierarchies of equations and W-algebras is discussed. The main result is an explicit formula showing that the former can be understood as a deformation of the latter.

Emili Bagan, Martin Lavelle, David McMullan

We consider an electron which is electromagnetically dressed in such a way that it is both gauge invariant and that it has the associated electric and magnetic fields expected of a moving charge. We study the propagator of this dressed electron and, for small velocities, show explicitly at one loop that at the natural (on-shell) renormalisation point, $p_0=m

José D. Edelstein, Carlos Núñez, Fidel A. Schaposnik

We discuss the connection between the construction of Bogomol&#39;nyi bounds and equations in three dimensional gravitational theories and the existence of an underlying $N=2$ local supersymmetric structure. We show that, appart from matter self duality equations, a first order equation for the gravitational field (whose consistency condition gives the Einst

S. M. Kuzenko, J. V Yarevskaya

Starting with a manifestly conformal ($O(d,2)$ invariant) mechanics model in $d$ space and 2 time dimensions, we derive the action for a massless spinning particle in $d$-dimensional anti-de Sitter space. The action obtained possesses both gauge $N$-extended worldline supersymmetry and local $O(N)$ invarince. Thus we improve the old statement by Howe et al.

C. N. Leung, Y. J. Ng, A. W. Ackley

Using the nonperturbative Schwinger-Dyson equation, we show that chiral symmetry in weak-coupling massless QED is dynamically broken by a constant but arbitrarily strong external magnetic field.

S. Randjbar-Daemi, J. Strathdee

Feynman rules for the vacuum amplitude of fermions coupled to external gauge and Higgs fields in a domain wall lattice model are derived using time--dependent perturbation theory. They have a clear and simple structure corresponding to 1--loop vacuum graphs. Their continuum approximations are extracted by isolating the infrared singularities and it is shown

C. Adler

Within the framework of algebraic quantum field theory, we construct explicitly localized morphisms of a Haag-Kastler net in 1+1-dimensional Minkowski space showing abelian braid group statistics. Moreover, we investigate the scattering theory of the corresponding quantum fields.

D. K. Park

One-dimensional $δ^{&#39;}$-function potential is discussed in the framework of Green&#39;s function formalism without invoking perturbation expansion. It is shown that the energy-dependent Green&#39;s function for this case is crucially dependent on the boundary conditions which are provided by self-adjoint extension method. The most general Green&#39;s fun

Gerhard Buchalla, Andrzej J. Buras, Markus E. Lautenbacher

We review the present status of QCD corrections to weak decays beyond the leading logarithmic approximation including particle-antiparticle mixing and rare and CP violating decays. After presenting the basic formalism for these calculations we discuss in detail the effective hamiltonians for all decays for which the next-to-leading corrections are known. Sub

V. Barger, M. S. Berger, R. J. N. Phillips

We point out that high-mass thresholds in the evolution of the strong-interaction coupling parameter $\alpha_s$, due to gluinos, squarks and possible new heavy quarks, could introduce appreciable corrections to the transverse momentum dependence of jet production at the Tevatron. If the new thresholds were near scale $\mu = 200$~GeV, then within the limits o

Brian D. Fields, Kimmo Kainulainen, Keith A. Olive

We compute the nucleosynthesis bounds on the masses of stable Dirac and Majorana neutrinos by solving an evolution equation network comprising of all neutrino species which in the Dirac case includes different helicity states as separate species. We will not commit ourselves to any particular value of the nucleosynthesis bound on effective number of light ne

Derek B. Leinweber

An examination of the symmetries manifest in the QCD path integral for current matrix elements reveals various equalities among the quark sector contributions. QCD equalities among octet baryon magnetic moments lead to a determination of the disconnected sea-quark contribution to nucleon magnetic moments, which is the most reliable determination in the liter

Gautam Bhattacharyya, Debajyoti Choudhury

From non-observation at LEP1, a lower mass limit of 45 GeV has been established on any additional sequential fermion beyond the three generations. Precision measurements have further constrained the number of such additional generations, either degenerate or nearly so, to be at most one. LEP2, an energy-upgraded version of LEP1, would provide greater mass-re

H. Anlauf, H. D. Dahmen, P. Manakos, T. Ohl

This manual describes version 2.2 of the Monte Carlo event generator UNIBAB for large angle Bhabha scattering at LEP and SLC. UNIBAB implements higher order electromagnetic radiative corrections and the effects of soft photon exponentiation in a photon shower approach. Weak corrections are included through the use of an electroweak library.