October 1995 arXiv papers — page 5

J. P. Nunes, H. J. Schnitzer

The path integral computation of field strength correlation functions for two dimensional Yang-Mills theories over Riemann surfaces is studied. The calculation is carried out by abelianization, which leads to correlators that are topological. They are nontrivial as a result of the topological obstructions to the abelianization. It is shown in the large N lim

Pavel Etingof, David Kazhdan

This paper consists of two parts. In the first part we show that any Poisson algebraic group over a field of characteristic zero and any Poisson Lie group admits a local quantization. This answers positively a question of Drinfeld. In the second part we apply our techniques of quantization to obtain some nontrivial examples of quantization of Poisson homogen

J. P. Nunes, H. J. Schnitzer

We continue our analysis of the field strength correlation functions of two-dimensional QCD on Riemann surfaces by studying the large $N$ limit of these correlation functions on the sphere for gauge group $U(N)$. Our results allow us to exhibit an explicit master field for the field strength $F_{μν}$ in a ``topological gauge'', given by a single mast

Ziwei Lin, Miklos Gyulassy

The dilepton spectra from open charm decay in $p+A$ reactions at $\sqrt s=200$ AGeV are proposed to constrain gluon shadowing in nuclei. We show that the required measurements are feasible at RHIC.

Andrei P. Kirilyuk

The true dynamical randomness is obtained as a natural fundamental property of deterministic quantum systems. It provides quantum chaos passing to the classical dynamical chaos under the ordinary semiclassical transition, which extends the correspondence principle to chaotic systems. In return one should accept the modified form of quantum formalism (present

M. Paczuski, S. Maslov, P. Bak

The dynamics of complex systems in nature often occurs in terms of punctuations, or avalanches, rather than following a smooth, gradual path. A comprehensive theory of avalanche dynamics in models of growth, interface depinning, and evolution is presented. Specifically, we include the Bak-Sneppen evolution model, the Sneppen interface depinning model, the Za

Angelica de Oliveira-Costa, George F. Smoot, Alexei A. Starobinsky

Although the cubic T^3 "small universe" has been ruled out by COBE/DMR results as an interesting cosmological model, we still have the possibility of living in a universe with a more anisotropic topology such as a rectangular T^3 "small universe" with one or two of its dimensions significantly smaller than the present horizon (which we refer

Eric J. Bakker

The high-resolution (R = 10^4) near-ultraviolet IUE spectrum of the peculiar post Asymptotic Giant Branch (post-AGB) supergiant HD101584 (F0Iape) has been analyzed. In the wavelength range between 2500 and 3000ang, 291 out of 332 absorption features are identified. The main contribution comes from FeII, CrII and MnII. Most of the absorption features are blen

Henrik Bruus, Caio H. Lewenkopf, Eduardo R. Mucciolo

We propose the autocorrelator of conductance peak heights as a signature of the underlying chaotic dynamics in quantum dots in the Coulomb blockade regime. This correlation function is directly accessible to experiments and its decay width contains interesting information about the underlying electron dynamics. Analytical results are derived in the framework

JLQCD Collaboration

Status report is made of our quenched study of heavy-light matrix elements employing the Wilson quark action for heavy quark. Results obtained up to now with 200 configurations at $β=6.1$ on a $24^3\times64$ lattice and with 100 configurations at $β=6.3$ on a $32^3 \times80$ lattice suggest that the pseudoscalar decay constant varies little over this range o

Kiyomi Okamoto

We analytically study the ground-state quantum phase transition between the Haldane phase and the large-$D$ (LD) phase of the $S=1/2$ ferromagnetic-antiferromagnetic alternating Heisenberg chain with on-site anisotropy. We transform this model into a generalized version of the alternating antiferromagnetic Heisenberg model with anisotropy. In the transformed

P. Podles

Covariant differential calculi and exterior algebras on quantum homogeneous spaces endowed with the action of inhomogeneous quantum groups are classified. In the case of quantum Minkowski spaces they have the same dimensions as in the classical case. Formal solutions of the corresponding Klein--Gordon and Dirac equations are found. The Fock space constructio

P. Podles

Coquasitriangular universal ${\cal R}$ matrices on quantum Lorentz and quantum Poincaré groups are classified. The results extend (under certain assumptions) to inhomogeneous quantum groups of [10]. Enveloping algebras on those objects are described.

J. R. Anglin, W. H. Zurek

We study environmentally induced decoherence of an electromagnetic field in a homogeneous, linear, dielectric medium. We derive an independent oscillator model for such an environment, which is sufficiently realistic to encompass essentially all of linear physical optics. Applying the ``predictability sieve'' to the quantum field, and introducing the

Raymond E. Goldstein, Adriana I. Pesci, Michael J. Shelley

An analytical method is developed describing the approach to a finite-time singularity associated with collapse of a narrow fluid layer in an unstable Hele-Shaw flow. Under the separation of time scales near a bifurcation point, a long-wavelength mode entrains higher-frequency modes, as described by a version of Hill's equation. In the slaved dynamics, t

M. K. Gaidarov, A. N. Antonov, G. S. Anagnostatos, S. E. Massen

Proton momentum distributions of the $^{12}C$, $^{16}O$, $^{40}Ca$, $^{56}Fe$ and $^{208}$Pb nuclei are calculated by a model using the natural orbital representation and the experimental data for the momentum distribution of the $^{4}He$ nucleus. The model allows realistic momentum distributions to be obtained using only hole-state natural orbitals (or mean

Hitoshi Nishino

We present mechanisms for generating conical singularities both in three and four-dimensions in the systems with copies of scalar or chiral multiplets coupled to $N=2$ or $N=1$ supergravity. Our mechanisms are useful for supersymmetry breaking, maintaining the zero cosmological constants in three and four-dimensions. A strong coupling duality connecting thes

S. James Gates,, Lubna Rana

Utilizing techniques suggested by the recently obtained construction of off-shell spinning particles, we propose the arbitrary $N$-extension of supersymmetry for the KdV system. It is further suggested that the ${\aleph}_0$ extension for the SKdV system provides a paradigm for {\underline {all}} supersymmetric completely integrable systems.

S. James Gates,, Lubna Rana

Extending our prior investigation, we give a new off-shell construction of theories of spinning particles propagating in Minkowski spaces with arbitrary $N$-extended supersymmetry on the world-line. The basis of the new off-shell formulation is provided by realizations of new algebraic structures ${\cal G}{\cal R}$(${\rm d}, N$) that are certain generalizati

W. Siegel

The massless superfield content of four-dimensional compactifications of closed superstrings with extended (N=2, 3, or 4) supersymmetry is derived by multiplying two (N=0, 1, or 2) Yang-Mills multiplets. In some cases these superfields are known, and the low-energy actions are determined from the fact that the compensator (dilaton) supermultiplets occur quad

Horst G. Kausch

Conformal field theory at $c=-2$ provides the simplest example of a theory with ``logarithmic'' operators. We examine in detail the $(ξ,η)$ ghost system and Coulomb gas construction at $c=-2$ and show that, in contradistinction to minimal models, they can not be described in terms of conformal families of {\em primary\/} fields alone but necessarily

P. Pouliot

We present a dual description for $SU(N)$ supersymmetric gauge theory with an antisymmetric tensor and fundamentals, and no superpotential. This duality is derived from the dualities of Seiberg. Under a perturbation of the superpotential, the dual theory breaks supersymmetry at tree level.

Don Colladay, Alan Kostelecky

We investigate the issue of testing CPT invariance in the neutral-$D$ system, using $D$ events obtained either from fixed-target experiments or from a tau-charm factory. For both types of experiments we show that the expected suppression of mixing in the $D$ system, normally viewed as a disadvantage for CP tests, allows unsuppressed measurement of certain pa

A. Casher, S. Nussinov

The inability to achieve in the present universe, via electromagnetic or gravitational acceleration, Planck energies for elementary particles is suggested on the basis of several, some relatively sophisticated, failed attempts. This failure is essential for schemes were the superplanckian regime for the energies of elementary particles is ``Unphysical'&#

Michael Gronau, Jonathan L. Rosner

Decay rates of $B^0(t)\toπ^+π^-,~B^0\toπ^- K^+,~B^+\toπ^+ K^0~ (K_S\toπ^+π^-$) and of charge-conjugate processes are studied within flavor SU(3) symmetry and first-order SU(3) breaking. We show that these measurements can determine with a reasonable accuracy the two angles, $α$ and $γ$, of the Cabibbo-Kobayashi-Maskawa unitarity triangle.

Xiangdong Ji

I begin with a general discussion about importance of constructing a picture of the nucleon in terms of QCD degrees of freedom, emphasizing the role of spin structure functions. I then give a short overview on the theoretical and experimental status of the spin structure of the nucleon. Following that, I mention several upcoming experiments to measure the fl

M. Pitkänen

The p-adic description of Higgs mechanism provides excellent predictions for elementary particle and hadron masses. In this work the construction of p-adic field theory limit of Quantum TGD is considered. Topological condensate defined as a manifold obtained by gluing together p-adic spacetime regions with different values of $p$ is identified as 'quantu

J. Manjavidze

It is shown that there is the possibility to find at least in the perturbation framework the Matsubara theory from the $S-$matrix interpretation of the real-time finite-temperature theory if the system under consideration is in an equilibrium state.

Wei-Shu Hou, Guey-Lin Lin

In the general two Higgs doublet model with flavor changing neutral Higgs couplings, neutral Higgs bosons may decay dominantly via $t\bar c$ or $\bar tc$ final states. At the linear collider, $e^+e^- \to h^0A^0$ or $H^0A^0$ production processes may result in $b\bar bt\bar c$, $W^+W^-t\bar c$ or $tt\bar c\bar c$ (or $\bar t\bar tcc$) final states. The process

Yu. B. Yufryakov

We consider hybrid states with heavy quarks in the frame of recently proposed constituent gluon model. Limiting regimes for model Hamiltonian are discussed. It is shown that these regimes match smoothly, hence predictions of the model are definite enough. We predict lowest $c \bar c g$ hybrids at $4.1 \pm 0.1$ GeV and $b \bar b g$ hybrids at $10.5 \pm 0.1$ G

Yu. S. Kalashnikova, Yu. B. Yufryakov

The model for hybrid excitations of the QCD string with quarks is presented starting from the perturbation theory in the nonperturbative background. The propagation of a system containing $q \bar q$-pair and gluon is considered. The simplified version of the Hamiltonian, including both long-range nonperturbative interaction and Coulomb force, is derived. The

M. A. Moinester, D. Ashery, L. G. Landsberg, H. J. Lipkin

The strange-anticharmed Pentaquark is a $uud\bar{c}s$ or $udd\bar{c}s$ five-quark baryon that is expected to be either a narrow resonance, or possibly even stable against strong and electromagnetic decay. We describe this hyperon here, its structure, binding energy and lifetime, resonance width, production mechanisms, production cross sections, and decay mod

Akira Takamura

We apply the $1/N_c$ expansion in QCD to the baryon vertices. We find new model independent properties for the isoscalar and isovector baryon vertices from the view point of $1/N_c$ expansion in QCD. One of these results, $I=J$ rule, have been already found. The other properties, new $I=J$ rules, are the rules about the isospin and strangeness dependence for

Makoto Oka

The status of theoretical studies of the $H$ dibaryon is reviewed. Some recent developments including the effect of the instanton induced interaction and the QCD sum rule results are discussed in detail.

J. J. Godina

We calculate the transverse muon polarization in the $K^+_{\mu3}$ process arising from the Yukawa couplings of charged Higgs boson in a general two-Higgs doublet model where spontaneous violation of CP is present

E. Papageorgiu

Assuming that a horizontal abelian (gauge) symmetry is at the origin of texture zeros in the fermion mass matrices we show how realistic mass patterns can be generated stepwise with a small number of effective operators from GUT's and string theory. It is interesting to note that, in the minimal scenario, if the up quark and the down quark mass matrices

Stephen R. Sharpe, Yan Zhang

We formulate quenched chiral perturbation theory for heavy-light mesons coupled to pions, and calculate the one-loop chiral logarithmic corrections to $f_B$, $f_{B_{s}}$, $B_B$ and $B_{B_{s}}$. We also calculate these corrections for ``partially quenched'' theories. In both theories, the chiral logarithms diverge in the chiral limit, indicating that

A. Soni

Status of weak matrix elements is reviewed. In particular, $\epspeps$, $\bkastg$, $B_K$, $B_B$ and $B_{B_s}$ are discussed and the overall situation with respect to the lattice effort and some of its phenomenological implications are summarized. For $\epspeps$ the need for the relevant matrix elements is stressed in view of the forthcoming improved experimen

Richard W. Haymaker

The spatial distribution of fields and currents in confining theories can give direct evidence of dual superconductivity. We review the behavior of vortices in the lattice Higgs effective theory. We discuss the techniques for finding these properties and calculating the superconductivity parameters in lattice simulations. We have seen dual Abrikosov vortices

A. Vladikas

We briefly review and compare three methods (one perturbative, one based on Ward Identities and one non-perturbative) for the calculation of the renormalization constants of lattice operators. The following results are presented: (a) non perturbative renormalization of the operators with light quarks; (b) the renormalization constants with a heavy (charm) qu

Wataru Ootani, Yutaka Ito, Keiji Nishigaki, Yasuhiro Kishimoto

Sensitive n-type and p-type germanium thermistors were fabricated by the melt doping technique and by the neutron transmutation doping (NTD) technique, respectively, aiming at a use for the cryogenic thermal detector, or bolometer of Tokyo dark matter search programme. We report on the measurements of the sensitivities of these thermistors. In particular, th

Tonatiuh Matos, Darío Núñez, Hernando Quevedo

Three different classes of static solutions of the Einstein--Maxwell equations non--minimally coupled to a dilaton field are presented. The solutions are given in general in terms of two arbitrary harmonic functions and involve among others an arbitrary parameter which determines their applicability as charged black holes, dilaton black holes or strings. Mos

F. C. Alcaraz, J. C. Xavier

The $Q$-state Potts model in two dimensions in the presence of external magnetic fields is studied. For general $Q\geq3$ special choices of these magnetic fields produce effective models with smaller $Z(Q&#39;)$ symmetry $(Q&#39;< Q)$. The phase diagram of these models and their critical behaviour are explored by conventional finite-size scaling and conforma

Vijay S. Pande, Alexander Yu. Grosberg, Toyoichi Tanaka

Protein sequences are believed to have been selected to provide the stability of, and reliable renaturation to, an encoded unique spatial fold. In recently proposed theoretical schemes, this selection is modeled as ``minimal frustration,&#39;&#39; or ``optimal energy&#39;&#39; of the desirable target conformation over all possible sequences, such that the ``

O. Heinonen, M. D. Johnson

Field-theoretical methods have been shown to be useful in constructing simple effective theories for two-dimensional (2D) systems. These effective theories are usually studied by perturbing around a mean-field approximation, so the question whether such an approximation is meaningful arises immediately. We here study 2D interacting electrons in a half-filled

Klaus Frahm, Axel M&#34;uller--Groeling, Jean-Louis Pichard

We derive an analytical theory for two interacting electrons in a $d$--dimensional random potential. Our treatment is based on an effective random matrix Hamiltonian. After mapping the problem on a nonlinear $σ$ model, we exploit similarities with the theory of disordered metals to identify a scaling parameter, investigate the level correlation function, and

N. M. Plakida, V. S. Oudovenko, P. Horsch, A. I. Liechtenstein

The pairing of quasiparticles in a CuO$_2$ plane is studied within a spin polaron formulation of the $t$-$t^{&#39;}$-$J$ model. Our numerical solution of the Eliashberg equations unambiguously shows d-wave pairing between spin polarons on different sublattices mediated by the exchange of spin-fluctuations, and a strong doping dependence of the quasiparticle

G. S. Uhrig, R. Vlaming

The phase diagram of the model of spinless fermions with repulsive nearest neighbour interaction is calculated analytically on a hypercubic lattice in infinite dimensions $(d\to \infty)$. In spite of its simplicity the model displays a rich phase diagram depending on the doping $δ$, the interaction $U$ and the temperature $T$. The system can be in the homoge

N. R. Claughton, M. Leadbeater, C. J. Lambert, V. N. Prigodin

Analytic predictions for resonant transport in three generic structures are presented. For a structure comprising a normal (N) contact - normal dot (NDOT) - superconducting (S) contact, we predict that finite voltage, differential conductance resonances are destroyed by the switching on of superconductivity in the S-contact. In the weak coupling limit, the s

P. Polaszek

A new combinatorial, analytical approach to the ground-state energy problem of spin glasses with different concentrations of +/- J interactions is developed. The energy e_0 is expressed in terms of the fraction of broken bonds mu_0 and expanded into a fast converging series of the average length of a segment between two frustrated plaquettes of a minimum-wei

Yohei Saika, Kiyomi Okamoto

We investigate the long-distance asymptotic behavior of the dimer correlations in the spin-1/2 alternating $XY$chain both at T=0 and at sufficiently low-temperatures. The correlations consist of the dimer long-range order part and the exponentially decaying one. Although the dimer long-range order takes the different values depending on the choice of the spi

C. Peterson, O. Sommelius, B. Soderberg

A new Monte Carlo method for computing thermodynamical properties of very large polyelectrolytes is presented. It is based on a renormalization group relating the original polymer to a smaller system, where in addition to the naively rescaled forces, a corrective nearest-neighbor interaction originating from the short distance Coulomb cutoff is introduced. T

Yihu Fang, Robert C. Duncan, Arlin P. S. Crotts, Jill Bechtold

We describe a robust Bayesian statistical method for determining Lyman alpha forest cloud sizes in spherical and in thin disk geometries, using absorption in adjacent sightlines toward closely separated QSO pairs and groups, apply this method to the available data, and discuss implications of our results for models of Ly alpha clouds. Under the assumption of

Benoit Tremblay, David Merritt

We present fully nonparametric estimates of the frequency function of elliptical galaxy intrinsic shapes under the axisymmetric and triaxial hypotheses. If elliptical galaxies are assumed to be oblate or prolate, the frequency function of intrinsic shapes is negative for axis ratios near unity due to the lack of apparently round galaxies. Both axisymmetric h

P. P. Eggleton, L. G. Kiseleva

About 5-15% of stellar systems are at least triple. About 1% of systems with a primary of $\tgs 1 \Mscun$ are triple with a {\it longer} peri od that is less than 30y, and so may in principle be capable of Roche-lobe overflow in both the inner and the outer orbits, at different times. We discuss possible evolutionary paths for these systems, some of which ma

Barbara Ryden, Adrian Melott

Using two-dimensional numerical simulations of gravitational clustering, with initial power spectra of a power-law form with index n, we compare the properties of voids in real space to their properties in redshift space. Both the void probability function (VPF) and the underdense probability function (UPF) are enhanced in redshift space. The enhancement is

Vahe Petrosian, Theodore T. Lee

Many of the important conclusions about Gamma-Ray Bursts follow from the distributions of various quantities such as peak flux or duration. We show that for astrophysical transients such as bursts, multiple selection thresholds can lead to various forms of data truncation, which can strongly affect the distributions obtained from the data if not accounted fo

Barbara S. Ryden

I compute the estimated distribution function f(q) for the apparent axis ratio q of various types of stellar systems, using a nonparametric kernel method. I then invert f(q) to find the distribution of intrinsic axis ratios, using two different hypotheses: first, that the stellar systems are all oblate, and second, that they are all prolate. The shapes of gl

D. P. Bennett, C. Alcock, R. A. Allsman, T. S. Axelrod

We provide a status report on our search for dark matter in our Galaxy in the form of massive compact halo objects (or Machos), using gravitational microlensing of background stars. This search uses a very large format CCD camera on the dedicated 1.27m telescope at Mt.~Stromlo, Australia, and has been taking data for almost 3 years. At present, we are in the

Edward L. Wright, Gary Hinshaw, Charles L. Bennett

A major goal of cosmology is to obtain sensitive, high resolution maps of the Cosmic Microwave Background (CMB) anisotropy. Such maps, as would be produced by the recently proposed Microwave Anisotropy Probe (MAP), will contain a wealth of primary information about conditions in the early universe. To mitigate systematic effects when observing the microwave

Helio J. Rocha-Pinto, Walter J. Maciel

We derive a new metallicity distribution of G dwarfs in the solar neighbourhood, using uvby photometry and up-to-date parallaxes. Our distribution comprises 287 G dwarfs within 25 pc from the Sun, and differs considerably from the classic solar neighbourhood distribution of Pagel & Patchett and Pagel by having a prominent single peak around [Fe/H] = -0.20 de

D. Shahar, D. C. Tsui, M. Shayegan, E. Shimshoni

We examine the longitudinal, non-linear, current-voltage characteristics near the quantum Hall liquid to insulator transition and show that a simple mapping exists between the characteristics on the quantum Hall side and those on the insulating side of the transition. More precisely, at filling factors related by the law of corresponding states the current a

I. I. Tkachev

Symmetry restoration processes during the non-equilibrium stage of ``preheating&#39;&#39; after inflation is studied. It is shown that symmetry restoration is very efficient when the majority of created particles are concentrated at energies much smaller than the temperature $T$ in equilibrium. The strength of symmetry restoration measured in terms of the eq

Ruth Durrer, Joachim Laukenmann

The aim of this paper is to show, that the &#39;oscillating universe&#39; is a viable alternative to inflation. We remind that this model provides a natural solution to the flatness or entropy and to the horizon problem of standard cosmology. We study the evolution of density perturbations and determine the power spectrum in a closed universe. The results le

S. Wycech, J. Skalski, R. Smolanczuk, J. Dobaczewski

Nuclear capture of antiprotons from atomic states is studied. Partial widths for single nucleon capture events leading to cold residual nuclei are calculated. Recent CERN experiments that compare the neutron and proton captures are analysed. Nuclear density distributions at extreme nuclear surface are calculated and tested against the experimental results.

Paul S. Aspinwall

We carefully analyze the N=2 dual pair of string theories in four dimensions introduced by Ferrara, Harvey, Strominger and Vafa. The analysis shows that a second discrete degree of freedom must be switched on in addition to the known `Wilson line&#39; to achieve a non-perturbatively consistent theory. We also identify the phase transition this model undergoe

Ivan G. Avramidi

The main results are: 1. A manifestly covariant technique for the calculation of De Witt coefficients is elaborated; 2. The coefficients $a_3$ and $a_4$ are calculated; 3. Covariant methods for the study of the nonlocal structure of the effective action are developed. The terms of first and second order in background fields in De Witt coefficients are calcul

H. R. Fiebig, H. Markum, A. Mihály, K. Rabitsch

A method for the extraction of an effective meson-meson potential from Green functions, which can be obtained from a lattice simulation, is presented. Simulations are carried out for compact QED and QCD in four dimensions using the quenched approximation and the hopping parameter expansion. In a further study, a heavy-light meson is considered employing a co

Liang Chen, S. Moukouri

The one-dimensional (1D) $t-J$ model is investigated using the density matrix renormalization group (DMRG) method. We report for the first time a generalization of the DMRG method to the case of arbitrary band filling and prove a theorem with respect to the reduced density matrix that accelerates the numerical computation. Lastly, using the extended DMRG met

D. F. Wang

In this work, we introduce long range version of the extended Hubbard model. The system is defined on a non-uniform lattice. We show that the system is integrable. The ground state, the ground state energies, the energy spectrum are also found for the system. Another long range version of the extended Hubbard model is also introduced on a uniform lattice, an

S. V. Faleev, P. G. Silvestrov

It is shown that the series of renormalon--type graphs, which consist in the chain of insertions to one soft(hard) gluon(photon) line is in fact ill defined. Each new type of insertions, which appears in the higher orders of perturbation theory, generates the correction to renormalon of the order of $\sim 1$. However, this series of the corrections to the as

Mohan Rajagopal, Roger Romani

We compute model atmospheres and emergent spectra for low field (B<10^10 G) neutron stars, using new opacity and equation of state data from the OPAL project. These computations, incorporating improved treatments of flux transport and convective stability, provide spectra for hydrogen, solar abundance and iron atmospheres. We compare our results to high fiel

Kikuo Harigaya, Yukihiro Shimoi, Shuji Abe

Exciton effects on conjugated polymers are investigated in the soliton lattice system. We use the Su-Schrieffer-Heeger model with long-range Coulomb interactions treated by the single-excitation configuration-interaction method. The soliton band is present in the Peierls gap of the doped system. There appears a new kind of the exciton where an electron-hole

S. Perez Bergliaffa, G. Romero, H. Vucetich

A realistic axiomatic formulation of nonrelativistic quantum mechanics for a single microsystem with spin is presented, from which the most important theorems of the theory can be deduced. In comparison with previous formulations, the formal aspect has been improved by the use of certain mathematical theories, such as the theory of equipped spaces, and group

Santiago E. Perez Bergliaffa, Gustavo E. Romero, Hector Vucetich

We present an axiomatization of non-relativistic Quantum Mechanics for a system with an arbitrary number of components. The interpretation of our system of axioms is realistic and objective. The EPR paradox and its relation with realism is discussed in this framework. It is shown that there is no contradiction between realism and recent experimental results.

Asher Peres

A generalized Kochen-Specker theorem is proved. It is shown that there exist sets of $n$ projection operators, representing $n$ yes-no questions about a quantum system, such that none of the $2^n$ possible answers is compatible with sum rules imposed by quantum mechanics. Namely, if a subset of commuting projection operators sums up to a matrix having only e

D. G. Pak

A three-dimensional $q$-Lie algebra of $SU_q(2)$ is realized in terms of first- and second-order differential operators. Starting from the $q$-Lie algebra one has constructed a left-covariant differential calculus on the quantum group. The proposed construction is inverse to the standard Woronowicz approach; the left-invariant vector fields are introduced as

M. Sambataro

We discuss a mapping procedure from a space of colorless three-quark clusters into a space of elementary baryons and illustrate it in the context of a three-color extension of the Lipkin model recently developed. Special attention is addressed to the problem of the formation of unphysical states in the mapped space. A correspondence is established between qu

HoSeong La

Area preserving diffeomorphisms of a 2-d compact Riemannian manifold with or without boundary are studied. We find two classes of decompositions of a Riemannian metric, namely, h- and g-decomposition, that help to formulate a gravitational theory which is area preserving diffeomorphism (SDiff$M$-) invariant but not necessarily diffeomorphism invariant. The g

S. Deser, R. Jackiw

We discuss some aspects of the two-dimensional scalar field, considering particularly the action for the conformal anomaly as an ``improved&#39;&#39; gravitational coupling, and the possibility of introducing a dual coupling, which provides a ``chiral&#39;&#39; energy-momentum tensor improvement.

Haye Hinrichsen, Achim Kempf

Small corrections to the uncertainty relations, with effects in the ultraviolet and/or infrared, have been discussed in the context of string theory and quantum gravity. Such corrections lead to small but finite minimal uncertainties in position and/or momentum measurements. It has been shown that these effects could indeed provide natural cutoffs in quantum

M. Olshanetsky

Knizhnik-Zamolodchikov-Bernard (KZB) equation on an elliptic curve with a marked point is derived by the classical Hamiltonian reduction and further quantization. We consider classical Hamiltonian systems on cotangent bundle to the loop group $L(GL(N,{\bf C}))$ extended by the shift operators, to be related to the elliptic module. After the reduction we obta

Kyoungtae Kimm, Kimyeong Lee, Taejin Lee

We introduce the self-dual abelian gauged $O(3)$ sigma models where the Maxwell and Chern-Simons terms constitute the kinetic terms for the gauge field. These models have quite rich structures and various limits. Our models are found to exhibit both symmetric and broken phases of the gauge group. We discuss the pure Chern-Simons limit in some detail and stud

E. Abdalla

Using the well-known result for the fermionic determinant in terms of a WZW theory, we write QCD$_2$ in bosonized form. After some manipulations we give two versions of the theory, where it is factorized as a product of the conformally invariant WZW models, ghost terms, and a WZW action perturbed off criticality. We first prove that the latter is an integrab

S. Geer, T. Asakawa

We define and discuss a set of (4N - 4) parameters that can be used to analyse events in which N jets have been produced in high energy hadron-hadron collisions. These multijet variables are the multijet mass and (4N - 5) independent dimensionless parameters. To illustrate the use of the variables QCD predictions are presented for events with up to five jets

J. F. Gunion

The doubly charged Higgs bosons $Δ^{--}$ that are present in exotic Higgs representations can have lepton-number-violating couplings to $e^-e^-$. We discuss general constraints and phenomenology for the $Δ^{--}$ and demonstrate that extremely small values for the $e^-e^-\rightarrowΔ^{--}$ coupling (some 8 orders of magnitude smaller than the current limit) w

Thomas G. Rizzo

We briefly discuss two possible manifestations of the lepton number violating reaction $e^-e^- \to W_i^-W_j^{(*)-}$, which probes the masses and mixings of heavy Majorana neutrinos, at the Next Linear Collider(NLC). Cross sections for this process are shown to be potentially quite large at center of mass energies of order 1-1.5 TeV. (Talk presented at the Sa

K. Takenaga

Electroweak theory with two massless Higgs doublets is studied by solving renormalization group equations for coupling constants in one-loop approximation. A cutoff~$Λ$, at which one of quartic couplings in the Higgs potential blows up, is obtained by imposing constraints from the oblique parameter $T$ on the quartic couplings at low energy. We find $Λ\simeq

M. Spira

A program for the calculation of the total Higgs production cross section via gluon fusion at hadron colliders including next--to--leading order QCD corrections is presented. It is suitable especially for Standard Model Higgs bosons and the neutral Higgs particles of the minimal supersymmetric extension. The program provides a model--independent calculation

G. Altarelli, S. Petrarca, F. Rapuano

Using the recent relatively precise experimental results on the pion structure function, obtained from Drell--Yan processes, we quantitatively test an old model where the structure function of any hadron is determined by that of its constituent quarks. In this model the pion structure function can be predicted from the known nucleon structure function. We fi

J. Kwiecinski

The theory part of the conference is summarized with certain emphasis on the results concerning the pomeron in soft and hard processes.

Barry R. Holstein

Recently methods have been developed which exploit the chiral symmetry of QCD in order to make rigorous contact with low energy particle physics phenomenology. In these lectures we present a pedagogical introduction to these techniques.

M. J. Strassler

A mechanism is suggested by which the dynamics of confinement could be responsible for the fermion mass matrix. In this approach the large top quark Yukawa coupling is generated naturally during confinement, while those of the other quarks and leptons stem from non-renormalizable couplings at the Planck scale and are suppressed. Below the confinement scale(s

S. Geer

This paper describes an experimental search for antiproton decay at the Fermilab Antiproton Accumulator. The E868 (APEX) experimental setup is described. The APEX data is expected to be sensitive to antiproton decay if the antiproton lifetimes is less than a few times 100 000 years.

P. R. Brady, S. Droz, W. Israel, S. M. Morsink

The paper develops a $(2+2)$-imbedding formalism adapted to a double foliation of spacetime by a net of two intersecting families of lightlike hypersurfaces. The formalism is two-dimensionally covariant, and leads to simple, geometrically transparent and tractable expressions for the Einstein field equations and the Einstein-Hilbert action, and it should fin

M. Yu. Konstantinov

The so called &#39;&#39;Principle of the self-consistency&#39;&#39; for space-time models with causality violation, which was firstly formulated by I.D.Novikov, is discussed for the test particle motion and for test scalar field. It is shown that the constraints, which provide the self-concistensy of test particle motion have pure geometrical (topological) n

Matthias Holschneider

In this short paper we discuss how the position - scale half-space of wavelet analysis may be cut into different regions. We discuss conditions under which they are independent in the sense that the Töplitz operators associated with their characteristic functions commute modulo smoothing operators. This shall be used to define microlocal classes of distribut

M. Guerrero, R. M. Noack

We map out the phase diagram of the one--dimensional Anderson lattice by studying the ground state magnetization as a function of band--filling using the density matrix renormalization group technique. For strong coupling, we find that the quarter--filled system has an S=0 ground state with strong antiferromagnetic correlations. As additional electrons are p

Dmitry Rinberg, Vladimir Cherepanov, Victor Steinberg

We report the first experimental observation of parametric generation of second sound (SS) by first sound (FS) in superfluid helium in a narrow temperature range in the vicinity of $T_λ$. The temperature dependence of the threshold FS amplitude is found to be in a good quantitative agreement with the theory suggested long time ago and corrected for a finite

J. V. Andersen, Y. Brechet

We use a macroscopic Hamiltonian approach to study the pinning of a solid--liquid--vapour contact line on an array of equidistant stripes of obstacles perpendicular to the liquid. We propose an estimate of the density of pinning stripes for which collective pinning of the contact line happens. This estimate is shown to be in good agreement with Langevin equa