December 1994 arXiv papers — page 2

Zurab Berezhiani

The supersymmetric $SU(6)$ model accompanied by the flavour-blind discrete symmetry $Z_3$ can succesfully deal with such key problems of SUSY GUTs, as are the gauge hierarchy/doublet-triplet splitting, $μ$-problem and flavour problem. The Higgs doublets arise as Goldstone modes of the spontaneously broken {\em accidental} global $SU(6)\times U(6)$ symmetry o

Takeshi Suzuki

We study the $SU(2)$ WZNW model over a family of elliptic curves. Starting from the formulation developed by Tsuchiya, Ueno and Yamada, we derive a system of differential equations which contains the Knizhnik-Zamolodchikov-Bernard equations. Our system completely determines the $N$-point functions and it is regarded as a natural elliptic analogue of the one

M. H. Ernst, J. R. Dorfman, R. Nix, D. Jacobs

Cellular automata lattice gases are useful systems for systematically exploring the connections between non-equilibrium statisitcal mechanics and dynamical systems theory. Here the chaotic properties of a Lorentz lattice gas are studied analytically and by computer simulations. The escape-rates, Lyapunov exponents, and KS entropies are estimated for a one-di

D. Ebert, M. Nagy. M. K. Volkov

In this article, the gap equation for the constituent quark mass in the U(2)*U(2) Nambu-Jona-Lasinio model for the 1/Nc approximation is investigated. It is shown that taking into account scalar isovector mesons plays an important role for the correct description of quark masses in this approximation. The role of the Ward identity in calculations of 1/Nc cor

Ofir E. Alon, Nimrod Moiseyev, Asher Peres

The momentum operator for a particle in a box is represented by an infinite order Hermitian matrix $P$. Its square $P^2$ is well defined (and diagonal), but its cube $P^3$ is ill defined, because $P P^2\neq P^2 P$. Truncating these matrices to a finite order restores the associative law, but leads to other curious results.

I. Aranson, M. Gitterman, B. Ya. Shapiro

Spontaneous nucleation and the consequent penetration of vortices into thin superconducting films and wires, subjected to a magnetic field, can be considered as a nonlinear stage of primary instability of the current-carrying superconducting state. The development of the instability leads to the formation of a chain of vortices in strips and helicoidal vorte

Michael Kernaghan, Asher Peres

A Kochen-Specker contradiction is produced with 36 vectors in a real 8-dimensional Hilbert space. These vectors can be combined into 30 distinct projection operators (14 of rank 2, and 16 of rank 1). A state-specific variant of this contradiction requires only 13 vectors, a remarkably low number for 8 dimensions.

Zhong-Qi Ma

Recently a stronger statement of Levinson's theorem for the Dirac equation was presented, where the limits of the phase shifts at $E=\pm M$ are related to the numbers of nodes of radial functions at the same energies, respectively. However, in this letter we show that this statement has to be modified because the limits of the phase shifts may be negativ

A. L. Barabanov

The suggestion is made that the excited state of the $^3 H$ nucleus found out recently in the reaction $H$ ($^6 He$,$α$) ({\it Pis'ma JETPh\/} {\bf 59} (1994) 301) has spin and parity $1/2^+$ and the same configuration that the ground one of $^6 He$. An amplitude of electromagnetic transition to the triton ground state is strongly suppressed, therefore t

Mu-In Park, Young-Jai Park

The operator ordering problem due to the quantization or regularization ambiguity in the Chern-Simons theory exists. However, we show that this can be avoided if we require Galilei covariance of the nonrelativistic Abelian Chern-Simons theory even at the quantum level for the extended sources. The covariance can be recovered only by choosing some particular

N. A. Saulina, M. V. Terentiev, K. N. Zyablyuk

The lagrangian of the N=1, D=10 dual supergravity interacting with the Yang-Mills matter multiplet is constructed starting immediately from the equations of motion obtained from the Bianchi Identities in the superspace approach. The difference is established in comparison with the Gates-Nishino lagrangian at the fourth order level in fermionic fields.

S. Naftulin

We discuss the structure of one-loop counterterms for the two-dimensional theory of gravitation in the covariant scheme and study the effect of quantum reparametrizations.Some of them are shown to be equivalent to the introduction of 2+$epsilon$-dimensional terms into the initially 2-dimensional theory. We also argue that the beta-function for the Einstein c

Masako Asano, Chigak Itoi, Shin-Ichi Kojima

Euclidean invariant Klein-Gordon, Dirac and massive Chern-Simons field theories are constructed in terms of a random walk with a spin factor on a three dimensional lattice. We exactly calculate the free energy and the correlation functions which allow us to obtain the critical diffusion constant and associated critical exponents. It is pointed out that these

M. Polyakov, M. Shmatikov

Production of strangeness in the low-energy ${\bar p} p$ annihilation is analyzed as a manifestation of the instanton induced multiquark vertex. Approach based on the {\it qualitative} properties of the 't Hooft mechanism provides a unified description of available experimental data on $K$- and $ϕ$-meson production. Crucial tests for the hypothesized mec

D. A. Dicus, B. Dutta, S. Nandi

We consider the implications of an extended color group, $SU\left( 3\right) _I\times SU\left( 3\right) _{II}$, spontaneously broken to $SU\left( 3\right) _c$ at a TeV or lower scale, for the hadronic colliders. The associated massive color octet gauge bosons (the colorons) can enhance the $t \overline{t}$ pair production at the Tevatron collider. At the LHC,

Avraham Schiller, Pradeep Kumar, Rainer Strack, Dieter Vollhardt

In this paper we study the effect of next-nearest-neighbor hopping on the dynamics of a single hole in an antiferromagnetic (Néel) background. In the framework of large dimensions the Green function of a hole can be obtained exactly. The exact density of states of a hole is thus calculated in large dimensions and on a Bethe lattice with large coordination nu

J. Dubois, P. Kumar

We propose a simple Ginzburg-Landau free energy to describe the magnetic phase transition in solid $^3$He. The free energy is analyzed with due consideration of the hard first order transitions at low magnetic fields. The resulting phase diagram contains all of the important features of the experimentally observed ph ase diagram. The free energy also yields

E. Demircan, P. Ao, Q. Niu

We investigate the interactions of collective excitations with vortices in superfluid systems, including $~^4$He and superconductors. The dynamical equations are obtained by the aid of the many-body wavefunction and the density-density correlation function. The scattering cross-section of collective excitations with a vortex is calculated in the Born approxi

Henk van Beijeren, J. R. Dorfman

The Lyapunov exponents and the KS entropy for a two dimensional Lorentz gas at low densities are defined for general non-equilibrium states and calculated with the use of a Lorentz-Boltzmann type equation. In equilibrium the density dependence of these quantities predicted by Krylov is recovered and explicit expressions are obtained. The relationship between

Y. Suto, T. Suginohara, Y. Inagaki

While the recent discovery of the Cepheid variables in the Virgo cluster galaxies puts additional support for the Hubble constant $H_0 \sim 80$km/sec/Mpc, a relatively lower value $H_0 \sim 50$km/sec/Mpc is suggested by other distance indicators based on the Sunyaev-Zel'dovich effect and the gravitational lens which probe the universe at higher redshifts

Anatoly A. Ovchinnikov

We present the exact ground-state wave function and energy of the generalized Hubbard model, subjected to the condition that the number of double occupied sites is conserved, for a wide, physically relevant range of parameters. For one hole and one double occupied site the existence of the ferromagnetic ground-state is proved which allow one to determine the

Kobayasi Yosiyuki, Takunaga Takenobu, Tanaka Hozumi

Analyzing compound nouns is one of the crucial issues for natural language processing systems, in particular for those systems that aim at a wide coverage of domains. In this paper, we propose a method to analyze structures of Japanese compound nouns by using both word collocations statistics and a thesaurus. An experiment is conducted with 160,000 word coll

E Corrigan

Lectures at the CRM-CAP Summer School 'Particles and Fields 94' August 16-24 1994, Banff, Alberta, Canada.

T. Mogami

A string field theory including open string fields is constructed in the temporal gauge. It consists of string interaction vertices similar to the light-cone gauge string field theory. A slight modification of the definition of the time coordinate is needed because of the existence of the open string end points.

A. Bochkarev

We review nonperturbative calculations of the rate of sphaleron transitions on the lattice in $1+1$-dimensional field theories and introduce a way to perform the gauge-invariant Gibbs averages in the classical non-Abelian Higgs theories.

M. Campostrini, P. Rossi, E. Vicari

We investigate the large-N critical behavior of 2-d lattice chiral models by Monte Carlo simulations of U(N) and SU(N) groups at large N. Numerical results confirm strong coupling analyses, i.e. the existence of a large-N second order phase transition at a finite $β_c$.

M. Campostrini, P. Rossi, E. Vicari

Two dimensional large-N chiral models on the square and honeycomb lattices are investigated by a strong coupling analysis. Strong coupling expansion turns out to be predictive for the evaluation of continuum physical quantities, to the point of showing asymptotic scaling. Indeed in the strong coupling region a quite large range of beta values exists where th

Yan V. Fyodorov, H-J. Sommers

We calculate analytically the distributions of "level curvatures" (LC) (the second derivatives of eigenvalues with respect to a magnetic flux) for a particle moving in a white-noise random potential. We find that the Zakrzewski-Delande conjecture is still valid even if the lowest weak localization corrections are taken into account. The ratio of mean

Atsushi Moriwaki

In this short note, we will show the following weak evidence of S. Lang conjecture over function fields. Let f : X ---> Y be a projective and surjective morphism of algebraic varieties over an algebraically closed field k of characteristic zero, whose generic fiber is geometrically irreducible and of general type. If f is not birationally trivial, then there

A. Moreo, S. Haas, A. Sandvik, E. Dagotto

The spectral weight ${\rm A({\bf p},ω)}$ of the two dimensional ${\rm t-J}$ and Hubbard models has been calculated using exact diagonalization and quantum Monte Carlo techniques, at several densities ${\rm 1.0 \leq \langle n \rangle \leq 0.5}$. The photoemission $(ω< 0)$ region contains two dominant distinct features, namely a low-energy quasiparticle peak w

Kyungsik Kang, Sin Kyu Kang

We have examined the evidence for the electroweak radiative corrections in the LEP precision data sets of 1993 and 1994 along with the intriguing possibility that the QED corrections only may be sufficient to fit the data within the framework of the minimal standard model. We find that the situation is very sensitive to the precise values of $M_W$. The curre

J. Skarha

Measurements of the $B_u$, $B_d$, and $B_s$ meson lifetime using semileptonic $B_u \rightarrow e \nu D^0 X, B_d \rightarrow e \nu D^* X, B_s \rightarrow l \nu D_s X$ events and exclusive $B_u \rightarrow \psi^{(\prime)} K^{(*)}, B_d \rightarrow \psi^{(\prime)} K^{(*)}_{(s)}, B_s \rightarrow \psi \phi$ events are presented. These results used the precise posi

E877 Collaboration, J. ~Barrette et. al

We present the results of an analysis of charged particle pseudorapidity distributions in the central region in collisions of a Au projectile with Al, Cu, Au, and U targets at an incident energy of 10.8~GeV/c per nucleon. The pseudorapidity distributions are presented as a function of transverse energy produced in the target or central pseudorapidity regions

R. Scognamillo

We consider the moduli space of stable principal G-bundles over a compact Riemann surface C of genus >1, with G a reductive algebraic group. We explicitly construct a map F from the generic fibre of the Hitchin map to a generalized Prym variety associated to a suitable Galois covering of C. The map F has finite fibres. In case G=PGl(2) one can check that the

A. P. Bakulev, S. V. Mikhailov

We analyze new QCD sum rules for the pion wave function $ϕ_π(x)$, obtained recently by A.V. Radyushkin in the framework of the non-local vacuum condensates method for non-diagonal correlators, and suggest a new approach for extracting wave functions of the $π$-meson and of its first resonances. As a result we obtain approximately the same form of the pion wa

Massimo Campostrini, Paolo Rossi, Ettore Vicari

The strong-coupling character expansion of lattice models is reanalyzed in the perspective of its complete algorithmization. The geometric problem of identifying, counting, and grouping together all possible contributions is disentangled from the group-theoretical problem of weighting them properly. The first problem is completely solved for all spin models

P. Bamert, C. P. Burgess, R. N. Mohapatra

We construct two new classes of models for double beta decay, each of which leads to an electron spectrum which differs from the decays which are usually considered. One of the classes has a spectrum which has not been considered to date, and which is softer than the usual two-neutrino decay of the Standard Model. We construct illustrative models to show how

Gabriel Lopes Cardoso, Dieter Lüst, Thomas Mohaupt

We present the computation of threshold functions for Abelian orbifold compactifications. Specifically, starting from the massive, moduli-dependent string spectrum after compactification, we derive the threshold functions as target space duality invariant free energies (sum over massive string states). In particular we work out the dependence on the continuo

A. Bianconi, S. Boffi

The response to longitudinally polarized electrons in coincident out-of-plane ($\vec{\mathrm e},{\mathrm e}&#39;{\mathrm p}$) reaction is discussed to study the role of final state interactions and quantum interference between different reaction channels, i.e. between direct (quasi) elastic proton emission and baryon resonance production. The high-energy sup

J. Satsuma, K. Kajiwara, B. Grammaticos, J. Hietarinta

By analogy to the continuous Painlevé II equation, we present particular solutions of the discrete Painlevé II (d-P$\rm_{II}$) equation. These solutions are of rational and special function (Airy) type. Our analysis is based on the bilinear formalism that allows us to obtain the $τ$ function for d-P$\rm_{II}$. Two different forms of bilinear d-P$\rm_{II}$ ar

C. Calude, D. I. Campbell, K. Svozil, D. Ştefănecu

Are minds subject to laws of physics? Are the laws of physics computable? Are conscious thought processes computable? Currently there is little agreement as to what are the right answers to these questions. Penrose goes one step further and asserts that: {\it a radical new theory is indeed needed, and I am suggesting, moreover, that this theory, when it is f

Ulf H. Danielsson

This is a writeup of a talk given at the Oskar Klein Centenery Symposium, Stockholm, September 19-21, 1994. It is an essay on the black hole information paradox and its connection with thermodynamics and the foundations of quantum mechanics.

P. Braun-Munzinger, J. Stachel

Production probabilities for strange clusters and strange matter in Au+Au collisions at AGS energy are obtained in the thermal fireball model. The only parameters of the model, the baryon chemical potential and temperature, were determined from a description of the rather complete set of hadron yields from Si+nucleus collisions at the AGS. For the production

J. Barrette

We present measurements of the pion transverse momentum (p_t) spectra in central Si-nucleus collisions in the rapidity range 2.0<y<5.0 for p_t down to and including p_t=0. The data exhibit an enhanced pion yield at low p_t compared to what is expected for a purely thermal spectral shape. This enhancement is used to determine the Delta-resonance abundance at

Valeri Frolov

In the talk different definitions of the black hole entropy are discussed and compared. It is shown that the Bekenstein-Hawking entropy $S^{BH}$ (defined by the response of the free energy of a system containing a black hole on the change of the temperature) differs from the statistical- mechanical entropy $S^{SM}=-\mbox{Tr}(\hatρ\ln \hatρ)$ (defined by coun

A. Mikovicć, B. Sazdović

We present a procedure for constructing actions describing propagation of W-strings on group manifolds by using the Hamiltonian canonical formalism and representations of W-algebras in terms of Kac-Moody currents. An explicit construction is given in the case of the $W_3$ string.

Peter Bouwknegt, Andreas W. W. Ludwig, Kareljan Schoutens

In these lectures, we study and compare two different formulations of $SU(2)$, level $k=1$, Wess-Zumino-Witten conformal field theory. The first, conventional, formulation employs the affine symmetry of the model; in this approach correlation functions are derived from the so-called Knizhnik-Zamolodchikov equations. The second formulation is based on an enti

P. Mayr, S. Stieberger

We investigate the low--energy properties of a Z_12 orbifold with continuous Wilson line moduli. They give rise to a (0,2) superstring compactification. Their Kaehler potentials and Yukawa couplings are calculated. We study the discrete symmetries of the model and their implications on the threshold corrections to the gauge couplings as well as for string un

Vidyut Jain, Robert Shrock

We study models of fermion mass matrices based on a flavor- and generation-dependent string-motivated U(1)$_A$ gauge symmetry and report two new classes of solutions to the requisite consistency conditions. In particular, we propose that the fundamental reason underlying the striking feature $m_b, \ m_τ<< m_t$ is that all of the elements of the down-quark an

W. Dimm, G. Peter Lepage, Paul B. Mackenzie

We discuss a program for replacing standard perturbative methods with Monte Carlo simulations in short distance lattice gauge theory calculations.

Massimo Campostrini, Paolo Rossi, Ettore Vicari

We consider a definition of the QCD running coupling constant $α(μ)$ related to Wilson loops of size $r{\times}t$ with arbitrary fixed $t/r$. The schemes defined by these couplings are very close to the $\overline{\rm MS}$ scheme (i.e.\ the one-loop perturbative correction to the coupling is small) for all values of $t/r$; in the $t/r\to\infty$ limit, the ``

M. Campostrini, P. Rossi, E. Vicari

Two dimensional $N=\infty$ lattice chiral models are investigate by a strong coupling analysis. Strong coupling expansion turns out to be predictive for the evaluation of continuum physical quantities, to the point of showing asymptotic scaling (within 5\%).

M. Campostrini, P. Rossi, E. Vicari

A general precedure is outlined for an algorithmic implementation of the strong coupling expansion of lattice chiral models on arbitrary lattices. A symbolic character expansion in terms of connected values of group integrals on skeleton diagrams may be obtained by a fully computerized approach.

The CDF Collaboration

This paper presents a measurement of J/psi,psi(2S) differential cross sections in p-pbar collisions at square root s = 1.8 TeV. The cross sections are measured above 4 GeV/c in the central region (|eta| < 0.6) using the dimuon decay channel. The fraction of events from B decays is measured, and used to calculate b quark cross sections and direct J/psi,psi(2S

Bruce P. Jensen, John G. Mc Laughlin, Adrian C. Ottewill

The quantum theory of linearized perturbations of the gravitational field of a Schwarzschild black hole is presented. The fundamental operators are seen to be the perturbed Weyl scalars $\dotΨ_0$ and $\dotΨ_4$ associated with the Newman-Penrose description of the classical theory. Formulae are obtained for the expectation values of the modulus squared of the

Eugene Lerman, Susan Tolman

A symplectic toric orbifold is a compact connected orbifold $M$, a symplectic form $ω$ on $M$, and an effective Hamiltonian action of a torus $T$ on $M$, where the dimension of $T$ is half the dimension of $M$. We prove that there is a one-to-one correspondence between symplectic toric orbifolds and convex rational simple polytopes with positive integers att

Rogier Brussee

Let $X$ be a simply connected 4-manifold containing a $(-1)$-sphere $e$. Fintushel and Stern prove that $$ D_c(\exp(te)) = D_c(B(t)) on e^\perp if c\cdot e is even, $$ $$ D_c(\exp(te)) = D_{c-e}(S(t)) on e^\perp if c \cdot e is odd, $$ for some universal series $B(t),S(t) \in \Q[x][[t]]$ with $x$ the class of a point. We show that their method can easily be

Viktor Dotsenko, A. B. Harris, David Sherrington, R. B. Stinchcombe

We study the critical properties of the weakly disordered $p$-component random Heisenberg ferromagnet. It is shown that if the specific heat critical exponent of the pure system is positive, the traditional renormalization group (RG) flows at dimensions $D=4-\e$, which are usually considered as describing the disorder-induced universal critical behavior, are

S. Q. Yang, D. Belitz

It is shown how a recent method to systematically extrapolate and resum the loop expansion for nonlinear sigma-models is related to solutions of the renormalization group equation. This relation is used to generalize the explicit equations of state obtained previously to models which display crossover phenomena. As an example we discuss Wegner&#39;s localiza

J. Igarashi, T. Tonegawa, M. Kaburagi, P. Fulde

Magnetic impurities coupled antiferromagnetically to a one-dimensional Heisenberg model are studied by numerical diagonalization of chains of finite clusters. By calculating the binding energy and the correlation function, it is shown that a local singlet develops around each impurity. This holds true for systems with a single impurity, with two impurities,

Markus Walther, Bernd J. Kroeger

An implemented approach which couples a constraint-based phonology component with an articulatory speech synthesizer is proposed. Articulatory gestures ensure a tight connection between both components, as they comprise both physical-phonetic and phonological aspects. The phonological modelling of e.g. syllabification and phonological processes such as Germa

J. Legare, J. W. Moffat

We present a derivation of the equation of motion for a test-particle in the framework of the nonsymmetric gravitational theory. Three possible couplings of the test-particle to the non-symmetric gravitational field are explored. The equation of motion is found to be similar in form to the standard geodesic equation of general relativity, but with an extra a

Carles Bona, Joan Masso, Edward Seidel, Joan Stela

We present a new formulation of the Einstein equations that casts them in an explicitly first order, flux-conservative, hyperbolic form. We show that this now can be done for a wide class of time slicing conditions, including maximal slicing, making it potentially very useful for numerical relativity. This development permits the application to the Einstein

N. Hata, R. J. Scherrer, G. Steigman, D. Thomas

We present new upper and lower bounds to the primordial abundances of deuterium and helium-3 based on observational data from the solar system and the interstellar medium. Independent of any model for the primordial production of the elements we find (at the 95\% C.L.): $1.5 \times 10^{-5} \le (D/H)_P \le 10.0 \times 10^{-5}$ and $(^3He/H)_P \le 2.6\times 10

Fay Dowker, Adrian Kent

We review the consistent histories formulations of quantum mechanics developed by Griffiths, Omn\`es and Gell-Mann and Hartle, and describe the classification of consistent sets. We illustrate some general features of consistent sets by a few simple lemmas and examples. We consider various interpretations of the formalism, and examine the new problems which

Christian Winkler, Hartmut M. Hofmann

We apply a stochastic method of minimizing the ground state energy in variational calculations of light nuclei using the Refined Resonating Group Model (RRGM). The method utilizes a bit representation of the width parameters to be varied. To find the best possible set of width parameters we use strategies familiar from biological evolution. Very complicated

M. G. Schmidt, C. Schubert

The worldline path integral approach to the Bern-Kosower formalism is reviewed, which offers an alternative to Feynman diagram calculations in quantum field theory. Recent progress in constructing a multiloop generalization of this formalism is reported.

A. Ceresole, R. D&#39;Auria, S. Ferrara, A. Van Proeyen

We consider duality transformations in N=2 Yang--Mills theory coupled to N=2 supergravity, in a manifestly symplectic and coordinate covariant setting. We give the essential of the geometrical framework which allows one to discuss stringy classical and quantum monodromies, the form of the spectrum of BPS saturated states and the Picard--Fuchs identities enco

O. Lechtenfeld, S. Samuel

The general d-dimensional twisted group lattice is solved. The irreducible representations of the corresponding group are constructed by an explicit procedure. It is proven that they are complete. All matrix representation solutions to the quantum hyperplane equations are obtained.

Chr. V. Christov, K. Goeke, P. V. Pobylitsa

We show that the $1/N_c$ rotational corrections to $g_A$, derived using the semiclassical quantization scheme in the NJL model, possess correct properties under charge conjugation.

Michael R. Gallis

Maximally predictive states, as defined in recent work by Zurek, Habib and Paz, are studied for more elaborate environment models than a linear coupling. An environment model which includes spatial correlations in the noise is considered in the non-dissipative regime. The Caldeira-Leggett model is also reconsidered in the context of an averaging procedure wh

Sergio Albeverio, Shao-Ming Fei

We study the highest weight and continuous tensor product representations of q-deformed Lie algebras through the mappings of a manifold into a locally compact group. As an example the highest weight representation of the q-deformed algebra $sl_q(2,\Cb)$ is calculated in detail.

B. M. Zupnik

We discuss the left-covariant 3-dimensional differential calculus on the quantum sphere $SU_q (2)/U(1) $. The $SU_q (2)$-spinor harmonics are treated as coordinates of the quantum sphere. We consider the gauge theory for the quantum group $SU_q (2)\times U(1) $ on the deformed Euclidean space $E_q (4)$. A $q$-generalization of the harmonic-gauge-field formal

L. L. Frankfurt, W. R. Greenberg, G. A. Miller, M. M. Sargsyan

We find that the final state interactions in the $d(e,e&#39;np)$ amplitude depend strongly on the final momentum of the spectator nucleon. This means that color transparency effects can be studied at rather low four-momentum transfer $Q^2\geq$ 4 (GeV/c)$^2$ using un-polarized and polarized deuteron targets.

Pradipta Bandyopadhyay

K.\ S.\ Lau had shown that a reflexive Banach space has the Mazur Intersection Property (MIP) if and only if every closed bounded convex set is the closed convex hull of its farthest points. In this work, we show that in general this latter property is equivalent to a property stronger than the MIP. As corollaries, we recapture the result of Lau and characte

David Goldberg, Freydoon Shahidi

We give an expository account of the theory of intertwining operators for connected reductive $p$--adic groups, and their connection with automorphic $L$--functions. Our purpose is to illustrate the relation between harmonic analysis and arithmetic. In particular, we describe how the theory of Plancherel measures allows us to compute certain local Langlands

Peter G. O. Freund

A simple solution of Witten&#39;s monopole equations is given.

Giovanni Felder

This note for the Proceedings of the International Congress of Mathematical Physics gives an account of a construction of an ``elliptic quantum group&#39;&#39; associated with each simple classical Lie algebra. It is closely related to elliptic face models of statistical mechanics, and, in its semiclassical limit, to the Wess-Zumino-Witten model of conformal

R. Brooks, A. Lue

We twist the monopole equations of Seiberg and Witten and show how these equations are realized in topological Yang-Mills theory. A Floer derivative and a Morse functional are found and are used to construct a unitary transformation between the usual Floer cohomologies and those of the monopole equations. Furthermore, these equations are seen to reside in th

Prem P. Srivastava

The renormalization of the two dimensional light-front quantized $ϕ^{4}$ theory is discussed. The mass renormalization condition and the renormalized constraint equation are shown to contain all the information to describe the phase transition in the theory, which is found to be of the second order in agreement with the conjecture of Simons and Griffith. We

Prem P. Srivastava

The spontaneous symmetry breaking (and Higgs) mechanism in the theory quantized on the light-front ({\it l.f.}), in the {\it discretized formulation}, is discussed. The infinite volume limit is taken to obtain the {\it continuum version}. The hamiltonian formulation is shown to contain a new ingredient in the form of nonlocal {\it constraint eqs.} which lead

M. R. Douglas, M. Li

We study the full set of planar Green&#39;s functions for a two-matrix model using the language of functions of non-commuting variables. Both the standard Schwinger-Dyson equations and equations determining connected Green&#39;s functions can be efficiently discussed and solved. This solution determines the master field for the model in the `$C$-representati

J. -B. Zuber

I review three different problems occuring in two dimensional field theory: 1) classification of conformal field theories; 2) construction of lattice integrable realizations of the latter; 3) solutions to the WDVV equations of topological field theories. I show that a structure of Coxeter group is hidden behind these three related problems.

A. A. Abrikosov

Analytic continuation of quantum statistical physics from imaginary to real time is analyzed. Adiabatic vanishing of interactions at real time infinities gives origin to singularities at complex times. This undermines the hypothesis of decoupling of interactions at $t \rightarrow \infty$. Hence an interacting thermal vacuum is a necessary component of the ex

K. Landsteiner, W. Lerche, A. Sevrin

We show that the BRST structure of the topological string is encoded in the ``small&#39;&#39; $N=4$ superconformal algebra, enabling us to obtain, in a non-trivial way, the string theory from hamiltonian reduction of $A(1|1)$. This leads to the important conclusion that not only ordinary string theories, but topological strings as well, can be obtained, or e

M. Bonini, M. D&#39;Attanasio, G. Marchesini

By using the exact renormalization group formulation we prove perturbatively the Slavnov-Taylor (ST) identities in SU(2) Yang-Mills theory. This results from two properties: {\it locality}, i.e. the ST identities are valid if their local part is valid; {\it solvability}, i.e. the local part of ST identities is valid if the couplings of the effective action w

Denis Bernard, Kazuhiro Hikami, Miki Wadati

The Yangian symmetry Y(su($n$)) of the Calogero-Sutherland-Moser spin model is reconsidered. The Yangian generators are constructed from two non-commuting su($n$)-loop algebras. The latters generate an infinite dimensional symmetry algebra which is a deformation of the $W_\infty$-algebra. We show that this deformed $W_\infty$-algebra contains an infinite num

M. J. Duff, Ramzi R. Khuri, J. X. Lu

We review the status of solitons in superstring theory, with a view to understanding the strong coupling regime. These {\it solitonic} solutions are non-singular field configurations which solve the empty-space low-energy field equations (generalized, whenever possible, to all orders in $α&#39;$), carry a non-vanishing topological &#34;magnetic&#34; charge a

Dinko Pocanic

We review two manifestations of chiral symmetry breaking in the pion sector. First, we examine the $ππ$ scattering amplitude at threshold, which is completely determined by the chiral symmetry breaking part of the strong interaction, and, thus, directly constrains the form of the low energy effective lagrangians. We review the current status of the $ππ$ scat

A. Makhlin

Using the general framework of quantum field kinetics we consider new principles to compute initial distribution of quarks and gluons after the first hard interaction of heavy ions. We start by rewriting the integral equations of QCD in the form which is generalizations of the familiar QCD evolution equations. These equations describe both space-time-- and $

A. Makhlin

Using the general framework of quantum field theory, we derive basic equations of quantum field kinetics. The main goal of this approach is to compute the observables associated with a quark-gluon plasma at different stages of its evolution. We start by rewriting the integral equations for the field correlators in different forms, depending on the relevant d

Paul Langacker

The implications of precision $Z$ and $W$-pole and neutral current data for testing the standard electroweak model, determining its parameters, and searching for new physics, are described.

C. M. Hung, E. V. Shuryak

We propose a new strategy for the experimental search of the QCD phase transition in heavy ion collisions: One may tune collision energy around the point where the lifetime of the fireball is expected to be longest. We demonstrate that the hydrodynamic evolution of excited nuclear matter does change dramatically as the initial energy density goes through the

A. Makhlin, E. Surdutovich, G. Welke

We re--examine the connection between interferometry and the Wigner representation for source freeze--out, and continuous emission. At the operator level, two equivalent representations of the two--particle spectrum are found, which contradict the standard expression of kinetic theory. The discrepancy is resolved using two toy models. Further, we revisit int

Cheuk-Yin Wong, Ren-Chuan Wang, Jian-Shi Wu

Previous results for the pair production probability in a strong electric field with a finite longitudinal separation are generalized to the case of a finite-length flux tube with transverse confinement. The threshold length of the flux tube, below which pair production cannot occur, increases as a result of transverse confinement.

Natalia I. Ussyukina, Andrei I. Davydychev

We study the problem of calculating two-loop three-point diagrams with irreducible numerators (i.e. numerators which cannot be expressed in terms of the denominators). For the case of massless internal particles and arbitrary (off-shell) external momenta, exact results are obtained in terms of polylogarithms. We also consider the tensor decomposition of two-

G. Zoeller, S. Hainzl, C. R. Muenz, M. Beyer

In the framework of the instantaneous Bethe Salpeter equation we investigate weak decays of B and D mesons. Mesons are described as q-bar q states interacting via a mixture of a scalar and a vector confining kernel and a one gluon exchange. The model parameters are fixed by a fit to the meson mass spectrum including also the light mesons. We calculate form f

J. W. Bos, D. W. Chang, S. C. Lee, Y. C. Lin

We examine the general lagrangian for baryon chiral perturbation theory with SU(3) flavor symmetry, up to the next-to-leading order. We consider both the strong and the weak interaction. The inverse of the baryon mass is treated as an additional small expansion parameter, and heavy fermion effective field theory techniques are employed to provide a consisten

Peter Levai, Berndt Muller, Xin-Nian Wang

Open charm production during the equilibration of a gluon dominated parton plasma is calculated, with both the time-dependent temperature and parton densities given by a set of rate equations. Including pre-thermal production, the total enhancement of open charm production over the initial gluon fusion depends sensitively on the initial parton density and th

Stephen D. Ellis, Davison E. Soper

We discuss cross sections for hadron + hadron to 2 jets + anything in which three jet variables are measured. Such cross sections are useful especially for determining parton distributions. We define a new cross section d sigma/dX_A dX_B d eta_* for which the perturbation theory is nicely behaved even in the kinematic regime where the parton distributions ar